1 /*
2 * Copyright 2013 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 #include "GrGLBufferImpl.h"
9 #include "GrGpuGL.h"
10
11 #define GL_CALL(GPU, X) GR_GL_CALL(GPU->glInterface(), X)
12
13 #ifdef SK_DEBUG
14 #define VALIDATE() this->validate()
15 #else
16 #define VALIDATE() do {} while(false)
17 #endif
18
19 // GL_STREAM_DRAW triggers an optimization in Chromium's GPU process where a client's vertex buffer
20 // objects are implemented as client-side-arrays on tile-deferred architectures.
21 #define DYNAMIC_USAGE_PARAM GR_GL_STREAM_DRAW
22
GrGLBufferImpl(GrGpuGL * gpu,const Desc & desc,GrGLenum bufferType)23 GrGLBufferImpl::GrGLBufferImpl(GrGpuGL* gpu, const Desc& desc, GrGLenum bufferType)
24 : fDesc(desc)
25 , fBufferType(bufferType)
26 , fLockPtr(NULL) {
27 if (0 == desc.fID) {
28 fCPUData = sk_malloc_flags(desc.fSizeInBytes, SK_MALLOC_THROW);
29 } else {
30 fCPUData = NULL;
31 }
32 VALIDATE();
33 }
34
release(GrGpuGL * gpu)35 void GrGLBufferImpl::release(GrGpuGL* gpu) {
36 // make sure we've not been abandoned or already released
37 if (NULL != fCPUData) {
38 VALIDATE();
39 sk_free(fCPUData);
40 fCPUData = NULL;
41 } else if (fDesc.fID && !fDesc.fIsWrapped) {
42 VALIDATE();
43 GL_CALL(gpu, DeleteBuffers(1, &fDesc.fID));
44 if (GR_GL_ARRAY_BUFFER == fBufferType) {
45 gpu->notifyVertexBufferDelete(fDesc.fID);
46 } else {
47 SkASSERT(GR_GL_ELEMENT_ARRAY_BUFFER == fBufferType);
48 gpu->notifyIndexBufferDelete(fDesc.fID);
49 }
50 fDesc.fID = 0;
51 }
52 fLockPtr = NULL;
53 }
54
abandon()55 void GrGLBufferImpl::abandon() {
56 fDesc.fID = 0;
57 fLockPtr = NULL;
58 sk_free(fCPUData);
59 fCPUData = NULL;
60 }
61
bind(GrGpuGL * gpu) const62 void GrGLBufferImpl::bind(GrGpuGL* gpu) const {
63 VALIDATE();
64 if (GR_GL_ARRAY_BUFFER == fBufferType) {
65 gpu->bindVertexBuffer(fDesc.fID);
66 } else {
67 SkASSERT(GR_GL_ELEMENT_ARRAY_BUFFER == fBufferType);
68 gpu->bindIndexBufferAndDefaultVertexArray(fDesc.fID);
69 }
70 }
71
lock(GrGpuGL * gpu)72 void* GrGLBufferImpl::lock(GrGpuGL* gpu) {
73 VALIDATE();
74 SkASSERT(!this->isLocked());
75 if (0 == fDesc.fID) {
76 fLockPtr = fCPUData;
77 } else if (gpu->caps()->bufferLockSupport()) {
78 this->bind(gpu);
79 // Let driver know it can discard the old data
80 GL_CALL(gpu, BufferData(fBufferType,
81 (GrGLsizeiptr) fDesc.fSizeInBytes,
82 NULL,
83 fDesc.fDynamic ? DYNAMIC_USAGE_PARAM : GR_GL_STATIC_DRAW));
84 GR_GL_CALL_RET(gpu->glInterface(),
85 fLockPtr,
86 MapBuffer(fBufferType, GR_GL_WRITE_ONLY));
87 }
88 return fLockPtr;
89 }
90
unlock(GrGpuGL * gpu)91 void GrGLBufferImpl::unlock(GrGpuGL* gpu) {
92 VALIDATE();
93 SkASSERT(this->isLocked());
94 if (0 != fDesc.fID) {
95 SkASSERT(gpu->caps()->bufferLockSupport());
96 this->bind(gpu);
97 GL_CALL(gpu, UnmapBuffer(fBufferType));
98 }
99 fLockPtr = NULL;
100 }
101
isLocked() const102 bool GrGLBufferImpl::isLocked() const {
103 VALIDATE();
104 return NULL != fLockPtr;
105 }
106
updateData(GrGpuGL * gpu,const void * src,size_t srcSizeInBytes)107 bool GrGLBufferImpl::updateData(GrGpuGL* gpu, const void* src, size_t srcSizeInBytes) {
108 SkASSERT(!this->isLocked());
109 VALIDATE();
110 if (srcSizeInBytes > fDesc.fSizeInBytes) {
111 return false;
112 }
113 if (0 == fDesc.fID) {
114 memcpy(fCPUData, src, srcSizeInBytes);
115 return true;
116 }
117 this->bind(gpu);
118 GrGLenum usage = fDesc.fDynamic ? DYNAMIC_USAGE_PARAM : GR_GL_STATIC_DRAW;
119
120 #if GR_GL_USE_BUFFER_DATA_NULL_HINT
121 if (fDesc.fSizeInBytes == srcSizeInBytes) {
122 GL_CALL(gpu, BufferData(fBufferType, (GrGLsizeiptr) srcSizeInBytes, src, usage));
123 } else {
124 // Before we call glBufferSubData we give the driver a hint using
125 // glBufferData with NULL. This makes the old buffer contents
126 // inaccessible to future draws. The GPU may still be processing
127 // draws that reference the old contents. With this hint it can
128 // assign a different allocation for the new contents to avoid
129 // flushing the gpu past draws consuming the old contents.
130 GL_CALL(gpu, BufferData(fBufferType, (GrGLsizeiptr) fDesc.fSizeInBytes, NULL, usage));
131 GL_CALL(gpu, BufferSubData(fBufferType, 0, (GrGLsizeiptr) srcSizeInBytes, src));
132 }
133 #else
134 // Note that we're cheating on the size here. Currently no methods
135 // allow a partial update that preserves contents of non-updated
136 // portions of the buffer (lock() does a glBufferData(..size, NULL..))
137 bool doSubData = false;
138 #if GR_GL_MAC_BUFFER_OBJECT_PERFOMANCE_WORKAROUND
139 static int N = 0;
140 // 128 was chosen experimentally. At 256 a slight hitchiness was noticed
141 // when dragging a Chromium window around with a canvas tab backgrounded.
142 doSubData = 0 == (N % 128);
143 ++N;
144 #endif
145 if (doSubData) {
146 // The workaround is to do a glBufferData followed by glBufferSubData.
147 // Chromium's command buffer may turn a glBufferSubData where the size
148 // exactly matches the buffer size into a glBufferData. So we tack 1
149 // extra byte onto the glBufferData.
150 GL_CALL(gpu, BufferData(fBufferType, srcSizeInBytes + 1, NULL, usage));
151 GL_CALL(gpu, BufferSubData(fBufferType, 0, srcSizeInBytes, src));
152 } else {
153 GL_CALL(gpu, BufferData(fBufferType, srcSizeInBytes, src, usage));
154 }
155 #endif
156 return true;
157 }
158
validate() const159 void GrGLBufferImpl::validate() const {
160 SkASSERT(GR_GL_ARRAY_BUFFER == fBufferType || GR_GL_ELEMENT_ARRAY_BUFFER == fBufferType);
161 // The following assert isn't valid when the buffer has been abandoned:
162 // SkASSERT((0 == fDesc.fID) == (NULL != fCPUData));
163 SkASSERT(0 != fDesc.fID || !fDesc.fIsWrapped);
164 SkASSERT(NULL == fCPUData || NULL == fLockPtr || fCPUData == fLockPtr);
165 }
166