Adding Blink bindings for WebGL 2

Source/core/html/canvas/WebGL2RenderingContextBase.cpp

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "config.h"
+#include "core/html/canvas/WebGL2RenderingContextBase.h"
+
+#include "bindings/core/v8/WebGLAny.h"
+#include "core/html/HTMLCanvasElement.h"
+#include "core/html/HTMLImageElement.h"
+#include "core/html/HTMLVideoElement.h"
+#include "core/html/ImageData.h"
+#include "core/html/canvas/WebGLActiveInfo.h"
+#include "core/html/canvas/WebGLBuffer.h"
+#include "core/html/canvas/WebGLFenceSync.h"
+#include "core/html/canvas/WebGLFramebuffer.h"
+#include "core/html/canvas/WebGLProgram.h"
+#include "core/html/canvas/WebGLQuery.h"
+#include "core/html/canvas/WebGLSampler.h"
+#include "core/html/canvas/WebGLSync.h"
+#include "core/html/canvas/WebGLTexture.h"
+#include "core/html/canvas/WebGLTransformFeedback.h"
+#include "core/html/canvas/WebGLUniformLocation.h"
+#include "core/html/canvas/WebGLVertexArrayObjectOES.h"
+
+#include "platform/NotImplemented.h"
+
+namespace blink {
+
+namespace {
+
+const GLuint WEBGL_TIMEOUT_IGNORED = 0xFFFFFFFF;
+
+Platform3DObject objectOrZero(const WebGLObject* object)
+{
+    return object ? object->object() : 0;
+}
+
+}
+
+WebGL2RenderingContextBase::WebGL2RenderingContextBase(HTMLCanvasElement* passedCanvas, PassOwnPtr<blink::WebGraphicsContext3D> context, const WebGLContextAttributes& requestedAttributes)
+    : WebGLRenderingContextBase(passedCanvas, context, requestedAttributes)
+{
+
+}
+
+WebGL2RenderingContextBase::~WebGL2RenderingContextBase()
+{
+
+}
+
+void WebGL2RenderingContextBase::copyBufferSubData(GLenum readTarget, GLenum writeTarget, GLintptr readOffset, GLintptr writeOffset, GLsizeiptr size)
+{
+    if (isContextLost())
+        return;
+
+    webContext()->copyBufferSubData(readTarget, writeTarget, readOffset, writeOffset, size);
+}
+
+void WebGL2RenderingContextBase::blitFramebuffer(GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1, GLint dstX0, GLint dstY0, GLint dstX1, GLint dstY1, GLbitfield mask, GLenum filter)
+{
+    if (isContextLost())
+        return;
+
+    webContext()->blitFramebufferCHROMIUM(srcX0, srcY0, srcX1, srcY1, dstX0, dstY0, dstX1, dstY1, mask, filter);
+}
+
+void WebGL2RenderingContextBase::framebufferTextureLayer(GLenum target, GLenum attachment, const WebGLTexture* texture, GLint level, GLint layer)
+{
+    if (isContextLost())
+        return;
+
+    if (texture && !texture->validate(contextGroup(), this)) {
+        synthesizeGLError(GL_INVALID_VALUE, "framebufferTextureLayer", "no texture or texture not from this context");
+        return;
+    }
+
+    webContext()->framebufferTextureLayer(target, attachment, objectOrZero(texture), level, layer);
+}
+
+ScriptValue WebGL2RenderingContextBase::getInternalformatParameter(ScriptState* scriptState, GLenum target, GLenum internalformat, GLenum pname)
+{
+    if (isContextLost())
+        return ScriptValue::createNull(scriptState);
+
+    notImplemented();
+    return ScriptValue::createNull(scriptState);
+}
+
+void WebGL2RenderingContextBase::invalidateFramebuffer(GLenum target, Vector<GLenum>& attachments)
+{
+    if (isContextLost())
+        return;
+
+    webContext()->invalidateFramebuffer(target, attachments.size(), attachments.data());
+}
+
+void WebGL2RenderingContextBase::invalidateSubFramebuffer(GLenum target, Vector<GLenum>& attachments, GLint x, GLint y, GLsizei width, GLsizei height)
+{
+    if (isContextLost())
+        return;
+
+    webContext()->invalidateSubFramebuffer(target, attachments.size(), attachments.data(), x, y, width, height);
+}
+
+void WebGL2RenderingContextBase::readBuffer(GLenum mode)
+{
+    if (isContextLost())
+        return;
+
+    webContext()->readBuffer(mode);
+}
+
+void WebGL2RenderingContextBase::renderbufferStorageMultisample(GLenum target, GLsizei samples, GLenum internalformat, GLsizei width, GLsizei height)
+{
+    if (isContextLost())
+        return;
+
+    webContext()->renderbufferStorageMultisampleEXT(target, samples, internalformat, width, height);
+}
+
+/* Texture objects */
+void WebGL2RenderingContextBase::texStorage2D(GLenum target, GLsizei levels, GLenum internalformat, GLsizei width, GLsizei height)
+{
+    if (isContextLost())
+        return;
+
+    webContext()->texStorage2DEXT(target, levels, internalformat, width, height);
+}
+
+void WebGL2RenderingContextBase::texStorage3D(GLenum target, GLsizei levels, GLenum internalformat, GLsizei width, GLsizei height, GLsizei depth)
+{
+    if (isContextLost())
+        return;
+
+    webContext()->texStorage3D(target, levels, internalformat, width, height, depth);
+}
+
+void WebGL2RenderingContextBase::texImage3D(GLenum target, GLint level, GLint internalformat, GLsizei width, GLsizei height, GLsizei depth, GLint border, GLenum format, GLenum type, DOMArrayBufferView* pixels)
+{
+    if (isContextLost())
+        return;
+
+    notImplemented();
+}
+
+void WebGL2RenderingContextBase::texSubImage3D(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLsizei width, GLsizei height, GLsizei depth, GLenum format, GLenum type, DOMArrayBufferView* pixels)
+{
+    if (isContextLost() || !pixels)
+        return;
+
+    // TODO: Ensure pixels is large enough to contain the desired texture dimensions.
+
+    void* data = pixels->baseAddress();
+    Vector<uint8_t> tempData;
+    bool changeUnpackAlignment = false;
+    if (data && (m_unpackFlipY || m_unpackPremultiplyAlpha)) {
+        if (!WebGLImageConversion::extractTextureData(width, height, format, type,
+            m_unpackAlignment,
+            m_unpackFlipY, m_unpackPremultiplyAlpha,
+            data,
+            tempData))
+            return;
+        data = tempData.data();
+        changeUnpackAlignment = true;
+    }
+    if (changeUnpackAlignment)
+        webContext()->pixelStorei(GL_UNPACK_ALIGNMENT, 1);
+    webContext()->texSubImage3D(target, level, xoffset, yoffset, zoffset, width, height, depth, format, type, data);
+    if (changeUnpackAlignment)
+        webContext()->pixelStorei(GL_UNPACK_ALIGNMENT, m_unpackAlignment);
+}
+
+void WebGL2RenderingContextBase::texSubImage3D(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLenum format, GLenum type, ImageData* pixels)
+{
+    if (isContextLost() || !pixels)
+        return;
+
+    Vector<uint8_t> data;
+    bool needConversion = true;
+    // The data from ImageData is always of format RGBA8.
+    // No conversion is needed if destination format is RGBA and type is USIGNED_BYTE and no Flip or Premultiply operation is required.
+    if (format == GL_RGBA && type == GL_UNSIGNED_BYTE && !m_unpackFlipY && !m_unpackPremultiplyAlpha) {
+        needConversion = false;
+    } else {
+        if (!WebGLImageConversion::extractImageData(pixels->data()->data(), pixels->size(), format, type, m_unpackFlipY, m_unpackPremultiplyAlpha, data)) {
+            synthesizeGLError(GL_INVALID_VALUE, "texSubImage3D", "bad image data");
+            return;
+        }
+    }
+    if (m_unpackAlignment != 1)
+        webContext()->pixelStorei(GL_UNPACK_ALIGNMENT, 1);
+    webContext()->texSubImage3D(target, level, xoffset, yoffset, zoffset, pixels->width(), pixels->height(), 1, format, type, needConversion ? data.data() : pixels->data()->data());
+    if (m_unpackAlignment != 1)
+        webContext()->pixelStorei(GL_UNPACK_ALIGNMENT, m_unpackAlignment);
+}
+
+void WebGL2RenderingContextBase::texSubImage3D(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLenum format, GLenum type, HTMLImageElement* image)
+{
+    if (isContextLost() || !image)
+        return;
+
+    notImplemented();
+}
+
+void WebGL2RenderingContextBase::texSubImage3D(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLenum format, GLenum type, HTMLCanvasElement* canvas)
+{
+    if (isContextLost())
+        return;
+
+    notImplemented();
+}
+
+void WebGL2RenderingContextBase::texSubImage3D(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLenum format, GLenum type, HTMLVideoElement* video)
+{
+    if (isContextLost())
+        return;
+
+    notImplemented();
+}
+
+void WebGL2RenderingContextBase::copyTexSubImage3D(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLint x, GLint y, GLsizei width, GLsizei height)
+{
+    if (isContextLost())
+        return;
+
+    notImplemented();
+}
+
+void WebGL2RenderingContextBase::compressedTexImage3D(GLenum target, GLint level, GLenum internalformat, GLsizei width, GLsizei height, GLsizei depth, GLint border, GLsizei imageSize, DOMArrayBufferView* data)
+{
+    if (isContextLost())
+        return;
+
+    notImplemented();
+}
+
+void WebGL2RenderingContextBase::compressedTexSubImage3D(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLsizei width, GLsizei height, GLsizei depth, GLenum format, GLsizei imageSize, DOMArrayBufferView* data)
+{
+    if (isContextLost())
+        return;
+
+    notImplemented();
+}
+
+GLint WebGL2RenderingContextBase::getFragDataLocation(WebGLProgram* program, const String& name)
+{
+    if (isContextLost() || !validateWebGLObject("getFragDataLocation", program))
+        return -1;
+
+    return webContext()->getFragDataLocation(objectOrZero(program), name.utf8().data());
+}
+
+void WebGL2RenderingContextBase::uniform1ui(const WebGLUniformLocation* location, GLuint v0)
+{
+    if (isContextLost() || !location)
+        return;
+
+    if (location->program() != m_currentProgram) {
+        synthesizeGLError(GL_INVALID_OPERATION, "uniform1ui", "location not for current program");
+        return;
+    }
+
+    webContext()->uniform1ui(location->location(), v0);
+}
+
+void WebGL2RenderingContextBase::uniform2ui(const WebGLUniformLocation* location, GLuint v0, GLuint v1)
+{
+    if (isContextLost() || !location)
+        return;
+
+    if (location->program() != m_currentProgram) {
+        synthesizeGLError(GL_INVALID_OPERATION, "uniform2ui", "location not for current program");
+        return;
+    }
+
+    webContext()->uniform2ui(location->location(), v0, v1);
+}
+
+void WebGL2RenderingContextBase::uniform3ui(const WebGLUniformLocation* location, GLuint v0, GLuint v1, GLuint v2)
+{
+    if (isContextLost() || !location)
+        return;
+
+    if (location->program() != m_currentProgram) {
+        synthesizeGLError(GL_INVALID_OPERATION, "uniform3ui", "location not for current program");
+        return;
+    }
+
+    webContext()->uniform3ui(location->location(), v0, v1, v2);
+}
+
+void WebGL2RenderingContextBase::uniform4ui(const WebGLUniformLocation* location, GLuint v0, GLuint v1, GLuint v2, GLuint v3)
+{
+    if (isContextLost() || !location)
+        return;
+
+    if (location->program() != m_currentProgram) {
+        synthesizeGLError(GL_INVALID_OPERATION, "uniform4ui", "location not for current program");
+        return;
+    }
+
+    webContext()->uniform4ui(location->location(), v0, v1, v2, v3);
+}
+
+void WebGL2RenderingContextBase::uniform1uiv(const WebGLUniformLocation* location, Vector<GLuint>& value)
+{
+    if (isContextLost() || validateUniformParameters("uniform1uiv", location, value.data(), value.size(), 1))
+        return;
+
+    webContext()->uniform1uiv(location->location(), value.size(), value.data());
+}
+
+void WebGL2RenderingContextBase::uniform2uiv(const WebGLUniformLocation* location, Vector<GLuint>& value)
+{
+    if (isContextLost() || !validateUniformParameters("uniform2uiv", location, value.data(), value.size(), 2))
+        return;
+
+    webContext()->uniform2uiv(location->location(), value.size() / 2, value.data());
+}
+
+void WebGL2RenderingContextBase::uniform3uiv(const WebGLUniformLocation* location, Vector<GLuint>& value)
+{
+    if (isContextLost() || !validateUniformParameters("uniform3uiv", location, value.data(), value.size(), 3))
+        return;
+
+    webContext()->uniform3uiv(location->location(), value.size() / 3, value.data());
+}
+
+void WebGL2RenderingContextBase::uniform4uiv(const WebGLUniformLocation* location, Vector<GLuint>& value)
+{
+    if (isContextLost() || !validateUniformParameters("uniform4uiv", location, value.data(), value.size(), 4))
+        return;
+
+    webContext()->uniform4uiv(location->location(), value.size() / 4, value.data());
+}
+
+void WebGL2RenderingContextBase::uniformMatrix2x3fv(const WebGLUniformLocation* location, GLboolean transpose, DOMFloat32Array* value)
+{
+    if (isContextLost() || !validateUniformMatrixParameters("uniformMatrix2x3fv", location, transpose, value, 6))
+        return;
+    webContext()->uniformMatrix2x3fv(location->location(), value->length() / 6, transpose, value->data());
+}
+
+void WebGL2RenderingContextBase::uniformMatrix2x3fv(const WebGLUniformLocation* location, GLboolean transpose, Vector<GLfloat>& value)
+{
+    if (isContextLost() || !validateUniformMatrixParameters("uniformMatrix2x3fv", location, transpose, value.data(), value.size(), 6))
+        return;
+    webContext()->uniformMatrix2x3fv(location->location(), value.size() / 6, transpose, value.data());
+}
+
+void WebGL2RenderingContextBase::uniformMatrix3x2fv(const WebGLUniformLocation* location, GLboolean transpose, DOMFloat32Array* value)
+{
+    if (isContextLost() || !validateUniformMatrixParameters("uniformMatrix3x2fv", location, transpose, value, 6))
+        return;
+    webContext()->uniformMatrix3x2fv(location->location(), value->length() / 6, transpose, value->data());
+}
+
+void WebGL2RenderingContextBase::uniformMatrix3x2fv(const WebGLUniformLocation* location, GLboolean transpose, Vector<GLfloat>& value)
+{
+    if (isContextLost() || !validateUniformMatrixParameters("uniformMatrix3x2fv", location, transpose, value.data(), value.size(), 6))
+        return;
+    webContext()->uniformMatrix3x2fv(location->location(), value.size() / 6, transpose, value.data());
+}
+
+void WebGL2RenderingContextBase::uniformMatrix2x4fv(const WebGLUniformLocation* location, GLboolean transpose, DOMFloat32Array* value)
+{
+    if (isContextLost() || !validateUniformMatrixParameters("uniformMatrix2x4fv", location, transpose, value, 8))
+        return;
+    webContext()->uniformMatrix2x4fv(location->location(), value->length() / 8, transpose, value->data());
+}
+
+void WebGL2RenderingContextBase::uniformMatrix2x4fv(const WebGLUniformLocation* location, GLboolean transpose, Vector<GLfloat>& value)
+{
+    if (isContextLost() || !validateUniformMatrixParameters("uniformMatrix2x4fv", location, transpose, value.data(), value.size(), 8))
+        return;
+    webContext()->uniformMatrix2x4fv(location->location(), value.size() / 8, transpose, value.data());
+}
+
+void WebGL2RenderingContextBase::uniformMatrix4x2fv(const WebGLUniformLocation* location, GLboolean transpose, DOMFloat32Array* value)
+{
+    if (isContextLost() || !validateUniformMatrixParameters("uniformMatrix4x2fv", location, transpose, value, 8))
+        return;
+    webContext()->uniformMatrix4x2fv(location->location(), value->length() / 8, transpose, value->data());
+}
+
+void WebGL2RenderingContextBase::uniformMatrix4x2fv(const WebGLUniformLocation* location, GLboolean transpose, Vector<GLfloat>& value)
+{
+    if (isContextLost() || !validateUniformMatrixParameters("uniformMatrix4x2fv", location, transpose, value.data(), value.size(), 8))
+        return;
+    webContext()->uniformMatrix4x2fv(location->location(), value.size() / 8, transpose, value.data());
+}
+
+void WebGL2RenderingContextBase::uniformMatrix3x4fv(const WebGLUniformLocation* location, GLboolean transpose, DOMFloat32Array* value)
+{
+    if (isContextLost() || !validateUniformMatrixParameters("uniformMatrix3x4fv", location, transpose, value, 12))
+        return;
+    webContext()->uniformMatrix3x4fv(location->location(), value->length() / 12, transpose, value->data());
+}
+
+void WebGL2RenderingContextBase::uniformMatrix3x4fv(const WebGLUniformLocation* location, GLboolean transpose, Vector<GLfloat>& value)
+{
+    if (isContextLost() || !validateUniformMatrixParameters("uniformMatrix3x4fv", location, transpose, value.data(), value.size(), 12))
+        return;
+    webContext()->uniformMatrix3x4fv(location->location(), value.size() / 12, transpose, value.data());
+}
+
+void WebGL2RenderingContextBase::uniformMatrix4x3fv(const WebGLUniformLocation* location, GLboolean transpose, DOMFloat32Array* value)
+{
+    if (isContextLost() || !validateUniformMatrixParameters("uniformMatrix4x3fv", location, transpose, value, 12))
+        return;
+    webContext()->uniformMatrix4x3fv(location->location(), value->length() / 12, transpose, value->data());
+}
+
+void WebGL2RenderingContextBase::uniformMatrix4x3fv(const WebGLUniformLocation* location, GLboolean transpose, Vector<GLfloat>& value)
+{
+    if (isContextLost() || !validateUniformMatrixParameters("uniformMatrix4x3fv", location, transpose, value.data(), value.size(), 12))
+        return;
+    webContext()->uniformMatrix4x3fv(location->location(), value.size() / 12, transpose, value.data());
+}
+
+void WebGL2RenderingContextBase::vertexAttribI4i(GLuint index, GLint x, GLint y, GLint z, GLint w)
+{
+    if (isContextLost())
+        return;
+
+    if (index >= m_maxVertexAttribs) {
+        synthesizeGLError(GL_INVALID_VALUE, "vertexAttribI4i", "index out of range");
+        return;
+    }
+
+    webContext()->vertexAttribI4i(index, x, y, z, w);
+    // TODO: Pretty sure this won't do what we want it to do. Same with the next 3 functions.
+    VertexAttribValue& attribValue = m_vertexAttribValue[index];
+    attribValue.value[0] = x;
+    attribValue.value[1] = y;
+    attribValue.value[2] = z;
+    attribValue.value[3] = w;
+}
+
+void WebGL2RenderingContextBase::vertexAttribI4iv(GLuint index, const Vector<GLint>& value)
+{
+    if (isContextLost())
+        return;
+
+    if (!value.data()) {
+        synthesizeGLError(GL_INVALID_VALUE, "vertexAttribI4iv", "no array");
+        return;
+    }
+    if (value.size() < 4) {
+        synthesizeGLError(GL_INVALID_VALUE, "vertexAttribI4iv", "invalid size");
+        return;
+    }
+    if (index >= m_maxVertexAttribs) {
+        synthesizeGLError(GL_INVALID_VALUE, "vertexAttribI4iv", "index out of range");
+        return;
+    }
+
+    webContext()->vertexAttribI4iv(index, value.data());
+    VertexAttribValue& attribValue = m_vertexAttribValue[index];
+    attribValue.value[0] = value[0];
+    attribValue.value[1] = value[1];
+    attribValue.value[2] = value[2];
+    attribValue.value[3] = value[3];
+}
+
+void WebGL2RenderingContextBase::vertexAttribI4ui(GLuint index, GLuint x, GLuint y, GLuint z, GLuint w)
+{
+    if (isContextLost())
+        return;
+
+    if (index >= m_maxVertexAttribs) {
+        synthesizeGLError(GL_INVALID_VALUE, "vertexAttribI4ui", "index out of range");
+        return;
+    }
+
+    webContext()->vertexAttribI4ui(index, x, y, z, w);
+    VertexAttribValue& attribValue = m_vertexAttribValue[index];
+    attribValue.value[0] = x;
+    attribValue.value[1] = y;
+    attribValue.value[2] = z;
+    attribValue.value[3] = w;
+}
+
+void WebGL2RenderingContextBase::vertexAttribI4uiv(GLuint index, const Vector<GLuint>& value)
+{
+    if (isContextLost())
+        return;
+
+    if (!value.data()) {
+        synthesizeGLError(GL_INVALID_VALUE, "vertexAttribI4uiv", "no array");
+        return;
+    }
+    if (value.size() < 4) {
+        synthesizeGLError(GL_INVALID_VALUE, "vertexAttribI4uiv", "invalid size");
+        return;
+    }
+    if (index >= m_maxVertexAttribs) {
+        synthesizeGLError(GL_INVALID_VALUE, "vertexAttribI4uiv", "index out of range");
+        return;
+    }
+
+    webContext()->vertexAttribI4uiv(index, value.data());
+    VertexAttribValue& attribValue = m_vertexAttribValue[index];
+    attribValue.value[0] = value[0];
+    attribValue.value[1] = value[1];
+    attribValue.value[2] = value[2];
+    attribValue.value[3] = value[3];
+}
+
+void WebGL2RenderingContextBase::vertexAttribIPointer(GLuint index, GLint size, GLenum type, GLsizei stride, GLintptr offset)
+{
+    if (isContextLost())
+        return;
+    if (index >= m_maxVertexAttribs) {
+        synthesizeGLError(GL_INVALID_VALUE, "vertexAttribIPointer", "index out of range");
+        return;
+    }
+    if (size < 1 || size > 4 || stride < 0 || stride > 255) {
+        synthesizeGLError(GL_INVALID_VALUE, "vertexAttribIPointer", "bad size or stride");
+        return;
+    }
+    if (!validateValueFitNonNegInt32("vertexAttribIPointer", "offset", offset))
+        return;
+    if (!m_boundArrayBuffer) {
+        synthesizeGLError(GL_INVALID_OPERATION, "vertexAttribIPointer", "no bound ARRAY_BUFFER");
+        return;
+    }
+    unsigned typeSize = sizeInBytes(type);
+    ASSERT((typeSize & (typeSize - 1)) == 0); // Ensure that the value is POT.
+    if ((stride & (typeSize - 1)) || (static_cast<GLintptr>(offset) & (typeSize - 1))) {
+        synthesizeGLError(GL_INVALID_OPERATION, "vertexAttribIPointer", "stride or offset not valid for type");
+        return;
+    }
+    GLsizei bytesPerElement = size * typeSize;
+
+    m_boundVertexArrayObject->setVertexAttribState(index, bytesPerElement, size, type, false, stride, static_cast<GLintptr>(offset), m_boundArrayBuffer);
+    webContext()->vertexAttribIPointer(index, size, type, stride, static_cast<GLintptr>(offset));
+}
+
+/* Writing to the drawing buffer */
+void WebGL2RenderingContextBase::vertexAttribDivisor(GLuint index, GLuint divisor)
+{
+    if (isContextLost())
+        return;
+
+    if (index >= m_maxVertexAttribs) {
+        synthesizeGLError(GL_INVALID_VALUE, "vertexAttribDivisor", "index out of range");
+        return;
+    }
+
+    m_boundVertexArrayObject->setVertexAttribDivisor(index, divisor);
+    webContext()->vertexAttribDivisorANGLE(index, divisor);
+}
+
+void WebGL2RenderingContextBase::drawArraysInstanced(GLenum mode, GLint first, GLsizei count, GLsizei instanceCount)
+{
+    if (!validateDrawArrays("drawArraysInstanced", mode, first, count))
+        return;
+
+    if (!validateDrawInstanced("drawArraysInstanced", instanceCount))
+        return;
+
+    clearIfComposited();
+
+    handleTextureCompleteness("drawArraysInstanced", true);
+    webContext()->drawArraysInstancedANGLE(mode, first, count, instanceCount);
+    handleTextureCompleteness("drawArraysInstanced", false);
+    markContextChanged(CanvasChanged);
+}
+
+void WebGL2RenderingContextBase::drawElementsInstanced(GLenum mode, GLsizei count, GLenum type, GLintptr offset, GLsizei instanceCount)
+{
+    if (!validateDrawElements("drawElementsInstanced", mode, count, type, offset))
+        return;
+
+    if (!validateDrawInstanced("drawElementsInstanced", instanceCount))
+        return;
+
+    clearIfComposited();
+
+    handleTextureCompleteness("drawElementsInstanced", true);
+    webContext()->drawElementsInstancedANGLE(mode, count, type, static_cast<GLintptr>(offset), instanceCount);
+    handleTextureCompleteness("drawElementsInstanced", false);
+    markContextChanged(CanvasChanged);
+}
+
+void WebGL2RenderingContextBase::drawBuffers(const Vector<GLenum>& buffers)
+{
+    if (isContextLost())
+        return;
+
+    GLsizei n = buffers.size();
+    const GLenum* bufs = buffers.data();
+    if (!m_framebufferBinding) {
+        if (n != 1) {
+            synthesizeGLError(GL_INVALID_VALUE, "drawBuffers", "more than one buffer");
+            return;
+        }
+        if (bufs[0] != GL_BACK && bufs[0] != GL_NONE) {
+            synthesizeGLError(GL_INVALID_OPERATION, "drawBuffers", "BACK or NONE");
+            return;
+        }
+        // Because the backbuffer is simulated on all current WebKit ports, we need to change BACK to COLOR_ATTACHMENT0.
+        GLenum value = (bufs[0] == GL_BACK) ? GL_COLOR_ATTACHMENT0 : GL_NONE;
+        webContext()->drawBuffersEXT(1, &value);
+        setBackDrawBuffer(bufs[0]);
+    } else {
+        if (n > maxDrawBuffers()) {
+            synthesizeGLError(GL_INVALID_VALUE, "drawBuffers", "more than max draw buffers");
+            return;
+        }
+        for (GLsizei i = 0; i < n; ++i) {
+            if (bufs[i] != GL_NONE && bufs[i] != static_cast<GLenum>(GL_COLOR_ATTACHMENT0_EXT + i)) {
+                synthesizeGLError(GL_INVALID_OPERATION, "drawBuffers", "COLOR_ATTACHMENTi_EXT or NONE");
+                return;
+            }
+        }
+        m_framebufferBinding->drawBuffers(buffers);
+    }
+}
+
+bool WebGL2RenderingContextBase::validateClearBuffer(const char* functionName, GLenum buffer, GLsizei size)
+{
+    switch (buffer) {
+    case GL_COLOR:
+    case GL_FRONT:
+    case GL_BACK:
+    case GL_FRONT_AND_BACK: {
+        if (size < 4) {
+            synthesizeGLError(GL_INVALID_VALUE, functionName, "invalid array size");
+            return false;
+        }
+        break;
+    }
+    case GL_DEPTH:
+    case GL_STENCIL: {
+        if (size < 1) {
+            synthesizeGLError(GL_INVALID_VALUE, functionName, "invalid array size");
+            return false;
+        }
+        break;
+    }
+    default:
+        synthesizeGLError(GL_INVALID_ENUM, functionName, "invalid buffer");
+        return false;
+    }
+    return true;
+}
+
+void WebGL2RenderingContextBase::clearBufferiv(GLenum buffer, GLint drawbuffer, DOMInt32Array* value)
+{
+    if (isContextLost() || !validateClearBuffer("clearBufferiv", buffer, value->length()))
+        return;
+
+    webContext()->clearBufferiv(buffer, drawbuffer, value->data());
+}
+
+void WebGL2RenderingContextBase::clearBufferiv(GLenum buffer, GLint drawbuffer, const Vector<GLint>& value)
+{
+    if (isContextLost() || !validateClearBuffer("clearBufferiv", buffer, value.size()))
+        return;
+
+    webContext()->clearBufferiv(buffer, drawbuffer, value.data());
+}
+
+void WebGL2RenderingContextBase::clearBufferuiv(GLenum buffer, GLint drawbuffer, DOMUint32Array* value)
+{
+    if (isContextLost() || !validateClearBuffer("clearBufferuiv", buffer, value->length()))
+        return;
+
+    webContext()->clearBufferuiv(buffer, drawbuffer, value->data());
+}
+
+void WebGL2RenderingContextBase::clearBufferuiv(GLenum buffer, GLint drawbuffer, const Vector<GLuint>& value)
+{
+    if (isContextLost() || !validateClearBuffer("clearBufferuiv", buffer, value.size()))
+        return;
+
+    webContext()->clearBufferuiv(buffer, drawbuffer, value.data());
+}
+
+void WebGL2RenderingContextBase::clearBufferfv(GLenum buffer, GLint drawbuffer, DOMFloat32Array* value)
+{
+    if (isContextLost() || !validateClearBuffer("clearBufferfv", buffer, value->length()))
+        return;
+
+    webContext()->clearBufferfv(buffer, drawbuffer, value->data());
+}
+
+void WebGL2RenderingContextBase::clearBufferfv(GLenum buffer, GLint drawbuffer, const Vector<GLfloat>& value)
+{
+    if (isContextLost() || !validateClearBuffer("clearBufferfv", buffer, value.size()))
+        return;
+
+    webContext()->clearBufferfv(buffer, drawbuffer, value.data());
+}
+
+void WebGL2RenderingContextBase::clearBufferfi(GLenum buffer, GLint drawbuffer, GLfloat depth, GLint stencil)
+{
+    if (isContextLost())
+        return;
+
+    webContext()->clearBufferfi(buffer, drawbuffer, depth, stencil);
+}
+
+PassRefPtr<WebGLQuery> WebGL2RenderingContextBase::createQuery()
+{
+    if (isContextLost())
+        return nullptr;
+    RefPtr<WebGLQuery> o = WebGLQuery::create(this);
+    addSharedObject(o.get());
+    return o;
+}
+
+void WebGL2RenderingContextBase::deleteQuery(WebGLQuery* query)
+{
+    deleteObject(query);
+}
+
+GLboolean WebGL2RenderingContextBase::isQuery(WebGLQuery* query)
+{
+    if (isContextLost() || !query)
+        return 0;
+
+    return webContext()->isQueryEXT(query->object());
+}
+
+void WebGL2RenderingContextBase::beginQuery(GLenum target, WebGLQuery* query)
+{
+    if (isContextLost() || !validateWebGLObject("beginQuery", query))
+        return;
+
+    webContext()->beginQueryEXT(target, query->object());
+}
+
+void WebGL2RenderingContextBase::endQuery(GLenum target)
+{
+    if (isContextLost())
+        return;
+
+    webContext()->endQueryEXT(target);
+}
+
+PassRefPtr<WebGLQuery> WebGL2RenderingContextBase::getQuery(GLenum target, GLenum pname)
+{
+    if (isContextLost())
+        return nullptr;
+
+    notImplemented();
+    return nullptr;
+}
+
+ScriptValue WebGL2RenderingContextBase::getQueryParameter(ScriptState* scriptState, WebGLQuery* query, GLenum pname)
+{
+    if (isContextLost() || !validateWebGLObject("getQueryParameter", query))
+        return ScriptValue::createNull(scriptState);
+
+    notImplemented();
+    return ScriptValue::createNull(scriptState);
+}
+
+PassRefPtr<WebGLSampler> WebGL2RenderingContextBase::createSampler()
+{
+    if (isContextLost())
+        return nullptr;
+    RefPtr<WebGLSampler> o = WebGLSampler::create(this);
+    addSharedObject(o.get());
+    return o;
+}
+
+void WebGL2RenderingContextBase::deleteSampler(WebGLSampler* sampler)
+{
+    deleteObject(sampler);
+}
+
+GLboolean WebGL2RenderingContextBase::isSampler(WebGLSampler* sampler)
+{
+    if (isContextLost() || !sampler)
+        return 0;
+
+    return webContext()->isSampler(sampler->object());
+}
+
+void WebGL2RenderingContextBase::bindSampler(GLuint unit, WebGLSampler* sampler)
+{
+    if (isContextLost() || !validateWebGLObject("bindSampler", sampler))
+        return;
+
+    webContext()->bindSampler(unit, objectOrZero(sampler));
+}
+
+void WebGL2RenderingContextBase::samplerParameteri(WebGLSampler* sampler, GLenum pname, GLint param)
+{
+    if (isContextLost() || !validateWebGLObject("samplerParameteri", sampler))
+        return;
+
+    webContext()->samplerParameteri(objectOrZero(sampler), pname, param);
+}
+
+void WebGL2RenderingContextBase::samplerParameteriv(WebGLSampler* sampler, GLenum pname, DOMInt32Array* param)
+{
+    if (isContextLost() || !validateWebGLObject("samplerParameteriv", sampler))
+        return;
+
+    // TODO: Ensure that param is long enough for pname.
+
+    webContext()->samplerParameteriv(objectOrZero(sampler), pname, param->data());
+}
+
+void WebGL2RenderingContextBase::samplerParameteriv(WebGLSampler* sampler, GLenum pname, const Vector<GLint>& param)
+{
+    if (isContextLost() || !validateWebGLObject("samplerParameteriv", sampler))
+        return;
+
+    // TODO: Ensure that param is long enough for pname.
+
+    webContext()->samplerParameteriv(objectOrZero(sampler), pname, param.data());
+}
+
+void WebGL2RenderingContextBase::samplerParameterf(WebGLSampler* sampler, GLenum pname, GLfloat param)
+{
+    if (isContextLost() || !validateWebGLObject("samplerParameterf", sampler))
+        return;
+
+    webContext()->samplerParameterf(objectOrZero(sampler), pname, param);
+}
+
+void WebGL2RenderingContextBase::samplerParameterfv(WebGLSampler* sampler, GLenum pname, DOMFloat32Array* param)
+{
+    if (isContextLost() || !validateWebGLObject("samplerParameterfv", sampler))
+        return;
+
+    // TODO: Ensure that param is long enough for pname.
+
+    webContext()->samplerParameterfv(objectOrZero(sampler), pname, param->data());
+}
+
+void WebGL2RenderingContextBase::samplerParameterfv(WebGLSampler* sampler, GLenum pname, const Vector<GLfloat>& param)
+{
+    if (isContextLost() || !validateWebGLObject("samplerParameterfv", sampler))
+        return;
+
+    // TODO: Ensure that param is long enough for pname.
+
+    webContext()->samplerParameterfv(objectOrZero(sampler), pname, param.data());
+}
+
+ScriptValue WebGL2RenderingContextBase::getSamplerParameter(ScriptState* scriptState, WebGLSampler* sampler, GLenum pname)
+{
+    if (isContextLost() || !validateWebGLObject("getSamplerParameter", sampler))
+        return ScriptValue::createNull(scriptState);
+
+    switch (pname) {
+    case GL_TEXTURE_COMPARE_FUNC:
+    case GL_TEXTURE_COMPARE_MODE:
+    case GL_TEXTURE_MAG_FILTER:
+    case GL_TEXTURE_MIN_FILTER:
+    case GL_TEXTURE_WRAP_R:
+    case GL_TEXTURE_WRAP_S:
+    case GL_TEXTURE_WRAP_T:
+        {
+            GLint value = 0;
+            webContext()->getSamplerParameteriv(objectOrZero(sampler), pname, &value);
+            return WebGLAny(scriptState, static_cast<unsigned>(value));
+        }
+    case GL_TEXTURE_MAX_LOD:
+    case GL_TEXTURE_MIN_LOD:
+        {
+            GLfloat value = 0.f;
+            webContext()->getSamplerParameterfv(objectOrZero(sampler), pname, &value);
+            return WebGLAny(scriptState, value);
+        }
+    default:
+        synthesizeGLError(GL_INVALID_ENUM, "getSamplerParameter", "invalid parameter name");
+        return ScriptValue::createNull(scriptState);
+    }
+}
+
+PassRefPtr<WebGLSync> WebGL2RenderingContextBase::fenceSync(GLenum condition, GLbitfield flags)
+{
+    if (isContextLost())
+        return nullptr;
+
+    RefPtr<WebGLSync> o = WebGLFenceSync::create(this, condition, flags);
+    addSharedObject(o.get());
+    return o.release();
+}
+
+GLboolean WebGL2RenderingContextBase::isSync(WebGLSync* sync)
+{
+    if (isContextLost() || !sync)
+        return 0;
+
+    return webContext()->isSync(sync->object());
+}
+
+void WebGL2RenderingContextBase::deleteSync(WebGLSync* sync)
+{
+    deleteObject(sync);
+}
+
+GLenum WebGL2RenderingContextBase::clientWaitSync(WebGLSync* sync, GLbitfield flags, GLuint timeout)
+{
+    if (isContextLost() || !validateWebGLObject("clientWaitSync", sync))
+        return GL_WAIT_FAILED;
+
+    GLuint64 timeout64 = (timeout == WEBGL_TIMEOUT_IGNORED ? GL_TIMEOUT_IGNORED : timeout);
+    return webContext()->clientWaitSync(objectOrZero(sync), flags, timeout64);
+}
+
+void WebGL2RenderingContextBase::waitSync(WebGLSync* sync, GLbitfield flags, GLuint timeout)
+{
+    if (isContextLost() || !validateWebGLObject("waitSync", sync))
+        return;
+
+    GLuint64 timeout64 = (timeout == WEBGL_TIMEOUT_IGNORED ? GL_TIMEOUT_IGNORED : timeout);
+    webContext()->waitSync(objectOrZero(sync), flags, timeout64);
+}
+
+ScriptValue WebGL2RenderingContextBase::getSyncParameter(ScriptState* scriptState, WebGLSync* sync, GLenum pname)
+{
+    if (isContextLost() || !validateWebGLObject("getSyncParameter", sync))
+        return ScriptValue::createNull(scriptState);
+
+    notImplemented();
+    return ScriptValue::createNull(scriptState);
+}
+
+PassRefPtr<WebGLTransformFeedback> WebGL2RenderingContextBase::createTransformFeedback()
+{
+    if (isContextLost())
+        return nullptr;
+    RefPtr<WebGLTransformFeedback> o = WebGLTransformFeedback::create(this);
+    addSharedObject(o.get());
+    return o;
+}
+
+void WebGL2RenderingContextBase::deleteTransformFeedback(WebGLTransformFeedback* feedback)
+{
+    deleteObject(feedback);
+}
+
+GLboolean WebGL2RenderingContextBase::isTransformFeedback(WebGLTransformFeedback* feedback)
+{
+    if (isContextLost() || !feedback)
+        return 0;
+
+    return webContext()->isTransformFeedback(feedback->object());
+}
+
+void WebGL2RenderingContextBase::bindTransformFeedback(GLenum target, WebGLTransformFeedback* feedback)
+{
+    if (isContextLost() || !validateWebGLObject("bindTransformFeedback", feedback))
+        return;
+
+    webContext()->bindTransformFeedback(target, objectOrZero(feedback));
+}
+
+void WebGL2RenderingContextBase::beginTransformFeedback(GLenum primitiveMode)
+{
+    if (isContextLost())
+        return;
+
+    webContext()->beginTransformFeedback(primitiveMode);
+}
+
+void WebGL2RenderingContextBase::endTransformFeedback()
+{
+    if (isContextLost())
+        return;
+
+    webContext()->endTransformFeedback();
+}
+
+void WebGL2RenderingContextBase::transformFeedbackVaryings(WebGLProgram* program, GLsizei count, const Vector<String>& varyings, GLenum bufferMode)
+{
+    if (isContextLost() || !validateWebGLObject("transformFeedbackVaryings", program))
+        return;
+
+    notImplemented();
+}
+
+PassRefPtr<WebGLActiveInfo> WebGL2RenderingContextBase::getTransformFeedbackVarying(WebGLProgram* program, GLuint index)
+{
+    if (isContextLost() || !validateWebGLObject("getTransformFeedbackVarying", program))
+        return nullptr;
+
+    notImplemented();
+    return nullptr;
+}
+
+void WebGL2RenderingContextBase::pauseTransformFeedback()
+{
+    if (isContextLost())
+        return;
+
+    webContext()->pauseTransformFeedback();
+}
+
+void WebGL2RenderingContextBase::resumeTransformFeedback()
+{
+    if (isContextLost())
+        return;
+
+    webContext()->resumeTransformFeedback();
+}
+
+void WebGL2RenderingContextBase::bindBufferBase(GLenum target, GLuint index, WebGLBuffer* buffer)
+{
+    if (isContextLost() || !validateWebGLObject("bindBufferBase", buffer))
+        return;
+
+    notImplemented();
+}
+
+void WebGL2RenderingContextBase::bindBufferRange(GLenum target, GLuint index, WebGLBuffer* buffer, GLintptr offset, GLsizeiptr size)
+{
+    if (isContextLost() || !validateWebGLObject("bindBufferRange", buffer))
+        return;
+
+    notImplemented();
+}
+
+ScriptValue WebGL2RenderingContextBase::getIndexedParameter(ScriptState* scriptState, GLenum target, GLuint index)
+{
+    if (isContextLost())
+        return ScriptValue::createNull(scriptState);
+
+    notImplemented();
+    return ScriptValue::createNull(scriptState);
+}
+
+Vector<GLuint> WebGL2RenderingContextBase::getUniformIndices(WebGLProgram* program, const Vector<String>& uniformNames)
+{
+    Vector<GLuint> result;
+    if (isContextLost() || !validateWebGLObject("getUniformIndices", program))
+        return result;
+
+    notImplemented();
+    // TODO: copy uniform names into array of const char*
+    /*result.resize(uniformNames.size());
+    webContext()->getUniformIndices(objectOrZero(program), uniformNames.size(), uniformNames.data(), result.data());*/
+    return result;
+}
+
+Vector<GLint> WebGL2RenderingContextBase::getActiveUniforms(WebGLProgram* program, const Vector<GLuint>& uniformIndices, GLenum pname)
+{
+    Vector<GLint> result;
+    if (isContextLost() || !validateWebGLObject("getActiveUniforms", program))
+        return result;
+
+    result.resize(uniformIndices.size());
+    webContext()->getActiveUniformsiv(objectOrZero(program), uniformIndices.size(), uniformIndices.data(), pname, result.data());
+    return result;
+}
+
+GLuint WebGL2RenderingContextBase::getUniformBlockIndex(WebGLProgram* program, const String& uniformBlockName)
+{
+    if (isContextLost() || !validateWebGLObject("getUniformBlockIndex", program))
+        return 0;
+    if (!validateString("getUniformBlockIndex", uniformBlockName))
+        return 0;
+
+    return webContext()->getUniformBlockIndex(objectOrZero(program), uniformBlockName.utf8().data());
+}
+
+ScriptValue WebGL2RenderingContextBase::getActiveUniformBlockParameter(ScriptState* scriptState, WebGLProgram* program, GLuint uniformBlockIndex, GLenum pname)
+{
+    if (isContextLost() || !validateWebGLObject("getActiveUniformBlockParameter", program))
+        return ScriptValue::createNull(scriptState);
+
+    switch (pname) {
+    case GL_UNIFORM_BLOCK_BINDING:
+    case GL_UNIFORM_BLOCK_DATA_SIZE:
+    case GL_UNIFORM_BLOCK_ACTIVE_UNIFORMS: {
+        GLint intValue = 0;
+        webContext()->getActiveUniformBlockiv(objectOrZero(program), uniformBlockIndex, pname, &intValue);
+        return WebGLAny(scriptState, static_cast<unsigned>(intValue));
+    }
+    case GL_UNIFORM_BLOCK_ACTIVE_UNIFORM_INDICES: {
+        GLint uniformCount = 0;
+        webContext()->getActiveUniformBlockiv(objectOrZero(program), uniformBlockIndex, GL_UNIFORM_BLOCK_ACTIVE_UNIFORMS, &uniformCount);
+
+        Vector<GLint> signedIndices(uniformCount);
+        Vector<GLuint> indices(uniformCount);
+        webContext()->getActiveUniformBlockiv(objectOrZero(program), uniformBlockIndex, pname, signedIndices.data());
+        for (GLint i = 0; i < uniformCount; ++i) {
+            indices[i] = static_cast<unsigned>(signedIndices[i]);
+        }
+
+        return WebGLAny(scriptState, DOMUint32Array::create(indices.data(), indices.size()));
+    }
+    case GL_UNIFORM_BLOCK_REFERENCED_BY_VERTEX_SHADER:
+    case GL_UNIFORM_BLOCK_REFERENCED_BY_FRAGMENT_SHADER: {
+        GLint boolValue = 0;
+        webContext()->getActiveUniformBlockiv(objectOrZero(program), uniformBlockIndex, pname, &boolValue);
+        return WebGLAny(scriptState, static_cast<bool>(boolValue));
+    }
+    default:
+        synthesizeGLError(GL_INVALID_ENUM, "getActiveUniformBlockParameter", "invalid pname");
+        return ScriptValue::createNull(scriptState);
+    }
+}
+
+String WebGL2RenderingContextBase::getActiveUniformBlockName(WebGLProgram* program, GLuint uniformBlockIndex)
+{
+    if (isContextLost() || !validateWebGLObject("getActiveUniformBlockName", program))
+        return String();
+
+    notImplemented();
+    return String();
+}
+
+void WebGL2RenderingContextBase::uniformBlockBinding(WebGLProgram* program, GLuint uniformBlockIndex, GLuint uniformBlockBinding)
+{
+    if (isContextLost() || !validateWebGLObject("uniformBlockBinding", program))
+        return;
+
+    webContext()->uniformBlockBinding(objectOrZero(program), uniformBlockIndex, uniformBlockBinding);
+}
+
+PassRefPtr<WebGLVertexArrayObjectOES> WebGL2RenderingContextBase::createVertexArray()
+{
+    if (isContextLost())
+        return nullptr;
+
+    RefPtr<WebGLVertexArrayObjectOES> o = WebGLVertexArrayObjectOES::create(this, WebGLVertexArrayObjectOES::VaoTypeUser);
+    addContextObject(o.get());
+    return o.release();
+}
+
+void WebGL2RenderingContextBase::deleteVertexArray(WebGLVertexArrayObjectOES* vertexArray)
+{
+    if (isContextLost() || !vertexArray)
+        return;
+
+    if (!vertexArray->isDefaultObject() && vertexArray == m_boundVertexArrayObject)
+        setBoundVertexArrayObject(nullptr);
+
+    vertexArray->deleteObject(webContext());
+}
+
+GLboolean WebGL2RenderingContextBase::isVertexArray(WebGLVertexArrayObjectOES* vertexArray)
+{
+    if (isContextLost() || !vertexArray)
+        return 0;
+
+    if (!vertexArray->hasEverBeenBound())
+        return 0;
+
+    return webContext()->isVertexArrayOES(vertexArray->object());
+}
+
+void WebGL2RenderingContextBase::bindVertexArray(WebGLVertexArrayObjectOES* vertexArray)
+{
+    if (isContextLost())
+        return;
+
+    if (vertexArray && (vertexArray->isDeleted() || !vertexArray->validate(0, this))) {
+        webContext()->synthesizeGLError(GL_INVALID_OPERATION);
+        return;
+    }
+
+    if (vertexArray && !vertexArray->isDefaultObject() && vertexArray->object()) {
+        webContext()->bindVertexArrayOES(objectOrZero(vertexArray));
+
+        vertexArray->setHasEverBeenBound();
+        setBoundVertexArrayObject(vertexArray);
+    } else {
+        webContext()->bindVertexArrayOES(0);
+        setBoundVertexArrayObject(nullptr);
+    }
+}
+
+void WebGL2RenderingContextBase::trace(Visitor* visitor)
+{
+    WebGLRenderingContextBase::trace(visitor);
+}
+
+} // namespace blink