1
2 /*
3 * Copyright 2011 Google Inc.
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9
10
11 #include "GrGLVertexBuffer.h"
12 #include "GrGpuGL.h"
13
14 #define GPUGL static_cast<GrGpuGL*>(getGpu())
15
16 #define GL_CALL(X) GR_GL_CALL(GPUGL->glInterface(), X)
17
GrGLVertexBuffer(GrGpuGL * gpu,GrGLuint id,size_t sizeInBytes,bool dynamic)18 GrGLVertexBuffer::GrGLVertexBuffer(GrGpuGL* gpu,
19 GrGLuint id,
20 size_t sizeInBytes,
21 bool dynamic)
22 : INHERITED(gpu, sizeInBytes, dynamic)
23 , fBufferID(id)
24 , fLockPtr(NULL) {
25 }
26
onRelease()27 void GrGLVertexBuffer::onRelease() {
28 // make sure we've not been abandoned
29 if (fBufferID) {
30 GPUGL->notifyVertexBufferDelete(this);
31 GL_CALL(DeleteBuffers(1, &fBufferID));
32 fBufferID = 0;
33 }
34 }
35
onAbandon()36 void GrGLVertexBuffer::onAbandon() {
37 fBufferID = 0;
38 fLockPtr = NULL;
39 }
40
bind() const41 void GrGLVertexBuffer::bind() const {
42 GL_CALL(BindBuffer(GR_GL_ARRAY_BUFFER, fBufferID));
43 GPUGL->notifyVertexBufferBind(this);
44 }
45
bufferID() const46 GrGLuint GrGLVertexBuffer::bufferID() const {
47 return fBufferID;
48 }
49
lock()50 void* GrGLVertexBuffer::lock() {
51 GrAssert(fBufferID);
52 GrAssert(!isLocked());
53 if (this->getGpu()->getCaps().fBufferLockSupport) {
54 this->bind();
55 // Let driver know it can discard the old data
56 GL_CALL(BufferData(GR_GL_ARRAY_BUFFER, this->sizeInBytes(), NULL,
57 this->dynamic() ? GR_GL_DYNAMIC_DRAW :
58 GR_GL_STATIC_DRAW));
59 GR_GL_CALL_RET(GPUGL->glInterface(),
60 fLockPtr,
61 MapBuffer(GR_GL_ARRAY_BUFFER, GR_GL_WRITE_ONLY));
62 return fLockPtr;
63 }
64 return NULL;
65 }
66
lockPtr() const67 void* GrGLVertexBuffer::lockPtr() const {
68 return fLockPtr;
69 }
70
unlock()71 void GrGLVertexBuffer::unlock() {
72
73 GrAssert(fBufferID);
74 GrAssert(isLocked());
75 GrAssert(this->getGpu()->getCaps().fBufferLockSupport);
76
77 this->bind();
78 GL_CALL(UnmapBuffer(GR_GL_ARRAY_BUFFER));
79 fLockPtr = NULL;
80 }
81
isLocked() const82 bool GrGLVertexBuffer::isLocked() const {
83 GrAssert(!this->isValid() || fBufferID);
84 #if GR_DEBUG
85 if (this->isValid() && this->getGpu()->getCaps().fBufferLockSupport) {
86 GrGLint mapped;
87 this->bind();
88 GL_CALL(GetBufferParameteriv(GR_GL_ARRAY_BUFFER,
89 GR_GL_BUFFER_MAPPED, &mapped));
90 GrAssert(!!mapped == !!fLockPtr);
91 }
92 #endif
93 return NULL != fLockPtr;
94 }
95
updateData(const void * src,size_t srcSizeInBytes)96 bool GrGLVertexBuffer::updateData(const void* src, size_t srcSizeInBytes) {
97 GrAssert(fBufferID);
98 GrAssert(!isLocked());
99 if (srcSizeInBytes > this->sizeInBytes()) {
100 return false;
101 }
102 this->bind();
103 GrGLenum usage = dynamic() ? GR_GL_DYNAMIC_DRAW : GR_GL_STATIC_DRAW;
104
105 #if GR_GL_USE_BUFFER_DATA_NULL_HINT
106 if (this->sizeInBytes() == srcSizeInBytes) {
107 GL_CALL(BufferData(GR_GL_ARRAY_BUFFER, srcSizeInBytes, src, usage));
108 } else {
109 // Before we call glBufferSubData we give the driver a hint using
110 // glBufferData with NULL. This makes the old buffer contents
111 // inaccessible to future draws. The GPU may still be processing
112 // draws that reference the old contents. With this hint it can
113 // assign a different allocation for the new contents to avoid
114 // flushing the gpu past draws consuming the old contents.
115 GL_CALL(BufferData(GR_GL_ARRAY_BUFFER,
116 this->sizeInBytes(), NULL, usage));
117 GL_CALL(BufferSubData(GR_GL_ARRAY_BUFFER, 0, srcSizeInBytes, src));
118 }
119 #else
120 // Note that we're cheating on the size here. Currently no methods
121 // allow a partial update that preserves contents of non-updated
122 // portions of the buffer (lock() does a glBufferData(..size, NULL..))
123 bool doSubData = false;
124 #if GR_GL_MAC_BUFFER_OBJECT_PERFOMANCE_WORKAROUND
125 static int N = 0;
126 // 128 was chosen experimentally. At 256 a slight hitchiness was noticed
127 // when dragging a Chromium window around with a canvas tab backgrounded.
128 doSubData = 0 == (N % 128);
129 ++N;
130 #endif
131 if (doSubData) {
132 // The workaround is to do a glBufferData followed by glBufferSubData.
133 // Chromium's command buffer may turn a glBufferSubData where the size
134 // exactly matches the buffer size into a glBufferData. So we tack 1
135 // extra byte onto the glBufferData.
136 GL_CALL(BufferData(GR_GL_ARRAY_BUFFER, srcSizeInBytes + 1,
137 NULL, usage));
138 GL_CALL(BufferSubData(GR_GL_ARRAY_BUFFER, 0, srcSizeInBytes, src));
139 } else {
140 GL_CALL(BufferData(GR_GL_ARRAY_BUFFER, srcSizeInBytes, src, usage));
141 }
142 #endif
143 return true;
144 }
145
146