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 #include "gl/SkNullGLContext.h"
10 #include "gl/GrGLInterface.h"
11 #include "GrGLDefines.h"
12 #include "GrGLNoOpInterface.h"
13 #include "SkTDArray.h"
14 #include "SkTLS.h"
15 
16 static SkNullGLContext::ContextState* current_context();
17 
18 /////////////////////////////////////////////////////////////////////////////////////////////////
19 
20 class BufferObj {
21 public:
22     SK_DECLARE_INST_COUNT(BufferObj);
23 
BufferObj(GrGLuint id)24     BufferObj(GrGLuint id) : fID(id), fDataPtr(NULL), fSize(0), fMapped(false) {}
~BufferObj()25     ~BufferObj() { SkDELETE_ARRAY(fDataPtr); }
26 
allocate(GrGLsizeiptr size,const GrGLchar * dataPtr)27     void allocate(GrGLsizeiptr size, const GrGLchar* dataPtr) {
28         if (fDataPtr) {
29             SkASSERT(0 != fSize);
30             SkDELETE_ARRAY(fDataPtr);
31         }
32 
33         fSize = size;
34         fDataPtr = SkNEW_ARRAY(char, size);
35     }
36 
id() const37     GrGLuint id() const          { return fID; }
dataPtr()38     GrGLchar* dataPtr()          { return fDataPtr; }
size() const39     GrGLsizeiptr size() const    { return fSize; }
40 
setMapped(bool mapped)41     void setMapped(bool mapped)  { fMapped = mapped; }
mapped() const42     bool mapped() const          { return fMapped; }
43 
44 private:
45     GrGLuint     fID;
46     GrGLchar*    fDataPtr;
47     GrGLsizeiptr fSize;         // size in bytes
48     bool         fMapped;
49 };
50 
51 // This class maintains a sparsely populated array of buffer pointers.
52 class BufferManager {
53 public:
54     SK_DECLARE_INST_COUNT(BufferManager);
55 
BufferManager()56     BufferManager() : fFreeListHead(kFreeListEnd) {}
57 
~BufferManager()58     ~BufferManager() {
59         // NULL out the entries that are really free list links rather than ptrs before deleting.
60         intptr_t curr = fFreeListHead;
61         while (kFreeListEnd != curr) {
62             intptr_t next = reinterpret_cast<intptr_t>(fBuffers[SkToS32(curr)]);
63             fBuffers[SkToS32(curr)] = NULL;
64             curr = next;
65         }
66 
67         fBuffers.deleteAll();
68     }
69 
lookUp(GrGLuint id)70     BufferObj* lookUp(GrGLuint id) {
71         BufferObj* buffer = fBuffers[id];
72         SkASSERT(buffer && buffer->id() == id);
73         return buffer;
74     }
75 
create()76     BufferObj* create() {
77         GrGLuint id;
78         BufferObj* buffer;
79 
80         if (kFreeListEnd == fFreeListHead) {
81             // no free slots - create a new one
82             id = fBuffers.count();
83             buffer = SkNEW_ARGS(BufferObj, (id));
84             *fBuffers.append() = buffer;
85         } else {
86             // grab the head of the free list and advance the head to the next free slot.
87             id = static_cast<GrGLuint>(fFreeListHead);
88             fFreeListHead = reinterpret_cast<intptr_t>(fBuffers[id]);
89 
90             buffer = SkNEW_ARGS(BufferObj, (id));
91             fBuffers[id] = buffer;
92         }
93 
94         return buffer;
95     }
96 
free(BufferObj * buffer)97     void free(BufferObj* buffer) {
98         SkASSERT(fBuffers.count() > 0);
99 
100         GrGLuint id = buffer->id();
101         SkDELETE(buffer);
102 
103         fBuffers[id] = reinterpret_cast<BufferObj*>(fFreeListHead);
104         fFreeListHead = id;
105     }
106 
107 private:
108     static const intptr_t kFreeListEnd = -1;
109     // Index of the first entry of fBuffers in the free list. Free slots in fBuffers are indices to
110     // the next free slot. The last free slot has a value of kFreeListEnd.
111     intptr_t                fFreeListHead;
112     SkTDArray<BufferObj*>   fBuffers;
113 };
114 
115 /**
116  * The state object for the null interface.
117  */
118 class SkNullGLContext::ContextState : public SkRefCnt {
119 public:
120     SK_DECLARE_INST_COUNT(ContextState);
121 
122     BufferManager   fBufferManager;
123     GrGLuint        fCurrArrayBuffer;
124     GrGLuint        fCurrElementArrayBuffer;
125     GrGLuint        fCurrProgramID;
126     GrGLuint        fCurrShaderID;
127 
128 
ContextState()129     ContextState()
130         : fCurrArrayBuffer(0)
131         , fCurrElementArrayBuffer(0)
132         , fCurrProgramID(0)
133         , fCurrShaderID(0) {}
134 
Get()135     static ContextState* Get() { return current_context(); }
136 };
137 
138 typedef SkNullGLContext::ContextState State;
139 
140 // Functions not declared in GrGLBogusInterface.h (not common with the Debug GL interface).
141 
142 namespace { // added to suppress 'no previous prototype' warning
143 
nullGLActiveTexture(GrGLenum texture)144 GrGLvoid GR_GL_FUNCTION_TYPE nullGLActiveTexture(GrGLenum texture) {}
nullGLAttachShader(GrGLuint program,GrGLuint shader)145 GrGLvoid GR_GL_FUNCTION_TYPE nullGLAttachShader(GrGLuint program, GrGLuint shader) {}
nullGLBeginQuery(GrGLenum target,GrGLuint id)146 GrGLvoid GR_GL_FUNCTION_TYPE nullGLBeginQuery(GrGLenum target, GrGLuint id) {}
nullGLBindAttribLocation(GrGLuint program,GrGLuint index,const char * name)147 GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindAttribLocation(GrGLuint program, GrGLuint index, const char* name) {}
nullGLBindTexture(GrGLenum target,GrGLuint texture)148 GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindTexture(GrGLenum target, GrGLuint texture) {}
nullGLBindVertexArray(GrGLuint id)149 GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindVertexArray(GrGLuint id) {}
150 
nullGLGenBuffers(GrGLsizei n,GrGLuint * ids)151 GrGLvoid GR_GL_FUNCTION_TYPE nullGLGenBuffers(GrGLsizei n, GrGLuint* ids) {
152     State* state = State::Get();
153     for (int i = 0; i < n; ++i) {
154         BufferObj* buffer = state->fBufferManager.create();
155         ids[i] = buffer->id();
156     }
157 }
158 
nullGLGenerateMipmap(GrGLenum target)159 GrGLvoid GR_GL_FUNCTION_TYPE nullGLGenerateMipmap(GrGLenum target) {}
160 
nullGLBufferData(GrGLenum target,GrGLsizeiptr size,const GrGLvoid * data,GrGLenum usage)161 GrGLvoid GR_GL_FUNCTION_TYPE nullGLBufferData(GrGLenum target,
162                                               GrGLsizeiptr size,
163                                               const GrGLvoid* data,
164                                               GrGLenum usage) {
165     State* state = State::Get();
166     GrGLuint id = 0;
167 
168     switch (target) {
169     case GR_GL_ARRAY_BUFFER:
170         id = state->fCurrArrayBuffer;
171         break;
172     case GR_GL_ELEMENT_ARRAY_BUFFER:
173         id = state->fCurrElementArrayBuffer;
174         break;
175     default:
176         SkFAIL("Unexpected target to nullGLBufferData");
177         break;
178     }
179 
180     if (id > 0) {
181         BufferObj* buffer = state->fBufferManager.lookUp(id);
182         buffer->allocate(size, (const GrGLchar*) data);
183     }
184 }
185 
nullGLPixelStorei(GrGLenum pname,GrGLint param)186 GrGLvoid GR_GL_FUNCTION_TYPE nullGLPixelStorei(GrGLenum pname, GrGLint param) {}
nullGLReadPixels(GrGLint x,GrGLint y,GrGLsizei width,GrGLsizei height,GrGLenum format,GrGLenum type,GrGLvoid * pixels)187 GrGLvoid GR_GL_FUNCTION_TYPE nullGLReadPixels(GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height, GrGLenum format, GrGLenum type, GrGLvoid* pixels) {}
nullGLUseProgram(GrGLuint program)188 GrGLvoid GR_GL_FUNCTION_TYPE nullGLUseProgram(GrGLuint program) {}
nullGLViewport(GrGLint x,GrGLint y,GrGLsizei width,GrGLsizei height)189 GrGLvoid GR_GL_FUNCTION_TYPE nullGLViewport(GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height) {}
nullGLBindFramebuffer(GrGLenum target,GrGLuint framebuffer)190 GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindFramebuffer(GrGLenum target, GrGLuint framebuffer) {}
nullGLBindRenderbuffer(GrGLenum target,GrGLuint renderbuffer)191 GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindRenderbuffer(GrGLenum target, GrGLuint renderbuffer) {}
nullGLDeleteFramebuffers(GrGLsizei n,const GrGLuint * framebuffers)192 GrGLvoid GR_GL_FUNCTION_TYPE nullGLDeleteFramebuffers(GrGLsizei n, const GrGLuint *framebuffers) {}
nullGLDeleteRenderbuffers(GrGLsizei n,const GrGLuint * renderbuffers)193 GrGLvoid GR_GL_FUNCTION_TYPE nullGLDeleteRenderbuffers(GrGLsizei n, const GrGLuint *renderbuffers) {}
nullGLFramebufferRenderbuffer(GrGLenum target,GrGLenum attachment,GrGLenum renderbuffertarget,GrGLuint renderbuffer)194 GrGLvoid GR_GL_FUNCTION_TYPE nullGLFramebufferRenderbuffer(GrGLenum target, GrGLenum attachment, GrGLenum renderbuffertarget, GrGLuint renderbuffer) {}
nullGLFramebufferTexture2D(GrGLenum target,GrGLenum attachment,GrGLenum textarget,GrGLuint texture,GrGLint level)195 GrGLvoid GR_GL_FUNCTION_TYPE nullGLFramebufferTexture2D(GrGLenum target, GrGLenum attachment, GrGLenum textarget, GrGLuint texture, GrGLint level) {}
196 
nullGLCreateProgram()197 GrGLuint GR_GL_FUNCTION_TYPE nullGLCreateProgram() {
198     return ++State::Get()->fCurrProgramID;
199 }
200 
nullGLCreateShader(GrGLenum type)201 GrGLuint GR_GL_FUNCTION_TYPE nullGLCreateShader(GrGLenum type) {
202     return ++State::Get()->fCurrShaderID;
203 }
204 
205 // same delete used for shaders and programs
nullGLDelete(GrGLuint program)206 GrGLvoid GR_GL_FUNCTION_TYPE nullGLDelete(GrGLuint program) {
207 }
208 
nullGLBindBuffer(GrGLenum target,GrGLuint buffer)209 GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindBuffer(GrGLenum target, GrGLuint buffer) {
210     State* state = State::Get();
211     switch (target) {
212     case GR_GL_ARRAY_BUFFER:
213         state->fCurrArrayBuffer = buffer;
214         break;
215     case GR_GL_ELEMENT_ARRAY_BUFFER:
216         state->fCurrElementArrayBuffer = buffer;
217         break;
218     }
219 }
220 
221 // deleting a bound buffer has the side effect of binding 0
nullGLDeleteBuffers(GrGLsizei n,const GrGLuint * ids)222 GrGLvoid GR_GL_FUNCTION_TYPE nullGLDeleteBuffers(GrGLsizei n, const GrGLuint* ids) {
223     State* state = State::Get();
224     for (int i = 0; i < n; ++i) {
225         if (ids[i] == state->fCurrArrayBuffer) {
226             state->fCurrArrayBuffer = 0;
227         }
228         if (ids[i] == state->fCurrElementArrayBuffer) {
229             state->fCurrElementArrayBuffer = 0;
230         }
231 
232         BufferObj* buffer = state->fBufferManager.lookUp(ids[i]);
233         state->fBufferManager.free(buffer);
234     }
235 }
236 
nullGLMapBufferRange(GrGLenum target,GrGLintptr offset,GrGLsizeiptr length,GrGLbitfield access)237 GrGLvoid* GR_GL_FUNCTION_TYPE nullGLMapBufferRange(GrGLenum target, GrGLintptr offset,
238                                                    GrGLsizeiptr length, GrGLbitfield access) {
239     State* state = State::Get();
240     GrGLuint id = 0;
241     switch (target) {
242         case GR_GL_ARRAY_BUFFER:
243             id = state->fCurrArrayBuffer;
244             break;
245         case GR_GL_ELEMENT_ARRAY_BUFFER:
246             id = state->fCurrElementArrayBuffer;
247             break;
248     }
249 
250     if (id > 0) {
251         // We just ignore the offset and length here.
252         BufferObj* buffer = state->fBufferManager.lookUp(id);
253         SkASSERT(!buffer->mapped());
254         buffer->setMapped(true);
255         return buffer->dataPtr();
256     }
257     return NULL;
258 }
259 
nullGLMapBuffer(GrGLenum target,GrGLenum access)260 GrGLvoid* GR_GL_FUNCTION_TYPE nullGLMapBuffer(GrGLenum target, GrGLenum access) {
261     State* state = State::Get();
262     GrGLuint id = 0;
263     switch (target) {
264         case GR_GL_ARRAY_BUFFER:
265             id = state->fCurrArrayBuffer;
266             break;
267         case GR_GL_ELEMENT_ARRAY_BUFFER:
268             id = state->fCurrElementArrayBuffer;
269             break;
270     }
271 
272     if (id > 0) {
273         BufferObj* buffer = state->fBufferManager.lookUp(id);
274         SkASSERT(!buffer->mapped());
275         buffer->setMapped(true);
276         return buffer->dataPtr();
277     }
278 
279     SkASSERT(false);
280     return NULL;            // no buffer bound to target
281 }
282 
nullGLFlushMappedBufferRange(GrGLenum target,GrGLintptr offset,GrGLsizeiptr length)283 GrGLvoid GR_GL_FUNCTION_TYPE nullGLFlushMappedBufferRange(GrGLenum target,
284                                                           GrGLintptr offset,
285                                                           GrGLsizeiptr length) {}
286 
287 
nullGLUnmapBuffer(GrGLenum target)288 GrGLboolean GR_GL_FUNCTION_TYPE nullGLUnmapBuffer(GrGLenum target) {
289     State* state = State::Get();
290     GrGLuint id = 0;
291     switch (target) {
292     case GR_GL_ARRAY_BUFFER:
293         id = state->fCurrArrayBuffer;
294         break;
295     case GR_GL_ELEMENT_ARRAY_BUFFER:
296         id = state->fCurrElementArrayBuffer;
297         break;
298     }
299     if (id > 0) {
300         BufferObj* buffer = state->fBufferManager.lookUp(id);
301         SkASSERT(buffer->mapped());
302         buffer->setMapped(false);
303         return GR_GL_TRUE;
304     }
305 
306     GrAlwaysAssert(false);
307     return GR_GL_FALSE; // GR_GL_INVALID_OPERATION;
308 }
309 
nullGLGetBufferParameteriv(GrGLenum target,GrGLenum pname,GrGLint * params)310 GrGLvoid GR_GL_FUNCTION_TYPE nullGLGetBufferParameteriv(GrGLenum target, GrGLenum pname, GrGLint* params) {
311     State* state = State::Get();
312     switch (pname) {
313         case GR_GL_BUFFER_MAPPED: {
314             *params = GR_GL_FALSE;
315             GrGLuint id = 0;
316             switch (target) {
317                 case GR_GL_ARRAY_BUFFER:
318                     id = state->fCurrArrayBuffer;
319                     break;
320                 case GR_GL_ELEMENT_ARRAY_BUFFER:
321                     id = state->fCurrElementArrayBuffer;
322                     break;
323             }
324             if (id > 0) {
325                 BufferObj* buffer = state->fBufferManager.lookUp(id);
326                 if (buffer->mapped()) {
327                     *params = GR_GL_TRUE;
328                 }
329             }
330             break; }
331         default:
332             SkFAIL("Unexpected pname to GetBufferParamateriv");
333             break;
334     }
335 };
336 
337 class NullInterface : public GrGLInterface {
338 public:
NullInterface(State * state)339     NullInterface(State* state) : fState(SkRef(state)) {}
~NullInterface()340     ~NullInterface() override {
341         fState->unref();
342     }
343     State* fState;
344 };
345 
346 } // end anonymous namespace
347 
create_null_interface(State * state)348 static GrGLInterface* create_null_interface(State* state) {
349     GrGLInterface* interface = SkNEW_ARGS(NullInterface, (state));
350 
351     interface->fStandard = kGL_GrGLStandard;
352 
353     GrGLInterface::Functions* functions = &interface->fFunctions;
354     functions->fActiveTexture = nullGLActiveTexture;
355     functions->fAttachShader = nullGLAttachShader;
356     functions->fBeginQuery = nullGLBeginQuery;
357     functions->fBindAttribLocation = nullGLBindAttribLocation;
358     functions->fBindBuffer = nullGLBindBuffer;
359     functions->fBindFragDataLocation = noOpGLBindFragDataLocation;
360     functions->fBindTexture = nullGLBindTexture;
361     functions->fBindVertexArray = nullGLBindVertexArray;
362     functions->fBlendColor = noOpGLBlendColor;
363     functions->fBlendEquation = noOpGLBlendEquation;
364     functions->fBlendFunc = noOpGLBlendFunc;
365     functions->fBufferData = nullGLBufferData;
366     functions->fBufferSubData = noOpGLBufferSubData;
367     functions->fClear = noOpGLClear;
368     functions->fClearColor = noOpGLClearColor;
369     functions->fClearStencil = noOpGLClearStencil;
370     functions->fColorMask = noOpGLColorMask;
371     functions->fCompileShader = noOpGLCompileShader;
372     functions->fCompressedTexImage2D = noOpGLCompressedTexImage2D;
373     functions->fCompressedTexSubImage2D = noOpGLCompressedTexSubImage2D;
374     functions->fCopyTexSubImage2D = noOpGLCopyTexSubImage2D;
375     functions->fCreateProgram = nullGLCreateProgram;
376     functions->fCreateShader = nullGLCreateShader;
377     functions->fCullFace = noOpGLCullFace;
378     functions->fDeleteBuffers = nullGLDeleteBuffers;
379     functions->fDeleteProgram = nullGLDelete;
380     functions->fDeleteQueries = noOpGLDeleteIds;
381     functions->fDeleteShader = nullGLDelete;
382     functions->fDeleteTextures = noOpGLDeleteIds;
383     functions->fDeleteVertexArrays = noOpGLDeleteIds;
384     functions->fDepthMask = noOpGLDepthMask;
385     functions->fDisable = noOpGLDisable;
386     functions->fDisableVertexAttribArray = noOpGLDisableVertexAttribArray;
387     functions->fDrawArrays = noOpGLDrawArrays;
388     functions->fDrawBuffer = noOpGLDrawBuffer;
389     functions->fDrawBuffers = noOpGLDrawBuffers;
390     functions->fDrawElements = noOpGLDrawElements;
391     functions->fEnable = noOpGLEnable;
392     functions->fEnableVertexAttribArray = noOpGLEnableVertexAttribArray;
393     functions->fEndQuery = noOpGLEndQuery;
394     functions->fFinish = noOpGLFinish;
395     functions->fFlush = noOpGLFlush;
396     functions->fFlushMappedBufferRange = nullGLFlushMappedBufferRange;
397     functions->fFrontFace = noOpGLFrontFace;
398     functions->fGenBuffers = nullGLGenBuffers;
399     functions->fGenerateMipmap = nullGLGenerateMipmap;
400     functions->fGenQueries = noOpGLGenIds;
401     functions->fGenTextures = noOpGLGenIds;
402     functions->fGenVertexArrays = noOpGLGenIds;
403     functions->fGetBufferParameteriv = nullGLGetBufferParameteriv;
404     functions->fGetError = noOpGLGetError;
405     functions->fGetIntegerv = noOpGLGetIntegerv;
406     functions->fGetQueryObjecti64v = noOpGLGetQueryObjecti64v;
407     functions->fGetQueryObjectiv = noOpGLGetQueryObjectiv;
408     functions->fGetQueryObjectui64v = noOpGLGetQueryObjectui64v;
409     functions->fGetQueryObjectuiv = noOpGLGetQueryObjectuiv;
410     functions->fGetQueryiv = noOpGLGetQueryiv;
411     functions->fGetProgramInfoLog = noOpGLGetInfoLog;
412     functions->fGetProgramiv = noOpGLGetShaderOrProgramiv;
413     functions->fGetShaderInfoLog = noOpGLGetInfoLog;
414     functions->fGetShaderiv = noOpGLGetShaderOrProgramiv;
415     functions->fGetString = noOpGLGetString;
416     functions->fGetStringi = noOpGLGetStringi;
417     functions->fGetTexLevelParameteriv = noOpGLGetTexLevelParameteriv;
418     functions->fGetUniformLocation = noOpGLGetUniformLocation;
419     functions->fInsertEventMarker = noOpGLInsertEventMarker;
420     functions->fLineWidth = noOpGLLineWidth;
421     functions->fLinkProgram = noOpGLLinkProgram;
422     functions->fMapBuffer = nullGLMapBuffer;
423     functions->fMapBufferRange = nullGLMapBufferRange;
424     functions->fPixelStorei = nullGLPixelStorei;
425     functions->fPopGroupMarker = noOpGLPopGroupMarker;
426     functions->fPushGroupMarker = noOpGLPushGroupMarker;
427     functions->fQueryCounter = noOpGLQueryCounter;
428     functions->fReadBuffer = noOpGLReadBuffer;
429     functions->fReadPixels = nullGLReadPixels;
430     functions->fScissor = noOpGLScissor;
431     functions->fShaderSource = noOpGLShaderSource;
432     functions->fStencilFunc = noOpGLStencilFunc;
433     functions->fStencilFuncSeparate = noOpGLStencilFuncSeparate;
434     functions->fStencilMask = noOpGLStencilMask;
435     functions->fStencilMaskSeparate = noOpGLStencilMaskSeparate;
436     functions->fStencilOp = noOpGLStencilOp;
437     functions->fStencilOpSeparate = noOpGLStencilOpSeparate;
438     functions->fTexImage2D = noOpGLTexImage2D;
439     functions->fTexParameteri = noOpGLTexParameteri;
440     functions->fTexParameteriv = noOpGLTexParameteriv;
441     functions->fTexSubImage2D = noOpGLTexSubImage2D;
442     functions->fTexStorage2D = noOpGLTexStorage2D;
443     functions->fDiscardFramebuffer = noOpGLDiscardFramebuffer;
444     functions->fUniform1f = noOpGLUniform1f;
445     functions->fUniform1i = noOpGLUniform1i;
446     functions->fUniform1fv = noOpGLUniform1fv;
447     functions->fUniform1iv = noOpGLUniform1iv;
448     functions->fUniform2f = noOpGLUniform2f;
449     functions->fUniform2i = noOpGLUniform2i;
450     functions->fUniform2fv = noOpGLUniform2fv;
451     functions->fUniform2iv = noOpGLUniform2iv;
452     functions->fUniform3f = noOpGLUniform3f;
453     functions->fUniform3i = noOpGLUniform3i;
454     functions->fUniform3fv = noOpGLUniform3fv;
455     functions->fUniform3iv = noOpGLUniform3iv;
456     functions->fUniform4f = noOpGLUniform4f;
457     functions->fUniform4i = noOpGLUniform4i;
458     functions->fUniform4fv = noOpGLUniform4fv;
459     functions->fUniform4iv = noOpGLUniform4iv;
460     functions->fUniformMatrix2fv = noOpGLUniformMatrix2fv;
461     functions->fUniformMatrix3fv = noOpGLUniformMatrix3fv;
462     functions->fUniformMatrix4fv = noOpGLUniformMatrix4fv;
463     functions->fUnmapBuffer = nullGLUnmapBuffer;
464     functions->fUseProgram = nullGLUseProgram;
465     functions->fVertexAttrib1f = noOpGLVertexAttrib1f;
466     functions->fVertexAttrib2fv = noOpGLVertexAttrib2fv;
467     functions->fVertexAttrib3fv = noOpGLVertexAttrib3fv;
468     functions->fVertexAttrib4fv = noOpGLVertexAttrib4fv;
469     functions->fVertexAttribPointer = noOpGLVertexAttribPointer;
470     functions->fViewport = nullGLViewport;
471     functions->fBindFramebuffer = nullGLBindFramebuffer;
472     functions->fBindRenderbuffer = nullGLBindRenderbuffer;
473     functions->fCheckFramebufferStatus = noOpGLCheckFramebufferStatus;
474     functions->fDeleteFramebuffers = nullGLDeleteFramebuffers;
475     functions->fDeleteRenderbuffers = nullGLDeleteRenderbuffers;
476     functions->fFramebufferRenderbuffer = nullGLFramebufferRenderbuffer;
477     functions->fFramebufferTexture2D = nullGLFramebufferTexture2D;
478     functions->fGenFramebuffers = noOpGLGenIds;
479     functions->fGenRenderbuffers = noOpGLGenIds;
480     functions->fGetFramebufferAttachmentParameteriv = noOpGLGetFramebufferAttachmentParameteriv;
481     functions->fGetRenderbufferParameteriv = noOpGLGetRenderbufferParameteriv;
482     functions->fRenderbufferStorage = noOpGLRenderbufferStorage;
483     functions->fRenderbufferStorageMultisample = noOpGLRenderbufferStorageMultisample;
484     functions->fBlitFramebuffer = noOpGLBlitFramebuffer;
485     functions->fResolveMultisampleFramebuffer = noOpGLResolveMultisampleFramebuffer;
486     functions->fMatrixLoadf = noOpGLMatrixLoadf;
487     functions->fMatrixLoadIdentity = noOpGLMatrixLoadIdentity;
488     functions->fBindFragDataLocationIndexed = noOpGLBindFragDataLocationIndexed;
489 
490     interface->fExtensions.init(kGL_GrGLStandard, functions->fGetString, functions->fGetStringi,
491                                 functions->fGetIntegerv);
492     return interface;
493 }
494 
495 //////////////////////////////////////////////////////////////////////////////
496 
create_tls()497 static void* create_tls() {
498     State** current = SkNEW(State*);
499     *current = NULL;
500     return current;
501 }
502 
delete_tls(void * ctx)503 static void delete_tls(void* ctx) {
504     State** current = static_cast<State**>(ctx);
505     if (*current) {
506         (*current)->unref();
507     }
508     SkDELETE(current);
509 }
510 
current_context()511 static State* current_context() {
512     return *static_cast<State**>(SkTLS::Get(create_tls, delete_tls));
513 }
514 
set_current_context(State * state)515 static void set_current_context(State* state) {
516     State** current = static_cast<State**>(SkTLS::Get(create_tls, delete_tls));
517     if (*current) {
518         (*current)->unref();
519     }
520     *current = state;
521     if (state) {
522         state->ref();
523     }
524 }
525 
526 #if GR_GL_PER_GL_FUNC_CALLBACK
set_current_context_from_interface(const GrGLInterface * interface)527 static void set_current_context_from_interface(const GrGLInterface* interface) {
528     set_current_context(reinterpret_cast<State*>(interface->fCallbackData));
529 }
530 #endif
531 
Create(GrGLStandard forcedGpuAPI)532 SkNullGLContext* SkNullGLContext::Create(GrGLStandard forcedGpuAPI) {
533     if (kGLES_GrGLStandard == forcedGpuAPI) {
534         return NULL;
535     }
536     SkNullGLContext* ctx = SkNEW(SkNullGLContext);
537     if (!ctx->isValid()) {
538         SkDELETE(ctx);
539         return NULL;
540     }
541     return ctx;
542 }
543 
SkNullGLContext()544 SkNullGLContext::SkNullGLContext() {
545     fState = SkNEW(ContextState);
546     GrGLInterface* interface = create_null_interface(fState);
547     fGL.reset(interface);
548 #if GR_GL_PER_GL_FUNC_CALLBACK
549     interface->fCallback = set_current_context_from_interface;
550     interface->fCallbackData = reinterpret_cast<GrGLInterfaceCallbackData>(fState);
551 #endif
552 }
553 
~SkNullGLContext()554 SkNullGLContext::~SkNullGLContext() {
555     fGL.reset(NULL);
556     fState->unref();
557 }
558 
makeCurrent() const559 void SkNullGLContext::makeCurrent() const { set_current_context(fState); }
560