1 /*
2 * Copyright 2011 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8
9
10 #include "GrGLVertexBuffer.h"
11 #include "GrGpuGL.h"
12
13 #define GPUGL static_cast<GrGpuGL*>(getGpu())
14
15 #define GL_CALL(X) GR_GL_CALL(GPUGL->glInterface(), X)
16
GrGLVertexBuffer(GrGpuGL * gpu,bool isWrapped,GrGLuint id,size_t sizeInBytes,bool dynamic)17 GrGLVertexBuffer::GrGLVertexBuffer(GrGpuGL* gpu,
18 bool isWrapped,
19 GrGLuint id,
20 size_t sizeInBytes,
21 bool dynamic)
22 : INHERITED(gpu, isWrapped, 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 && !this->isWrapped()) {
30 GPUGL->notifyVertexBufferDelete(this);
31 GL_CALL(DeleteBuffers(1, &fBufferID));
32 fBufferID = 0;
33 }
34
35 INHERITED::onRelease();
36 }
37
onAbandon()38 void GrGLVertexBuffer::onAbandon() {
39 fBufferID = 0;
40 fLockPtr = NULL;
41
42 INHERITED::onAbandon();
43 }
44
bind() const45 void GrGLVertexBuffer::bind() const {
46 GL_CALL(BindBuffer(GR_GL_ARRAY_BUFFER, fBufferID));
47 GPUGL->notifyVertexBufferBind(this);
48 }
49
bufferID() const50 GrGLuint GrGLVertexBuffer::bufferID() const {
51 return fBufferID;
52 }
53
lock()54 void* GrGLVertexBuffer::lock() {
55 GrAssert(fBufferID);
56 GrAssert(!isLocked());
57 if (this->getGpu()->getCaps().bufferLockSupport()) {
58 this->bind();
59 // Let driver know it can discard the old data
60 GL_CALL(BufferData(GR_GL_ARRAY_BUFFER, this->sizeInBytes(), NULL,
61 this->dynamic() ? GR_GL_DYNAMIC_DRAW :
62 GR_GL_STATIC_DRAW));
63 GR_GL_CALL_RET(GPUGL->glInterface(),
64 fLockPtr,
65 MapBuffer(GR_GL_ARRAY_BUFFER, GR_GL_WRITE_ONLY));
66 return fLockPtr;
67 }
68 return NULL;
69 }
70
lockPtr() const71 void* GrGLVertexBuffer::lockPtr() const {
72 return fLockPtr;
73 }
74
unlock()75 void GrGLVertexBuffer::unlock() {
76
77 GrAssert(fBufferID);
78 GrAssert(isLocked());
79 GrAssert(this->getGpu()->getCaps().bufferLockSupport());
80
81 this->bind();
82 GL_CALL(UnmapBuffer(GR_GL_ARRAY_BUFFER));
83 fLockPtr = NULL;
84 }
85
isLocked() const86 bool GrGLVertexBuffer::isLocked() const {
87 GrAssert(!this->isValid() || fBufferID);
88 // this check causes a lot of noise in the gl log
89 #if 0
90 if (this->isValid() && this->getGpu()->getCaps().fBufferLockSupport) {
91 GrGLint mapped;
92 this->bind();
93 GL_CALL(GetBufferParameteriv(GR_GL_ARRAY_BUFFER,
94 GR_GL_BUFFER_MAPPED, &mapped));
95 GrAssert(!!mapped == !!fLockPtr);
96 }
97 #endif
98 return NULL != fLockPtr;
99 }
100
updateData(const void * src,size_t srcSizeInBytes)101 bool GrGLVertexBuffer::updateData(const void* src, size_t srcSizeInBytes) {
102 GrAssert(fBufferID);
103 GrAssert(!isLocked());
104 if (srcSizeInBytes > this->sizeInBytes()) {
105 return false;
106 }
107 this->bind();
108 GrGLenum usage = dynamic() ? GR_GL_DYNAMIC_DRAW : GR_GL_STATIC_DRAW;
109
110 #if GR_GL_USE_BUFFER_DATA_NULL_HINT
111 if (this->sizeInBytes() == srcSizeInBytes) {
112 GL_CALL(BufferData(GR_GL_ARRAY_BUFFER, srcSizeInBytes, src, usage));
113 } else {
114 // Before we call glBufferSubData we give the driver a hint using
115 // glBufferData with NULL. This makes the old buffer contents
116 // inaccessible to future draws. The GPU may still be processing
117 // draws that reference the old contents. With this hint it can
118 // assign a different allocation for the new contents to avoid
119 // flushing the gpu past draws consuming the old contents.
120 GL_CALL(BufferData(GR_GL_ARRAY_BUFFER,
121 this->sizeInBytes(), NULL, usage));
122 GL_CALL(BufferSubData(GR_GL_ARRAY_BUFFER, 0, srcSizeInBytes, src));
123 }
124 #else
125 // Note that we're cheating on the size here. Currently no methods
126 // allow a partial update that preserves contents of non-updated
127 // portions of the buffer (lock() does a glBufferData(..size, NULL..))
128 bool doSubData = false;
129 #if GR_GL_MAC_BUFFER_OBJECT_PERFOMANCE_WORKAROUND
130 static int N = 0;
131 // 128 was chosen experimentally. At 256 a slight hitchiness was noticed
132 // when dragging a Chromium window around with a canvas tab backgrounded.
133 doSubData = 0 == (N % 128);
134 ++N;
135 #endif
136 if (doSubData) {
137 // The workaround is to do a glBufferData followed by glBufferSubData.
138 // Chromium's command buffer may turn a glBufferSubData where the size
139 // exactly matches the buffer size into a glBufferData. So we tack 1
140 // extra byte onto the glBufferData.
141 GL_CALL(BufferData(GR_GL_ARRAY_BUFFER, srcSizeInBytes + 1,
142 NULL, usage));
143 GL_CALL(BufferSubData(GR_GL_ARRAY_BUFFER, 0, srcSizeInBytes, src));
144 } else {
145 GL_CALL(BufferData(GR_GL_ARRAY_BUFFER, srcSizeInBytes, src, usage));
146 }
147 #endif
148 return true;
149 }
150