webrender_bindings/src/bindings.rs

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#![allow(clippy::missing_safety_doc)]
#![allow(clippy::not_unsafe_ptr_arg_deref)]

use gleam::gl;
use std::cell::RefCell;
#[cfg(not(target_os = "macos"))]
use std::ffi::OsString;
use std::ffi::{CStr, CString};
use std::io::Cursor;
use std::marker::PhantomData;
use std::ops::Range;
#[cfg(target_os = "android")]
use std::os::raw::c_int;
use std::os::raw::{c_char, c_float, c_void};
#[cfg(not(any(target_os = "macos", target_os = "windows")))]
use std::os::unix::ffi::OsStringExt;
#[cfg(target_os = "windows")]
use std::os::windows::ffi::OsStringExt;
use std::path::PathBuf;
use std::rc::Rc;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::sync::Arc;
use std::time::Duration;
use std::{env, mem, ptr, slice};
use thin_vec::ThinVec;

use euclid::SideOffsets2D;
use moz2d_renderer::Moz2dBlobImageHandler;
use nsstring::nsAString;
use num_cpus;
use program_cache::{remove_disk_cache, WrProgramCache};
use rayon;
use tracy_rs::register_thread_with_profiler;
use webrender::sw_compositor::SwCompositor;
use webrender::{
    api::units::*, api::*, render_api::*, set_profiler_hooks, AsyncPropertySampler, AsyncScreenshotHandle, Compositor,
    CompositorCapabilities, CompositorConfig, CompositorSurfaceTransform, DebugFlags, Device, MappableCompositor,
    MappedTileInfo, NativeSurfaceId, NativeSurfaceInfo, NativeTileId, PartialPresentCompositor, PipelineInfo,
    ProfilerHooks, RecordedFrameHandle, Renderer, RendererOptions, RendererStats, SWGLCompositeSurfaceInfo,
    SceneBuilderHooks, ShaderPrecacheFlags, Shaders, SharedShaders, TextureCacheConfig, UploadMethod,
    ONE_TIME_USAGE_HINT,
};
use wr_malloc_size_of::MallocSizeOfOps;

#[cfg(target_os = "macos")]
use core_foundation::string::CFString;
#[cfg(target_os = "macos")]
use core_graphics::font::CGFont;

extern "C" {
    #[cfg(target_os = "android")]
    fn __android_log_write(prio: c_int, tag: *const c_char, text: *const c_char) -> c_int;
}

/// The unique id for WR resource identification.
static NEXT_NAMESPACE_ID: AtomicUsize = AtomicUsize::new(1);

/// Special value handled in this wrapper layer to signify a redundant clip chain.
pub const ROOT_CLIP_CHAIN: u64 = !0;

fn next_namespace_id() -> IdNamespace {
    IdNamespace(NEXT_NAMESPACE_ID.fetch_add(1, Ordering::Relaxed) as u32)
}

/// Whether a border should be antialiased.
#[repr(C)]
#[derive(Eq, PartialEq, Copy, Clone)]
pub enum AntialiasBorder {
    No = 0,
    Yes,
}

/// Used to indicate if an image is opaque, or has an alpha channel.
#[repr(u8)]
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
pub enum OpacityType {
    Opaque = 0,
    HasAlphaChannel = 1,
}

/// cbindgen:field-names=[mHandle]
/// cbindgen:derive-lt=true
/// cbindgen:derive-lte=true
/// cbindgen:derive-neq=true
type WrEpoch = Epoch;
/// cbindgen:field-names=[mHandle]
/// cbindgen:derive-lt=true
/// cbindgen:derive-lte=true
/// cbindgen:derive-neq=true
pub type WrIdNamespace = IdNamespace;

/// cbindgen:field-names=[mNamespace, mHandle]
type WrDocumentId = DocumentId;
/// cbindgen:field-names=[mNamespace, mHandle]
type WrPipelineId = PipelineId;
/// cbindgen:field-names=[mNamespace, mHandle]
/// cbindgen:derive-neq=true
type WrImageKey = ImageKey;
/// cbindgen:field-names=[mNamespace, mHandle]
pub type WrFontKey = FontKey;
/// cbindgen:field-names=[mNamespace, mHandle]
pub type WrFontInstanceKey = FontInstanceKey;
/// cbindgen:field-names=[mNamespace, mHandle]
type WrYuvColorSpace = YuvColorSpace;
/// cbindgen:field-names=[mNamespace, mHandle]
type WrColorDepth = ColorDepth;
/// cbindgen:field-names=[mNamespace, mHandle]
type WrColorRange = ColorRange;

#[repr(C)]
pub struct WrSpaceAndClip {
    space: WrSpatialId,
    clip: WrClipId,
}

impl WrSpaceAndClip {
    fn from_webrender(sac: SpaceAndClipInfo) -> Self {
        WrSpaceAndClip {
            space: WrSpatialId { id: sac.spatial_id.0 },
            clip: WrClipId::from_webrender(sac.clip_id),
        }
    }

    fn to_webrender(&self, pipeline_id: WrPipelineId) -> SpaceAndClipInfo {
        SpaceAndClipInfo {
            spatial_id: self.space.to_webrender(pipeline_id),
            clip_id: self.clip.to_webrender(pipeline_id),
        }
    }
}

#[inline]
fn clip_chain_id_to_webrender(id: u64, pipeline_id: WrPipelineId) -> ClipId {
    if id == ROOT_CLIP_CHAIN {
        ClipId::root(pipeline_id)
    } else {
        ClipId::ClipChain(ClipChainId(id, pipeline_id))
    }
}

#[repr(C)]
pub struct WrSpaceAndClipChain {
    space: WrSpatialId,
    clip_chain: u64,
}

impl WrSpaceAndClipChain {
    fn to_webrender(&self, pipeline_id: WrPipelineId) -> SpaceAndClipInfo {
        //Warning: special case here to support dummy clip chain
        SpaceAndClipInfo {
            spatial_id: self.space.to_webrender(pipeline_id),
            clip_id: clip_chain_id_to_webrender(self.clip_chain, pipeline_id),
        }
    }
}

#[repr(C)]
pub enum WrStackingContextClip {
    None,
    ClipId(WrClipId),
    ClipChain(u64),
}

impl WrStackingContextClip {
    fn to_webrender(&self, pipeline_id: WrPipelineId) -> Option<ClipId> {
        match *self {
            WrStackingContextClip::None => None,
            WrStackingContextClip::ClipChain(id) => Some(clip_chain_id_to_webrender(id, pipeline_id)),
            WrStackingContextClip::ClipId(id) => Some(id.to_webrender(pipeline_id)),
        }
    }
}

unsafe fn make_slice<'a, T>(ptr: *const T, len: usize) -> &'a [T] {
    if ptr.is_null() {
        &[]
    } else {
        slice::from_raw_parts(ptr, len)
    }
}

unsafe fn make_slice_mut<'a, T>(ptr: *mut T, len: usize) -> &'a mut [T] {
    if ptr.is_null() {
        &mut []
    } else {
        slice::from_raw_parts_mut(ptr, len)
    }
}

pub struct DocumentHandle {
    api: RenderApi,
    document_id: DocumentId,
    // One of the two options below is Some and the other None at all times.
    // It would be nice to model with an enum, however it is tricky to express moving
    // a variant's content into another variant without movign the containing enum.
    hit_tester_request: Option<HitTesterRequest>,
    hit_tester: Option<Arc<dyn ApiHitTester>>,
}

impl DocumentHandle {
    pub fn new(
        api: RenderApi,
        hit_tester: Option<Arc<dyn ApiHitTester>>,
        size: DeviceIntSize,
        id: u32,
    ) -> DocumentHandle {
        let doc = api.add_document_with_id(size, id);
        let hit_tester_request = if hit_tester.is_none() {
            // Request the hit tester early to reduce the likelihood of blocking on the
            // first hit testing query.
            Some(api.request_hit_tester(doc))
        } else {
            None
        };

        DocumentHandle {
            api,
            document_id: doc,
            hit_tester_request,
            hit_tester,
        }
    }

    fn ensure_hit_tester(&mut self) {
        if self.hit_tester.is_none() {
            self.hit_tester = Some(self.hit_tester_request.take().unwrap().resolve());
        }
    }
}

#[repr(C)]
pub struct WrVecU8 {
    data: *mut u8,
    length: usize,
    capacity: usize,
}

impl WrVecU8 {
    fn into_vec(self) -> Vec<u8> {
        unsafe { Vec::from_raw_parts(self.data, self.length, self.capacity) }
    }

    // Equivalent to `into_vec` but clears self instead of consuming the value.
    fn flush_into_vec(&mut self) -> Vec<u8> {
        self.convert_into_vec::<u8>()
    }

    // Like flush_into_vec, but also does an unsafe conversion to the desired type.
    fn convert_into_vec<T>(&mut self) -> Vec<T> {
        let vec = unsafe {
            Vec::from_raw_parts(
                self.data as *mut T,
                self.length / mem::size_of::<T>(),
                self.capacity / mem::size_of::<T>(),
            )
        };
        self.data = ptr::null_mut();
        self.length = 0;
        self.capacity = 0;
        vec
    }

    fn from_vec(mut v: Vec<u8>) -> WrVecU8 {
        let w = WrVecU8 {
            data: v.as_mut_ptr(),
            length: v.len(),
            capacity: v.capacity(),
        };
        mem::forget(v);
        w
    }

    fn reserve(&mut self, len: usize) {
        let mut vec = self.flush_into_vec();
        vec.reserve(len);
        *self = Self::from_vec(vec);
    }

    fn push_bytes(&mut self, bytes: &[u8]) {
        let mut vec = self.flush_into_vec();
        vec.extend_from_slice(bytes);
        *self = Self::from_vec(vec);
    }
}

#[no_mangle]
pub extern "C" fn wr_vec_u8_push_bytes(v: &mut WrVecU8, bytes: ByteSlice) {
    v.push_bytes(bytes.as_slice());
}

#[no_mangle]
pub extern "C" fn wr_vec_u8_reserve(v: &mut WrVecU8, len: usize) {
    v.reserve(len);
}

#[no_mangle]
pub extern "C" fn wr_vec_u8_free(v: WrVecU8) {
    v.into_vec();
}

#[repr(C)]
pub struct ByteSlice<'a> {
    buffer: *const u8,
    len: usize,
    _phantom: PhantomData<&'a ()>,
}

impl<'a> ByteSlice<'a> {
    pub fn new(slice: &'a [u8]) -> ByteSlice<'a> {
        ByteSlice {
            buffer: slice.as_ptr(),
            len: slice.len(),
            _phantom: PhantomData,
        }
    }

    pub fn as_slice(&self) -> &'a [u8] {
        unsafe { make_slice(self.buffer, self.len) }
    }
}

#[repr(C)]
pub struct MutByteSlice<'a> {
    buffer: *mut u8,
    len: usize,
    _phantom: PhantomData<&'a ()>,
}

impl<'a> MutByteSlice<'a> {
    pub fn new(slice: &'a mut [u8]) -> MutByteSlice<'a> {
        let len = slice.len();
        MutByteSlice {
            buffer: slice.as_mut_ptr(),
            len,
            _phantom: PhantomData,
        }
    }

    pub fn as_mut_slice(&mut self) -> &'a mut [u8] {
        unsafe { make_slice_mut(self.buffer, self.len) }
    }
}

#[repr(C)]
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
pub struct WrImageDescriptor {
    pub format: ImageFormat,
    pub width: i32,
    pub height: i32,
    pub stride: i32,
    pub opacity: OpacityType,
    // TODO(gw): Remove this flag (use prim flags instead).
    pub prefer_compositor_surface: bool,
}

impl<'a> From<&'a WrImageDescriptor> for ImageDescriptor {
    fn from(desc: &'a WrImageDescriptor) -> ImageDescriptor {
        let mut flags = ImageDescriptorFlags::empty();

        if desc.opacity == OpacityType::Opaque {
            flags |= ImageDescriptorFlags::IS_OPAQUE;
        }

        ImageDescriptor {
            size: DeviceIntSize::new(desc.width, desc.height),
            stride: if desc.stride != 0 { Some(desc.stride) } else { None },
            format: desc.format,
            offset: 0,
            flags,
        }
    }
}

#[repr(u32)]
#[allow(dead_code)]
enum WrExternalImageType {
    RawData,
    NativeTexture,
    Invalid,
}

#[repr(C)]
struct WrExternalImage {
    image_type: WrExternalImageType,

    // external texture handle
    handle: u32,
    // external texture coordinate
    u0: f32,
    v0: f32,
    u1: f32,
    v1: f32,

    // external image buffer
    buff: *const u8,
    size: usize,
}

extern "C" {
    fn wr_renderer_lock_external_image(
        renderer: *mut c_void,
        external_image_id: ExternalImageId,
        channel_index: u8,
        rendering: ImageRendering,
    ) -> WrExternalImage;
    fn wr_renderer_unlock_external_image(renderer: *mut c_void, external_image_id: ExternalImageId, channel_index: u8);
}

#[repr(C)]
#[derive(Copy, Clone, Debug)]
pub struct WrExternalImageHandler {
    external_image_obj: *mut c_void,
}

impl ExternalImageHandler for WrExternalImageHandler {
    fn lock(&mut self, id: ExternalImageId, channel_index: u8, rendering: ImageRendering) -> ExternalImage {
        let image = unsafe { wr_renderer_lock_external_image(self.external_image_obj, id, channel_index, rendering) };
        ExternalImage {
            uv: TexelRect::new(image.u0, image.v0, image.u1, image.v1),
            source: match image.image_type {
                WrExternalImageType::NativeTexture => ExternalImageSource::NativeTexture(image.handle),
                WrExternalImageType::RawData => {
                    ExternalImageSource::RawData(unsafe { make_slice(image.buff, image.size) })
                }
                WrExternalImageType::Invalid => ExternalImageSource::Invalid,
            },
        }
    }

    fn unlock(&mut self, id: ExternalImageId, channel_index: u8) {
        unsafe {
            wr_renderer_unlock_external_image(self.external_image_obj, id, channel_index);
        }
    }
}

#[repr(C)]
#[derive(Clone, Copy)]
// Used for ComponentTransfer only
pub struct WrFilterData {
    funcR_type: ComponentTransferFuncType,
    R_values: *mut c_float,
    R_values_count: usize,
    funcG_type: ComponentTransferFuncType,
    G_values: *mut c_float,
    G_values_count: usize,
    funcB_type: ComponentTransferFuncType,
    B_values: *mut c_float,
    B_values_count: usize,
    funcA_type: ComponentTransferFuncType,
    A_values: *mut c_float,
    A_values_count: usize,
}

#[repr(u32)]
#[derive(Debug)]
pub enum WrAnimationType {
    Transform = 0,
    Opacity = 1,
    BackgroundColor = 2,
}

#[repr(C)]
pub struct WrAnimationProperty {
    effect_type: WrAnimationType,
    id: u64,
}

/// cbindgen:derive-eq=false
#[repr(C)]
#[derive(Debug)]
pub struct WrAnimationPropertyValue<T> {
    pub id: u64,
    pub value: T,
}

pub type WrTransformProperty = WrAnimationPropertyValue<LayoutTransform>;
pub type WrOpacityProperty = WrAnimationPropertyValue<f32>;
pub type WrColorProperty = WrAnimationPropertyValue<ColorF>;

/// cbindgen:field-names=[mHandle]
/// cbindgen:derive-lt=true
/// cbindgen:derive-lte=true
#[repr(C)]
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
pub struct WrWindowId(u64);

#[repr(C)]
#[derive(Debug)]
pub struct WrComputedTransformData {
    pub scale_from: LayoutSize,
    pub vertical_flip: bool,
    pub rotation: WrRotation,
}

fn get_proc_address(glcontext_ptr: *mut c_void, name: &str) -> *const c_void {
    extern "C" {
        fn get_proc_address_from_glcontext(glcontext_ptr: *mut c_void, procname: *const c_char) -> *const c_void;
    }

    let symbol_name = CString::new(name).unwrap();
    let symbol = unsafe { get_proc_address_from_glcontext(glcontext_ptr, symbol_name.as_ptr()) };
    symbol as *const _
}

#[repr(C)]
pub enum TelemetryProbe {
    SceneBuildTime = 0,
    SceneSwapTime = 1,
    FrameBuildTime = 2,
}

extern "C" {
    fn is_in_compositor_thread() -> bool;
    fn is_in_render_thread() -> bool;
    fn is_in_main_thread() -> bool;
    fn is_glcontext_gles(glcontext_ptr: *mut c_void) -> bool;
    fn is_glcontext_angle(glcontext_ptr: *mut c_void) -> bool;
    fn gfx_wr_resource_path_override() -> *const c_char;
    fn gfx_wr_use_optimized_shaders() -> bool;
    // TODO: make gfx_critical_error() work.
    // We still have problem to pass the error message from render/render_backend
    // thread to main thread now.
    #[allow(dead_code)]
    fn gfx_critical_error(msg: *const c_char);
    fn gfx_critical_note(msg: *const c_char);
    fn record_telemetry_time(probe: TelemetryProbe, time_ns: u64);
    fn gfx_wr_set_crash_annotation(annotation: CrashAnnotation, value: *const c_char);
    fn gfx_wr_clear_crash_annotation(annotation: CrashAnnotation);
}

struct CppNotifier {
    window_id: WrWindowId,
}

unsafe impl Send for CppNotifier {}

extern "C" {
    fn wr_notifier_wake_up(window_id: WrWindowId, composite_needed: bool);
    fn wr_notifier_new_frame_ready(window_id: WrWindowId);
    fn wr_notifier_nop_frame_done(window_id: WrWindowId);
    fn wr_notifier_external_event(window_id: WrWindowId, raw_event: usize);
    fn wr_schedule_render(window_id: WrWindowId);
    // NOTE: This moves away from pipeline_info.
    fn wr_finished_scene_build(window_id: WrWindowId, pipeline_info: &mut WrPipelineInfo);

    fn wr_transaction_notification_notified(handler: usize, when: Checkpoint);
}

impl RenderNotifier for CppNotifier {
    fn clone(&self) -> Box<dyn RenderNotifier> {
        Box::new(CppNotifier {
            window_id: self.window_id,
        })
    }

    fn wake_up(&self, composite_needed: bool) {
        unsafe {
            wr_notifier_wake_up(self.window_id, composite_needed);
        }
    }

    fn new_frame_ready(&self, _: DocumentId, _scrolled: bool, composite_needed: bool, render_time_ns: Option<u64>) {
        unsafe {
            if let Some(time) = render_time_ns {
                record_telemetry_time(TelemetryProbe::FrameBuildTime, time);
            }
            if composite_needed {
                wr_notifier_new_frame_ready(self.window_id);
            } else {
                wr_notifier_nop_frame_done(self.window_id);
            }
        }
    }

    fn external_event(&self, event: ExternalEvent) {
        unsafe {
            wr_notifier_external_event(self.window_id, event.unwrap());
        }
    }
}

struct MozCrashAnnotator;

unsafe impl Send for MozCrashAnnotator {}

impl CrashAnnotator for MozCrashAnnotator {
    fn set(&self, annotation: CrashAnnotation, value: &std::ffi::CStr) {
        unsafe {
            gfx_wr_set_crash_annotation(annotation, value.as_ptr());
        }
    }

    fn clear(&self, annotation: CrashAnnotation) {
        unsafe {
            gfx_wr_clear_crash_annotation(annotation);
        }
    }

    fn box_clone(&self) -> Box<dyn CrashAnnotator> {
        Box::new(MozCrashAnnotator)
    }
}

#[no_mangle]
pub extern "C" fn wr_renderer_set_clear_color(renderer: &mut Renderer, color: ColorF) {
    renderer.set_clear_color(color);
}

#[no_mangle]
pub extern "C" fn wr_renderer_set_external_image_handler(
    renderer: &mut Renderer,
    external_image_handler: &mut WrExternalImageHandler,
) {
    renderer.set_external_image_handler(Box::new(*external_image_handler));
}

#[no_mangle]
pub extern "C" fn wr_renderer_update(renderer: &mut Renderer) {
    renderer.update();
}

#[no_mangle]
pub extern "C" fn wr_renderer_render(
    renderer: &mut Renderer,
    width: i32,
    height: i32,
    buffer_age: usize,
    out_stats: &mut RendererStats,
    out_dirty_rects: &mut ThinVec<DeviceIntRect>,
) -> bool {
    match renderer.render(DeviceIntSize::new(width, height), buffer_age) {
        Ok(results) => {
            *out_stats = results.stats;
            out_dirty_rects.extend(results.dirty_rects);
            true
        }
        Err(errors) => {
            for e in errors {
                warn!(" Failed to render: {:?}", e);
                let msg = CString::new(format!("wr_renderer_render: {:?}", e)).unwrap();
                unsafe {
                    gfx_critical_note(msg.as_ptr());
                }
            }
            false
        }
    }
}

#[no_mangle]
pub extern "C" fn wr_renderer_force_redraw(renderer: &mut Renderer) {
    renderer.force_redraw();
}

#[no_mangle]
pub extern "C" fn wr_renderer_record_frame(
    renderer: &mut Renderer,
    image_format: ImageFormat,
    out_handle: &mut RecordedFrameHandle,
    out_width: &mut i32,
    out_height: &mut i32,
) -> bool {
    if let Some((handle, size)) = renderer.record_frame(image_format) {
        *out_handle = handle;
        *out_width = size.width;
        *out_height = size.height;

        true
    } else {
        false
    }
}

#[no_mangle]
pub extern "C" fn wr_renderer_map_recorded_frame(
    renderer: &mut Renderer,
    handle: RecordedFrameHandle,
    dst_buffer: *mut u8,
    dst_buffer_len: usize,
    dst_stride: usize,
) -> bool {
    renderer.map_recorded_frame(
        handle,
        unsafe { make_slice_mut(dst_buffer, dst_buffer_len) },
        dst_stride,
    )
}

#[no_mangle]
pub extern "C" fn wr_renderer_release_composition_recorder_structures(renderer: &mut Renderer) {
    renderer.release_composition_recorder_structures();
}

#[no_mangle]
pub extern "C" fn wr_renderer_get_screenshot_async(
    renderer: &mut Renderer,
    window_x: i32,
    window_y: i32,
    window_width: i32,
    window_height: i32,
    buffer_width: i32,
    buffer_height: i32,
    image_format: ImageFormat,
    screenshot_width: *mut i32,
    screenshot_height: *mut i32,
) -> AsyncScreenshotHandle {
    assert!(!screenshot_width.is_null());
    assert!(!screenshot_height.is_null());

    let (handle, size) = renderer.get_screenshot_async(
        DeviceIntRect::from_origin_and_size(
            DeviceIntPoint::new(window_x, window_y),
            DeviceIntSize::new(window_width, window_height),
        ),
        DeviceIntSize::new(buffer_width, buffer_height),
        image_format,
    );

    unsafe {
        *screenshot_width = size.width;
        *screenshot_height = size.height;
    }

    handle
}

#[no_mangle]
pub extern "C" fn wr_renderer_map_and_recycle_screenshot(
    renderer: &mut Renderer,
    handle: AsyncScreenshotHandle,
    dst_buffer: *mut u8,
    dst_buffer_len: usize,
    dst_stride: usize,
) -> bool {
    renderer.map_and_recycle_screenshot(
        handle,
        unsafe { make_slice_mut(dst_buffer, dst_buffer_len) },
        dst_stride,
    )
}

#[no_mangle]
pub extern "C" fn wr_renderer_release_profiler_structures(renderer: &mut Renderer) {
    renderer.release_profiler_structures();
}

// Call wr_renderer_render() before calling this function.
#[no_mangle]
pub unsafe extern "C" fn wr_renderer_readback(
    renderer: &mut Renderer,
    width: i32,
    height: i32,
    format: ImageFormat,
    dst_buffer: *mut u8,
    buffer_size: usize,
) {
    assert!(is_in_render_thread());

    let mut slice = make_slice_mut(dst_buffer, buffer_size);
    renderer.read_pixels_into(FramebufferIntSize::new(width, height).into(), format, &mut slice);
}

#[no_mangle]
pub unsafe extern "C" fn wr_renderer_set_profiler_ui(renderer: &mut Renderer, ui_str: *const u8, ui_str_len: usize) {
    let slice = std::slice::from_raw_parts(ui_str, ui_str_len);
    if let Ok(ui_str) = std::str::from_utf8(slice) {
        renderer.set_profiler_ui(ui_str);
    }
}

#[no_mangle]
pub unsafe extern "C" fn wr_renderer_delete(renderer: *mut Renderer) {
    let renderer = Box::from_raw(renderer);
    renderer.deinit();
    // let renderer go out of scope and get dropped
}

#[no_mangle]
pub unsafe extern "C" fn wr_renderer_accumulate_memory_report(
    renderer: &mut Renderer,
    report: &mut MemoryReport,
    swgl: *mut c_void,
) {
    *report += renderer.report_memory(swgl);
}

// cbindgen doesn't support tuples, so we have a little struct instead, with
// an Into implementation to convert from the tuple to the struct.
#[repr(C)]
pub struct WrPipelineEpoch {
    pipeline_id: WrPipelineId,
    document_id: WrDocumentId,
    epoch: WrEpoch,
}

impl<'a> From<(&'a (WrPipelineId, WrDocumentId), &'a WrEpoch)> for WrPipelineEpoch {
    fn from(tuple: (&(WrPipelineId, WrDocumentId), &WrEpoch)) -> WrPipelineEpoch {
        WrPipelineEpoch {
            pipeline_id: (tuple.0).0,
            document_id: (tuple.0).1,
            epoch: *tuple.1,
        }
    }
}

#[repr(C)]
pub struct WrPipelineIdAndEpoch {
    pipeline_id: WrPipelineId,
    epoch: WrEpoch,
}

impl<'a> From<(&WrPipelineId, &WrEpoch)> for WrPipelineIdAndEpoch {
    fn from(tuple: (&WrPipelineId, &WrEpoch)) -> WrPipelineIdAndEpoch {
        WrPipelineIdAndEpoch {
            pipeline_id: *tuple.0,
            epoch: *tuple.1,
        }
    }
}

#[repr(C)]
pub struct WrRemovedPipeline {
    pipeline_id: WrPipelineId,
    document_id: WrDocumentId,
}

impl<'a> From<&'a (WrPipelineId, WrDocumentId)> for WrRemovedPipeline {
    fn from(tuple: &(WrPipelineId, WrDocumentId)) -> WrRemovedPipeline {
        WrRemovedPipeline {
            pipeline_id: tuple.0,
            document_id: tuple.1,
        }
    }
}

#[repr(C)]
pub struct WrPipelineInfo {
    /// This contains an entry for each pipeline that was rendered, along with
    /// the epoch at which it was rendered. Rendered pipelines include the root
    /// pipeline and any other pipelines that were reachable via IFrame display
    /// items from the root pipeline.
    epochs: ThinVec<WrPipelineEpoch>,
    /// This contains an entry for each pipeline that was removed during the
    /// last transaction. These pipelines would have been explicitly removed by
    /// calling remove_pipeline on the transaction object; the pipeline showing
    /// up in this array means that the data structures have been torn down on
    /// the webrender side, and so any remaining data structures on the caller
    /// side can now be torn down also.
    removed_pipelines: ThinVec<WrRemovedPipeline>,
}

impl WrPipelineInfo {
    fn new(info: &PipelineInfo) -> Self {
        WrPipelineInfo {
            epochs: info.epochs.iter().map(WrPipelineEpoch::from).collect(),
            removed_pipelines: info.removed_pipelines.iter().map(WrRemovedPipeline::from).collect(),
        }
    }
}

#[no_mangle]
pub unsafe extern "C" fn wr_renderer_flush_pipeline_info(renderer: &mut Renderer, out: &mut WrPipelineInfo) {
    let info = renderer.flush_pipeline_info();
    *out = WrPipelineInfo::new(&info);
}

extern "C" {
    pub fn gecko_profiler_start_marker(name: *const c_char);
    pub fn gecko_profiler_end_marker(name: *const c_char);
    pub fn gecko_profiler_event_marker(name: *const c_char);
    pub fn gecko_profiler_add_text_marker(
        name: *const c_char,
        text_bytes: *const c_char,
        text_len: usize,
        microseconds: u64,
    );
    pub fn gecko_profiler_thread_is_being_profiled() -> bool;
}

/// Simple implementation of the WR ProfilerHooks trait to allow profile
/// markers to be seen in the Gecko profiler.
struct GeckoProfilerHooks;

impl ProfilerHooks for GeckoProfilerHooks {
    fn register_thread(&self, thread_name: &str) {
        gecko_profiler::register_thread(thread_name);
    }

    fn unregister_thread(&self) {
        gecko_profiler::unregister_thread();
    }

    fn begin_marker(&self, label: &CStr) {
        unsafe {
            gecko_profiler_start_marker(label.as_ptr());
        }
    }

    fn end_marker(&self, label: &CStr) {
        unsafe {
            gecko_profiler_end_marker(label.as_ptr());
        }
    }

    fn event_marker(&self, label: &CStr) {
        unsafe {
            gecko_profiler_event_marker(label.as_ptr());
        }
    }

    fn add_text_marker(&self, label: &CStr, text: &str, duration: Duration) {
        unsafe {
            // NB: This can be as_micros() once we require Rust 1.33.
            let micros = duration.subsec_micros() as u64 + duration.as_secs() * 1000 * 1000;
            let text_bytes = text.as_bytes();
            gecko_profiler_add_text_marker(
                label.as_ptr(),
                text_bytes.as_ptr() as *const c_char,
                text_bytes.len(),
                micros,
            );
        }
    }

    fn thread_is_being_profiled(&self) -> bool {
        unsafe { gecko_profiler_thread_is_being_profiled() }
    }
}

static PROFILER_HOOKS: GeckoProfilerHooks = GeckoProfilerHooks {};

#[allow(improper_ctypes)] // this is needed so that rustc doesn't complain about passing the &mut Transaction to an extern function
extern "C" {
    // These callbacks are invoked from the scene builder thread (aka the APZ
    // updater thread)
    fn apz_register_updater(window_id: WrWindowId);
    fn apz_pre_scene_swap(window_id: WrWindowId);
    fn apz_post_scene_swap(window_id: WrWindowId, pipeline_info: &WrPipelineInfo);
    fn apz_run_updater(window_id: WrWindowId);
    fn apz_deregister_updater(window_id: WrWindowId);

    // These callbacks are invoked from the render backend thread (aka the APZ
    // sampler thread)
    fn apz_register_sampler(window_id: WrWindowId);
    fn apz_sample_transforms(window_id: WrWindowId, generated_frame_id: *const u64, transaction: &mut Transaction);
    fn apz_deregister_sampler(window_id: WrWindowId);

    fn omta_register_sampler(window_id: WrWindowId);
    fn omta_sample(window_id: WrWindowId, transaction: &mut Transaction);
    fn omta_deregister_sampler(window_id: WrWindowId);
}

struct APZCallbacks {
    window_id: WrWindowId,
}

impl APZCallbacks {
    pub fn new(window_id: WrWindowId) -> Self {
        APZCallbacks { window_id }
    }
}

impl SceneBuilderHooks for APZCallbacks {
    fn register(&self) {
        unsafe { apz_register_updater(self.window_id) }
    }

    fn pre_scene_build(&self) {
        unsafe {
            gecko_profiler_start_marker(b"SceneBuilding\0".as_ptr() as *const c_char);
        }
    }

    fn pre_scene_swap(&self, scenebuild_time: u64) {
        unsafe {
            record_telemetry_time(TelemetryProbe::SceneBuildTime, scenebuild_time);
            apz_pre_scene_swap(self.window_id);
        }
    }

    fn post_scene_swap(&self, _document_ids: &Vec<DocumentId>, info: PipelineInfo, sceneswap_time: u64) {
        let mut info = WrPipelineInfo::new(&info);
        unsafe {
            record_telemetry_time(TelemetryProbe::SceneSwapTime, sceneswap_time);
            apz_post_scene_swap(self.window_id, &info);
        }

        // After a scene swap we should schedule a render for the next vsync,
        // otherwise there's no guarantee that the new scene will get rendered
        // anytime soon
        unsafe { wr_finished_scene_build(self.window_id, &mut info) }
        unsafe {
            gecko_profiler_end_marker(b"SceneBuilding\0".as_ptr() as *const c_char);
        }
    }

    fn post_resource_update(&self, _document_ids: &Vec<DocumentId>) {
        unsafe { wr_schedule_render(self.window_id) }
        unsafe {
            gecko_profiler_end_marker(b"SceneBuilding\0".as_ptr() as *const c_char);
        }
    }

    fn post_empty_scene_build(&self) {
        unsafe {
            gecko_profiler_end_marker(b"SceneBuilding\0".as_ptr() as *const c_char);
        }
    }

    fn poke(&self) {
        unsafe { apz_run_updater(self.window_id) }
    }

    fn deregister(&self) {
        unsafe { apz_deregister_updater(self.window_id) }
    }
}

struct SamplerCallback {
    window_id: WrWindowId,
}

impl SamplerCallback {
    pub fn new(window_id: WrWindowId) -> Self {
        SamplerCallback { window_id }
    }
}

impl AsyncPropertySampler for SamplerCallback {
    fn register(&self) {
        unsafe {
            apz_register_sampler(self.window_id);
            omta_register_sampler(self.window_id);
        }
    }

    fn sample(&self, _document_id: DocumentId, generated_frame_id: Option<u64>) -> Vec<FrameMsg> {
        let generated_frame_id_value;
        let generated_frame_id: *const u64 = match generated_frame_id {
            Some(id) => {
                generated_frame_id_value = id;
                &generated_frame_id_value
            }
            None => ptr::null_mut(),
        };
        let mut transaction = Transaction::new();
        unsafe {
            // XXX: When we implement scroll-linked animations, we will probably
            // need to call apz_sample_transforms prior to omta_sample.
            omta_sample(self.window_id, &mut transaction);
            apz_sample_transforms(self.window_id, generated_frame_id, &mut transaction)
        };
        transaction.get_frame_ops()
    }

    fn deregister(&self) {
        unsafe {
            apz_deregister_sampler(self.window_id);
            omta_deregister_sampler(self.window_id);
        }
    }
}

extern "C" {
    fn wr_register_thread_local_arena();
}

pub struct WrThreadPool(Arc<rayon::ThreadPool>);

#[no_mangle]
pub extern "C" fn wr_thread_pool_new(low_priority: bool) -> *mut WrThreadPool {
    // Clamp the number of workers between 1 and 8. We get diminishing returns
    // with high worker counts and extra overhead because of rayon and font
    // management.
    let num_threads = num_cpus::get().max(2).min(8);

    let priority_tag = if low_priority { "LP" } else { "" };

    let worker = rayon::ThreadPoolBuilder::new()
        .thread_name(move |idx| format!("WRWorker{}#{}", priority_tag, idx))
        .num_threads(num_threads)
        .start_handler(move |idx| {
            unsafe {
                wr_register_thread_local_arena();
            }
            let name = format!("WRWorker{}#{}", priority_tag, idx);
            register_thread_with_profiler(name.clone());
            gecko_profiler::register_thread(&name);
        })
        .exit_handler(|_idx| {
            gecko_profiler::unregister_thread();
        })
        .build();

    let workers = Arc::new(worker.unwrap());

    // This effectively leaks the thread pool. Not great but we only create one and it lives
    // for as long as the browser.
    // Do this to avoid intermittent race conditions with nsThreadManager shutdown.
    // A better fix would involve removing the dependency between implicit nsThreadManager
    // and webrender's threads, or be able to synchronously terminate rayon's thread pool.
    mem::forget(Arc::clone(&workers));

    Box::into_raw(Box::new(WrThreadPool(workers)))
}

#[no_mangle]
pub unsafe extern "C" fn wr_thread_pool_delete(thread_pool: *mut WrThreadPool) {
    Box::from_raw(thread_pool);
}

#[no_mangle]
pub unsafe extern "C" fn wr_program_cache_new(
    prof_path: &nsAString,
    thread_pool: *mut WrThreadPool,
) -> *mut WrProgramCache {
    let workers = &(*thread_pool).0;
    let program_cache = WrProgramCache::new(prof_path, workers);
    Box::into_raw(Box::new(program_cache))
}

#[no_mangle]
pub unsafe extern "C" fn wr_program_cache_delete(program_cache: *mut WrProgramCache) {
    Box::from_raw(program_cache);
}

#[no_mangle]
pub unsafe extern "C" fn wr_try_load_startup_shaders_from_disk(program_cache: *mut WrProgramCache) {
    (*program_cache).try_load_startup_shaders_from_disk();
}

#[no_mangle]
pub unsafe extern "C" fn remove_program_binary_disk_cache(prof_path: &nsAString) -> bool {
    match remove_disk_cache(prof_path) {
        Ok(_) => true,
        Err(_) => {
            error!("Failed to remove program binary disk cache");
            false
        }
    }
}

// This matches IsEnvSet in gfxEnv.h
fn env_var_to_bool(key: &'static str) -> bool {
    env::var(key).ok().map_or(false, |v| !v.is_empty())
}

// Call MakeCurrent before this.
fn wr_device_new(gl_context: *mut c_void, pc: Option<&mut WrProgramCache>) -> Device {
    assert!(unsafe { is_in_render_thread() });

    let gl;
    if unsafe { is_glcontext_gles(gl_context) } {
        gl = unsafe { gl::GlesFns::load_with(|symbol| get_proc_address(gl_context, symbol)) };
    } else {
        gl = unsafe { gl::GlFns::load_with(|symbol| get_proc_address(gl_context, symbol)) };
    }

    let version = gl.get_string(gl::VERSION);

    info!("WebRender - OpenGL version new {}", version);

    let upload_method = if unsafe { is_glcontext_angle(gl_context) } {
        UploadMethod::Immediate
    } else {
        UploadMethod::PixelBuffer(ONE_TIME_USAGE_HINT)
    };

    let resource_override_path = unsafe {
        let override_charptr = gfx_wr_resource_path_override();
        if override_charptr.is_null() {
            None
        } else {
            match CStr::from_ptr(override_charptr).to_str() {
                Ok(override_str) => Some(PathBuf::from(override_str)),
                _ => None,
            }
        }
    };

    let use_optimized_shaders = unsafe { gfx_wr_use_optimized_shaders() };

    let cached_programs = pc.map(|cached_programs| Rc::clone(cached_programs.rc_get()));

    Device::new(
        gl,
        Some(Box::new(MozCrashAnnotator)),
        resource_override_path,
        use_optimized_shaders,
        upload_method,
        cached_programs,
        true,
        true,
        None,
        false,
        false,
    )
}

extern "C" {
    fn wr_compositor_create_surface(
        compositor: *mut c_void,
        id: NativeSurfaceId,
        virtual_offset: DeviceIntPoint,
        tile_size: DeviceIntSize,
        is_opaque: bool,
    );
    fn wr_compositor_create_external_surface(compositor: *mut c_void, id: NativeSurfaceId, is_opaque: bool);
    fn wr_compositor_destroy_surface(compositor: *mut c_void, id: NativeSurfaceId);
    fn wr_compositor_create_tile(compositor: *mut c_void, id: NativeSurfaceId, x: i32, y: i32);
    fn wr_compositor_destroy_tile(compositor: *mut c_void, id: NativeSurfaceId, x: i32, y: i32);
    fn wr_compositor_attach_external_image(
        compositor: *mut c_void,
        id: NativeSurfaceId,
        external_image: ExternalImageId,
    );
    fn wr_compositor_bind(
        compositor: *mut c_void,
        id: NativeTileId,
        offset: &mut DeviceIntPoint,
        fbo_id: &mut u32,
        dirty_rect: DeviceIntRect,
        valid_rect: DeviceIntRect,
    );
    fn wr_compositor_unbind(compositor: *mut c_void);
    fn wr_compositor_begin_frame(compositor: *mut c_void);
    fn wr_compositor_add_surface(
        compositor: *mut c_void,
        id: NativeSurfaceId,
        transform: &CompositorSurfaceTransform,
        clip_rect: DeviceIntRect,
        image_rendering: ImageRendering,
    );
    fn wr_compositor_start_compositing(
        compositor: *mut c_void,
        clear_color: ColorF,
        dirty_rects: *const DeviceIntRect,
        num_dirty_rects: usize,
        opaque_rects: *const DeviceIntRect,
        num_opaque_rects: usize,
    );
    fn wr_compositor_end_frame(compositor: *mut c_void);
    fn wr_compositor_enable_native_compositor(compositor: *mut c_void, enable: bool);
    fn wr_compositor_deinit(compositor: *mut c_void);
    fn wr_compositor_get_capabilities(compositor: *mut c_void, caps: *mut CompositorCapabilities);
    fn wr_compositor_map_tile(
        compositor: *mut c_void,
        id: NativeTileId,
        dirty_rect: DeviceIntRect,
        valid_rect: DeviceIntRect,
        data: &mut *mut c_void,
        stride: &mut i32,
    );
    fn wr_compositor_unmap_tile(compositor: *mut c_void);

    fn wr_partial_present_compositor_set_buffer_damage_region(
        compositor: *mut c_void,
        rects: *const DeviceIntRect,
        n_rects: usize,
    );
}

pub struct WrCompositor(*mut c_void);

impl Compositor for WrCompositor {
    fn create_surface(
        &mut self,
        id: NativeSurfaceId,
        virtual_offset: DeviceIntPoint,
        tile_size: DeviceIntSize,
        is_opaque: bool,
    ) {
        unsafe {
            wr_compositor_create_surface(self.0, id, virtual_offset, tile_size, is_opaque);
        }
    }

    fn create_external_surface(&mut self, id: NativeSurfaceId, is_opaque: bool) {
        unsafe {
            wr_compositor_create_external_surface(self.0, id, is_opaque);
        }
    }

    fn destroy_surface(&mut self, id: NativeSurfaceId) {
        unsafe {
            wr_compositor_destroy_surface(self.0, id);
        }
    }

    fn create_tile(&mut self, id: NativeTileId) {
        unsafe {
            wr_compositor_create_tile(self.0, id.surface_id, id.x, id.y);
        }
    }

    fn destroy_tile(&mut self, id: NativeTileId) {
        unsafe {
            wr_compositor_destroy_tile(self.0, id.surface_id, id.x, id.y);
        }
    }

    fn attach_external_image(&mut self, id: NativeSurfaceId, external_image: ExternalImageId) {
        unsafe {
            wr_compositor_attach_external_image(self.0, id, external_image);
        }
    }

    fn bind(&mut self, id: NativeTileId, dirty_rect: DeviceIntRect, valid_rect: DeviceIntRect) -> NativeSurfaceInfo {
        let mut surface_info = NativeSurfaceInfo {
            origin: DeviceIntPoint::zero(),
            fbo_id: 0,
        };

        unsafe {
            wr_compositor_bind(
                self.0,
                id,
                &mut surface_info.origin,
                &mut surface_info.fbo_id,
                dirty_rect,
                valid_rect,
            );
        }

        surface_info
    }

    fn unbind(&mut self) {
        unsafe {
            wr_compositor_unbind(self.0);
        }
    }

    fn begin_frame(&mut self) {
        unsafe {
            wr_compositor_begin_frame(self.0);
        }
    }

    fn add_surface(
        &mut self,
        id: NativeSurfaceId,
        transform: CompositorSurfaceTransform,
        clip_rect: DeviceIntRect,
        image_rendering: ImageRendering,
    ) {
        unsafe {
            wr_compositor_add_surface(self.0, id, &transform, clip_rect, image_rendering);
        }
    }

    fn start_compositing(&mut self, clear_color: ColorF, dirty_rects: &[DeviceIntRect], opaque_rects: &[DeviceIntRect]) {
        unsafe {
            wr_compositor_start_compositing(
                self.0,
                clear_color,
                dirty_rects.as_ptr(),
                dirty_rects.len(),
                opaque_rects.as_ptr(),
                opaque_rects.len(),
            );
        }
    }

    fn end_frame(&mut self) {
        unsafe {
            wr_compositor_end_frame(self.0);
        }
    }

    fn enable_native_compositor(&mut self, enable: bool) {
        unsafe {
            wr_compositor_enable_native_compositor(self.0, enable);
        }
    }

    fn deinit(&mut self) {
        unsafe {
            wr_compositor_deinit(self.0);
        }
    }

    fn get_capabilities(&self) -> CompositorCapabilities {
        unsafe {
            let mut caps: CompositorCapabilities = Default::default();
            wr_compositor_get_capabilities(self.0, &mut caps);
            caps
        }
    }
}

extern "C" {
    fn wr_swgl_lock_composite_surface(
        ctx: *mut c_void,
        external_image_id: ExternalImageId,
        composite_info: *mut SWGLCompositeSurfaceInfo,
    ) -> bool;
    fn wr_swgl_unlock_composite_surface(ctx: *mut c_void, external_image_id: ExternalImageId);
}

impl MappableCompositor for WrCompositor {
    /// Map a tile's underlying buffer so it can be used as the backing for
    /// a SWGL framebuffer. This is intended to be a replacement for 'bind'
    /// in any compositors that intend to directly interoperate with SWGL
    /// while supporting some form of native layers.
    fn map_tile(
        &mut self,
        id: NativeTileId,
        dirty_rect: DeviceIntRect,
        valid_rect: DeviceIntRect,
    ) -> Option<MappedTileInfo> {
        let mut tile_info = MappedTileInfo {
            data: ptr::null_mut(),
            stride: 0,
        };

        unsafe {
            wr_compositor_map_tile(
                self.0,
                id,
                dirty_rect,
                valid_rect,
                &mut tile_info.data,
                &mut tile_info.stride,
            );
        }

        if !tile_info.data.is_null() && tile_info.stride != 0 {
            Some(tile_info)
        } else {
            None
        }
    }

    /// Unmap a tile that was was previously mapped via map_tile to signal
    /// that SWGL is done rendering to the buffer.
    fn unmap_tile(&mut self) {
        unsafe {
            wr_compositor_unmap_tile(self.0);
        }
    }

    fn lock_composite_surface(
        &mut self,
        ctx: *mut c_void,
        external_image_id: ExternalImageId,
        composite_info: *mut SWGLCompositeSurfaceInfo,
    ) -> bool {
        unsafe { wr_swgl_lock_composite_surface(ctx, external_image_id, composite_info) }
    }
    fn unlock_composite_surface(&mut self, ctx: *mut c_void, external_image_id: ExternalImageId) {
        unsafe { wr_swgl_unlock_composite_surface(ctx, external_image_id) }
    }
}

pub struct WrPartialPresentCompositor(*mut c_void);

impl PartialPresentCompositor for WrPartialPresentCompositor {
    fn set_buffer_damage_region(&mut self, rects: &[DeviceIntRect]) {
        unsafe {
            wr_partial_present_compositor_set_buffer_damage_region(self.0, rects.as_ptr(), rects.len());
        }
    }
}

/// A wrapper around a strong reference to a Shaders object.
pub struct WrShaders(SharedShaders);

// Call MakeCurrent before this.
#[no_mangle]
pub extern "C" fn wr_window_new(
    window_id: WrWindowId,
    window_width: i32,
    window_height: i32,
    is_main_window: bool,
    support_low_priority_transactions: bool,
    support_low_priority_threadpool: bool,
    allow_texture_swizzling: bool,
    allow_scissored_cache_clears: bool,
    swgl_context: *mut c_void,
    gl_context: *mut c_void,
    surface_origin_is_top_left: bool,
    program_cache: Option<&mut WrProgramCache>,
    shaders: Option<&mut WrShaders>,
    thread_pool: *mut WrThreadPool,
    thread_pool_low_priority: *mut WrThreadPool,
    size_of_op: VoidPtrToSizeFn,
    enclosing_size_of_op: VoidPtrToSizeFn,
    document_id: u32,
    compositor: *mut c_void,
    use_native_compositor: bool,
    use_partial_present: bool,
    max_partial_present_rects: usize,
    draw_previous_partial_present_regions: bool,
    out_handle: &mut *mut DocumentHandle,
    out_renderer: &mut *mut Renderer,
    out_max_texture_size: *mut i32,
    out_err: &mut *mut c_char,
    enable_gpu_markers: bool,
    panic_on_gl_error: bool,
    picture_tile_width: i32,
    picture_tile_height: i32,
    reject_software_rasterizer: bool,
    low_quality_pinch_zoom: bool,
) -> bool {
    assert!(unsafe { is_in_render_thread() });

    let software = !swgl_context.is_null();
    let (gl, sw_gl) = if software {
        let ctx = swgl::Context::from(swgl_context);
        ctx.make_current();
        (Rc::new(ctx) as Rc<dyn gl::Gl>, Some(ctx))
    } else {
        let gl = unsafe {
            if gl_context.is_null() {
                panic!("Native GL context required when not using SWGL!");
            } else if is_glcontext_gles(gl_context) {
                gl::GlesFns::load_with(|symbol| get_proc_address(gl_context, symbol))
            } else {
                gl::GlFns::load_with(|symbol| get_proc_address(gl_context, symbol))
            }
        };
        (gl, None)
    };

    let version = gl.get_string(gl::VERSION);

    info!("WebRender - OpenGL version new {}", version);

    let workers = unsafe { Arc::clone(&(*thread_pool).0) };
    let workers_low_priority = unsafe {
        if support_low_priority_threadpool {
            Arc::clone(&(*thread_pool_low_priority).0)
        } else {
            Arc::clone(&(*thread_pool).0)
        }
    };

    let upload_method = if !gl_context.is_null() && unsafe { is_glcontext_angle(gl_context) } {
        UploadMethod::Immediate
    } else {
        UploadMethod::PixelBuffer(ONE_TIME_USAGE_HINT)
    };

    let precache_flags = if env_var_to_bool("MOZ_WR_PRECACHE_SHADERS") {
        ShaderPrecacheFlags::FULL_COMPILE
    } else {
        ShaderPrecacheFlags::empty()
    };

    let cached_programs = program_cache.map(|program_cache| Rc::clone(&program_cache.rc_get()));

    let color = if cfg!(target_os = "android") {
        // The color is for avoiding black flash before receiving display list.
        ColorF::new(1.0, 1.0, 1.0, 1.0)
    } else {
        ColorF::new(0.0, 0.0, 0.0, 0.0)
    };

    let compositor_config = if software {
        CompositorConfig::Native {
            compositor: Box::new(SwCompositor::new(
                sw_gl.unwrap(),
                Box::new(WrCompositor(compositor)),
                use_native_compositor,
            )),
        }
    } else if use_native_compositor {
        CompositorConfig::Native {
            compositor: Box::new(WrCompositor(compositor)),
        }
    } else {
        CompositorConfig::Draw {
            max_partial_present_rects,
            draw_previous_partial_present_regions,
            partial_present: if use_partial_present {
                Some(Box::new(WrPartialPresentCompositor(compositor)))
            } else {
                None
            },
        }
    };

    let picture_tile_size = if picture_tile_width > 0 && picture_tile_height > 0 {
        Some(DeviceIntSize::new(picture_tile_width, picture_tile_height))
    } else {
        None
    };

    let texture_cache_config = if is_main_window {
        TextureCacheConfig::DEFAULT
    } else {
        TextureCacheConfig {
            color8_linear_texture_size: 512,
            color8_nearest_texture_size: 512,
            color8_glyph_texture_size: 512,
            alpha8_texture_size: 512,
            alpha8_glyph_texture_size: 512,
            alpha16_texture_size: 512,
        }
    };

    let opts = RendererOptions {
        enable_aa: true,
        force_subpixel_aa: false,
        enable_subpixel_aa: cfg!(not(target_os = "android")),
        support_low_priority_transactions,
        allow_texture_swizzling,
        blob_image_handler: Some(Box::new(Moz2dBlobImageHandler::new(
            workers.clone(),
            workers_low_priority,
        ))),
        crash_annotator: Some(Box::new(MozCrashAnnotator)),
        workers: Some(workers),
        size_of_op: Some(size_of_op),
        enclosing_size_of_op: Some(enclosing_size_of_op),
        cached_programs,
        resource_override_path: unsafe {
            let override_charptr = gfx_wr_resource_path_override();
            if override_charptr.is_null() {
                None
            } else {
                match CStr::from_ptr(override_charptr).to_str() {
                    Ok(override_str) => Some(PathBuf::from(override_str)),
                    _ => None,
                }
            }
        },
        use_optimized_shaders: unsafe { gfx_wr_use_optimized_shaders() },
        renderer_id: Some(window_id.0),
        upload_method,
        scene_builder_hooks: Some(Box::new(APZCallbacks::new(window_id))),
        sampler: Some(Box::new(SamplerCallback::new(window_id))),
        max_internal_texture_size: Some(8192), // We want to tile if larger than this
        clear_color: color,
        precache_flags,
        namespace_alloc_by_client: true,
        // SWGL doesn't support the GL_ALWAYS depth comparison function used by
        // `clear_caches_with_quads`, but scissored clears work well.
        clear_caches_with_quads: !software && !allow_scissored_cache_clears,
        // SWGL supports KHR_blend_equation_advanced safely, but we haven't yet
        // tested other HW platforms determine if it is safe to allow them.
        allow_advanced_blend_equation: software,
        surface_origin_is_top_left,
        compositor_config,
        enable_gpu_markers,
        panic_on_gl_error,
        picture_tile_size,
        texture_cache_config,
        reject_software_rasterizer,
        low_quality_pinch_zoom,
        ..Default::default()
    };

    // Ensure the WR profiler callbacks are hooked up to the Gecko profiler.
    set_profiler_hooks(Some(&PROFILER_HOOKS));

    let window_size = DeviceIntSize::new(window_width, window_height);
    let notifier = Box::new(CppNotifier { window_id });
    let (renderer, sender) = match Renderer::new(gl, notifier, opts, shaders.map(|sh| &sh.0)) {
        Ok((renderer, sender)) => (renderer, sender),
        Err(e) => {
            warn!(" Failed to create a Renderer: {:?}", e);
            let msg = CString::new(format!("wr_window_new: {:?}", e)).unwrap();
            unsafe {
                gfx_critical_note(msg.as_ptr());
            }
            *out_err = msg.into_raw();
            return false;
        }
    };

    unsafe {
        *out_max_texture_size = renderer.get_max_texture_size();
    }
    *out_handle = Box::into_raw(Box::new(DocumentHandle::new(
        sender.create_api_by_client(next_namespace_id()),
        None,
        window_size,
        document_id,
    )));
    *out_renderer = Box::into_raw(Box::new(renderer));

    true
}

#[no_mangle]
pub unsafe extern "C" fn wr_api_free_error_msg(msg: *mut c_char) {
    if !msg.is_null() {
        CString::from_raw(msg);
    }
}

#[no_mangle]
pub unsafe extern "C" fn wr_api_delete_document(dh: &mut DocumentHandle) {
    dh.api.delete_document(dh.document_id);
}

#[no_mangle]
pub extern "C" fn wr_api_clone(dh: &mut DocumentHandle, out_handle: &mut *mut DocumentHandle) {
    assert!(unsafe { is_in_compositor_thread() });

    dh.ensure_hit_tester();

    let handle = DocumentHandle {
        api: dh.api.create_sender().create_api_by_client(next_namespace_id()),
        document_id: dh.document_id,
        hit_tester: dh.hit_tester.clone(),
        hit_tester_request: None,
    };
    *out_handle = Box::into_raw(Box::new(handle));
}

#[no_mangle]
pub unsafe extern "C" fn wr_api_delete(dh: *mut DocumentHandle) {
    let _ = Box::from_raw(dh);
}

#[no_mangle]
pub unsafe extern "C" fn wr_api_stop_render_backend(dh: &mut DocumentHandle) {
    dh.api.stop_render_backend();
}

#[no_mangle]
pub unsafe extern "C" fn wr_api_shut_down(dh: &mut DocumentHandle) {
    dh.api.shut_down(true);
}

#[no_mangle]
pub unsafe extern "C" fn wr_api_notify_memory_pressure(dh: &mut DocumentHandle) {
    dh.api.notify_memory_pressure();
}

#[no_mangle]
pub extern "C" fn wr_api_set_debug_flags(dh: &mut DocumentHandle, flags: DebugFlags) {
    dh.api.set_debug_flags(flags);
}

#[no_mangle]
pub unsafe extern "C" fn wr_api_accumulate_memory_report(
    dh: &mut DocumentHandle,
    report: &mut MemoryReport,
    // we manually expand VoidPtrToSizeFn here because cbindgen otherwise fails to fold the Option<fn()>
    // https://github.com/eqrion/cbindgen/issues/552
    size_of_op: unsafe extern "C" fn(ptr: *const c_void) -> usize,
    enclosing_size_of_op: Option<unsafe extern "C" fn(ptr: *const c_void) -> usize>,
) {
    let ops = MallocSizeOfOps::new(size_of_op, enclosing_size_of_op);
    *report += dh.api.report_memory(ops);
}

#[no_mangle]
pub unsafe extern "C" fn wr_api_clear_all_caches(dh: &mut DocumentHandle) {
    dh.api.send_debug_cmd(DebugCommand::ClearCaches(ClearCache::all()));
}

#[no_mangle]
pub unsafe extern "C" fn wr_api_enable_native_compositor(dh: &mut DocumentHandle, enable: bool) {
    dh.api.send_debug_cmd(DebugCommand::EnableNativeCompositor(enable));
}

#[no_mangle]
pub unsafe extern "C" fn wr_api_enable_multithreading(dh: &mut DocumentHandle, enable: bool) {
    dh.api.send_debug_cmd(DebugCommand::EnableMultithreading(enable));
}

#[no_mangle]
pub unsafe extern "C" fn wr_api_set_batching_lookback(dh: &mut DocumentHandle, count: u32) {
    dh.api.send_debug_cmd(DebugCommand::SetBatchingLookback(count));
}

fn make_transaction(do_async: bool) -> Transaction {
    let mut transaction = Transaction::new();
    // Ensure that we either use async scene building or not based on the
    // gecko pref, regardless of what the default is. We can remove this once
    // the scene builder thread is enabled everywhere and working well.
    if do_async {
        transaction.use_scene_builder_thread();
    } else {
        transaction.skip_scene_builder();
    }
    transaction
}

#[no_mangle]
pub extern "C" fn wr_transaction_new(do_async: bool) -> *mut Transaction {
    Box::into_raw(Box::new(make_transaction(do_async)))
}

#[no_mangle]
pub extern "C" fn wr_transaction_delete(txn: *mut Transaction) {
    unsafe {
        let _ = Box::from_raw(txn);
    }
}

#[no_mangle]
pub extern "C" fn wr_transaction_set_low_priority(txn: &mut Transaction, low_priority: bool) {
    txn.set_low_priority(low_priority);
}

#[no_mangle]
pub extern "C" fn wr_transaction_is_empty(txn: &Transaction) -> bool {
    txn.is_empty()
}

#[no_mangle]
pub extern "C" fn wr_transaction_resource_updates_is_empty(txn: &Transaction) -> bool {
    txn.resource_updates.is_empty()
}

#[no_mangle]
pub extern "C" fn wr_transaction_is_rendered_frame_invalidated(txn: &Transaction) -> bool {
    txn.invalidate_rendered_frame
}

#[no_mangle]
pub extern "C" fn wr_transaction_notify(txn: &mut Transaction, when: Checkpoint, event: usize) {
    struct GeckoNotification(usize);
    impl NotificationHandler for GeckoNotification {
        fn notify(&self, when: Checkpoint) {
            unsafe {
                wr_transaction_notification_notified(self.0, when);
            }
        }
    }

    let handler = Box::new(GeckoNotification(event));
    txn.notify(NotificationRequest::new(when, handler));
}

#[no_mangle]
pub extern "C" fn wr_transaction_update_epoch(txn: &mut Transaction, pipeline_id: WrPipelineId, epoch: WrEpoch) {
    txn.update_epoch(pipeline_id, epoch);
}

#[no_mangle]
pub extern "C" fn wr_transaction_set_root_pipeline(txn: &mut Transaction, pipeline_id: WrPipelineId) {
    txn.set_root_pipeline(pipeline_id);
}

#[no_mangle]
pub extern "C" fn wr_transaction_remove_pipeline(txn: &mut Transaction, pipeline_id: WrPipelineId) {
    txn.remove_pipeline(pipeline_id);
}

#[no_mangle]
pub extern "C" fn wr_transaction_set_display_list(
    txn: &mut Transaction,
    epoch: WrEpoch,
    background: ColorF,
    viewport_size: LayoutSize,
    pipeline_id: WrPipelineId,
    dl_descriptor: BuiltDisplayListDescriptor,
    dl_data: &mut WrVecU8,
) {
    let color = if background.a == 0.0 { None } else { Some(background) };

    // See the documentation of set_display_list in api.rs. I don't think
    // it makes a difference in gecko at the moment(until APZ is figured out)
    // but I suppose it is a good default.
    let preserve_frame_state = true;

    let dl_vec = dl_data.flush_into_vec();
    let dl = BuiltDisplayList::from_data(dl_vec, dl_descriptor);

    txn.set_display_list(epoch, color, viewport_size, (pipeline_id, dl), preserve_frame_state);
}

#[no_mangle]
pub extern "C" fn wr_transaction_set_document_view(txn: &mut Transaction, doc_rect: &DeviceIntRect) {
    txn.set_document_view(*doc_rect);
}

#[no_mangle]
pub extern "C" fn wr_transaction_generate_frame(txn: &mut Transaction, id: u64) {
    txn.generate_frame(id);
}

#[no_mangle]
pub extern "C" fn wr_transaction_invalidate_rendered_frame(txn: &mut Transaction) {
    txn.invalidate_rendered_frame();
}

fn wr_animation_properties_into_vec<T>(
    animation_array: *const WrAnimationPropertyValue<T>,
    array_count: usize,
    vec: &mut Vec<PropertyValue<T>>,
) where
    T: Copy,
{
    if array_count > 0 {
        debug_assert!(
            vec.capacity() - vec.len() >= array_count,
            "The Vec should have fufficient free capacity"
        );
        let slice = unsafe { make_slice(animation_array, array_count) };

        for element in slice.iter() {
            let prop = PropertyValue {
                key: PropertyBindingKey::new(element.id),
                value: element.value,
            };

            vec.push(prop);
        }
    }
}

#[no_mangle]
pub extern "C" fn wr_transaction_update_dynamic_properties(
    txn: &mut Transaction,
    opacity_array: *const WrOpacityProperty,
    opacity_count: usize,
    transform_array: *const WrTransformProperty,
    transform_count: usize,
    color_array: *const WrColorProperty,
    color_count: usize,
) {
    let mut properties = DynamicProperties {
        transforms: Vec::with_capacity(transform_count),
        floats: Vec::with_capacity(opacity_count),
        colors: Vec::with_capacity(color_count),
    };

    wr_animation_properties_into_vec(transform_array, transform_count, &mut properties.transforms);

    wr_animation_properties_into_vec(opacity_array, opacity_count, &mut properties.floats);

    wr_animation_properties_into_vec(color_array, color_count, &mut properties.colors);

    txn.update_dynamic_properties(properties);
}

#[no_mangle]
pub extern "C" fn wr_transaction_append_transform_properties(
    txn: &mut Transaction,
    transform_array: *const WrTransformProperty,
    transform_count: usize,
) {
    if transform_count == 0 {
        return;
    }

    let mut transforms = Vec::with_capacity(transform_count);
    wr_animation_properties_into_vec(transform_array, transform_count, &mut transforms);

    txn.append_dynamic_transform_properties(transforms);
}

#[no_mangle]
pub extern "C" fn wr_transaction_scroll_layer(
    txn: &mut Transaction,
    pipeline_id: WrPipelineId,
    scroll_id: u64,
    new_scroll_origin: LayoutPoint,
) {
    let scroll_id = ExternalScrollId(scroll_id, pipeline_id);
    txn.scroll_node_with_id(new_scroll_origin, scroll_id, ScrollClamping::NoClamping);
}

#[no_mangle]
pub extern "C" fn wr_transaction_set_is_transform_async_zooming(
    txn: &mut Transaction,
    animation_id: u64,
    is_zooming: bool,
) {
    txn.set_is_transform_async_zooming(is_zooming, PropertyBindingId::new(animation_id));
}

#[no_mangle]
pub extern "C" fn wr_transaction_set_quality_settings(txn: &mut Transaction, force_subpixel_aa_where_possible: bool) {
    txn.set_quality_settings(QualitySettings {
        force_subpixel_aa_where_possible,
    });
}

#[no_mangle]
pub extern "C" fn wr_resource_updates_add_image(
    txn: &mut Transaction,
    image_key: WrImageKey,
    descriptor: &WrImageDescriptor,
    bytes: &mut WrVecU8,
) {
    txn.add_image(
        image_key,
        descriptor.into(),
        ImageData::new(bytes.flush_into_vec()),
        None,
    );
}

#[no_mangle]
pub extern "C" fn wr_resource_updates_add_blob_image(
    txn: &mut Transaction,
    image_key: BlobImageKey,
    descriptor: &WrImageDescriptor,
    bytes: &mut WrVecU8,
    visible_rect: DeviceIntRect,
) {
    txn.add_blob_image(
        image_key,
        descriptor.into(),
        Arc::new(bytes.flush_into_vec()),
        visible_rect,
        if descriptor.format == ImageFormat::BGRA8 {
            Some(256)
        } else {
            None
        },
    );
}

#[no_mangle]
pub extern "C" fn wr_resource_updates_add_external_image(
    txn: &mut Transaction,
    image_key: WrImageKey,
    descriptor: &WrImageDescriptor,
    external_image_id: ExternalImageId,
    image_type: &ExternalImageType,
    channel_index: u8,
) {
    txn.add_image(
        image_key,
        descriptor.into(),
        ImageData::External(ExternalImageData {
            id: external_image_id,
            channel_index,
            image_type: *image_type,
        }),
        None,
    );
}

#[no_mangle]
pub extern "C" fn wr_resource_updates_update_image(
    txn: &mut Transaction,
    key: WrImageKey,
    descriptor: &WrImageDescriptor,
    bytes: &mut WrVecU8,
) {
    txn.update_image(
        key,
        descriptor.into(),
        ImageData::new(bytes.flush_into_vec()),
        &DirtyRect::All,
    );
}

#[no_mangle]
pub extern "C" fn wr_resource_updates_set_blob_image_visible_area(
    txn: &mut Transaction,
    key: BlobImageKey,
    area: &DeviceIntRect,
) {
    txn.set_blob_image_visible_area(key, *area);
}

#[no_mangle]
pub extern "C" fn wr_resource_updates_update_external_image(
    txn: &mut Transaction,
    key: WrImageKey,
    descriptor: &WrImageDescriptor,
    external_image_id: ExternalImageId,
    image_type: &ExternalImageType,
    channel_index: u8,
) {
    txn.update_image(
        key,
        descriptor.into(),
        ImageData::External(ExternalImageData {
            id: external_image_id,
            channel_index,
            image_type: *image_type,
        }),
        &DirtyRect::All,
    );
}

#[no_mangle]
pub extern "C" fn wr_resource_updates_update_external_image_with_dirty_rect(
    txn: &mut Transaction,
    key: WrImageKey,
    descriptor: &WrImageDescriptor,
    external_image_id: ExternalImageId,
    image_type: &ExternalImageType,
    channel_index: u8,
    dirty_rect: DeviceIntRect,
) {
    txn.update_image(
        key,
        descriptor.into(),
        ImageData::External(ExternalImageData {
            id: external_image_id,
            channel_index,
            image_type: *image_type,
        }),
        &DirtyRect::Partial(dirty_rect),
    );
}

#[no_mangle]
pub extern "C" fn wr_resource_updates_update_blob_image(
    txn: &mut Transaction,
    image_key: BlobImageKey,
    descriptor: &WrImageDescriptor,
    bytes: &mut WrVecU8,
    visible_rect: DeviceIntRect,
    dirty_rect: LayoutIntRect,
) {
    txn.update_blob_image(
        image_key,
        descriptor.into(),
        Arc::new(bytes.flush_into_vec()),
        visible_rect,
        &DirtyRect::Partial(dirty_rect),
    );
}

#[no_mangle]
pub extern "C" fn wr_resource_updates_delete_image(txn: &mut Transaction, key: WrImageKey) {
    txn.delete_image(key);
}

#[no_mangle]
pub extern "C" fn wr_resource_updates_delete_blob_image(txn: &mut Transaction, key: BlobImageKey) {
    txn.delete_blob_image(key);
}

#[no_mangle]
pub extern "C" fn wr_api_send_transaction(dh: &mut DocumentHandle, transaction: &mut Transaction, is_async: bool) {
    if transaction.is_empty() {
        return;
    }
    let new_txn = make_transaction(is_async);
    let txn = mem::replace(transaction, new_txn);
    dh.api.send_transaction(dh.document_id, txn);
}

#[no_mangle]
pub unsafe extern "C" fn wr_transaction_clear_display_list(
    txn: &mut Transaction,
    epoch: WrEpoch,
    pipeline_id: WrPipelineId,
) {
    let preserve_frame_state = true;
    let frame_builder = WebRenderFrameBuilder::new(pipeline_id);

    txn.set_display_list(
        epoch,
        None,
        LayoutSize::new(0.0, 0.0),
        frame_builder.dl_builder.finalize(),
        preserve_frame_state,
    );
}

#[no_mangle]
pub extern "C" fn wr_api_send_external_event(dh: &mut DocumentHandle, evt: usize) {
    assert!(unsafe { !is_in_render_thread() });

    dh.api.send_external_event(ExternalEvent::from_raw(evt));
}

#[no_mangle]
pub extern "C" fn wr_resource_updates_add_raw_font(
    txn: &mut Transaction,
    key: WrFontKey,
    bytes: &mut WrVecU8,
    index: u32,
) {
    txn.add_raw_font(key, bytes.flush_into_vec(), index);
}

fn generate_capture_path(path: *const c_char) -> Option<PathBuf> {
    use std::fs::{create_dir_all, File};
    use std::io::Write;

    let cstr = unsafe { CStr::from_ptr(path) };
    let local_dir = PathBuf::from(&*cstr.to_string_lossy());

    // On Android we need to write into a particular folder on external
    // storage so that (a) it can be written without requiring permissions
    // and (b) it can be pulled off via `adb pull`. This env var is set
    // in GeckoLoader.java.
    // When running in Firefox CI, the MOZ_UPLOAD_DIR variable is set to a path
    // that taskcluster will export artifacts from, so let's put it there.
    let mut path = if let Ok(storage_path) = env::var("PUBLIC_STORAGE") {
        PathBuf::from(storage_path).join(local_dir)
    } else if let Ok(storage_path) = env::var("MOZ_UPLOAD_DIR") {
        PathBuf::from(storage_path).join(local_dir)
    } else if let Some(storage_path) = dirs::home_dir() {
        storage_path.join(local_dir)
    } else {
        local_dir
    };

    // Increment the extension until we find a fresh path
    while path.is_dir() {
        let count: u32 = path
            .extension()
            .and_then(|x| x.to_str())
            .and_then(|x| x.parse().ok())
            .unwrap_or(0);
        path.set_extension((count + 1).to_string());
    }

    // Use warn! so that it gets emitted to logcat on android as well
    let border = "--------------------------\n";
    warn!("{} Capturing WR state to: {:?}\n{}", &border, &path, &border);

    let _ = create_dir_all(&path);
    match File::create(path.join("wr.txt")) {
        Ok(mut file) => {
            // The Gecko HG revision is available at compile time
            if let Some(moz_revision) = option_env!("GECKO_HEAD_REV") {
                writeln!(file, "mozilla-central {}", moz_revision).unwrap();
            }
            Some(path)
        }
        Err(e) => {
            warn!("Unable to create path '{:?}' for capture: {:?}", path, e);
            None
        }
    }
}

#[no_mangle]
pub extern "C" fn wr_api_capture(dh: &mut DocumentHandle, path: *const c_char, bits_raw: u32) {
    if let Some(path) = generate_capture_path(path) {
        let bits = CaptureBits::from_bits(bits_raw as _).unwrap();
        dh.api.save_capture(path, bits);
    }
}

#[no_mangle]
pub extern "C" fn wr_api_start_capture_sequence(dh: &mut DocumentHandle, path: *const c_char, bits_raw: u32) {
    if let Some(path) = generate_capture_path(path) {
        let bits = CaptureBits::from_bits(bits_raw as _).unwrap();
        dh.api.start_capture_sequence(path, bits);
    }
}

#[no_mangle]
pub extern "C" fn wr_api_stop_capture_sequence(dh: &mut DocumentHandle) {
    let border = "--------------------------\n";
    warn!("{} Stop capturing WR state\n{}", &border, &border);
    dh.api.stop_capture_sequence();
}

#[cfg(target_os = "windows")]
fn read_font_descriptor(bytes: &mut WrVecU8, index: u32) -> NativeFontHandle {
    let wchars = bytes.convert_into_vec::<u16>();
    NativeFontHandle {
        path: PathBuf::from(OsString::from_wide(&wchars)),
        index,
    }
}

#[cfg(target_os = "macos")]
fn read_font_descriptor(bytes: &mut WrVecU8, _index: u32) -> NativeFontHandle {
    let chars = bytes.flush_into_vec();
    let name = String::from_utf8(chars).unwrap();
    let font = match CGFont::from_name(&CFString::new(&*name)) {
        Ok(font) => font,
        Err(_) => {
            // If for some reason we failed to load a font descriptor, then our
            // only options are to either abort or substitute a fallback font.
            // It is preferable to use a fallback font instead so that rendering
            // can at least still proceed in some fashion without erroring.
            // Lucida Grande is the fallback font in Gecko, so use that here.
            CGFont::from_name(&CFString::from_static_string("Lucida Grande"))
                .expect("Failed reading font descriptor and could not load fallback font")
        }
    };
    NativeFontHandle(font)
}

#[cfg(not(any(target_os = "macos", target_os = "windows")))]
fn read_font_descriptor(bytes: &mut WrVecU8, index: u32) -> NativeFontHandle {
    let chars = bytes.flush_into_vec();
    NativeFontHandle {
        path: PathBuf::from(OsString::from_vec(chars)),
        index,
    }
}

#[no_mangle]
pub extern "C" fn wr_resource_updates_add_font_descriptor(
    txn: &mut Transaction,
    key: WrFontKey,
    bytes: &mut WrVecU8,
    index: u32,
) {
    let native_font_handle = read_font_descriptor(bytes, index);
    txn.add_native_font(key, native_font_handle);
}

#[no_mangle]
pub extern "C" fn wr_resource_updates_delete_font(txn: &mut Transaction, key: WrFontKey) {
    txn.delete_font(key);
}

#[no_mangle]
pub extern "C" fn wr_resource_updates_add_font_instance(
    txn: &mut Transaction,
    key: WrFontInstanceKey,
    font_key: WrFontKey,
    glyph_size: f32,
    options: *const FontInstanceOptions,
    platform_options: *const FontInstancePlatformOptions,
    variations: &mut WrVecU8,
) {
    txn.add_font_instance(
        key,
        font_key,
        glyph_size,
        unsafe { options.as_ref().cloned() },
        unsafe { platform_options.as_ref().cloned() },
        variations.convert_into_vec::<FontVariation>(),
    );
}

#[no_mangle]
pub extern "C" fn wr_resource_updates_delete_font_instance(txn: &mut Transaction, key: WrFontInstanceKey) {
    txn.delete_font_instance(key);
}

#[no_mangle]
pub extern "C" fn wr_resource_updates_clear(txn: &mut Transaction) {
    txn.resource_updates.clear();
}

#[no_mangle]
pub unsafe extern "C" fn wr_api_get_namespace(dh: &mut DocumentHandle) -> WrIdNamespace {
    dh.api.get_namespace_id()
}

#[no_mangle]
pub unsafe extern "C" fn wr_api_wake_scene_builder(dh: &mut DocumentHandle) {
    dh.api.wake_scene_builder();
}

#[no_mangle]
pub unsafe extern "C" fn wr_api_flush_scene_builder(dh: &mut DocumentHandle) {
    dh.api.flush_scene_builder();
}

// RenderThread WIP notes:
// In order to separate the compositor thread (or ipc receiver) and the render
// thread, some of the logic below needs to be rewritten. In particular
// the WrWindowState and Notifier implementations aren't designed to work with
// a separate render thread.
// As part of that I am moving the bindings closer to WebRender's API boundary,
// and moving more of the logic in C++ land.
// This work is tracked by bug 1328602.
//
// See RenderThread.h for some notes about how the pieces fit together.

pub struct WebRenderFrameBuilder {
    pub root_pipeline_id: WrPipelineId,
    pub dl_builder: DisplayListBuilder,
}

impl WebRenderFrameBuilder {
    pub fn new(root_pipeline_id: WrPipelineId) -> WebRenderFrameBuilder {
        WebRenderFrameBuilder {
            root_pipeline_id,
            dl_builder: DisplayListBuilder::new(root_pipeline_id),
        }
    }
    pub fn with_capacity(root_pipeline_id: WrPipelineId, capacity: usize) -> WebRenderFrameBuilder {
        WebRenderFrameBuilder {
            root_pipeline_id,
            dl_builder: DisplayListBuilder::with_capacity(root_pipeline_id, capacity),
        }
    }
}

pub struct WrState {
    pipeline_id: WrPipelineId,
    frame_builder: WebRenderFrameBuilder,
}

#[no_mangle]
pub extern "C" fn wr_state_new(pipeline_id: WrPipelineId, capacity: usize) -> *mut WrState {
    assert!(unsafe { !is_in_render_thread() });

    let state = Box::new(WrState {
        pipeline_id,
        frame_builder: WebRenderFrameBuilder::with_capacity(pipeline_id, capacity),
    });

    Box::into_raw(state)
}

#[no_mangle]
pub extern "C" fn wr_state_delete(state: *mut WrState) {
    assert!(unsafe { !is_in_render_thread() });

    unsafe {
        Box::from_raw(state);
    }
}

#[no_mangle]
pub extern "C" fn wr_dp_save(state: &mut WrState) {
    state.frame_builder.dl_builder.save();
}

#[no_mangle]
pub extern "C" fn wr_dp_restore(state: &mut WrState) {
    state.frame_builder.dl_builder.restore();
}

#[no_mangle]
pub extern "C" fn wr_dp_clear_save(state: &mut WrState) {
    state.frame_builder.dl_builder.clear_save();
}

#[repr(u8)]
#[derive(PartialEq, Eq, Debug)]
pub enum WrReferenceFrameKind {
    Transform,
    Perspective,
}

#[repr(u8)]
#[derive(PartialEq, Eq, Debug)]
pub enum WrRotation {
    Degree0,
    Degree90,
    Degree180,
    Degree270,
}

/// IMPORTANT: If you add fields to this struct, you need to also add initializers
/// for those fields in WebRenderAPI.h.
#[repr(C)]
pub struct WrStackingContextParams {
    pub clip: WrStackingContextClip,
    pub animation: *const WrAnimationProperty,
    pub opacity: *const f32,
    pub computed_transform: *const WrComputedTransformData,
    pub transform_style: TransformStyle,
    pub reference_frame_kind: WrReferenceFrameKind,
    pub is_2d_scale_translation: bool,
    pub should_snap: bool,
    pub scrolling_relative_to: *const u64,
    pub prim_flags: PrimitiveFlags,
    pub mix_blend_mode: MixBlendMode,
    pub flags: StackingContextFlags,
}

#[no_mangle]
pub extern "C" fn wr_dp_push_stacking_context(
    state: &mut WrState,
    bounds: LayoutRect,
    spatial_id: WrSpatialId,
    params: &WrStackingContextParams,
    transform: *const LayoutTransform,
    filters: *const FilterOp,
    filter_count: usize,
    filter_datas: *const WrFilterData,
    filter_datas_count: usize,
    glyph_raster_space: RasterSpace,
) -> WrSpatialId {
    debug_assert!(unsafe { !is_in_render_thread() });

    let c_filters = unsafe { make_slice(filters, filter_count) };
    let mut filters: Vec<FilterOp> = c_filters.iter().copied().collect();

    let c_filter_datas = unsafe { make_slice(filter_datas, filter_datas_count) };
    let r_filter_datas: Vec<FilterData> = c_filter_datas
        .iter()
        .map(|c_filter_data| FilterData {
            func_r_type: c_filter_data.funcR_type,
            r_values: unsafe { make_slice(c_filter_data.R_values, c_filter_data.R_values_count).to_vec() },
            func_g_type: c_filter_data.funcG_type,
            g_values: unsafe { make_slice(c_filter_data.G_values, c_filter_data.G_values_count).to_vec() },
            func_b_type: c_filter_data.funcB_type,
            b_values: unsafe { make_slice(c_filter_data.B_values, c_filter_data.B_values_count).to_vec() },
            func_a_type: c_filter_data.funcA_type,
            a_values: unsafe { make_slice(c_filter_data.A_values, c_filter_data.A_values_count).to_vec() },
        })
        .collect();

    let transform_ref = unsafe { transform.as_ref() };
    let mut transform_binding = transform_ref.map(|t| PropertyBinding::Value(*t));

    let computed_ref = unsafe { params.computed_transform.as_ref() };
    let opacity_ref = unsafe { params.opacity.as_ref() };
    let mut has_opacity_animation = false;
    let anim = unsafe { params.animation.as_ref() };
    if let Some(anim) = anim {
        debug_assert!(anim.id > 0);
        match anim.effect_type {
            WrAnimationType::Opacity => {
                filters.push(FilterOp::Opacity(
                    PropertyBinding::Binding(
                        PropertyBindingKey::new(anim.id),
                        // We have to set the static opacity value as
                        // the value for the case where the animation is
                        // in not in-effect (e.g. in the delay phase
                        // with no corresponding fill mode).
                        opacity_ref.cloned().unwrap_or(1.0),
                    ),
                    1.0,
                ));
                has_opacity_animation = true;
            }
            WrAnimationType::Transform => {
                transform_binding = Some(PropertyBinding::Binding(
                    PropertyBindingKey::new(anim.id),
                    // Same as above opacity case.
                    transform_ref.cloned().unwrap_or_else(LayoutTransform::identity),
                ));
            }
            _ => unreachable!("{:?} should not create a stacking context", anim.effect_type),
        }
    }

    if let Some(opacity) = opacity_ref {
        if !has_opacity_animation && *opacity < 1.0 {
            filters.push(FilterOp::Opacity(PropertyBinding::Value(*opacity), *opacity));
        }
    }

    let mut wr_spatial_id = spatial_id.to_webrender(state.pipeline_id);
    let wr_clip_id = params.clip.to_webrender(state.pipeline_id);

    let mut origin = bounds.min;

    // Note: 0 has special meaning in WR land, standing for ROOT_REFERENCE_FRAME.
    // However, it is never returned by `push_reference_frame`, and we need to return
    // an option here across FFI, so we take that 0 value for the None semantics.
    // This is resolved into proper `Maybe<WrSpatialId>` inside `WebRenderAPI::PushStackingContext`.
    let mut result = WrSpatialId { id: 0 };
    if let Some(transform_binding) = transform_binding {
        let is_2d_scale_translation = params.is_2d_scale_translation;
        let should_snap = params.should_snap;
        let scrolling_relative_to = match unsafe { params.scrolling_relative_to.as_ref() } {
            Some(scroll_id) => {
                debug_assert_eq!(params.reference_frame_kind, WrReferenceFrameKind::Perspective);
                Some(ExternalScrollId(*scroll_id, state.pipeline_id))
            }
            None => None,
        };

        let reference_frame_kind = match params.reference_frame_kind {
            WrReferenceFrameKind::Transform => ReferenceFrameKind::Transform {
                is_2d_scale_translation,
                should_snap,
            },
            WrReferenceFrameKind::Perspective => ReferenceFrameKind::Perspective { scrolling_relative_to },
        };
        wr_spatial_id = state.frame_builder.dl_builder.push_reference_frame(
            origin,
            wr_spatial_id,
            params.transform_style,
            transform_binding,
            reference_frame_kind,
        );

        origin = LayoutPoint::zero();
        result.id = wr_spatial_id.0;
        assert_ne!(wr_spatial_id.0, 0);
    } else if let Some(data) = computed_ref {
        let rotation = match data.rotation {
            WrRotation::Degree0 => Rotation::Degree0,
            WrRotation::Degree90 => Rotation::Degree90,
            WrRotation::Degree180 => Rotation::Degree180,
            WrRotation::Degree270 => Rotation::Degree270,
        };
        wr_spatial_id = state.frame_builder.dl_builder.push_computed_frame(
            origin,
            wr_spatial_id,
            Some(data.scale_from),
            data.vertical_flip,
            rotation,
        );

        origin = LayoutPoint::zero();
        result.id = wr_spatial_id.0;
        assert_ne!(wr_spatial_id.0, 0);
    }

    state.frame_builder.dl_builder.push_stacking_context(
        origin,
        wr_spatial_id,
        params.prim_flags,
        wr_clip_id,
        params.transform_style,
        params.mix_blend_mode,
        &filters,
        &r_filter_datas,
        &[],
        glyph_raster_space,
        params.flags,
    );

    result
}

#[no_mangle]
pub extern "C" fn wr_dp_pop_stacking_context(state: &mut WrState, is_reference_frame: bool) {
    debug_assert!(unsafe { !is_in_render_thread() });
    state.frame_builder.dl_builder.pop_stacking_context();
    if is_reference_frame {
        state.frame_builder.dl_builder.pop_reference_frame();
    }
}

#[no_mangle]
pub extern "C" fn wr_dp_define_clipchain(
    state: &mut WrState,
    parent_clipchain_id: *const u64,
    clips: *const WrClipId,
    clips_count: usize,
) -> u64 {
    debug_assert!(unsafe { is_in_main_thread() });
    let parent = unsafe { parent_clipchain_id.as_ref() }.map(|id| ClipChainId(*id, state.pipeline_id));

    let pipeline_id = state.pipeline_id;
    let clips = unsafe { make_slice(clips, clips_count) }
        .iter()
        .map(|clip_id| clip_id.to_webrender(pipeline_id));

    let clipchain_id = state.frame_builder.dl_builder.define_clip_chain(parent, clips);
    assert!(clipchain_id.1 == state.pipeline_id);
    clipchain_id.0
}

#[no_mangle]
pub extern "C" fn wr_dp_define_image_mask_clip_with_parent_clip_chain(
    state: &mut WrState,
    parent: &WrSpaceAndClipChain,
    mask: ImageMask,
    points: *const LayoutPoint,
    point_count: usize,
    fill_rule: FillRule,
) -> WrClipId {
    debug_assert!(unsafe { is_in_main_thread() });

    let c_points = unsafe { make_slice(points, point_count) };
    let points: Vec<LayoutPoint> = c_points.iter().copied().collect();

    let clip_id = state.frame_builder.dl_builder.define_clip_image_mask(
        &parent.to_webrender(state.pipeline_id),
        mask,
        &points,
        fill_rule,
    );
    WrClipId::from_webrender(clip_id)
}

#[no_mangle]
pub extern "C" fn wr_dp_define_rounded_rect_clip(
    state: &mut WrState,
    space: WrSpatialId,
    complex: ComplexClipRegion,
) -> WrClipId {
    debug_assert!(unsafe { is_in_main_thread() });

    let space_and_clip = SpaceAndClipInfo {
        spatial_id: space.to_webrender(state.pipeline_id),
        clip_id: ClipId::root(state.pipeline_id),
    };

    let clip_id = state
        .frame_builder
        .dl_builder
        .define_clip_rounded_rect(&space_and_clip, complex);
    WrClipId::from_webrender(clip_id)
}

#[no_mangle]
pub extern "C" fn wr_dp_define_rounded_rect_clip_with_parent_clip_chain(
    state: &mut WrState,
    parent: &WrSpaceAndClipChain,
    complex: ComplexClipRegion,
) -> WrClipId {
    debug_assert!(unsafe { is_in_main_thread() });

    let clip_id = state
        .frame_builder
        .dl_builder
        .define_clip_rounded_rect(&parent.to_webrender(state.pipeline_id), complex);
    WrClipId::from_webrender(clip_id)
}

#[no_mangle]
pub extern "C" fn wr_dp_define_rect_clip(
    state: &mut WrState,
    space: WrSpatialId,
    clip_rect: LayoutRect,
) -> WrClipId {
    debug_assert!(unsafe { is_in_main_thread() });

    let space_and_clip = SpaceAndClipInfo {
        spatial_id: space.to_webrender(state.pipeline_id),
        clip_id: ClipId::root(state.pipeline_id),
    };

    let clip_id = state
        .frame_builder
        .dl_builder
        .define_clip_rect(&space_and_clip, clip_rect);
    WrClipId::from_webrender(clip_id)
}

#[no_mangle]
pub extern "C" fn wr_dp_define_rect_clip_with_parent_clip_chain(
    state: &mut WrState,
    parent: &WrSpaceAndClipChain,
    clip_rect: LayoutRect,
) -> WrClipId {
    debug_assert!(unsafe { is_in_main_thread() });

    let clip_id = state
        .frame_builder
        .dl_builder
        .define_clip_rect(&parent.to_webrender(state.pipeline_id), clip_rect);
    WrClipId::from_webrender(clip_id)
}

#[no_mangle]
pub extern "C" fn wr_dp_define_sticky_frame(
    state: &mut WrState,
    parent_spatial_id: WrSpatialId,
    content_rect: LayoutRect,
    top_margin: *const f32,
    right_margin: *const f32,
    bottom_margin: *const f32,
    left_margin: *const f32,
    vertical_bounds: StickyOffsetBounds,
    horizontal_bounds: StickyOffsetBounds,
    applied_offset: LayoutVector2D,
) -> WrSpatialId {
    assert!(unsafe { is_in_main_thread() });
    let spatial_id = state.frame_builder.dl_builder.define_sticky_frame(
        parent_spatial_id.to_webrender(state.pipeline_id),
        content_rect,
        SideOffsets2D::new(
            unsafe { top_margin.as_ref() }.cloned(),
            unsafe { right_margin.as_ref() }.cloned(),
            unsafe { bottom_margin.as_ref() }.cloned(),
            unsafe { left_margin.as_ref() }.cloned(),
        ),
        vertical_bounds,
        horizontal_bounds,
        applied_offset,
    );

    WrSpatialId { id: spatial_id.0 }
}

#[no_mangle]
pub extern "C" fn wr_dp_define_scroll_layer(
    state: &mut WrState,
    external_scroll_id: u64,
    parent: &WrSpaceAndClip,
    content_rect: LayoutRect,
    clip_rect: LayoutRect,
    scroll_offset: LayoutPoint,
) -> WrSpaceAndClip {
    assert!(unsafe { is_in_main_thread() });

    let space_and_clip = state.frame_builder.dl_builder.define_scroll_frame(
        &parent.to_webrender(state.pipeline_id),
        ExternalScrollId(external_scroll_id, state.pipeline_id),
        content_rect,
        clip_rect,
        ScrollSensitivity::Script,
        // TODO(gw): We should also update the Gecko-side APIs to provide
        //           this as a vector rather than a point.
        scroll_offset.to_vector(),
    );

    WrSpaceAndClip::from_webrender(space_and_clip)
}

#[no_mangle]
pub extern "C" fn wr_dp_push_iframe(
    state: &mut WrState,
    rect: LayoutRect,
    clip: LayoutRect,
    _is_backface_visible: bool,
    parent: &WrSpaceAndClipChain,
    pipeline_id: WrPipelineId,
    ignore_missing_pipeline: bool,
) {
    debug_assert!(unsafe { is_in_main_thread() });

    state.frame_builder.dl_builder.push_iframe(
        rect,
        clip,
        &parent.to_webrender(state.pipeline_id),
        pipeline_id,
        ignore_missing_pipeline,
    );
}

// A helper fn to construct a PrimitiveFlags
fn prim_flags(is_backface_visible: bool, prefer_compositor_surface: bool) -> PrimitiveFlags {
    let mut flags = PrimitiveFlags::empty();

    if is_backface_visible {
        flags |= PrimitiveFlags::IS_BACKFACE_VISIBLE;
    }

    if prefer_compositor_surface {
        flags |= PrimitiveFlags::PREFER_COMPOSITOR_SURFACE;
    }

    flags
}

fn prim_flags2(
    is_backface_visible: bool,
    prefer_compositor_surface: bool,
    supports_external_compositing: bool,
) -> PrimitiveFlags {
    let mut flags = PrimitiveFlags::empty();

    if supports_external_compositing {
        flags |= PrimitiveFlags::SUPPORTS_EXTERNAL_COMPOSITOR_SURFACE;
    }

    flags | prim_flags(is_backface_visible, prefer_compositor_surface)
}

fn common_item_properties_for_rect(
    state: &mut WrState,
    clip_rect: LayoutRect,
    is_backface_visible: bool,
    parent: &WrSpaceAndClipChain,
) -> CommonItemProperties {
    let space_and_clip = parent.to_webrender(state.pipeline_id);

    CommonItemProperties {
        // NB: the damp-e10s talos-test will frequently crash on startup if we
        // early-return here for empty rects. I couldn't figure out why, but
        // it's pretty harmless to feed these through, so, uh, we do?
        clip_rect,
        clip_id: space_and_clip.clip_id,
        spatial_id: space_and_clip.spatial_id,
        flags: prim_flags(is_backface_visible, /* prefer_compositor_surface */ false),
    }
}

#[no_mangle]
pub extern "C" fn wr_dp_push_rect(
    state: &mut WrState,
    rect: LayoutRect,
    clip: LayoutRect,
    is_backface_visible: bool,
    parent: &WrSpaceAndClipChain,
    color: ColorF,
) {
    debug_assert!(unsafe { !is_in_render_thread() });

    let prim_info = common_item_properties_for_rect(state, clip, is_backface_visible, parent);

    state.frame_builder.dl_builder.push_rect(&prim_info, rect, color);
}

#[no_mangle]
pub extern "C" fn wr_dp_push_rect_with_animation(
    state: &mut WrState,
    rect: LayoutRect,
    clip: LayoutRect,
    is_backface_visible: bool,
    parent: &WrSpaceAndClipChain,
    color: ColorF,
    animation: *const WrAnimationProperty,
) {
    debug_assert!(unsafe { !is_in_render_thread() });

    let prim_info = common_item_properties_for_rect(state, clip, is_backface_visible, parent);

    let anim = unsafe { animation.as_ref() };
    if let Some(anim) = anim {
        debug_assert!(anim.id > 0);
        match anim.effect_type {
            WrAnimationType::BackgroundColor => state.frame_builder.dl_builder.push_rect_with_animation(
                &prim_info,
                rect,
                PropertyBinding::Binding(PropertyBindingKey::new(anim.id), color),
            ),
            _ => unreachable!("Didn't expect {:?} animation", anim.effect_type),
        }
    }
}

#[no_mangle]
pub extern "C" fn wr_dp_push_rect_with_parent_clip(
    state: &mut WrState,
    rect: LayoutRect,
    clip_rect: LayoutRect,
    is_backface_visible: bool,
    parent: &WrSpaceAndClip,
    color: ColorF,
) {
    debug_assert!(unsafe { !is_in_render_thread() });

    let space_and_clip = parent.to_webrender(state.pipeline_id);

    let prim_info = CommonItemProperties {
        clip_rect,
        clip_id: space_and_clip.clip_id,
        spatial_id: space_and_clip.spatial_id,
        flags: prim_flags(is_backface_visible, /* prefer_compositor_surface */ false),
    };

    state.frame_builder.dl_builder.push_rect(&prim_info, rect, color);
}

#[no_mangle]
pub extern "C" fn wr_dp_push_backdrop_filter_with_parent_clip(
    state: &mut WrState,
    rect: LayoutRect,
    clip: LayoutRect,
    is_backface_visible: bool,
    parent: &WrSpaceAndClip,
    filters: *const FilterOp,
    filter_count: usize,
    filter_datas: *const WrFilterData,
    filter_datas_count: usize,
) {
    debug_assert!(unsafe { !is_in_render_thread() });

    let c_filters = unsafe { make_slice(filters, filter_count) };
    let filters: Vec<FilterOp> = c_filters.iter().copied().collect();

    let c_filter_datas = unsafe { make_slice(filter_datas, filter_datas_count) };
    let filter_datas: Vec<FilterData> = c_filter_datas
        .iter()
        .map(|c_filter_data| FilterData {
            func_r_type: c_filter_data.funcR_type,
            r_values: unsafe { make_slice(c_filter_data.R_values, c_filter_data.R_values_count).to_vec() },
            func_g_type: c_filter_data.funcG_type,
            g_values: unsafe { make_slice(c_filter_data.G_values, c_filter_data.G_values_count).to_vec() },
            func_b_type: c_filter_data.funcB_type,
            b_values: unsafe { make_slice(c_filter_data.B_values, c_filter_data.B_values_count).to_vec() },
            func_a_type: c_filter_data.funcA_type,
            a_values: unsafe { make_slice(c_filter_data.A_values, c_filter_data.A_values_count).to_vec() },
        })
        .collect();

    let space_and_clip = parent.to_webrender(state.pipeline_id);

    let clip_rect = clip.intersection(&rect);
    if clip_rect.is_none() {
        return;
    }

    let prim_info = CommonItemProperties {
        clip_rect: clip_rect.unwrap(),
        clip_id: space_and_clip.clip_id,
        spatial_id: space_and_clip.spatial_id,
        flags: prim_flags(is_backface_visible, /* prefer_compositor_surface */ false),
    };

    state
        .frame_builder
        .dl_builder
        .push_backdrop_filter(&prim_info, &filters, &filter_datas, &[]);
}

#[no_mangle]
pub extern "C" fn wr_dp_push_clear_rect(
    state: &mut WrState,
    rect: LayoutRect,
    clip_rect: LayoutRect,
    parent: &WrSpaceAndClipChain,
) {
    debug_assert!(unsafe { !is_in_render_thread() });

    let space_and_clip = parent.to_webrender(state.pipeline_id);

    let prim_info = CommonItemProperties {
        clip_rect,
        clip_id: space_and_clip.clip_id,
        spatial_id: space_and_clip.spatial_id,
        flags: prim_flags(true, /* prefer_compositor_surface */ false),
    };

    state.frame_builder.dl_builder.push_clear_rect(&prim_info, rect);
}

#[no_mangle]
pub extern "C" fn wr_dp_push_hit_test(
    state: &mut WrState,
    rect: LayoutRect,
    clip: LayoutRect,
    is_backface_visible: bool,
    parent: &WrSpaceAndClipChain,
    scroll_id: u64,
    hit_info: u16,
) {
    debug_assert!(unsafe { !is_in_render_thread() });

    let space_and_clip = parent.to_webrender(state.pipeline_id);

    let clip_rect = clip.intersection(&rect);
    if clip_rect.is_none() {
        return;
    }
    let tag = (scroll_id, hit_info);

    let prim_info = CommonItemProperties {
        clip_rect: clip_rect.unwrap(),
        clip_id: space_and_clip.clip_id,
        spatial_id: space_and_clip.spatial_id,
        flags: prim_flags(is_backface_visible, /* prefer_compositor_surface */ false),
    };

    state.frame_builder.dl_builder.push_hit_test(&prim_info, tag);
}

#[no_mangle]
pub extern "C" fn wr_dp_push_image(
    state: &mut WrState,
    bounds: LayoutRect,
    clip: LayoutRect,
    is_backface_visible: bool,
    parent: &WrSpaceAndClipChain,
    image_rendering: ImageRendering,
    key: WrImageKey,
    premultiplied_alpha: bool,
    color: ColorF,
    prefer_compositor_surface: bool,
    supports_external_compositing: bool,
) {
    debug_assert!(unsafe { is_in_main_thread() || is_in_compositor_thread() });

    let space_and_clip = parent.to_webrender(state.pipeline_id);

    let prim_info = CommonItemProperties {
        clip_rect: clip,
        clip_id: space_and_clip.clip_id,
        spatial_id: space_and_clip.spatial_id,
        flags: prim_flags2(
            is_backface_visible,
            prefer_compositor_surface,
            supports_external_compositing,
        ),
    };

    let alpha_type = if premultiplied_alpha {
        AlphaType::PremultipliedAlpha
    } else {
        AlphaType::Alpha
    };

    state
        .frame_builder
        .dl_builder
        .push_image(&prim_info, bounds, image_rendering, alpha_type, key, color);
}

#[no_mangle]
pub extern "C" fn wr_dp_push_repeating_image(
    state: &mut WrState,
    bounds: LayoutRect,
    clip: LayoutRect,
    is_backface_visible: bool,
    parent: &WrSpaceAndClipChain,
    stretch_size: LayoutSize,
    tile_spacing: LayoutSize,
    image_rendering: ImageRendering,
    key: WrImageKey,
    premultiplied_alpha: bool,
    color: ColorF,
) {
    debug_assert!(unsafe { is_in_main_thread() || is_in_compositor_thread() });

    let space_and_clip = parent.to_webrender(state.pipeline_id);

    let prim_info = CommonItemProperties {
        clip_rect: clip,
        clip_id: space_and_clip.clip_id,
        spatial_id: space_and_clip.spatial_id,
        flags: prim_flags(is_backface_visible, /* prefer_compositor_surface */ false),
    };

    let alpha_type = if premultiplied_alpha {
        AlphaType::PremultipliedAlpha
    } else {
        AlphaType::Alpha
    };

    state.frame_builder.dl_builder.push_repeating_image(
        &prim_info,
        bounds,
        stretch_size,
        tile_spacing,
        image_rendering,
        alpha_type,
        key,
        color,
    );
}

/// Push a 3 planar yuv image.
#[no_mangle]
pub extern "C" fn wr_dp_push_yuv_planar_image(
    state: &mut WrState,
    bounds: LayoutRect,
    clip: LayoutRect,
    is_backface_visible: bool,
    parent: &WrSpaceAndClipChain,
    image_key_0: WrImageKey,
    image_key_1: WrImageKey,
    image_key_2: WrImageKey,
    color_depth: WrColorDepth,
    color_space: WrYuvColorSpace,
    color_range: WrColorRange,
    image_rendering: ImageRendering,
    prefer_compositor_surface: bool,
    supports_external_compositing: bool,
) {
    debug_assert!(unsafe { is_in_main_thread() || is_in_compositor_thread() });

    let space_and_clip = parent.to_webrender(state.pipeline_id);

    let prim_info = CommonItemProperties {
        clip_rect: clip,
        clip_id: space_and_clip.clip_id,
        spatial_id: space_and_clip.spatial_id,
        flags: prim_flags2(
            is_backface_visible,
            prefer_compositor_surface,
            supports_external_compositing,
        ),
    };

    state.frame_builder.dl_builder.push_yuv_image(
        &prim_info,
        bounds,
        YuvData::PlanarYCbCr(image_key_0, image_key_1, image_key_2),
        color_depth,
        color_space,
        color_range,
        image_rendering,
    );
}

/// Push a 2 planar NV12 image.
#[no_mangle]
pub extern "C" fn wr_dp_push_yuv_NV12_image(
    state: &mut WrState,
    bounds: LayoutRect,
    clip: LayoutRect,
    is_backface_visible: bool,
    parent: &WrSpaceAndClipChain,
    image_key_0: WrImageKey,
    image_key_1: WrImageKey,
    color_depth: WrColorDepth,
    color_space: WrYuvColorSpace,
    color_range: WrColorRange,
    image_rendering: ImageRendering,
    prefer_compositor_surface: bool,
    supports_external_compositing: bool,
) {
    debug_assert!(unsafe { is_in_main_thread() || is_in_compositor_thread() });

    let space_and_clip = parent.to_webrender(state.pipeline_id);

    let prim_info = CommonItemProperties {
        clip_rect: clip,
        clip_id: space_and_clip.clip_id,
        spatial_id: space_and_clip.spatial_id,
        flags: prim_flags2(
            is_backface_visible,
            prefer_compositor_surface,
            supports_external_compositing,
        ),
    };

    state.frame_builder.dl_builder.push_yuv_image(
        &prim_info,
        bounds,
        YuvData::NV12(image_key_0, image_key_1),
        color_depth,
        color_space,
        color_range,
        image_rendering,
    );
}

/// Push a yuv interleaved image.
#[no_mangle]
pub extern "C" fn wr_dp_push_yuv_interleaved_image(
    state: &mut WrState,
    bounds: LayoutRect,
    clip: LayoutRect,
    is_backface_visible: bool,
    parent: &WrSpaceAndClipChain,
    image_key_0: WrImageKey,
    color_depth: WrColorDepth,
    color_space: WrYuvColorSpace,
    color_range: WrColorRange,
    image_rendering: ImageRendering,
    prefer_compositor_surface: bool,
    supports_external_compositing: bool,
) {
    debug_assert!(unsafe { is_in_main_thread() || is_in_compositor_thread() });

    let space_and_clip = parent.to_webrender(state.pipeline_id);

    let prim_info = CommonItemProperties {
        clip_rect: clip,
        clip_id: space_and_clip.clip_id,
        spatial_id: space_and_clip.spatial_id,
        flags: prim_flags2(
            is_backface_visible,
            prefer_compositor_surface,
            supports_external_compositing,
        ),
    };

    state.frame_builder.dl_builder.push_yuv_image(
        &prim_info,
        bounds,
        YuvData::InterleavedYCbCr(image_key_0),
        color_depth,
        color_space,
        color_range,
        image_rendering,
    );
}

#[no_mangle]
pub extern "C" fn wr_dp_push_text(
    state: &mut WrState,
    bounds: LayoutRect,
    clip: LayoutRect,
    is_backface_visible: bool,
    parent: &WrSpaceAndClipChain,
    color: ColorF,
    font_key: WrFontInstanceKey,
    glyphs: *const GlyphInstance,
    glyph_count: u32,
    glyph_options: *const GlyphOptions,
) {
    debug_assert!(unsafe { is_in_main_thread() });

    let glyph_slice = unsafe { make_slice(glyphs, glyph_count as usize) };

    let space_and_clip = parent.to_webrender(state.pipeline_id);

    let prim_info = CommonItemProperties {
        clip_rect: clip,
        spatial_id: space_and_clip.spatial_id,
        clip_id: space_and_clip.clip_id,
        flags: prim_flags(is_backface_visible, /* prefer_compositor_surface */ false),
    };

    state
        .frame_builder
        .dl_builder
        .push_text(&prim_info, bounds, &glyph_slice, font_key, color, unsafe {
            glyph_options.as_ref().cloned()
        });
}

#[no_mangle]
pub extern "C" fn wr_dp_push_shadow(
    state: &mut WrState,
    _bounds: LayoutRect,
    _clip: LayoutRect,
    _is_backface_visible: bool,
    parent: &WrSpaceAndClipChain,
    shadow: Shadow,
    should_inflate: bool,
) {
    debug_assert!(unsafe { is_in_main_thread() });

    state
        .frame_builder
        .dl_builder
        .push_shadow(&parent.to_webrender(state.pipeline_id), shadow, should_inflate);
}

#[no_mangle]
pub extern "C" fn wr_dp_pop_all_shadows(state: &mut WrState) {
    debug_assert!(unsafe { is_in_main_thread() });

    state.frame_builder.dl_builder.pop_all_shadows();
}

#[no_mangle]
pub extern "C" fn wr_dp_push_line(
    state: &mut WrState,
    clip: &LayoutRect,
    is_backface_visible: bool,
    parent: &WrSpaceAndClipChain,
    bounds: &LayoutRect,
    wavy_line_thickness: f32,
    orientation: LineOrientation,
    color: &ColorF,
    style: LineStyle,
) {
    debug_assert!(unsafe { is_in_main_thread() });

    let space_and_clip = parent.to_webrender(state.pipeline_id);

    let prim_info = CommonItemProperties {
        clip_rect: *clip,
        clip_id: space_and_clip.clip_id,
        spatial_id: space_and_clip.spatial_id,
        flags: prim_flags(is_backface_visible, /* prefer_compositor_surface */ false),
    };

    state
        .frame_builder
        .dl_builder
        .push_line(&prim_info, bounds, wavy_line_thickness, orientation, color, style);
}

#[no_mangle]
pub extern "C" fn wr_dp_push_border(
    state: &mut WrState,
    rect: LayoutRect,
    clip: LayoutRect,
    is_backface_visible: bool,
    parent: &WrSpaceAndClipChain,
    do_aa: AntialiasBorder,
    widths: LayoutSideOffsets,
    top: BorderSide,
    right: BorderSide,
    bottom: BorderSide,
    left: BorderSide,
    radius: BorderRadius,
) {
    debug_assert!(unsafe { is_in_main_thread() });

    let border_details = BorderDetails::Normal(NormalBorder {
        left,
        right,
        top,
        bottom,
        radius,
        do_aa: do_aa == AntialiasBorder::Yes,
    });

    let space_and_clip = parent.to_webrender(state.pipeline_id);

    let prim_info = CommonItemProperties {
        clip_rect: clip,
        clip_id: space_and_clip.clip_id,
        spatial_id: space_and_clip.spatial_id,
        flags: prim_flags(is_backface_visible, /* prefer_compositor_surface */ false),
    };

    state
        .frame_builder
        .dl_builder
        .push_border(&prim_info, rect, widths, border_details);
}

#[repr(C)]
pub struct WrBorderImage {
    widths: LayoutSideOffsets,
    image: WrImageKey,
    width: i32,
    height: i32,
    fill: bool,
    slice: DeviceIntSideOffsets,
    outset: LayoutSideOffsets,
    repeat_horizontal: RepeatMode,
    repeat_vertical: RepeatMode,
}

#[no_mangle]
pub extern "C" fn wr_dp_push_border_image(
    state: &mut WrState,
    rect: LayoutRect,
    clip: LayoutRect,
    is_backface_visible: bool,
    parent: &WrSpaceAndClipChain,
    params: &WrBorderImage,
) {
    debug_assert!(unsafe { is_in_main_thread() });
    let border_details = BorderDetails::NinePatch(NinePatchBorder {
        source: NinePatchBorderSource::Image(params.image),
        width: params.width,
        height: params.height,
        slice: params.slice,
        fill: params.fill,
        outset: params.outset,
        repeat_horizontal: params.repeat_horizontal,
        repeat_vertical: params.repeat_vertical,
    });
    let space_and_clip = parent.to_webrender(state.pipeline_id);

    let prim_info = CommonItemProperties {
        clip_rect: clip,
        clip_id: space_and_clip.clip_id,
        spatial_id: space_and_clip.spatial_id,
        flags: prim_flags(is_backface_visible, /* prefer_compositor_surface */ false),
    };

    state
        .frame_builder
        .dl_builder
        .push_border(&prim_info, rect, params.widths, border_details);
}

#[no_mangle]
pub extern "C" fn wr_dp_push_border_gradient(
    state: &mut WrState,
    rect: LayoutRect,
    clip: LayoutRect,
    is_backface_visible: bool,
    parent: &WrSpaceAndClipChain,
    widths: LayoutSideOffsets,
    width: i32,
    height: i32,
    fill: bool,
    slice: DeviceIntSideOffsets,
    start_point: LayoutPoint,
    end_point: LayoutPoint,
    stops: *const GradientStop,
    stops_count: usize,
    extend_mode: ExtendMode,
    outset: LayoutSideOffsets,
) {
    debug_assert!(unsafe { is_in_main_thread() });

    let stops_slice = unsafe { make_slice(stops, stops_count) };
    let stops_vector = stops_slice.to_owned();

    let gradient = state
        .frame_builder
        .dl_builder
        .create_gradient(start_point, end_point, stops_vector, extend_mode);

    let border_details = BorderDetails::NinePatch(NinePatchBorder {
        source: NinePatchBorderSource::Gradient(gradient),
        width,
        height,
        slice,
        fill,
        outset,
        repeat_horizontal: RepeatMode::Stretch,
        repeat_vertical: RepeatMode::Stretch,
    });

    let space_and_clip = parent.to_webrender(state.pipeline_id);

    let prim_info = CommonItemProperties {
        clip_rect: clip,
        clip_id: space_and_clip.clip_id,
        spatial_id: space_and_clip.spatial_id,
        flags: prim_flags(is_backface_visible, /* prefer_compositor_surface */ false),
    };

    state
        .frame_builder
        .dl_builder
        .push_border(&prim_info, rect, widths, border_details);
}

#[no_mangle]
pub extern "C" fn wr_dp_push_border_radial_gradient(
    state: &mut WrState,
    rect: LayoutRect,
    clip: LayoutRect,
    is_backface_visible: bool,
    parent: &WrSpaceAndClipChain,
    widths: LayoutSideOffsets,
    fill: bool,
    center: LayoutPoint,
    radius: LayoutSize,
    stops: *const GradientStop,
    stops_count: usize,
    extend_mode: ExtendMode,
    outset: LayoutSideOffsets,
) {
    debug_assert!(unsafe { is_in_main_thread() });

    let stops_slice = unsafe { make_slice(stops, stops_count) };
    let stops_vector = stops_slice.to_owned();

    let slice = SideOffsets2D::new(
        widths.top as i32,
        widths.right as i32,
        widths.bottom as i32,
        widths.left as i32,
    );

    let gradient = state
        .frame_builder
        .dl_builder
        .create_radial_gradient(center, radius, stops_vector, extend_mode);

    let border_details = BorderDetails::NinePatch(NinePatchBorder {
        source: NinePatchBorderSource::RadialGradient(gradient),
        width: rect.width() as i32,
        height: rect.height() as i32,
        slice,
        fill,
        outset,
        repeat_horizontal: RepeatMode::Stretch,
        repeat_vertical: RepeatMode::Stretch,
    });

    let space_and_clip = parent.to_webrender(state.pipeline_id);

    let prim_info = CommonItemProperties {
        clip_rect: clip,
        clip_id: space_and_clip.clip_id,
        spatial_id: space_and_clip.spatial_id,
        flags: prim_flags(is_backface_visible, /* prefer_compositor_surface */ false),
    };

    state
        .frame_builder
        .dl_builder
        .push_border(&prim_info, rect, widths, border_details);
}

#[no_mangle]
pub extern "C" fn wr_dp_push_border_conic_gradient(
    state: &mut WrState,
    rect: LayoutRect,
    clip: LayoutRect,
    is_backface_visible: bool,
    parent: &WrSpaceAndClipChain,
    widths: LayoutSideOffsets,
    fill: bool,
    center: LayoutPoint,
    angle: f32,
    stops: *const GradientStop,
    stops_count: usize,
    extend_mode: ExtendMode,
    outset: LayoutSideOffsets,
) {
    debug_assert!(unsafe { is_in_main_thread() });

    let stops_slice = unsafe { make_slice(stops, stops_count) };
    let stops_vector = stops_slice.to_owned();

    let slice = SideOffsets2D::new(
        widths.top as i32,
        widths.right as i32,
        widths.bottom as i32,
        widths.left as i32,
    );

    let gradient = state
        .frame_builder
        .dl_builder
        .create_conic_gradient(center, angle, stops_vector, extend_mode);

    let border_details = BorderDetails::NinePatch(NinePatchBorder {
        source: NinePatchBorderSource::ConicGradient(gradient),
        width: rect.width() as i32,
        height: rect.height() as i32,
        slice,
        fill,
        outset,
        repeat_horizontal: RepeatMode::Stretch,
        repeat_vertical: RepeatMode::Stretch,
    });

    let space_and_clip = parent.to_webrender(state.pipeline_id);

    let prim_info = CommonItemProperties {
        clip_rect: clip,
        clip_id: space_and_clip.clip_id,
        spatial_id: space_and_clip.spatial_id,
        flags: prim_flags(is_backface_visible, /* prefer_compositor_surface */ false),
    };

    state
        .frame_builder
        .dl_builder
        .push_border(&prim_info, rect, widths, border_details);
}

#[no_mangle]
pub extern "C" fn wr_dp_push_linear_gradient(
    state: &mut WrState,
    rect: LayoutRect,
    clip: LayoutRect,
    is_backface_visible: bool,
    parent: &WrSpaceAndClipChain,
    start_point: LayoutPoint,
    end_point: LayoutPoint,
    stops: *const GradientStop,
    stops_count: usize,
    extend_mode: ExtendMode,
    tile_size: LayoutSize,
    tile_spacing: LayoutSize,
) {
    debug_assert!(unsafe { is_in_main_thread() });

    let stops_slice = unsafe { make_slice(stops, stops_count) };
    let stops_vector = stops_slice.to_owned();

    let gradient = state
        .frame_builder
        .dl_builder
        .create_gradient(start_point, end_point, stops_vector, extend_mode);

    let space_and_clip = parent.to_webrender(state.pipeline_id);

    let prim_info = CommonItemProperties {
        clip_rect: clip,
        clip_id: space_and_clip.clip_id,
        spatial_id: space_and_clip.spatial_id,
        flags: prim_flags(is_backface_visible, /* prefer_compositor_surface */ false),
    };

    state
        .frame_builder
        .dl_builder
        .push_gradient(&prim_info, rect, gradient, tile_size, tile_spacing);
}

#[no_mangle]
pub extern "C" fn wr_dp_push_radial_gradient(
    state: &mut WrState,
    rect: LayoutRect,
    clip: LayoutRect,
    is_backface_visible: bool,
    parent: &WrSpaceAndClipChain,
    center: LayoutPoint,
    radius: LayoutSize,
    stops: *const GradientStop,
    stops_count: usize,
    extend_mode: ExtendMode,
    tile_size: LayoutSize,
    tile_spacing: LayoutSize,
) {
    debug_assert!(unsafe { is_in_main_thread() });

    let stops_slice = unsafe { make_slice(stops, stops_count) };
    let stops_vector = stops_slice.to_owned();

    let gradient = state
        .frame_builder
        .dl_builder
        .create_radial_gradient(center, radius, stops_vector, extend_mode);

    let space_and_clip = parent.to_webrender(state.pipeline_id);

    let prim_info = CommonItemProperties {
        clip_rect: clip,
        clip_id: space_and_clip.clip_id,
        spatial_id: space_and_clip.spatial_id,
        flags: prim_flags(is_backface_visible, /* prefer_compositor_surface */ false),
    };

    state
        .frame_builder
        .dl_builder
        .push_radial_gradient(&prim_info, rect, gradient, tile_size, tile_spacing);
}

#[no_mangle]
pub extern "C" fn wr_dp_push_conic_gradient(
    state: &mut WrState,
    rect: LayoutRect,
    clip: LayoutRect,
    is_backface_visible: bool,
    parent: &WrSpaceAndClipChain,
    center: LayoutPoint,
    angle: f32,
    stops: *const GradientStop,
    stops_count: usize,
    extend_mode: ExtendMode,
    tile_size: LayoutSize,
    tile_spacing: LayoutSize,
) {
    debug_assert!(unsafe { is_in_main_thread() });

    let stops_slice = unsafe { make_slice(stops, stops_count) };
    let stops_vector = stops_slice.to_owned();

    let gradient = state
        .frame_builder
        .dl_builder
        .create_conic_gradient(center, angle, stops_vector, extend_mode);

    let space_and_clip = parent.to_webrender(state.pipeline_id);

    let prim_info = CommonItemProperties {
        clip_rect: clip,
        clip_id: space_and_clip.clip_id,
        spatial_id: space_and_clip.spatial_id,
        flags: prim_flags(is_backface_visible, /* prefer_compositor_surface */ false),
    };

    state
        .frame_builder
        .dl_builder
        .push_conic_gradient(&prim_info, rect, gradient, tile_size, tile_spacing);
}

#[no_mangle]
pub extern "C" fn wr_dp_push_box_shadow(
    state: &mut WrState,
    _rect: LayoutRect,
    clip: LayoutRect,
    is_backface_visible: bool,
    parent: &WrSpaceAndClipChain,
    box_bounds: LayoutRect,
    offset: LayoutVector2D,
    color: ColorF,
    blur_radius: f32,
    spread_radius: f32,
    border_radius: BorderRadius,
    clip_mode: BoxShadowClipMode,
) {
    debug_assert!(unsafe { is_in_main_thread() });

    let space_and_clip = parent.to_webrender(state.pipeline_id);

    let prim_info = CommonItemProperties {
        clip_rect: clip,
        clip_id: space_and_clip.clip_id,
        spatial_id: space_and_clip.spatial_id,
        flags: prim_flags(is_backface_visible, /* prefer_compositor_surface */ false),
    };

    state.frame_builder.dl_builder.push_box_shadow(
        &prim_info,
        box_bounds,
        offset,
        color,
        blur_radius,
        spread_radius,
        border_radius,
        clip_mode,
    );
}

#[no_mangle]
pub extern "C" fn wr_dp_start_item_group(state: &mut WrState) {
    state.frame_builder.dl_builder.start_item_group();
}

#[no_mangle]
pub extern "C" fn wr_dp_cancel_item_group(state: &mut WrState, discard: bool) {
    state.frame_builder.dl_builder.cancel_item_group(discard);
}

#[no_mangle]
pub extern "C" fn wr_dp_finish_item_group(state: &mut WrState, key: ItemKey) -> bool {
    state.frame_builder.dl_builder.finish_item_group(key)
}

#[no_mangle]
pub extern "C" fn wr_dp_push_reuse_items(state: &mut WrState, key: ItemKey) {
    state.frame_builder.dl_builder.push_reuse_items(key);
}

#[no_mangle]
pub extern "C" fn wr_dp_set_cache_size(state: &mut WrState, cache_size: usize) {
    state.frame_builder.dl_builder.set_cache_size(cache_size);
}

#[no_mangle]
pub extern "C" fn wr_dump_display_list(
    state: &mut WrState,
    indent: usize,
    start: *const usize,
    end: *const usize,
) -> usize {
    let start = unsafe { start.as_ref().cloned() };
    let end = unsafe { end.as_ref().cloned() };
    let range = Range { start, end };
    let mut sink = Cursor::new(Vec::new());
    let index = state
        .frame_builder
        .dl_builder
        .emit_display_list(indent, range, &mut sink);

    // For Android, dump to logcat instead of stderr. This is the same as
    // what printf_stderr does on the C++ side.

    #[cfg(target_os = "android")]
    unsafe {
        let gecko = CString::new("Gecko").unwrap();
        let sink = CString::new(sink.into_inner()).unwrap();
        __android_log_write(4 /* info */, gecko.as_ptr(), sink.as_ptr());
    }

    #[cfg(not(target_os = "android"))]
    eprint!("{}", String::from_utf8(sink.into_inner()).unwrap());

    index
}

#[no_mangle]
pub extern "C" fn wr_dump_serialized_display_list(state: &mut WrState) {
    state.frame_builder.dl_builder.dump_serialized_display_list();
}

#[no_mangle]
pub unsafe extern "C" fn wr_api_finalize_builder(
    state: &mut WrState,
    dl_descriptor: &mut BuiltDisplayListDescriptor,
    dl_data: &mut WrVecU8,
) {
    let frame_builder = mem::replace(&mut state.frame_builder, WebRenderFrameBuilder::new(state.pipeline_id));
    let (_, dl) = frame_builder.dl_builder.finalize();
    let (data, descriptor) = dl.into_data();
    *dl_data = WrVecU8::from_vec(data);
    *dl_descriptor = descriptor;
}

#[repr(C)]
pub struct HitResult {
    pipeline_id: WrPipelineId,
    scroll_id: u64,
    hit_info: u16,
}

#[no_mangle]
pub extern "C" fn wr_api_hit_test(dh: &mut DocumentHandle, point: WorldPoint, out_results: &mut ThinVec<HitResult>) {
    dh.ensure_hit_tester();

    let result = dh.hit_tester.as_ref().unwrap().hit_test(None, point);

    for item in &result.items {
        out_results.push(HitResult {
            pipeline_id: item.pipeline,
            scroll_id: item.tag.0,
            hit_info: item.tag.1,
        });
    }
}

pub type VecU8 = Vec<u8>;
pub type ArcVecU8 = Arc<VecU8>;

#[no_mangle]
pub extern "C" fn wr_add_ref_arc(arc: &ArcVecU8) -> *const VecU8 {
    Arc::into_raw(arc.clone())
}

#[no_mangle]
pub unsafe extern "C" fn wr_dec_ref_arc(arc: *const VecU8) {
    Arc::from_raw(arc);
}

// TODO: nical
// Update for the new blob image interface changes.
//
extern "C" {
    // TODO: figure out the API for tiled blob images.
    pub fn wr_moz2d_render_cb(
        blob: ByteSlice,
        format: ImageFormat,
        render_rect: &LayoutIntRect,
        visible_rect: &DeviceIntRect,
        tile_size: u16,
        tile_offset: &TileOffset,
        dirty_rect: Option<&LayoutIntRect>,
        output: MutByteSlice,
    ) -> bool;
}

#[no_mangle]
pub extern "C" fn wr_root_scroll_node_id() -> WrSpatialId {
    // The PipelineId doesn't matter here, since we just want the numeric part of the id
    // produced for any given root reference frame.
    WrSpatialId {
        id: SpatialId::root_scroll_node(PipelineId(0, 0)).0,
    }
}

#[no_mangle]
pub extern "C" fn wr_root_clip_id() -> WrClipId {
    // The PipelineId doesn't matter here, since we just want the numeric part of the id
    // produced for any given root reference frame.
    WrClipId::from_webrender(ClipId::root(PipelineId(0, 0)))
}

#[repr(C)]
#[derive(Clone, Copy)]
pub struct WrClipId {
    id: usize,
}

impl WrClipId {
    fn to_webrender(&self, pipeline_id: WrPipelineId) -> ClipId {
        ClipId::Clip(self.id, pipeline_id)
    }

    fn from_webrender(clip_id: ClipId) -> Self {
        match clip_id {
            ClipId::Clip(id, _) => WrClipId { id },
            ClipId::ClipChain(_) => panic!("Unexpected clip chain"),
        }
    }
}

#[repr(C)]
#[derive(Clone, Copy)]
pub struct WrSpatialId {
    id: usize,
}

impl WrSpatialId {
    fn to_webrender(&self, pipeline_id: WrPipelineId) -> SpatialId {
        SpatialId::new(self.id, pipeline_id)
    }
}

#[no_mangle]
pub unsafe extern "C" fn wr_device_delete(device: *mut Device) {
    Box::from_raw(device);
}

// Call MakeCurrent before this.
#[no_mangle]
pub extern "C" fn wr_shaders_new(
    gl_context: *mut c_void,
    program_cache: Option<&mut WrProgramCache>,
    precache_shaders: bool,
) -> *mut WrShaders {
    let mut device = wr_device_new(gl_context, program_cache);

    let precache_flags = if precache_shaders || env_var_to_bool("MOZ_WR_PRECACHE_SHADERS") {
        ShaderPrecacheFlags::FULL_COMPILE
    } else {
        ShaderPrecacheFlags::ASYNC_COMPILE
    };

    let opts = RendererOptions {
        precache_flags,
        ..Default::default()
    };

    let gl_type = device.gl().get_type();
    device.begin_frame();

    let shaders = Rc::new(RefCell::new(match Shaders::new(&mut device, gl_type, &opts) {
        Ok(shaders) => shaders,
        Err(e) => {
            warn!(" Failed to create a Shaders: {:?}", e);
            let msg = CString::new(format!("wr_shaders_new: {:?}", e)).unwrap();
            unsafe {
                gfx_critical_note(msg.as_ptr());
            }
            return ptr::null_mut();
        }
    }));

    let shaders = WrShaders(shaders);

    device.end_frame();
    Box::into_raw(Box::new(shaders))
}

#[no_mangle]
pub unsafe extern "C" fn wr_shaders_delete(shaders: *mut WrShaders, gl_context: *mut c_void) {
    let mut device = wr_device_new(gl_context, None);
    let shaders = Box::from_raw(shaders);
    if let Ok(shaders) = Rc::try_unwrap(shaders.0) {
        shaders.into_inner().deinit(&mut device);
    }
    // let shaders go out of scope and get dropped
}

#[no_mangle]
pub unsafe extern "C" fn wr_program_cache_report_memory(
    cache: *const WrProgramCache,
    size_of_op: VoidPtrToSizeFn,
) -> usize {
    (*cache).program_cache.report_memory(size_of_op)
}