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      1 /*
      2  * Copyright (C) 2009 Apple Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  * 1. Redistributions of source code must retain the above copyright
      8  *    notice, this list of conditions and the following disclaimer.
      9  * 2. Redistributions in binary form must reproduce the above copyright
     10  *    notice, this list of conditions and the following disclaimer in the
     11  *    documentation and/or other materials provided with the distribution.
     12  *
     13  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
     14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
     17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     24  */
     25 
     26 #ifndef WebGLRenderingContext_h
     27 #define WebGLRenderingContext_h
     28 
     29 #include "CanvasRenderingContext.h"
     30 #include "ExceptionCode.h"
     31 #include "Float32Array.h"
     32 #include "GraphicsContext3D.h"
     33 #include "Int32Array.h"
     34 #include "PlatformString.h"
     35 #include "Timer.h"
     36 #include "Uint8Array.h"
     37 #include "WebGLGetInfo.h"
     38 
     39 #include <wtf/OwnArrayPtr.h>
     40 
     41 namespace WebCore {
     42 
     43 class WebGLActiveInfo;
     44 class WebGLBuffer;
     45 class WebGLContextAttributes;
     46 class WebGLExtension;
     47 class WebGLFramebuffer;
     48 class WebGLObject;
     49 class WebGLProgram;
     50 class WebGLRenderbuffer;
     51 class WebGLShader;
     52 class WebGLTexture;
     53 class WebGLUniformLocation;
     54 class WebKitLoseContext;
     55 class HTMLImageElement;
     56 class HTMLVideoElement;
     57 class ImageBuffer;
     58 class ImageData;
     59 class IntSize;
     60 class OESStandardDerivatives;
     61 class OESTextureFloat;
     62 class OESVertexArrayObject;
     63 class WebGLVertexArrayObjectOES;
     64 
     65 class WebGLRenderingContext : public CanvasRenderingContext {
     66 public:
     67     static PassOwnPtr<WebGLRenderingContext> create(HTMLCanvasElement*, WebGLContextAttributes*);
     68     virtual ~WebGLRenderingContext();
     69 
     70     virtual bool is3d() const { return true; }
     71     virtual bool isAccelerated() const { return true; }
     72     virtual bool paintsIntoCanvasBuffer() const;
     73 
     74     void activeTexture(GC3Denum texture, ExceptionCode&);
     75     void attachShader(WebGLProgram*, WebGLShader*, ExceptionCode&);
     76     void bindAttribLocation(WebGLProgram*, GC3Duint index, const String& name, ExceptionCode&);
     77     void bindBuffer(GC3Denum target, WebGLBuffer*, ExceptionCode&);
     78     void bindFramebuffer(GC3Denum target, WebGLFramebuffer*, ExceptionCode&);
     79     void bindRenderbuffer(GC3Denum target, WebGLRenderbuffer*, ExceptionCode&);
     80     void bindTexture(GC3Denum target, WebGLTexture*, ExceptionCode&);
     81     void blendColor(GC3Dfloat red, GC3Dfloat green, GC3Dfloat blue, GC3Dfloat alpha);
     82     void blendEquation(GC3Denum mode);
     83     void blendEquationSeparate(GC3Denum modeRGB, GC3Denum modeAlpha);
     84     void blendFunc(GC3Denum sfactor, GC3Denum dfactor);
     85     void blendFuncSeparate(GC3Denum srcRGB, GC3Denum dstRGB, GC3Denum srcAlpha, GC3Denum dstAlpha);
     86 
     87     void bufferData(GC3Denum target, GC3Dsizeiptr size, GC3Denum usage, ExceptionCode&);
     88     void bufferData(GC3Denum target, ArrayBuffer* data, GC3Denum usage, ExceptionCode&);
     89     void bufferData(GC3Denum target, ArrayBufferView* data, GC3Denum usage, ExceptionCode&);
     90     void bufferSubData(GC3Denum target, GC3Dintptr offset, ArrayBuffer* data, ExceptionCode&);
     91     void bufferSubData(GC3Denum target, GC3Dintptr offset, ArrayBufferView* data, ExceptionCode&);
     92 
     93     GC3Denum checkFramebufferStatus(GC3Denum target);
     94     void clear(GC3Dbitfield mask);
     95     void clearColor(GC3Dfloat red, GC3Dfloat green, GC3Dfloat blue, GC3Dfloat alpha);
     96     void clearDepth(GC3Dfloat);
     97     void clearStencil(GC3Dint);
     98     void colorMask(GC3Dboolean red, GC3Dboolean green, GC3Dboolean blue, GC3Dboolean alpha);
     99     void compileShader(WebGLShader*, ExceptionCode&);
    100 
    101     // void compressedTexImage2D(GC3Denum target, GC3Dint level, GC3Denum internalformat, GC3Dsizei width, GC3Dsizei height, GC3Dint border, GC3Dsizei imageSize, const void* data);
    102     // void compressedTexSubImage2D(GC3Denum target, GC3Dint level, GC3Dint xoffset, GC3Dint yoffset, GC3Dsizei width, GC3Dsizei GC3Dsizei height, GC3Denum format, GC3Dsizei imageSize, const void* data);
    103 
    104     void copyTexImage2D(GC3Denum target, GC3Dint level, GC3Denum internalformat, GC3Dint x, GC3Dint y, GC3Dsizei width, GC3Dsizei height, GC3Dint border);
    105     void copyTexSubImage2D(GC3Denum target, GC3Dint level, GC3Dint xoffset, GC3Dint yoffset, GC3Dint x, GC3Dint y, GC3Dsizei width, GC3Dsizei height);
    106 
    107     PassRefPtr<WebGLBuffer> createBuffer();
    108     PassRefPtr<WebGLFramebuffer> createFramebuffer();
    109     PassRefPtr<WebGLProgram> createProgram();
    110     PassRefPtr<WebGLRenderbuffer> createRenderbuffer();
    111     PassRefPtr<WebGLShader> createShader(GC3Denum type, ExceptionCode&);
    112     PassRefPtr<WebGLTexture> createTexture();
    113 
    114     void cullFace(GC3Denum mode);
    115 
    116     void deleteBuffer(WebGLBuffer*);
    117     void deleteFramebuffer(WebGLFramebuffer*);
    118     void deleteProgram(WebGLProgram*);
    119     void deleteRenderbuffer(WebGLRenderbuffer*);
    120     void deleteShader(WebGLShader*);
    121     void deleteTexture(WebGLTexture*);
    122 
    123     void depthFunc(GC3Denum);
    124     void depthMask(GC3Dboolean);
    125     void depthRange(GC3Dfloat zNear, GC3Dfloat zFar);
    126     void detachShader(WebGLProgram*, WebGLShader*, ExceptionCode&);
    127     void disable(GC3Denum cap);
    128     void disableVertexAttribArray(GC3Duint index, ExceptionCode&);
    129     void drawArrays(GC3Denum mode, GC3Dint first, GC3Dsizei count, ExceptionCode&);
    130     void drawElements(GC3Denum mode, GC3Dsizei count, GC3Denum type, GC3Dintptr offset, ExceptionCode&);
    131 
    132     void enable(GC3Denum cap);
    133     void enableVertexAttribArray(GC3Duint index, ExceptionCode&);
    134     void finish();
    135     void flush();
    136     void framebufferRenderbuffer(GC3Denum target, GC3Denum attachment, GC3Denum renderbuffertarget, WebGLRenderbuffer*, ExceptionCode&);
    137     void framebufferTexture2D(GC3Denum target, GC3Denum attachment, GC3Denum textarget, WebGLTexture*, GC3Dint level, ExceptionCode&);
    138     void frontFace(GC3Denum mode);
    139     void generateMipmap(GC3Denum target);
    140 
    141     PassRefPtr<WebGLActiveInfo> getActiveAttrib(WebGLProgram*, GC3Duint index, ExceptionCode&);
    142     PassRefPtr<WebGLActiveInfo> getActiveUniform(WebGLProgram*, GC3Duint index, ExceptionCode&);
    143     bool getAttachedShaders(WebGLProgram*, Vector<WebGLShader*>&, ExceptionCode&);
    144     GC3Dint getAttribLocation(WebGLProgram*, const String& name);
    145     WebGLGetInfo getBufferParameter(GC3Denum target, GC3Denum pname, ExceptionCode&);
    146     PassRefPtr<WebGLContextAttributes> getContextAttributes();
    147     GC3Denum getError();
    148     WebGLExtension* getExtension(const String& name);
    149     WebGLGetInfo getFramebufferAttachmentParameter(GC3Denum target, GC3Denum attachment, GC3Denum pname, ExceptionCode&);
    150     WebGLGetInfo getParameter(GC3Denum pname, ExceptionCode&);
    151     WebGLGetInfo getProgramParameter(WebGLProgram*, GC3Denum pname, ExceptionCode&);
    152     String getProgramInfoLog(WebGLProgram*, ExceptionCode&);
    153     WebGLGetInfo getRenderbufferParameter(GC3Denum target, GC3Denum pname, ExceptionCode&);
    154     WebGLGetInfo getShaderParameter(WebGLShader*, GC3Denum pname, ExceptionCode&);
    155     String getShaderInfoLog(WebGLShader*, ExceptionCode&);
    156 
    157     // TBD
    158     // void glGetShaderPrecisionFormat (GC3Denum shadertype, GC3Denum precisiontype, GC3Dint* range, GC3Dint* precision);
    159 
    160     String getShaderSource(WebGLShader*, ExceptionCode&);
    161     Vector<String> getSupportedExtensions();
    162     WebGLGetInfo getTexParameter(GC3Denum target, GC3Denum pname, ExceptionCode&);
    163     WebGLGetInfo getUniform(WebGLProgram*, const WebGLUniformLocation*, ExceptionCode&);
    164     PassRefPtr<WebGLUniformLocation> getUniformLocation(WebGLProgram*, const String&, ExceptionCode&);
    165     WebGLGetInfo getVertexAttrib(GC3Duint index, GC3Denum pname, ExceptionCode&);
    166     GC3Dsizeiptr getVertexAttribOffset(GC3Duint index, GC3Denum pname);
    167 
    168     void hint(GC3Denum target, GC3Denum mode);
    169     GC3Dboolean isBuffer(WebGLBuffer*);
    170     bool isContextLost();
    171     GC3Dboolean isEnabled(GC3Denum cap);
    172     GC3Dboolean isFramebuffer(WebGLFramebuffer*);
    173     GC3Dboolean isProgram(WebGLProgram*);
    174     GC3Dboolean isRenderbuffer(WebGLRenderbuffer*);
    175     GC3Dboolean isShader(WebGLShader*);
    176     GC3Dboolean isTexture(WebGLTexture*);
    177 
    178     void lineWidth(GC3Dfloat);
    179     void linkProgram(WebGLProgram*, ExceptionCode&);
    180     void pixelStorei(GC3Denum pname, GC3Dint param);
    181     void polygonOffset(GC3Dfloat factor, GC3Dfloat units);
    182     void readPixels(GC3Dint x, GC3Dint y, GC3Dsizei width, GC3Dsizei height, GC3Denum format, GC3Denum type, ArrayBufferView* pixels, ExceptionCode&);
    183     void releaseShaderCompiler();
    184     void renderbufferStorage(GC3Denum target, GC3Denum internalformat, GC3Dsizei width, GC3Dsizei height);
    185     void sampleCoverage(GC3Dfloat value, GC3Dboolean invert);
    186     void scissor(GC3Dint x, GC3Dint y, GC3Dsizei width, GC3Dsizei height);
    187     void shaderSource(WebGLShader*, const String&, ExceptionCode&);
    188     void stencilFunc(GC3Denum func, GC3Dint ref, GC3Duint mask);
    189     void stencilFuncSeparate(GC3Denum face, GC3Denum func, GC3Dint ref, GC3Duint mask);
    190     void stencilMask(GC3Duint);
    191     void stencilMaskSeparate(GC3Denum face, GC3Duint mask);
    192     void stencilOp(GC3Denum fail, GC3Denum zfail, GC3Denum zpass);
    193     void stencilOpSeparate(GC3Denum face, GC3Denum fail, GC3Denum zfail, GC3Denum zpass);
    194 
    195     void texImage2D(GC3Denum target, GC3Dint level, GC3Denum internalformat,
    196                     GC3Dsizei width, GC3Dsizei height, GC3Dint border,
    197                     GC3Denum format, GC3Denum type, ArrayBufferView*, ExceptionCode&);
    198     void texImage2D(GC3Denum target, GC3Dint level, GC3Denum internalformat,
    199                     GC3Denum format, GC3Denum type, ImageData*, ExceptionCode&);
    200     void texImage2D(GC3Denum target, GC3Dint level, GC3Denum internalformat,
    201                     GC3Denum format, GC3Denum type, HTMLImageElement*, ExceptionCode&);
    202     void texImage2D(GC3Denum target, GC3Dint level, GC3Denum internalformat,
    203                     GC3Denum format, GC3Denum type, HTMLCanvasElement*, ExceptionCode&);
    204 #if ENABLE(VIDEO)
    205     void texImage2D(GC3Denum target, GC3Dint level, GC3Denum internalformat,
    206                     GC3Denum format, GC3Denum type, HTMLVideoElement*, ExceptionCode&);
    207 #endif
    208 
    209     void texParameterf(GC3Denum target, GC3Denum pname, GC3Dfloat param);
    210     void texParameteri(GC3Denum target, GC3Denum pname, GC3Dint param);
    211 
    212     void texSubImage2D(GC3Denum target, GC3Dint level, GC3Dint xoffset, GC3Dint yoffset,
    213                        GC3Dsizei width, GC3Dsizei height,
    214                        GC3Denum format, GC3Denum type, ArrayBufferView*, ExceptionCode&);
    215     void texSubImage2D(GC3Denum target, GC3Dint level, GC3Dint xoffset, GC3Dint yoffset,
    216                        GC3Denum format, GC3Denum type, ImageData*, ExceptionCode&);
    217     void texSubImage2D(GC3Denum target, GC3Dint level, GC3Dint xoffset, GC3Dint yoffset,
    218                        GC3Denum format, GC3Denum type, HTMLImageElement*, ExceptionCode&);
    219     void texSubImage2D(GC3Denum target, GC3Dint level, GC3Dint xoffset, GC3Dint yoffset,
    220                        GC3Denum format, GC3Denum type, HTMLCanvasElement*, ExceptionCode&);
    221 #if ENABLE(VIDEO)
    222     void texSubImage2D(GC3Denum target, GC3Dint level, GC3Dint xoffset, GC3Dint yoffset,
    223                        GC3Denum format, GC3Denum type, HTMLVideoElement*, ExceptionCode&);
    224 #endif
    225 
    226     void uniform1f(const WebGLUniformLocation* location, GC3Dfloat x, ExceptionCode&);
    227     void uniform1fv(const WebGLUniformLocation* location, Float32Array* v, ExceptionCode&);
    228     void uniform1fv(const WebGLUniformLocation* location, GC3Dfloat* v, GC3Dsizei size, ExceptionCode&);
    229     void uniform1i(const WebGLUniformLocation* location, GC3Dint x, ExceptionCode&);
    230     void uniform1iv(const WebGLUniformLocation* location, Int32Array* v, ExceptionCode&);
    231     void uniform1iv(const WebGLUniformLocation* location, GC3Dint* v, GC3Dsizei size, ExceptionCode&);
    232     void uniform2f(const WebGLUniformLocation* location, GC3Dfloat x, GC3Dfloat y, ExceptionCode&);
    233     void uniform2fv(const WebGLUniformLocation* location, Float32Array* v, ExceptionCode&);
    234     void uniform2fv(const WebGLUniformLocation* location, GC3Dfloat* v, GC3Dsizei size, ExceptionCode&);
    235     void uniform2i(const WebGLUniformLocation* location, GC3Dint x, GC3Dint y, ExceptionCode&);
    236     void uniform2iv(const WebGLUniformLocation* location, Int32Array* v, ExceptionCode&);
    237     void uniform2iv(const WebGLUniformLocation* location, GC3Dint* v, GC3Dsizei size, ExceptionCode&);
    238     void uniform3f(const WebGLUniformLocation* location, GC3Dfloat x, GC3Dfloat y, GC3Dfloat z, ExceptionCode&);
    239     void uniform3fv(const WebGLUniformLocation* location, Float32Array* v, ExceptionCode&);
    240     void uniform3fv(const WebGLUniformLocation* location, GC3Dfloat* v, GC3Dsizei size, ExceptionCode&);
    241     void uniform3i(const WebGLUniformLocation* location, GC3Dint x, GC3Dint y, GC3Dint z, ExceptionCode&);
    242     void uniform3iv(const WebGLUniformLocation* location, Int32Array* v, ExceptionCode&);
    243     void uniform3iv(const WebGLUniformLocation* location, GC3Dint* v, GC3Dsizei size, ExceptionCode&);
    244     void uniform4f(const WebGLUniformLocation* location, GC3Dfloat x, GC3Dfloat y, GC3Dfloat z, GC3Dfloat w, ExceptionCode&);
    245     void uniform4fv(const WebGLUniformLocation* location, Float32Array* v, ExceptionCode&);
    246     void uniform4fv(const WebGLUniformLocation* location, GC3Dfloat* v, GC3Dsizei size, ExceptionCode&);
    247     void uniform4i(const WebGLUniformLocation* location, GC3Dint x, GC3Dint y, GC3Dint z, GC3Dint w, ExceptionCode&);
    248     void uniform4iv(const WebGLUniformLocation* location, Int32Array* v, ExceptionCode&);
    249     void uniform4iv(const WebGLUniformLocation* location, GC3Dint* v, GC3Dsizei size, ExceptionCode&);
    250     void uniformMatrix2fv(const WebGLUniformLocation* location, GC3Dboolean transpose, Float32Array* value, ExceptionCode&);
    251     void uniformMatrix2fv(const WebGLUniformLocation* location, GC3Dboolean transpose, GC3Dfloat* value, GC3Dsizei size, ExceptionCode&);
    252     void uniformMatrix3fv(const WebGLUniformLocation* location, GC3Dboolean transpose, Float32Array* value, ExceptionCode&);
    253     void uniformMatrix3fv(const WebGLUniformLocation* location, GC3Dboolean transpose, GC3Dfloat* value, GC3Dsizei size, ExceptionCode&);
    254     void uniformMatrix4fv(const WebGLUniformLocation* location, GC3Dboolean transpose, Float32Array* value, ExceptionCode&);
    255     void uniformMatrix4fv(const WebGLUniformLocation* location, GC3Dboolean transpose, GC3Dfloat* value, GC3Dsizei size, ExceptionCode&);
    256 
    257     void useProgram(WebGLProgram*, ExceptionCode&);
    258     void validateProgram(WebGLProgram*, ExceptionCode&);
    259 
    260     void vertexAttrib1f(GC3Duint index, GC3Dfloat x);
    261     void vertexAttrib1fv(GC3Duint index, Float32Array* values);
    262     void vertexAttrib1fv(GC3Duint index, GC3Dfloat* values, GC3Dsizei size);
    263     void vertexAttrib2f(GC3Duint index, GC3Dfloat x, GC3Dfloat y);
    264     void vertexAttrib2fv(GC3Duint index, Float32Array* values);
    265     void vertexAttrib2fv(GC3Duint index, GC3Dfloat* values, GC3Dsizei size);
    266     void vertexAttrib3f(GC3Duint index, GC3Dfloat x, GC3Dfloat y, GC3Dfloat z);
    267     void vertexAttrib3fv(GC3Duint index, Float32Array* values);
    268     void vertexAttrib3fv(GC3Duint index, GC3Dfloat* values, GC3Dsizei size);
    269     void vertexAttrib4f(GC3Duint index, GC3Dfloat x, GC3Dfloat y, GC3Dfloat z, GC3Dfloat w);
    270     void vertexAttrib4fv(GC3Duint index, Float32Array* values);
    271     void vertexAttrib4fv(GC3Duint index, GC3Dfloat* values, GC3Dsizei size);
    272     void vertexAttribPointer(GC3Duint index, GC3Dint size, GC3Denum type, GC3Dboolean normalized,
    273                              GC3Dsizei stride, GC3Dintptr offset, ExceptionCode&);
    274 
    275     void viewport(GC3Dint x, GC3Dint y, GC3Dsizei width, GC3Dsizei height);
    276 
    277     void forceLostContext();
    278     void onLostContext();
    279     void restoreContext();
    280 
    281     GraphicsContext3D* graphicsContext3D() const { return m_context.get(); }
    282 #if USE(ACCELERATED_COMPOSITING)
    283     virtual PlatformLayer* platformLayer() const { return m_context->platformLayer(); }
    284 #endif
    285 
    286     void reshape(int width, int height);
    287 
    288     void markLayerComposited();
    289     virtual void paintRenderingResultsToCanvas();
    290     virtual PassRefPtr<ImageData> paintRenderingResultsToImageData();
    291 
    292     void removeObject(WebGLObject*);
    293 
    294     unsigned getMaxVertexAttribs() const { return m_maxVertexAttribs; }
    295 
    296     // Helpers for JSC bindings.
    297     int getNumberOfExtensions();
    298     WebGLExtension* getExtensionNumber(int i);
    299 
    300   private:
    301     friend class WebGLObject;
    302     friend class OESVertexArrayObject;
    303 
    304     WebGLRenderingContext(HTMLCanvasElement*, PassRefPtr<GraphicsContext3D>, GraphicsContext3D::Attributes);
    305     void initializeNewContext();
    306     void setupFlags();
    307 
    308     void addObject(WebGLObject*);
    309     void detachAndRemoveAllObjects();
    310     WebGLTexture* findTexture(Platform3DObject);
    311     WebGLRenderbuffer* findRenderbuffer(Platform3DObject);
    312     WebGLBuffer* findBuffer(Platform3DObject);
    313     WebGLShader* findShader(Platform3DObject);
    314 
    315     void markContextChanged();
    316     void cleanupAfterGraphicsCall(bool changed)
    317     {
    318         if (changed)
    319             markContextChanged();
    320     }
    321 
    322     // Query whether it is built on top of compliant GLES2 implementation.
    323     bool isGLES2Compliant() { return m_isGLES2Compliant; }
    324     // Query if the GL implementation is NPOT strict.
    325     bool isGLES2NPOTStrict() { return m_isGLES2NPOTStrict; }
    326     // Query if the GL implementation generates errors on out-of-bounds buffer accesses.
    327     bool isErrorGeneratedOnOutOfBoundsAccesses() { return m_isErrorGeneratedOnOutOfBoundsAccesses; }
    328     // Query if the GL implementation initializes textures/renderbuffers to 0.
    329     bool isResourceSafe() { return m_isResourceSafe; }
    330     // Query if depth_stencil buffer is supported.
    331     bool isDepthStencilSupported() { return m_isDepthStencilSupported; }
    332 
    333     // Helper to return the size in bytes of OpenGL data types
    334     // like GL_FLOAT, GL_INT, etc.
    335     unsigned int sizeInBytes(GC3Denum type);
    336 
    337     // Basic validation of count and offset against number of elements in element array buffer
    338     bool validateElementArraySize(GC3Dsizei count, GC3Denum type, GC3Dintptr offset);
    339 
    340     // Conservative but quick index validation
    341     bool validateIndexArrayConservative(GC3Denum type, int& numElementsRequired);
    342 
    343     // Precise but slow index validation -- only done if conservative checks fail
    344     bool validateIndexArrayPrecise(GC3Dsizei count, GC3Denum type, GC3Dintptr offset, int& numElementsRequired);
    345     // If numElements <= 0, we only check if each enabled vertex attribute is bound to a buffer.
    346     bool validateRenderingState(int numElements);
    347 
    348     bool validateWebGLObject(WebGLObject*);
    349 
    350 #if ENABLE(VIDEO)
    351     PassRefPtr<Image> videoFrameToImage(HTMLVideoElement*);
    352 #endif
    353 
    354     RefPtr<GraphicsContext3D> m_context;
    355 
    356     class WebGLRenderingContextRestoreTimer : public TimerBase {
    357     public:
    358         WebGLRenderingContextRestoreTimer(WebGLRenderingContext* context) : m_context(context) { }
    359     private:
    360         virtual void fired();
    361         WebGLRenderingContext* m_context;
    362     };
    363 
    364     WebGLRenderingContextRestoreTimer m_restoreTimer;
    365 
    366     bool m_needsUpdate;
    367     bool m_markedCanvasDirty;
    368     HashSet<RefPtr<WebGLObject> > m_canvasObjects;
    369 
    370     // List of bound VBO's. Used to maintain info about sizes for ARRAY_BUFFER and stored values for ELEMENT_ARRAY_BUFFER
    371     RefPtr<WebGLBuffer> m_boundArrayBuffer;
    372 
    373     RefPtr<WebGLVertexArrayObjectOES> m_defaultVertexArrayObject;
    374     RefPtr<WebGLVertexArrayObjectOES> m_boundVertexArrayObject;
    375     void setBoundVertexArrayObject(PassRefPtr<WebGLVertexArrayObjectOES> arrayObject)
    376     {
    377         if (arrayObject)
    378             m_boundVertexArrayObject = arrayObject;
    379         else
    380             m_boundVertexArrayObject = m_defaultVertexArrayObject;
    381     }
    382 
    383     class VertexAttribValue {
    384     public:
    385         VertexAttribValue()
    386         {
    387             initValue();
    388         }
    389 
    390         void initValue()
    391         {
    392             value[0] = 0.0f;
    393             value[1] = 0.0f;
    394             value[2] = 0.0f;
    395             value[3] = 1.0f;
    396         }
    397 
    398         GC3Dfloat value[4];
    399     };
    400     Vector<VertexAttribValue> m_vertexAttribValue;
    401     unsigned m_maxVertexAttribs;
    402     RefPtr<WebGLBuffer> m_vertexAttrib0Buffer;
    403     long m_vertexAttrib0BufferSize;
    404     GC3Dfloat m_vertexAttrib0BufferValue[4];
    405     bool m_forceAttrib0BufferRefill;
    406     bool m_vertexAttrib0UsedBefore;
    407 
    408     RefPtr<WebGLProgram> m_currentProgram;
    409     RefPtr<WebGLFramebuffer> m_framebufferBinding;
    410     RefPtr<WebGLRenderbuffer> m_renderbufferBinding;
    411     class TextureUnitState {
    412     public:
    413         RefPtr<WebGLTexture> m_texture2DBinding;
    414         RefPtr<WebGLTexture> m_textureCubeMapBinding;
    415     };
    416     Vector<TextureUnitState> m_textureUnits;
    417     unsigned long m_activeTextureUnit;
    418 
    419     RefPtr<WebGLTexture> m_blackTexture2D;
    420     RefPtr<WebGLTexture> m_blackTextureCubeMap;
    421 
    422     // Fixed-size cache of reusable image buffers for video texImage2D calls.
    423     class LRUImageBufferCache {
    424     public:
    425         LRUImageBufferCache(int capacity);
    426         // The pointer returned is owned by the image buffer map.
    427         ImageBuffer* imageBuffer(const IntSize& size);
    428     private:
    429         void bubbleToFront(int idx);
    430         OwnArrayPtr<OwnPtr<ImageBuffer> > m_buffers;
    431         int m_capacity;
    432     };
    433     LRUImageBufferCache m_videoCache;
    434 
    435     GC3Dint m_maxTextureSize;
    436     GC3Dint m_maxCubeMapTextureSize;
    437     GC3Dint m_maxTextureLevel;
    438     GC3Dint m_maxCubeMapTextureLevel;
    439 
    440     GC3Dint m_packAlignment;
    441     GC3Dint m_unpackAlignment;
    442     bool m_unpackFlipY;
    443     bool m_unpackPremultiplyAlpha;
    444     GC3Denum m_unpackColorspaceConversion;
    445     bool m_contextLost;
    446     GraphicsContext3D::Attributes m_attributes;
    447 
    448     bool m_layerCleared;
    449     GC3Dfloat m_clearColor[4];
    450     bool m_scissorEnabled;
    451     GC3Dfloat m_clearDepth;
    452     GC3Dint m_clearStencil;
    453     GC3Dboolean m_colorMask[4];
    454 
    455     long m_stencilBits;
    456     GC3Duint m_stencilMask, m_stencilMaskBack;
    457     GC3Dint m_stencilFuncRef, m_stencilFuncRefBack; // Note that these are the user specified values, not the internal clamped value.
    458     GC3Duint m_stencilFuncMask, m_stencilFuncMaskBack;
    459 
    460     bool m_isGLES2Compliant;
    461     bool m_isGLES2NPOTStrict;
    462     bool m_isErrorGeneratedOnOutOfBoundsAccesses;
    463     bool m_isResourceSafe;
    464     bool m_isDepthStencilSupported;
    465 
    466     // Enabled extension objects.
    467     RefPtr<OESTextureFloat> m_oesTextureFloat;
    468     RefPtr<OESStandardDerivatives> m_oesStandardDerivatives;
    469     RefPtr<OESVertexArrayObject> m_oesVertexArrayObject;
    470     RefPtr<WebKitLoseContext> m_webkitLoseContext;
    471 
    472     // Helpers for getParameter and others
    473     WebGLGetInfo getBooleanParameter(GC3Denum);
    474     WebGLGetInfo getBooleanArrayParameter(GC3Denum);
    475     WebGLGetInfo getFloatParameter(GC3Denum);
    476     WebGLGetInfo getIntParameter(GC3Denum);
    477     WebGLGetInfo getUnsignedIntParameter(GC3Denum);
    478     WebGLGetInfo getWebGLFloatArrayParameter(GC3Denum);
    479     WebGLGetInfo getWebGLIntArrayParameter(GC3Denum);
    480 
    481     // Clear the backbuffer if it was composited since the last operation.
    482     // clearMask is set to the bitfield of any clear that would happen anyway at this time
    483     // and the function returns true if that clear is now unnecessary.
    484     bool clearIfComposited(GC3Dbitfield clearMask = 0);
    485 
    486     void texImage2DBase(GC3Denum target, GC3Dint level, GC3Denum internalformat,
    487                         GC3Dsizei width, GC3Dsizei height, GC3Dint border,
    488                         GC3Denum format, GC3Denum type, void* pixels, ExceptionCode&);
    489     void texImage2DImpl(GC3Denum target, GC3Dint level, GC3Denum internalformat,
    490                         GC3Denum format, GC3Denum type, Image*,
    491                         bool flipY, bool premultiplyAlpha, ExceptionCode&);
    492     void texSubImage2DBase(GC3Denum target, GC3Dint level, GC3Dint xoffset, GC3Dint yoffset,
    493                            GC3Dsizei width, GC3Dsizei height,
    494                            GC3Denum format, GC3Denum type, void* pixels, ExceptionCode&);
    495     void texSubImage2DImpl(GC3Denum target, GC3Dint level, GC3Dint xoffset, GC3Dint yoffset,
    496                            GC3Denum format, GC3Denum type,
    497                            Image* image, bool flipY, bool premultiplyAlpha, ExceptionCode&);
    498 
    499     void handleNPOTTextures(bool prepareToDraw);
    500 
    501     void createFallbackBlackTextures1x1();
    502 
    503     // Helper function for copyTex{Sub}Image, check whether the internalformat
    504     // and the color buffer format of the current bound framebuffer combination
    505     // is valid.
    506     bool isTexInternalFormatColorBufferCombinationValid(GC3Denum texInternalFormat,
    507                                                         GC3Denum colorBufferFormat);
    508 
    509     // Helper function to get the bound framebuffer's color buffer format.
    510     GC3Denum getBoundFramebufferColorFormat();
    511 
    512     // Helper function to get the bound framebuffer's width.
    513     int getBoundFramebufferWidth();
    514 
    515     // Helper function to get the bound framebuffer's height.
    516     int getBoundFramebufferHeight();
    517 
    518     // Helper function to check if size is non-negative.
    519     // Generate GL error and return false for negative inputs; otherwise, return true.
    520     bool validateSize(GC3Dint x, GC3Dint y);
    521 
    522     // Helper function to check if all characters in the string belong to the
    523     // ASCII subset as defined in GLSL ES 1.0 spec section 3.1.
    524     bool validateString(const String&);
    525 
    526     // Helper function to check target and texture bound to the target.
    527     // Generate GL errors and return 0 if target is invalid or texture bound is
    528     // null.  Otherwise, return the texture bound to the target.
    529     WebGLTexture* validateTextureBinding(GC3Denum target, bool useSixEnumsForCubeMap);
    530 
    531     // Helper function to check input format/type for functions {copy}Tex{Sub}Image.
    532     // Generates GL error and returns false if parameters are invalid.
    533     bool validateTexFuncFormatAndType(GC3Denum format, GC3Denum type);
    534 
    535     // Helper function to check input level for functions {copy}Tex{Sub}Image.
    536     // Generates GL error and returns false if level is invalid.
    537     bool validateTexFuncLevel(GC3Denum target, GC3Dint level);
    538 
    539     // Helper function to check input parameters for functions {copy}Tex{Sub}Image.
    540     // Generates GL error and returns false if parameters are invalid.
    541     bool validateTexFuncParameters(GC3Denum target, GC3Dint level,
    542                                    GC3Denum internalformat,
    543                                    GC3Dsizei width, GC3Dsizei height, GC3Dint border,
    544                                    GC3Denum format, GC3Denum type);
    545 
    546     // Helper function to validate that the given ArrayBufferView
    547     // is of the correct type and contains enough data for the texImage call.
    548     // Generates GL error and returns false if parameters are invalid.
    549     bool validateTexFuncData(GC3Dsizei width, GC3Dsizei height,
    550                              GC3Denum format, GC3Denum type,
    551                              ArrayBufferView* pixels);
    552 
    553     // Helper function to validate mode for draw{Arrays/Elements}.
    554     bool validateDrawMode(GC3Denum);
    555 
    556     // Helper function to validate if front/back stencilMask and stencilFunc settings are the same.
    557     bool validateStencilSettings();
    558 
    559     // Helper function to validate stencil func.
    560     bool validateStencilFunc(GC3Denum);
    561 
    562     // Helper function for texParameterf and texParameteri.
    563     void texParameter(GC3Denum target, GC3Denum pname, GC3Dfloat parami, GC3Dint paramf, bool isFloat);
    564 
    565     // Helper function to print warnings to console. Currently
    566     // used only to warn about use of obsolete functions.
    567     void printWarningToConsole(const String&);
    568 
    569     // Helper function to validate input parameters for framebuffer functions.
    570     // Generate GL error if parameters are illegal.
    571     bool validateFramebufferFuncParameters(GC3Denum target, GC3Denum attachment);
    572 
    573     // Helper function to validate blend equation mode.
    574     bool validateBlendEquation(GC3Denum);
    575 
    576     // Helper function to validate blend func factors.
    577     bool validateBlendFuncFactors(GC3Denum src, GC3Denum dst);
    578 
    579     // Helper function to validate a GL capability.
    580     bool validateCapability(GC3Denum);
    581 
    582     // Helper function to validate input parameters for uniform functions.
    583     bool validateUniformParameters(const WebGLUniformLocation*, Float32Array*, GC3Dsizei mod);
    584     bool validateUniformParameters(const WebGLUniformLocation*, Int32Array*, GC3Dsizei mod);
    585     bool validateUniformParameters(const WebGLUniformLocation*, void*, GC3Dsizei size, GC3Dsizei mod);
    586     bool validateUniformMatrixParameters(const WebGLUniformLocation*, GC3Dboolean transpose, Float32Array*, GC3Dsizei mod);
    587     bool validateUniformMatrixParameters(const WebGLUniformLocation*, GC3Dboolean transpose, void*, GC3Dsizei size, GC3Dsizei mod);
    588 
    589     // Helper function to validate parameters for bufferData.
    590     // Return the current bound buffer to target, or 0 if parameters are invalid.
    591     WebGLBuffer* validateBufferDataParameters(GC3Denum target, GC3Denum usage);
    592 
    593     // Helper function for tex{Sub}Image2D to make sure image is ready.
    594     bool validateHTMLImageElement(HTMLImageElement*);
    595 
    596     // Helper functions for vertexAttribNf{v}.
    597     void vertexAttribfImpl(GC3Duint index, GC3Dsizei expectedSize, GC3Dfloat, GC3Dfloat, GC3Dfloat, GC3Dfloat);
    598     void vertexAttribfvImpl(GC3Duint index, Float32Array*, GC3Dsizei expectedSize);
    599     void vertexAttribfvImpl(GC3Duint index, GC3Dfloat*, GC3Dsizei size, GC3Dsizei expectedSize);
    600 
    601     // Helper function for delete* (deleteBuffer, deleteProgram, etc) functions.
    602     // Return false if caller should return without further processing.
    603     bool deleteObject(WebGLObject*);
    604 
    605     // Helper function for bind* (bindBuffer, bindTexture, etc) and useProgram.
    606     // If the object has already been deleted, set deleted to true upon return.
    607     // Return false if caller should return without further processing.
    608     bool checkObjectToBeBound(WebGLObject*, bool& deleted);
    609 
    610     // Helpers for simulating vertexAttrib0
    611     void initVertexAttrib0();
    612     bool simulateVertexAttrib0(GC3Dsizei numVertex);
    613     void restoreStatesAfterVertexAttrib0Simulation();
    614 
    615     friend class WebGLStateRestorer;
    616 };
    617 
    618 } // namespace WebCore
    619 
    620 #endif
    621