GrGLCreateNullInterface.cpp revision e788430144d1474329878abd1ddb39cc0ca52a0a 
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#include "gl/GrGLInterface.h"
11#include "../GrTDArray.h"
12
13GrGLvoid GR_GL_FUNCTION_TYPE nullGLActiveTexture(GrGLenum texture) {}
14GrGLvoid GR_GL_FUNCTION_TYPE nullGLAttachShader(GrGLuint program, GrGLuint shader) {}
15GrGLvoid GR_GL_FUNCTION_TYPE nullGLBeginQuery(GrGLenum target, GrGLuint id) {}
16GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindAttribLocation(GrGLuint program, GrGLuint index, const char* name) {}
17GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindTexture(GrGLenum target, GrGLuint texture) {}
18GrGLvoid GR_GL_FUNCTION_TYPE nullGLBlendColor(GrGLclampf red, GrGLclampf green, GrGLclampf blue, GrGLclampf alpha) {}
19GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindFragDataLocation(GrGLuint program, GrGLuint colorNumber, const GrGLchar* name) {}
20GrGLvoid GR_GL_FUNCTION_TYPE nullGLBlendFunc(GrGLenum sfactor, GrGLenum dfactor) {}
21GrGLvoid GR_GL_FUNCTION_TYPE nullGLBlendEquation(GrGLenum mode) {}
22GrGLvoid GR_GL_FUNCTION_TYPE nullGLBufferData(GrGLenum target, GrGLsizeiptr size, const GrGLvoid* data, GrGLenum usage) {}
23GrGLvoid GR_GL_FUNCTION_TYPE nullGLBufferSubData(GrGLenum target, GrGLintptr offset, GrGLsizeiptr size, const GrGLvoid* data) {}
24GrGLvoid GR_GL_FUNCTION_TYPE nullGLClear(GrGLbitfield mask) {}
25GrGLvoid GR_GL_FUNCTION_TYPE nullGLClearColor(GrGLclampf red, GrGLclampf green, GrGLclampf blue, GrGLclampf alpha) {}
26GrGLvoid GR_GL_FUNCTION_TYPE nullGLClearStencil(GrGLint s) {}
27GrGLvoid GR_GL_FUNCTION_TYPE nullGLColorMask(GrGLboolean red, GrGLboolean green, GrGLboolean blue, GrGLboolean alpha) {}
28GrGLvoid GR_GL_FUNCTION_TYPE nullGLCompileShader(GrGLuint shader) {}
29GrGLvoid GR_GL_FUNCTION_TYPE nullGLCompressedTexImage2D(GrGLenum target, GrGLint level, GrGLenum internalformat, GrGLsizei width, GrGLsizei height, GrGLint border, GrGLsizei imageSize, const GrGLvoid* data) {}
30GrGLvoid GR_GL_FUNCTION_TYPE nullGLCullFace(GrGLenum mode) {}
31GrGLvoid GR_GL_FUNCTION_TYPE nullGLDepthMask(GrGLboolean flag) {}
32GrGLvoid GR_GL_FUNCTION_TYPE nullGLDisable(GrGLenum cap) {}
33GrGLvoid GR_GL_FUNCTION_TYPE nullGLDisableVertexAttribArray(GrGLuint index) {}
34GrGLvoid GR_GL_FUNCTION_TYPE nullGLDrawArrays(GrGLenum mode, GrGLint first, GrGLsizei count) {}
35GrGLvoid GR_GL_FUNCTION_TYPE nullGLDrawBuffer(GrGLenum mode) {}
36GrGLvoid GR_GL_FUNCTION_TYPE nullGLDrawBuffers(GrGLsizei n, const GrGLenum* bufs) {}
37GrGLvoid GR_GL_FUNCTION_TYPE nullGLDrawElements(GrGLenum mode, GrGLsizei count, GrGLenum type, const GrGLvoid* indices) {}
38GrGLvoid GR_GL_FUNCTION_TYPE nullGLEnable(GrGLenum cap) {}
39GrGLvoid GR_GL_FUNCTION_TYPE nullGLEnableVertexAttribArray(GrGLuint index) {}
40GrGLvoid GR_GL_FUNCTION_TYPE nullGLEndQuery(GrGLenum target) {}
41GrGLvoid GR_GL_FUNCTION_TYPE nullGLFinish() {}
42GrGLvoid GR_GL_FUNCTION_TYPE nullGLFlush() {}
43GrGLvoid GR_GL_FUNCTION_TYPE nullGLFrontFace(GrGLenum mode) {}
44GrGLvoid GR_GL_FUNCTION_TYPE nullGLLineWidth(GrGLfloat width) {}
45GrGLvoid GR_GL_FUNCTION_TYPE nullGLLinkProgram(GrGLuint program) {}
46GrGLvoid GR_GL_FUNCTION_TYPE nullGLPixelStorei(GrGLenum pname, GrGLint param) {}
47GrGLvoid GR_GL_FUNCTION_TYPE nullGLQueryCounter(GrGLuint id, GrGLenum target) {}
48GrGLvoid GR_GL_FUNCTION_TYPE nullGLReadBuffer(GrGLenum src) {}
49GrGLvoid GR_GL_FUNCTION_TYPE nullGLReadPixels(GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height, GrGLenum format, GrGLenum type, GrGLvoid* pixels) {}
50GrGLvoid GR_GL_FUNCTION_TYPE nullGLScissor(GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height) {}
51GrGLvoid GR_GL_FUNCTION_TYPE nullGLShaderSource(GrGLuint shader, GrGLsizei count, const char** str, const GrGLint* length) {}
52GrGLvoid GR_GL_FUNCTION_TYPE nullGLStencilFunc(GrGLenum func, GrGLint ref, GrGLuint mask) {}
53GrGLvoid GR_GL_FUNCTION_TYPE nullGLStencilFuncSeparate(GrGLenum face, GrGLenum func, GrGLint ref, GrGLuint mask) {}
54GrGLvoid GR_GL_FUNCTION_TYPE nullGLStencilMask(GrGLuint mask) {}
55GrGLvoid GR_GL_FUNCTION_TYPE nullGLStencilMaskSeparate(GrGLenum face, GrGLuint mask) {}
56GrGLvoid GR_GL_FUNCTION_TYPE nullGLStencilOp(GrGLenum fail, GrGLenum zfail, GrGLenum zpass) {}
57GrGLvoid GR_GL_FUNCTION_TYPE nullGLStencilOpSeparate(GrGLenum face, GrGLenum fail, GrGLenum zfail, GrGLenum zpass) {}
58GrGLvoid GR_GL_FUNCTION_TYPE nullGLTexImage2D(GrGLenum target, GrGLint level, GrGLint internalformat, GrGLsizei width, GrGLsizei height, GrGLint border, GrGLenum format, GrGLenum type, const GrGLvoid* pixels) {}
59GrGLvoid GR_GL_FUNCTION_TYPE nullGLTexParameteri(GrGLenum target, GrGLenum pname, GrGLint param) {}
60GrGLvoid GR_GL_FUNCTION_TYPE nullGLTexStorage2D(GrGLenum target, GrGLsizei levels, GrGLenum internalformat, GrGLsizei width, GrGLsizei height) {}
61GrGLvoid GR_GL_FUNCTION_TYPE nullGLTexSubImage2D(GrGLenum target, GrGLint level, GrGLint xoffset, GrGLint yoffset, GrGLsizei width, GrGLsizei height, GrGLenum format, GrGLenum type, const GrGLvoid* pixels) {}
62GrGLvoid GR_GL_FUNCTION_TYPE nullGLUniform1f(GrGLint location, GrGLfloat v0) {}
63GrGLvoid GR_GL_FUNCTION_TYPE nullGLUniform1i(GrGLint location, GrGLint v0) {}
64GrGLvoid GR_GL_FUNCTION_TYPE nullGLUniform1fv(GrGLint location, GrGLsizei count, const GrGLfloat* v) {}
65GrGLvoid GR_GL_FUNCTION_TYPE nullGLUniform1iv(GrGLint location, GrGLsizei count, const GrGLint* v) {}
66GrGLvoid GR_GL_FUNCTION_TYPE nullGLUniform2f(GrGLint location, GrGLfloat v0, GrGLfloat v1) {}
67GrGLvoid GR_GL_FUNCTION_TYPE nullGLUniform2i(GrGLint location, GrGLint v0, GrGLint v1) {}
68GrGLvoid GR_GL_FUNCTION_TYPE nullGLUniform2fv(GrGLint location, GrGLsizei count, const GrGLfloat* v) {}
69GrGLvoid GR_GL_FUNCTION_TYPE nullGLUniform2iv(GrGLint location, GrGLsizei count, const GrGLint* v) {}
70GrGLvoid GR_GL_FUNCTION_TYPE nullGLUniform3f(GrGLint location, GrGLfloat v0, GrGLfloat v1, GrGLfloat v2) {}
71GrGLvoid GR_GL_FUNCTION_TYPE nullGLUniform3i(GrGLint location, GrGLint v0, GrGLint v1, GrGLint v2) {}
72GrGLvoid GR_GL_FUNCTION_TYPE nullGLUniform3fv(GrGLint location, GrGLsizei count, const GrGLfloat* v) {}
73GrGLvoid GR_GL_FUNCTION_TYPE nullGLUniform3iv(GrGLint location, GrGLsizei count, const GrGLint* v) {}
74GrGLvoid GR_GL_FUNCTION_TYPE nullGLUniform4f(GrGLint location, GrGLfloat v0, GrGLfloat v1, GrGLfloat v2, GrGLfloat v3) {}
75GrGLvoid GR_GL_FUNCTION_TYPE nullGLUniform4i(GrGLint location, GrGLint v0, GrGLint v1, GrGLint v2, GrGLint v3) {}
76GrGLvoid GR_GL_FUNCTION_TYPE nullGLUniform4fv(GrGLint location, GrGLsizei count, const GrGLfloat* v) {}
77GrGLvoid GR_GL_FUNCTION_TYPE nullGLUniform4iv(GrGLint location, GrGLsizei count, const GrGLint* v) {}
78GrGLvoid GR_GL_FUNCTION_TYPE nullGLUniformMatrix2fv(GrGLint location, GrGLsizei count, GrGLboolean transpose, const GrGLfloat* value) {}
79GrGLvoid GR_GL_FUNCTION_TYPE nullGLUniformMatrix3fv(GrGLint location, GrGLsizei count, GrGLboolean transpose, const GrGLfloat* value) {}
80GrGLvoid GR_GL_FUNCTION_TYPE nullGLUniformMatrix4fv(GrGLint location, GrGLsizei count, GrGLboolean transpose, const GrGLfloat* value) {}
81GrGLvoid GR_GL_FUNCTION_TYPE nullGLUseProgram(GrGLuint program) {}
82GrGLvoid GR_GL_FUNCTION_TYPE nullGLVertexAttrib4fv(GrGLuint indx, const GrGLfloat* values) {}
83GrGLvoid GR_GL_FUNCTION_TYPE nullGLVertexAttribPointer(GrGLuint indx, GrGLint size, GrGLenum type, GrGLboolean normalized, GrGLsizei stride, const GrGLvoid* ptr) {}
84GrGLvoid GR_GL_FUNCTION_TYPE nullGLViewport(GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height) {}
85GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindFramebuffer(GrGLenum target, GrGLuint framebuffer) {}
86GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindRenderbuffer(GrGLenum target, GrGLuint renderbuffer) {}
87GrGLvoid GR_GL_FUNCTION_TYPE nullGLDeleteFramebuffers(GrGLsizei n, const GrGLuint *framebuffers) {}
88GrGLvoid GR_GL_FUNCTION_TYPE nullGLDeleteRenderbuffers(GrGLsizei n, const GrGLuint *renderbuffers) {}
89GrGLvoid GR_GL_FUNCTION_TYPE nullGLFramebufferRenderbuffer(GrGLenum target, GrGLenum attachment, GrGLenum renderbuffertarget, GrGLuint renderbuffer) {}
90GrGLvoid GR_GL_FUNCTION_TYPE nullGLFramebufferTexture2D(GrGLenum target, GrGLenum attachment, GrGLenum textarget, GrGLuint texture, GrGLint level) {}
91GrGLvoid GR_GL_FUNCTION_TYPE nullGLGetFramebufferAttachmentParameteriv(GrGLenum target, GrGLenum attachment, GrGLenum pname, GrGLint* params) {}
92GrGLvoid GR_GL_FUNCTION_TYPE nullGLGetRenderbufferParameteriv(GrGLenum target, GrGLenum pname, GrGLint* params) {}
93GrGLvoid GR_GL_FUNCTION_TYPE nullGLRenderbufferStorage(GrGLenum target, GrGLenum internalformat, GrGLsizei width, GrGLsizei height) {}
94GrGLvoid GR_GL_FUNCTION_TYPE nullGLRenderbufferStorageMultisample(GrGLenum target, GrGLsizei samples, GrGLenum internalformat, GrGLsizei width, GrGLsizei height) {}
95GrGLvoid GR_GL_FUNCTION_TYPE nullGLBlitFramebuffer(GrGLint srcX0, GrGLint srcY0, GrGLint srcX1, GrGLint srcY1, GrGLint dstX0, GrGLint dstY0, GrGLint dstX1, GrGLint dstY1, GrGLbitfield mask, GrGLenum filter) {}
96GrGLvoid GR_GL_FUNCTION_TYPE nullGLResolveMultisampleFramebuffer() {}
97GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindFragDataLocationIndexed(GrGLuint program, GrGLuint colorNumber, GrGLuint index, const GrGLchar * name) {}
98
99GrGLenum GR_GL_FUNCTION_TYPE nullGLCheckFramebufferStatus(GrGLenum target) {
100    return GR_GL_FRAMEBUFFER_COMPLETE;
101}
102
103GrGLuint GR_GL_FUNCTION_TYPE nullGLCreateProgram() {
104    static int gCurrID = 0;
105    return ++gCurrID;
106}
107
108GrGLuint GR_GL_FUNCTION_TYPE nullGLCreateShader(GrGLenum type) {
109    static int gCurrID = 0;
110    return ++gCurrID;
111}
112
113// same delete used for shaders and programs
114GrGLvoid GR_GL_FUNCTION_TYPE nullGLDelete(GrGLuint program) {
115}
116
117// same function used for all glGen*(GLsize i, GLuint*) functions
118GrGLvoid GR_GL_FUNCTION_TYPE nullGLGenIds(GrGLsizei n, GrGLuint* ids) {
119    static int gCurrID = 0;
120    for (int i = 0; i < n; ++i) {
121        ids[i] = ++gCurrID;
122    }
123}
124// same delete function for all glDelete*(GLsize i, const GLuint*) except buffers
125GrGLvoid GR_GL_FUNCTION_TYPE nullGLDeleteIds(GrGLsizei n, const GrGLuint* ids) {}
126
127// In debug builds we do asserts that ensure we agree with GL about when a buffer
128// is mapped.
129static GrTDArray<GrGLuint> gMappedBuffers;
130static GrGLuint gCurrArrayBuffer;
131static GrGLuint gCurrElementArrayBuffer;
132
133GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindBuffer(GrGLenum target, GrGLuint buffer) {
134    switch (target) {
135    case GR_GL_ARRAY_BUFFER:
136        gCurrArrayBuffer = buffer;
137        break;
138    case GR_GL_ELEMENT_ARRAY_BUFFER:
139        gCurrElementArrayBuffer = buffer;
140        break;
141    }
142}
143
144// deleting a bound buffer has the side effect of binding 0
145GrGLvoid GR_GL_FUNCTION_TYPE nullGLDeleteBuffers(GrGLsizei n, const GrGLuint* ids) {
146    for (int i = 0; i < n; ++i) {
147        if (ids[i] == gCurrArrayBuffer) {
148            gCurrArrayBuffer = 0;
149        }
150        if (ids[i] == gCurrElementArrayBuffer) {
151            gCurrElementArrayBuffer = 0;
152        }
153        for (int j = 0; j < gMappedBuffers.count(); ++j) {
154            if (gMappedBuffers[j] == ids[i]) {
155                gMappedBuffers.remove(j);
156                // don't break b/c we didn't check for dupes on insert
157                --j;
158            }
159        }
160    }
161}
162
163GrGLvoid* GR_GL_FUNCTION_TYPE nullGLMapBuffer(GrGLenum target, GrGLenum access) {
164    // We just reserve 32MB of RAM for all locks and hope its big enough
165    static SkAutoMalloc gBufferData(32 * (1 << 20));
166    GrGLuint buf = 0;
167    switch (target) {
168        case GR_GL_ARRAY_BUFFER:
169            buf = gCurrArrayBuffer;
170            break;
171        case GR_GL_ELEMENT_ARRAY_BUFFER:
172            buf = gCurrElementArrayBuffer;
173            break;
174    }
175    if (buf) {
176        *gMappedBuffers.append() = buf;
177    }
178    return gBufferData.get();
179}
180
181GrGLboolean GR_GL_FUNCTION_TYPE nullGLUnmapBuffer(GrGLenum target) {
182    GrGLuint buf = 0;
183    switch (target) {
184    case GR_GL_ARRAY_BUFFER:
185        buf = gCurrArrayBuffer;
186        break;
187    case GR_GL_ELEMENT_ARRAY_BUFFER:
188        buf = gCurrElementArrayBuffer;
189        break;
190    }
191    if (buf) {
192        for (int i = 0; i < gMappedBuffers.count(); ++i) {
193            if (gMappedBuffers[i] == buf) {
194                gMappedBuffers.remove(i);
195                // don't break b/c we didn't check for dupes on insert
196                --i;
197            }
198        }
199    }
200    return GR_GL_TRUE;
201}
202
203GrGLvoid GR_GL_FUNCTION_TYPE nullGLGetBufferParameteriv(GrGLenum target, GrGLenum pname, GrGLint* params) {
204    switch (pname) {
205        case GR_GL_BUFFER_MAPPED: {
206            *params = GR_GL_FALSE;
207            GrGLuint buf = 0;
208            switch (target) {
209                case GR_GL_ARRAY_BUFFER:
210                    buf = gCurrArrayBuffer;
211                    break;
212                case GR_GL_ELEMENT_ARRAY_BUFFER:
213                    buf = gCurrElementArrayBuffer;
214                    break;
215            }
216            if (buf) {
217                for (int i = 0; i < gMappedBuffers.count(); ++i) {
218                    if (gMappedBuffers[i] == buf) {
219                        *params = GR_GL_TRUE;
220                        break;
221                    }
222                }
223            }
224            break; }
225        default:
226            GrCrash("Unexpected pname to GetBufferParamateriv");
227            break;
228    }
229};
230
231GrGLenum GR_GL_FUNCTION_TYPE nullGLGetError() {
232    return GR_GL_NO_ERROR;
233}
234
235GrGLvoid GR_GL_FUNCTION_TYPE nullGLGetIntegerv(GrGLenum pname, GrGLint* params) {
236    switch (pname) {
237        case GR_GL_STENCIL_BITS:
238            *params = 8;
239            break;
240        case GR_GL_SAMPLES:
241            *params = 1;
242            break;
243        case GR_GL_FRAMEBUFFER_BINDING:
244            *params = 0;
245            break;
246        case GR_GL_VIEWPORT:
247            params[0] = 0;
248            params[1] = 0;
249            params[2] = 800;
250            params[3] = 600;
251            break;
252        case GR_GL_MAX_TEXTURE_IMAGE_UNITS:
253            *params = 8;
254            break;
255        case GR_GL_MAX_FRAGMENT_UNIFORM_VECTORS:
256            *params = 16;
257            break;
258        case GR_GL_MAX_FRAGMENT_UNIFORM_COMPONENTS:
259            *params = 16 * 4;
260            break;
261        case GR_GL_NUM_COMPRESSED_TEXTURE_FORMATS:
262            *params = 0;
263            break;
264        case GR_GL_COMPRESSED_TEXTURE_FORMATS:
265            break;
266        case GR_GL_MAX_TEXTURE_SIZE:
267            *params = 8192;
268            break;
269        case GR_GL_MAX_RENDERBUFFER_SIZE:
270            *params = 8192;
271            break;
272        case GR_GL_MAX_SAMPLES:
273            *params = 32;
274            break;
275        case GR_GL_MAX_VERTEX_ATTRIBS:
276            *params = 16;
277            break;
278        case GR_GL_MAX_TEXTURE_UNITS:
279            *params = 8;
280            break;
281        default:
282            GrCrash("Unexpected pname to GetIntegerv");
283    }
284}
285// used for both the program and shader info logs
286GrGLvoid GR_GL_FUNCTION_TYPE nullGLGetInfoLog(GrGLuint program, GrGLsizei bufsize, GrGLsizei* length, char* infolog) {
287    if (length) {
288        *length = 0;
289    }
290    if (bufsize > 0) {
291        *infolog = 0;
292    }
293}
294
295// used for both the program and shader params
296GrGLvoid GR_GL_FUNCTION_TYPE nullGLGetShaderOrProgramiv(GrGLuint program, GrGLenum pname, GrGLint* params) {
297    switch (pname) {
298        case GR_GL_LINK_STATUS:  // fallthru
299        case GR_GL_COMPILE_STATUS:
300            *params = GR_GL_TRUE;
301            break;
302        case GR_GL_INFO_LOG_LENGTH:
303            *params = 0;
304            break;
305        // we don't expect any other pnames
306        default:
307            GrCrash("Unexpected pname to GetProgramiv");
308            break;
309    }
310}
311
312namespace {
313template <typename T>
314void query_result(GrGLenum GLtarget, GrGLenum pname, T *params) {
315    switch (pname) {
316        case GR_GL_QUERY_RESULT_AVAILABLE:
317            *params = GR_GL_TRUE;
318            break;
319        case GR_GL_QUERY_RESULT:
320            *params = 0;
321            break;
322        default:
323            GrCrash("Unexpected pname passed to GetQueryObject.");
324            break;
325    }
326}
327}
328
329// Queries on the null GL just don't do anything at all. We could potentially make
330// the timers work.
331GrGLvoid GR_GL_FUNCTION_TYPE nullGLGetQueryiv(GrGLenum GLtarget, GrGLenum pname, GrGLint *params) {
332    switch (pname) {
333        case GR_GL_CURRENT_QUERY:
334            *params = 0;
335            break;
336        case GR_GL_QUERY_COUNTER_BITS:
337            *params = 32;
338            break;
339        default:
340            GrCrash("Unexpected pname passed GetQueryiv.");
341    }
342}
343GrGLvoid GR_GL_FUNCTION_TYPE nullGLGetQueryObjecti64v(GrGLuint id, GrGLenum pname, GrGLint64 *params) {
344    query_result(id, pname, params);
345}
346GrGLvoid GR_GL_FUNCTION_TYPE nullGLGetQueryObjectiv(GrGLuint id, GrGLenum pname, GrGLint *params) {
347    query_result(id, pname, params);
348}
349GrGLvoid GR_GL_FUNCTION_TYPE nullGLGetQueryObjectui64v(GrGLuint id, GrGLenum pname, GrGLuint64 *params) {
350    query_result(id, pname, params);
351}
352GrGLvoid GR_GL_FUNCTION_TYPE nullGLGetQueryObjectuiv(GrGLuint id, GrGLenum pname, GrGLuint *params) {
353    query_result(id, pname, params);
354}
355
356const GrGLubyte* GR_GL_FUNCTION_TYPE nullGLGetString(GrGLenum name) {
357    switch (name) {
358        case GR_GL_EXTENSIONS:
359            return (const GrGLubyte*)"GL_ARB_framebuffer_object GL_ARB_blend_func_extended GL_ARB_timer_query GL_ARB_draw_buffers GL_ARB_occlusion_query GL_EXT_blend_color GL_EXT_stencil_wrap";
360        case GR_GL_VERSION:
361            return (const GrGLubyte*)"4.0 Null GL";
362        case GR_GL_SHADING_LANGUAGE_VERSION:
363            return (const GrGLubyte*)"4.20.8 Null GLSL";
364        default:
365            GrCrash("Unexpected name to GetString");
366            return NULL;
367    }
368}
369
370// we used to use this to query stuff about externally created textures, now we just
371// require clients to tell us everything about the texture.
372GrGLvoid GR_GL_FUNCTION_TYPE nullGLGetTexLevelParameteriv(GrGLenum target, GrGLint level, GrGLenum pname, GrGLint* params) {
373    GrCrash("Should never query texture parameters.");
374}
375
376GrGLint GR_GL_FUNCTION_TYPE nullGLGetUniformLocation(GrGLuint program, const char* name) {
377    static int gUniLocation = 0;
378    return ++gUniLocation;
379}
380
381const GrGLInterface* GrGLCreateNullInterface() {
382    // The gl functions are not context-specific so we create one global
383    // interface
384    static SkAutoTUnref<GrGLInterface> glInterface;
385    if (!glInterface.get()) {
386        GrGLInterface* interface = new GrGLInterface;
387        glInterface.reset(interface);
388        interface->fBindingsExported = kDesktop_GrGLBinding;
389        interface->fActiveTexture = nullGLActiveTexture;
390        interface->fAttachShader = nullGLAttachShader;
391        interface->fBeginQuery = nullGLBeginQuery;
392        interface->fBindAttribLocation = nullGLBindAttribLocation;
393        interface->fBindBuffer = nullGLBindBuffer;
394        interface->fBindFragDataLocation = nullGLBindFragDataLocation;
395        interface->fBindTexture = nullGLBindTexture;
396        interface->fBlendColor = nullGLBlendColor;
397        interface->fBlendFunc = nullGLBlendFunc;
398        interface->fBlendEquation = nullGLBlendEquation;
399        interface->fBufferData = nullGLBufferData;
400        interface->fBufferSubData = nullGLBufferSubData;
401        interface->fClear = nullGLClear;
402        interface->fClearColor = nullGLClearColor;
403        interface->fClearStencil = nullGLClearStencil;
404        interface->fColorMask = nullGLColorMask;
405        interface->fCompileShader = nullGLCompileShader;
406        interface->fCompressedTexImage2D = nullGLCompressedTexImage2D;
407        interface->fCreateProgram = nullGLCreateProgram;
408        interface->fCreateShader = nullGLCreateShader;
409        interface->fCullFace = nullGLCullFace;
410        interface->fDeleteBuffers = nullGLDeleteBuffers;
411        interface->fDeleteProgram = nullGLDelete;
412        interface->fDeleteQueries = nullGLDeleteIds;
413        interface->fDeleteShader = nullGLDelete;
414        interface->fDeleteTextures = nullGLDeleteIds;
415        interface->fDepthMask = nullGLDepthMask;
416        interface->fDisable = nullGLDisable;
417        interface->fDisableVertexAttribArray = nullGLDisableVertexAttribArray;
418        interface->fDrawArrays = nullGLDrawArrays;
419        interface->fDrawBuffer = nullGLDrawBuffer;
420        interface->fDrawBuffers = nullGLDrawBuffers;
421        interface->fDrawElements = nullGLDrawElements;
422        interface->fEnable = nullGLEnable;
423        interface->fEnableVertexAttribArray = nullGLEnableVertexAttribArray;
424        interface->fEndQuery = nullGLEndQuery;
425        interface->fFinish = nullGLFinish;
426        interface->fFlush = nullGLFlush;
427        interface->fFrontFace = nullGLFrontFace;
428        interface->fGenBuffers = nullGLGenIds;
429        interface->fGenQueries = nullGLGenIds;
430        interface->fGenTextures = nullGLGenIds;
431        interface->fGetBufferParameteriv = nullGLGetBufferParameteriv;
432        interface->fGetError = nullGLGetError;
433        interface->fGetIntegerv = nullGLGetIntegerv;
434        interface->fGetQueryObjecti64v = nullGLGetQueryObjecti64v;
435        interface->fGetQueryObjectiv = nullGLGetQueryObjectiv;
436        interface->fGetQueryObjectui64v = nullGLGetQueryObjectui64v;
437        interface->fGetQueryObjectuiv = nullGLGetQueryObjectuiv;
438        interface->fGetQueryiv = nullGLGetQueryiv;
439        interface->fGetProgramInfoLog = nullGLGetInfoLog;
440        interface->fGetProgramiv = nullGLGetShaderOrProgramiv;
441        interface->fGetShaderInfoLog = nullGLGetInfoLog;
442        interface->fGetShaderiv = nullGLGetShaderOrProgramiv;
443        interface->fGetString = nullGLGetString;
444        interface->fGetTexLevelParameteriv = nullGLGetTexLevelParameteriv;
445        interface->fGetUniformLocation = nullGLGetUniformLocation;
446        interface->fLineWidth = nullGLLineWidth;
447        interface->fLinkProgram = nullGLLinkProgram;
448        interface->fPixelStorei = nullGLPixelStorei;
449        interface->fQueryCounter = nullGLQueryCounter;
450        interface->fReadBuffer = nullGLReadBuffer;
451        interface->fReadPixels = nullGLReadPixels;
452        interface->fScissor = nullGLScissor;
453        interface->fShaderSource = nullGLShaderSource;
454        interface->fStencilFunc = nullGLStencilFunc;
455        interface->fStencilFuncSeparate = nullGLStencilFuncSeparate;
456        interface->fStencilMask = nullGLStencilMask;
457        interface->fStencilMaskSeparate = nullGLStencilMaskSeparate;
458        interface->fStencilOp = nullGLStencilOp;
459        interface->fStencilOpSeparate = nullGLStencilOpSeparate;
460        interface->fTexImage2D = nullGLTexImage2D;
461        interface->fTexParameteri = nullGLTexParameteri;
462        interface->fTexSubImage2D = nullGLTexSubImage2D;
463        interface->fTexStorage2D = nullGLTexStorage2D;
464        interface->fUniform1f = nullGLUniform1f;
465        interface->fUniform1i = nullGLUniform1i;
466        interface->fUniform1fv = nullGLUniform1fv;
467        interface->fUniform1iv = nullGLUniform1iv;
468        interface->fUniform2f = nullGLUniform2f;
469        interface->fUniform2i = nullGLUniform2i;
470        interface->fUniform2fv = nullGLUniform2fv;
471        interface->fUniform2iv = nullGLUniform2iv;
472        interface->fUniform3f = nullGLUniform3f;
473        interface->fUniform3i = nullGLUniform3i;
474        interface->fUniform3fv = nullGLUniform3fv;
475        interface->fUniform3iv = nullGLUniform3iv;
476        interface->fUniform4f = nullGLUniform4f;
477        interface->fUniform4i = nullGLUniform4i;
478        interface->fUniform4fv = nullGLUniform4fv;
479        interface->fUniform4iv = nullGLUniform4iv;
480        interface->fUniformMatrix2fv = nullGLUniformMatrix2fv;
481        interface->fUniformMatrix3fv = nullGLUniformMatrix3fv;
482        interface->fUniformMatrix4fv = nullGLUniformMatrix4fv;
483        interface->fUseProgram = nullGLUseProgram;
484        interface->fVertexAttrib4fv = nullGLVertexAttrib4fv;
485        interface->fVertexAttribPointer = nullGLVertexAttribPointer;
486        interface->fViewport = nullGLViewport;
487        interface->fBindFramebuffer = nullGLBindFramebuffer;
488        interface->fBindRenderbuffer = nullGLBindRenderbuffer;
489        interface->fCheckFramebufferStatus = nullGLCheckFramebufferStatus;
490        interface->fDeleteFramebuffers = nullGLDeleteFramebuffers;
491        interface->fDeleteRenderbuffers = nullGLDeleteRenderbuffers;
492        interface->fFramebufferRenderbuffer = nullGLFramebufferRenderbuffer;
493        interface->fFramebufferTexture2D = nullGLFramebufferTexture2D;
494        interface->fGenFramebuffers = nullGLGenIds;
495        interface->fGenRenderbuffers = nullGLGenIds;
496        interface->fGetFramebufferAttachmentParameteriv = nullGLGetFramebufferAttachmentParameteriv;
497        interface->fGetRenderbufferParameteriv = nullGLGetRenderbufferParameteriv;
498        interface->fRenderbufferStorage = nullGLRenderbufferStorage;
499        interface->fRenderbufferStorageMultisample = nullGLRenderbufferStorageMultisample;
500        interface->fBlitFramebuffer = nullGLBlitFramebuffer;
501        interface->fResolveMultisampleFramebuffer = nullGLResolveMultisampleFramebuffer;
502        interface->fMapBuffer = nullGLMapBuffer;
503        interface->fUnmapBuffer = nullGLUnmapBuffer;
504        interface->fBindFragDataLocationIndexed = nullGLBindFragDataLocationIndexed;
505    }
506    glInterface.get()->ref();
507    return glInterface.get();
508}
509