1/* This Source Code Form is subject to the terms of the Mozilla Public 2 * License, v. 2.0. If a copy of the MPL was not distributed with this 3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ 4 5#include shared,rect,render_task,gpu_cache,gradient 6 7#define PI 3.141592653589793 8 9varying vec2 v_pos; 10 11flat varying vec2 v_center; 12flat varying float v_start_offset; 13flat varying float v_offset_scale; 14flat varying float v_angle; 15 16#ifdef WR_VERTEX_SHADER 17 18#define EXTEND_MODE_REPEAT 1 19 20PER_INSTANCE in vec4 aTaskRect; 21PER_INSTANCE in vec2 aCenter; 22PER_INSTANCE in vec2 aScale; 23PER_INSTANCE in float aStartOffset; 24PER_INSTANCE in float aEndOffset; 25PER_INSTANCE in float aAngle; 26PER_INSTANCE in int aExtendMode; 27PER_INSTANCE in int aGradientStopsAddress; 28 29void main(void) { 30 // Store 1/d where d = end_offset - start_offset 31 // If d = 0, we can't get its reciprocal. Instead, just use a zero scale. 32 float d = aEndOffset - aStartOffset; 33 v_offset_scale = d != 0.0 ? 1.0 / d : 0.0; 34 35 vec2 pos = mix(aTaskRect.xy, aTaskRect.zw, aPosition.xy); 36 gl_Position = uTransform * vec4(pos, 0.0, 1.0); 37 38 v_angle = PI / 2.0 - aAngle; 39 v_start_offset = aStartOffset * v_offset_scale; 40 41 // v_pos and v_center are in a coordinate space relative to the task rect 42 // (so they are independent of the task origin). 43 v_center = aCenter * v_offset_scale; 44 v_pos = (aTaskRect.zw - aTaskRect.xy) * aPosition.xy * v_offset_scale * aScale; 45 46 v_gradient_repeat = float(aExtendMode == EXTEND_MODE_REPEAT); 47 v_gradient_address = aGradientStopsAddress; 48} 49#endif 50 51 52#ifdef WR_FRAGMENT_SHADER 53 54void main(void) { 55 // Use inverse trig to find the angle offset from the relative position. 56 vec2 current_dir = v_pos - v_center; 57 float current_angle = atan(current_dir.y, current_dir.x) + v_angle; 58 float offset = fract(current_angle / (2.0 * PI)) * v_offset_scale - v_start_offset; 59 60 oFragColor = sample_gradient(offset); 61} 62 63#endif 64