1 // Copyright 2018 Citra Emulator Project
2 // Licensed under GPLv2 or any later version
3 // Refer to the license.txt file included.
4 
5 #include <deque>
6 #include <vector>
7 #include "common/alignment.h"
8 #include "common/assert.h"
9 #include "common/microprofile.h"
10 #include "video_core/renderer_opengl/gl_state.h"
11 #include "video_core/renderer_opengl/gl_stream_buffer.h"
12 
13 MICROPROFILE_DEFINE(OpenGL_StreamBuffer, "OpenGL", "Stream Buffer Orphaning",
14                     MP_RGB(128, 128, 192));
15 
16 namespace OpenGL {
17 
OGLStreamBuffer(GLenum target,GLsizeiptr size,bool array_buffer_for_amd,bool prefer_coherent)18 OGLStreamBuffer::OGLStreamBuffer(GLenum target, GLsizeiptr size, bool array_buffer_for_amd,
19                                  bool prefer_coherent)
20     : gl_target(target), buffer_size(size) {
21     gl_buffer.Create();
22     glBindBuffer(gl_target, gl_buffer.handle);
23 
24     GLsizeiptr allocate_size = size;
25     if (array_buffer_for_amd) {
26         // On AMD GPU there is a strange crash in indexed drawing. The crash happens when the buffer
27         // read position is near the end and is an out-of-bound access to the vertex buffer. This is
28         // probably a bug in the driver and is related to the usage of vec3<byte> attributes in the
29         // vertex array. Doubling the allocation size for the vertex buffer seems to avoid the
30         // crash.
31         allocate_size *= 2;
32     }
33 
34     if (GLAD_GL_ARB_buffer_storage) {
35         persistent = true;
36         coherent = prefer_coherent;
37         GLbitfield flags =
38             GL_MAP_WRITE_BIT | GL_MAP_PERSISTENT_BIT | (coherent ? GL_MAP_COHERENT_BIT : 0);
39         glBufferStorage(gl_target, allocate_size, nullptr, flags);
40         mapped_ptr = static_cast<u8*>(glMapBufferRange(
41             gl_target, 0, buffer_size, flags | (coherent ? 0 : GL_MAP_FLUSH_EXPLICIT_BIT)));
42     } else {
43         glBufferData(gl_target, allocate_size, nullptr, GL_STREAM_DRAW);
44     }
45 }
46 
~OGLStreamBuffer()47 OGLStreamBuffer::~OGLStreamBuffer() {
48     if (persistent) {
49         glBindBuffer(gl_target, gl_buffer.handle);
50         glUnmapBuffer(gl_target);
51     }
52     gl_buffer.Release();
53 }
54 
GetHandle() const55 GLuint OGLStreamBuffer::GetHandle() const {
56     return gl_buffer.handle;
57 }
58 
GetSize() const59 GLsizeiptr OGLStreamBuffer::GetSize() const {
60     return buffer_size;
61 }
62 
Map(GLsizeiptr size,GLintptr alignment)63 std::tuple<u8*, GLintptr, bool> OGLStreamBuffer::Map(GLsizeiptr size, GLintptr alignment) {
64     ASSERT(size <= buffer_size);
65     ASSERT(alignment <= buffer_size);
66     mapped_size = size;
67 
68     if (alignment > 0) {
69         buffer_pos = Common::AlignUp<std::size_t>(buffer_pos, alignment);
70     }
71 
72     bool invalidate = false;
73     if (buffer_pos + size > buffer_size) {
74         buffer_pos = 0;
75         invalidate = true;
76 
77         if (persistent) {
78             glUnmapBuffer(gl_target);
79         }
80     }
81 
82     if (invalidate || !persistent) {
83         MICROPROFILE_SCOPE(OpenGL_StreamBuffer);
84         GLbitfield flags = GL_MAP_WRITE_BIT | (persistent ? GL_MAP_PERSISTENT_BIT : 0) |
85                            (coherent ? GL_MAP_COHERENT_BIT : GL_MAP_FLUSH_EXPLICIT_BIT) |
86                            (invalidate ? GL_MAP_INVALIDATE_BUFFER_BIT : GL_MAP_UNSYNCHRONIZED_BIT);
87         mapped_ptr = static_cast<u8*>(
88             glMapBufferRange(gl_target, buffer_pos, buffer_size - buffer_pos, flags));
89         mapped_offset = buffer_pos;
90     }
91 
92     return std::make_tuple(mapped_ptr + buffer_pos - mapped_offset, buffer_pos, invalidate);
93 }
94 
Unmap(GLsizeiptr size)95 void OGLStreamBuffer::Unmap(GLsizeiptr size) {
96     ASSERT(size <= mapped_size);
97 
98     if (!coherent && size > 0) {
99         glFlushMappedBufferRange(gl_target, buffer_pos - mapped_offset, size);
100     }
101 
102     if (!persistent) {
103         glUnmapBuffer(gl_target);
104     }
105 
106     buffer_pos += size;
107 }
108 
109 } // namespace OpenGL
110