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 
23 
BufferObj(GrGLuint id)24     BufferObj(GrGLuint id) : fID(id), fDataPtr(nullptr), fSize(0), fMapped(false) {}
~BufferObj()25     ~BufferObj() { delete[] fDataPtr; }
26 
allocate(GrGLsizeiptr size,const GrGLchar * dataPtr)27     void allocate(GrGLsizeiptr size, const GrGLchar* dataPtr) {
28         if (fDataPtr) {
29             SkASSERT(0 != fSize);
30             delete[] fDataPtr;
31         }
32 
33         fSize = size;
34         fDataPtr = new 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 
55 
BufferManager()56     BufferManager() : fFreeListHead(kFreeListEnd) {}
57 
~BufferManager()58     ~BufferManager() {
59         // nullptr 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)] = nullptr;
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 = new 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 = new 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         delete 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 
121 
122     BufferManager   fBufferManager;
123     GrGLuint        fCurrArrayBuffer;
124     GrGLuint        fCurrElementArrayBuffer;
125     GrGLuint        fCurrPixelPackBuffer;
126     GrGLuint        fCurrPixelUnpackBuffer;
127     GrGLuint        fCurrProgramID;
128     GrGLuint        fCurrShaderID;
129 
130 
ContextState()131     ContextState()
132         : fCurrArrayBuffer(0)
133         , fCurrElementArrayBuffer(0)
134         , fCurrPixelPackBuffer(0)
135         , fCurrPixelUnpackBuffer(0)
136         , fCurrProgramID(0)
137         , fCurrShaderID(0) {}
138 
Get()139     static ContextState* Get() { return current_context(); }
140 };
141 
142 typedef SkNullGLContext::ContextState State;
143 
144 // Functions not declared in GrGLBogusInterface.h (not common with the Debug GL interface).
145 
146 namespace { // added to suppress 'no previous prototype' warning
147 
nullGLActiveTexture(GrGLenum texture)148 GrGLvoid GR_GL_FUNCTION_TYPE nullGLActiveTexture(GrGLenum texture) {}
nullGLAttachShader(GrGLuint program,GrGLuint shader)149 GrGLvoid GR_GL_FUNCTION_TYPE nullGLAttachShader(GrGLuint program, GrGLuint shader) {}
nullGLBeginQuery(GrGLenum target,GrGLuint id)150 GrGLvoid GR_GL_FUNCTION_TYPE nullGLBeginQuery(GrGLenum target, GrGLuint id) {}
nullGLBindAttribLocation(GrGLuint program,GrGLuint index,const char * name)151 GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindAttribLocation(GrGLuint program, GrGLuint index, const char* name) {}
nullGLBindTexture(GrGLenum target,GrGLuint texture)152 GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindTexture(GrGLenum target, GrGLuint texture) {}
nullGLBindVertexArray(GrGLuint id)153 GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindVertexArray(GrGLuint id) {}
154 
nullGLGenBuffers(GrGLsizei n,GrGLuint * ids)155 GrGLvoid GR_GL_FUNCTION_TYPE nullGLGenBuffers(GrGLsizei n, GrGLuint* ids) {
156     State* state = State::Get();
157     for (int i = 0; i < n; ++i) {
158         BufferObj* buffer = state->fBufferManager.create();
159         ids[i] = buffer->id();
160     }
161 }
162 
nullGLGenerateMipmap(GrGLenum target)163 GrGLvoid GR_GL_FUNCTION_TYPE nullGLGenerateMipmap(GrGLenum target) {}
164 
nullGLBufferData(GrGLenum target,GrGLsizeiptr size,const GrGLvoid * data,GrGLenum usage)165 GrGLvoid GR_GL_FUNCTION_TYPE nullGLBufferData(GrGLenum target,
166                                               GrGLsizeiptr size,
167                                               const GrGLvoid* data,
168                                               GrGLenum usage) {
169     State* state = State::Get();
170     GrGLuint id = 0;
171 
172     switch (target) {
173     case GR_GL_ARRAY_BUFFER:
174         id = state->fCurrArrayBuffer;
175         break;
176     case GR_GL_ELEMENT_ARRAY_BUFFER:
177         id = state->fCurrElementArrayBuffer;
178         break;
179     case GR_GL_PIXEL_PACK_BUFFER:
180         id = state->fCurrPixelPackBuffer;
181         break;
182     case GR_GL_PIXEL_UNPACK_BUFFER:
183         id = state->fCurrPixelUnpackBuffer;
184         break;
185     default:
186         SkFAIL("Unexpected target to nullGLBufferData");
187         break;
188     }
189 
190     if (id > 0) {
191         BufferObj* buffer = state->fBufferManager.lookUp(id);
192         buffer->allocate(size, (const GrGLchar*) data);
193     }
194 }
195 
nullGLPixelStorei(GrGLenum pname,GrGLint param)196 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)197 GrGLvoid GR_GL_FUNCTION_TYPE nullGLReadPixels(GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height, GrGLenum format, GrGLenum type, GrGLvoid* pixels) {}
nullGLUseProgram(GrGLuint program)198 GrGLvoid GR_GL_FUNCTION_TYPE nullGLUseProgram(GrGLuint program) {}
nullGLViewport(GrGLint x,GrGLint y,GrGLsizei width,GrGLsizei height)199 GrGLvoid GR_GL_FUNCTION_TYPE nullGLViewport(GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height) {}
nullGLBindFramebuffer(GrGLenum target,GrGLuint framebuffer)200 GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindFramebuffer(GrGLenum target, GrGLuint framebuffer) {}
nullGLBindRenderbuffer(GrGLenum target,GrGLuint renderbuffer)201 GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindRenderbuffer(GrGLenum target, GrGLuint renderbuffer) {}
nullGLDeleteFramebuffers(GrGLsizei n,const GrGLuint * framebuffers)202 GrGLvoid GR_GL_FUNCTION_TYPE nullGLDeleteFramebuffers(GrGLsizei n, const GrGLuint *framebuffers) {}
nullGLDeleteRenderbuffers(GrGLsizei n,const GrGLuint * renderbuffers)203 GrGLvoid GR_GL_FUNCTION_TYPE nullGLDeleteRenderbuffers(GrGLsizei n, const GrGLuint *renderbuffers) {}
nullGLFramebufferRenderbuffer(GrGLenum target,GrGLenum attachment,GrGLenum renderbuffertarget,GrGLuint renderbuffer)204 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)205 GrGLvoid GR_GL_FUNCTION_TYPE nullGLFramebufferTexture2D(GrGLenum target, GrGLenum attachment, GrGLenum textarget, GrGLuint texture, GrGLint level) {}
206 
nullGLCreateProgram()207 GrGLuint GR_GL_FUNCTION_TYPE nullGLCreateProgram() {
208     return ++State::Get()->fCurrProgramID;
209 }
210 
nullGLCreateShader(GrGLenum type)211 GrGLuint GR_GL_FUNCTION_TYPE nullGLCreateShader(GrGLenum type) {
212     return ++State::Get()->fCurrShaderID;
213 }
214 
215 // same delete used for shaders and programs
nullGLDelete(GrGLuint program)216 GrGLvoid GR_GL_FUNCTION_TYPE nullGLDelete(GrGLuint program) {
217 }
218 
nullGLBindBuffer(GrGLenum target,GrGLuint buffer)219 GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindBuffer(GrGLenum target, GrGLuint buffer) {
220     State* state = State::Get();
221     switch (target) {
222     case GR_GL_ARRAY_BUFFER:
223         state->fCurrArrayBuffer = buffer;
224         break;
225     case GR_GL_ELEMENT_ARRAY_BUFFER:
226         state->fCurrElementArrayBuffer = buffer;
227         break;
228     case GR_GL_PIXEL_PACK_BUFFER:
229         state->fCurrPixelPackBuffer = buffer;
230         break;
231     case GR_GL_PIXEL_UNPACK_BUFFER:
232         state->fCurrPixelUnpackBuffer = buffer;
233         break;
234     }
235 }
236 
237 // deleting a bound buffer has the side effect of binding 0
nullGLDeleteBuffers(GrGLsizei n,const GrGLuint * ids)238 GrGLvoid GR_GL_FUNCTION_TYPE nullGLDeleteBuffers(GrGLsizei n, const GrGLuint* ids) {
239     State* state = State::Get();
240     for (int i = 0; i < n; ++i) {
241         if (ids[i] == state->fCurrArrayBuffer) {
242             state->fCurrArrayBuffer = 0;
243         }
244         if (ids[i] == state->fCurrElementArrayBuffer) {
245             state->fCurrElementArrayBuffer = 0;
246         }
247         if (ids[i] == state->fCurrPixelPackBuffer) {
248             state->fCurrPixelPackBuffer = 0;
249         }
250         if (ids[i] == state->fCurrPixelUnpackBuffer) {
251             state->fCurrPixelUnpackBuffer = 0;
252         }
253 
254         BufferObj* buffer = state->fBufferManager.lookUp(ids[i]);
255         state->fBufferManager.free(buffer);
256     }
257 }
258 
nullGLMapBufferRange(GrGLenum target,GrGLintptr offset,GrGLsizeiptr length,GrGLbitfield access)259 GrGLvoid* GR_GL_FUNCTION_TYPE nullGLMapBufferRange(GrGLenum target, GrGLintptr offset,
260                                                    GrGLsizeiptr length, GrGLbitfield 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         case GR_GL_PIXEL_PACK_BUFFER:
271             id = state->fCurrPixelPackBuffer;
272             break;
273         case GR_GL_PIXEL_UNPACK_BUFFER:
274             id = state->fCurrPixelUnpackBuffer;
275             break;
276     }
277 
278     if (id > 0) {
279         // We just ignore the offset and length here.
280         BufferObj* buffer = state->fBufferManager.lookUp(id);
281         SkASSERT(!buffer->mapped());
282         buffer->setMapped(true);
283         return buffer->dataPtr();
284     }
285     return nullptr;
286 }
287 
nullGLMapBuffer(GrGLenum target,GrGLenum access)288 GrGLvoid* GR_GL_FUNCTION_TYPE nullGLMapBuffer(GrGLenum target, GrGLenum access) {
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         case GR_GL_PIXEL_PACK_BUFFER:
299             id = state->fCurrPixelPackBuffer;
300             break;
301         case GR_GL_PIXEL_UNPACK_BUFFER:
302             id = state->fCurrPixelUnpackBuffer;
303             break;
304     }
305 
306     if (id > 0) {
307         BufferObj* buffer = state->fBufferManager.lookUp(id);
308         SkASSERT(!buffer->mapped());
309         buffer->setMapped(true);
310         return buffer->dataPtr();
311     }
312 
313     SkASSERT(false);
314     return nullptr;            // no buffer bound to target
315 }
316 
nullGLFlushMappedBufferRange(GrGLenum target,GrGLintptr offset,GrGLsizeiptr length)317 GrGLvoid GR_GL_FUNCTION_TYPE nullGLFlushMappedBufferRange(GrGLenum target,
318                                                           GrGLintptr offset,
319                                                           GrGLsizeiptr length) {}
320 
321 
nullGLUnmapBuffer(GrGLenum target)322 GrGLboolean GR_GL_FUNCTION_TYPE nullGLUnmapBuffer(GrGLenum target) {
323     State* state = State::Get();
324     GrGLuint id = 0;
325     switch (target) {
326     case GR_GL_ARRAY_BUFFER:
327         id = state->fCurrArrayBuffer;
328         break;
329     case GR_GL_ELEMENT_ARRAY_BUFFER:
330         id = state->fCurrElementArrayBuffer;
331         break;
332     case GR_GL_PIXEL_PACK_BUFFER:
333         id = state->fCurrPixelPackBuffer;
334         break;
335     case GR_GL_PIXEL_UNPACK_BUFFER:
336         id = state->fCurrPixelUnpackBuffer;
337         break;
338     }
339     if (id > 0) {
340         BufferObj* buffer = state->fBufferManager.lookUp(id);
341         SkASSERT(buffer->mapped());
342         buffer->setMapped(false);
343         return GR_GL_TRUE;
344     }
345 
346     GrAlwaysAssert(false);
347     return GR_GL_FALSE; // GR_GL_INVALID_OPERATION;
348 }
349 
nullGLGetBufferParameteriv(GrGLenum target,GrGLenum pname,GrGLint * params)350 GrGLvoid GR_GL_FUNCTION_TYPE nullGLGetBufferParameteriv(GrGLenum target, GrGLenum pname, GrGLint* params) {
351     State* state = State::Get();
352     switch (pname) {
353         case GR_GL_BUFFER_MAPPED: {
354             *params = GR_GL_FALSE;
355             GrGLuint id = 0;
356             switch (target) {
357                 case GR_GL_ARRAY_BUFFER:
358                     id = state->fCurrArrayBuffer;
359                     break;
360                 case GR_GL_ELEMENT_ARRAY_BUFFER:
361                     id = state->fCurrElementArrayBuffer;
362                     break;
363                 case GR_GL_PIXEL_PACK_BUFFER:
364                     id = state->fCurrPixelPackBuffer;
365                     break;
366                 case GR_GL_PIXEL_UNPACK_BUFFER:
367                     id = state->fCurrPixelUnpackBuffer;
368                     break;
369             }
370             if (id > 0) {
371                 BufferObj* buffer = state->fBufferManager.lookUp(id);
372                 if (buffer->mapped()) {
373                     *params = GR_GL_TRUE;
374                 }
375             }
376             break; }
377         default:
378             SkFAIL("Unexpected pname to GetBufferParamateriv");
379             break;
380     }
381 };
382 
383 class NullInterface : public GrGLInterface {
384 public:
NullInterface(State * state)385     NullInterface(State* state) : fState(SkRef(state)) {}
~NullInterface()386     ~NullInterface() override {
387         fState->unref();
388     }
389     State* fState;
390 };
391 
392 } // end anonymous namespace
393 
create_null_interface(State * state)394 static GrGLInterface* create_null_interface(State* state) {
395     GrGLInterface* interface = new NullInterface(state);
396 
397     interface->fStandard = kGL_GrGLStandard;
398 
399     GrGLInterface::Functions* functions = &interface->fFunctions;
400     functions->fActiveTexture = nullGLActiveTexture;
401     functions->fAttachShader = nullGLAttachShader;
402     functions->fBeginQuery = nullGLBeginQuery;
403     functions->fBindAttribLocation = nullGLBindAttribLocation;
404     functions->fBindBuffer = nullGLBindBuffer;
405     functions->fBindFragDataLocation = noOpGLBindFragDataLocation;
406     functions->fBindTexture = nullGLBindTexture;
407     functions->fBindVertexArray = nullGLBindVertexArray;
408     functions->fBlendColor = noOpGLBlendColor;
409     functions->fBlendEquation = noOpGLBlendEquation;
410     functions->fBlendFunc = noOpGLBlendFunc;
411     functions->fBufferData = nullGLBufferData;
412     functions->fBufferSubData = noOpGLBufferSubData;
413     functions->fClear = noOpGLClear;
414     functions->fClearColor = noOpGLClearColor;
415     functions->fClearStencil = noOpGLClearStencil;
416     functions->fColorMask = noOpGLColorMask;
417     functions->fCompileShader = noOpGLCompileShader;
418     functions->fCompressedTexImage2D = noOpGLCompressedTexImage2D;
419     functions->fCompressedTexSubImage2D = noOpGLCompressedTexSubImage2D;
420     functions->fCopyTexSubImage2D = noOpGLCopyTexSubImage2D;
421     functions->fCreateProgram = nullGLCreateProgram;
422     functions->fCreateShader = nullGLCreateShader;
423     functions->fCullFace = noOpGLCullFace;
424     functions->fDeleteBuffers = nullGLDeleteBuffers;
425     functions->fDeleteProgram = nullGLDelete;
426     functions->fDeleteQueries = noOpGLDeleteIds;
427     functions->fDeleteShader = nullGLDelete;
428     functions->fDeleteTextures = noOpGLDeleteIds;
429     functions->fDeleteVertexArrays = noOpGLDeleteIds;
430     functions->fDepthMask = noOpGLDepthMask;
431     functions->fDisable = noOpGLDisable;
432     functions->fDisableVertexAttribArray = noOpGLDisableVertexAttribArray;
433     functions->fDrawArrays = noOpGLDrawArrays;
434     functions->fDrawArraysInstanced = noOpGLDrawArraysInstanced;
435     functions->fDrawBuffer = noOpGLDrawBuffer;
436     functions->fDrawBuffers = noOpGLDrawBuffers;
437     functions->fDrawElements = noOpGLDrawElements;
438     functions->fDrawElementsInstanced = noOpGLDrawElementsInstanced;
439     functions->fEnable = noOpGLEnable;
440     functions->fEnableVertexAttribArray = noOpGLEnableVertexAttribArray;
441     functions->fEndQuery = noOpGLEndQuery;
442     functions->fFinish = noOpGLFinish;
443     functions->fFlush = noOpGLFlush;
444     functions->fFlushMappedBufferRange = nullGLFlushMappedBufferRange;
445     functions->fFrontFace = noOpGLFrontFace;
446     functions->fGenBuffers = nullGLGenBuffers;
447     functions->fGenerateMipmap = nullGLGenerateMipmap;
448     functions->fGenQueries = noOpGLGenIds;
449     functions->fGenTextures = noOpGLGenIds;
450     functions->fGenVertexArrays = noOpGLGenIds;
451     functions->fGetBufferParameteriv = nullGLGetBufferParameteriv;
452     functions->fGetError = noOpGLGetError;
453     functions->fGetIntegerv = noOpGLGetIntegerv;
454     functions->fGetQueryObjecti64v = noOpGLGetQueryObjecti64v;
455     functions->fGetQueryObjectiv = noOpGLGetQueryObjectiv;
456     functions->fGetQueryObjectui64v = noOpGLGetQueryObjectui64v;
457     functions->fGetQueryObjectuiv = noOpGLGetQueryObjectuiv;
458     functions->fGetQueryiv = noOpGLGetQueryiv;
459     functions->fGetProgramInfoLog = noOpGLGetInfoLog;
460     functions->fGetProgramiv = noOpGLGetShaderOrProgramiv;
461     functions->fGetShaderInfoLog = noOpGLGetInfoLog;
462     functions->fGetShaderiv = noOpGLGetShaderOrProgramiv;
463     functions->fGetString = noOpGLGetString;
464     functions->fGetStringi = noOpGLGetStringi;
465     functions->fGetTexLevelParameteriv = noOpGLGetTexLevelParameteriv;
466     functions->fGetUniformLocation = noOpGLGetUniformLocation;
467     functions->fInsertEventMarker = noOpGLInsertEventMarker;
468     functions->fLineWidth = noOpGLLineWidth;
469     functions->fLinkProgram = noOpGLLinkProgram;
470     functions->fMapBuffer = nullGLMapBuffer;
471     functions->fMapBufferRange = nullGLMapBufferRange;
472     functions->fPixelStorei = nullGLPixelStorei;
473     functions->fPopGroupMarker = noOpGLPopGroupMarker;
474     functions->fPushGroupMarker = noOpGLPushGroupMarker;
475     functions->fQueryCounter = noOpGLQueryCounter;
476     functions->fReadBuffer = noOpGLReadBuffer;
477     functions->fReadPixels = nullGLReadPixels;
478     functions->fScissor = noOpGLScissor;
479     functions->fShaderSource = noOpGLShaderSource;
480     functions->fStencilFunc = noOpGLStencilFunc;
481     functions->fStencilFuncSeparate = noOpGLStencilFuncSeparate;
482     functions->fStencilMask = noOpGLStencilMask;
483     functions->fStencilMaskSeparate = noOpGLStencilMaskSeparate;
484     functions->fStencilOp = noOpGLStencilOp;
485     functions->fStencilOpSeparate = noOpGLStencilOpSeparate;
486     functions->fTexImage2D = noOpGLTexImage2D;
487     functions->fTexParameteri = noOpGLTexParameteri;
488     functions->fTexParameteriv = noOpGLTexParameteriv;
489     functions->fTexSubImage2D = noOpGLTexSubImage2D;
490     functions->fTexStorage2D = noOpGLTexStorage2D;
491     functions->fDiscardFramebuffer = noOpGLDiscardFramebuffer;
492     functions->fUniform1f = noOpGLUniform1f;
493     functions->fUniform1i = noOpGLUniform1i;
494     functions->fUniform1fv = noOpGLUniform1fv;
495     functions->fUniform1iv = noOpGLUniform1iv;
496     functions->fUniform2f = noOpGLUniform2f;
497     functions->fUniform2i = noOpGLUniform2i;
498     functions->fUniform2fv = noOpGLUniform2fv;
499     functions->fUniform2iv = noOpGLUniform2iv;
500     functions->fUniform3f = noOpGLUniform3f;
501     functions->fUniform3i = noOpGLUniform3i;
502     functions->fUniform3fv = noOpGLUniform3fv;
503     functions->fUniform3iv = noOpGLUniform3iv;
504     functions->fUniform4f = noOpGLUniform4f;
505     functions->fUniform4i = noOpGLUniform4i;
506     functions->fUniform4fv = noOpGLUniform4fv;
507     functions->fUniform4iv = noOpGLUniform4iv;
508     functions->fUniformMatrix2fv = noOpGLUniformMatrix2fv;
509     functions->fUniformMatrix3fv = noOpGLUniformMatrix3fv;
510     functions->fUniformMatrix4fv = noOpGLUniformMatrix4fv;
511     functions->fUnmapBuffer = nullGLUnmapBuffer;
512     functions->fUseProgram = nullGLUseProgram;
513     functions->fVertexAttrib1f = noOpGLVertexAttrib1f;
514     functions->fVertexAttrib2fv = noOpGLVertexAttrib2fv;
515     functions->fVertexAttrib3fv = noOpGLVertexAttrib3fv;
516     functions->fVertexAttrib4fv = noOpGLVertexAttrib4fv;
517     functions->fVertexAttribDivisor = noOpGLVertexAttribDivisor;
518     functions->fVertexAttribIPointer = noOpGLVertexAttribIPointer;
519     functions->fVertexAttribPointer = noOpGLVertexAttribPointer;
520     functions->fViewport = nullGLViewport;
521     functions->fBindFramebuffer = nullGLBindFramebuffer;
522     functions->fBindRenderbuffer = nullGLBindRenderbuffer;
523     functions->fCheckFramebufferStatus = noOpGLCheckFramebufferStatus;
524     functions->fDeleteFramebuffers = nullGLDeleteFramebuffers;
525     functions->fDeleteRenderbuffers = nullGLDeleteRenderbuffers;
526     functions->fFramebufferRenderbuffer = nullGLFramebufferRenderbuffer;
527     functions->fFramebufferTexture2D = nullGLFramebufferTexture2D;
528     functions->fGenFramebuffers = noOpGLGenIds;
529     functions->fGenRenderbuffers = noOpGLGenIds;
530     functions->fGetFramebufferAttachmentParameteriv = noOpGLGetFramebufferAttachmentParameteriv;
531     functions->fGetRenderbufferParameteriv = noOpGLGetRenderbufferParameteriv;
532     functions->fRenderbufferStorage = noOpGLRenderbufferStorage;
533     functions->fRenderbufferStorageMultisample = noOpGLRenderbufferStorageMultisample;
534     functions->fBlitFramebuffer = noOpGLBlitFramebuffer;
535     functions->fResolveMultisampleFramebuffer = noOpGLResolveMultisampleFramebuffer;
536     functions->fMatrixLoadf = noOpGLMatrixLoadf;
537     functions->fMatrixLoadIdentity = noOpGLMatrixLoadIdentity;
538     functions->fBindFragDataLocationIndexed = noOpGLBindFragDataLocationIndexed;
539 
540     interface->fExtensions.init(kGL_GrGLStandard, functions->fGetString, functions->fGetStringi,
541                                 functions->fGetIntegerv, nullptr, GR_EGL_NO_DISPLAY);
542     return interface;
543 }
544 
545 //////////////////////////////////////////////////////////////////////////////
546 
create_tls()547 static void* create_tls() {
548     State** current = new State*;
549     *current = nullptr;
550     return current;
551 }
552 
delete_tls(void * ctx)553 static void delete_tls(void* ctx) {
554     State** current = static_cast<State**>(ctx);
555     if (*current) {
556         (*current)->unref();
557     }
558     delete current;
559 }
560 
current_context()561 static State* current_context() {
562     return *static_cast<State**>(SkTLS::Get(create_tls, delete_tls));
563 }
564 
set_current_context(State * state)565 static void set_current_context(State* state) {
566     State** current = static_cast<State**>(SkTLS::Get(create_tls, delete_tls));
567     if (*current) {
568         (*current)->unref();
569     }
570     *current = state;
571     if (state) {
572         state->ref();
573     }
574 }
575 
576 #if GR_GL_PER_GL_FUNC_CALLBACK
set_current_context_from_interface(const GrGLInterface * interface)577 static void set_current_context_from_interface(const GrGLInterface* interface) {
578     set_current_context(reinterpret_cast<State*>(interface->fCallbackData));
579 }
580 #endif
581 
Create()582 SkNullGLContext* SkNullGLContext::Create() {
583     SkNullGLContext* ctx = new SkNullGLContext;
584     if (!ctx->isValid()) {
585         delete ctx;
586         return nullptr;
587     }
588     return ctx;
589 }
590 
SkNullGLContext()591 SkNullGLContext::SkNullGLContext() {
592     fState = new ContextState;
593     GrGLInterface* interface = create_null_interface(fState);
594     this->init(interface);
595 #if GR_GL_PER_GL_FUNC_CALLBACK
596     interface->fCallback = set_current_context_from_interface;
597     interface->fCallbackData = reinterpret_cast<GrGLInterfaceCallbackData>(fState);
598 #endif
599 }
600 
~SkNullGLContext()601 SkNullGLContext::~SkNullGLContext() {
602     this->teardown();
603     fState->unref();
604 }
605 
onPlatformMakeCurrent() const606 void SkNullGLContext::onPlatformMakeCurrent() const { set_current_context(fState); }
607