The Tor Browser: content/canvas/src/WebGLContextValidate.cpp@deefc01c0e14 (annotated)

content/canvas/src/WebGLContextValidate.cpp@deefc01c0e14 (annotated)

content/canvas/src/WebGLContextValidate.cpp

Thu, 15 Jan 2015 21:03:48 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 15 Jan 2015 21:03:48 +0100
branch: TOR_BUG_9701
changeset 11: deefc01c0e14
permissions: -rw-r--r--

Integrate friendly tips from Tor colleagues to make (or not) 4.5 alpha 3;
This includes removal of overloaded (but unused) methods, and addition of
a overlooked call to DataStruct::SetData(nsISupports, uint32_t, bool.)

 /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "WebGLContext.h"
 #include "WebGLBuffer.h"
 #include "WebGLVertexAttribData.h"
 #include "WebGLShader.h"
 #include "WebGLProgram.h"
 #include "WebGLUniformLocation.h"
 #include "WebGLFramebuffer.h"
 #include "WebGLRenderbuffer.h"
 #include "WebGLTexture.h"
 #include "WebGLVertexArray.h"
 #include "GLContext.h"
 #include "CanvasUtils.h"
 #include "mozilla/CheckedInt.h"
 #include "mozilla/Preferences.h"
 #include "mozilla/Services.h"
 #include "jsfriendapi.h"
 #include "angle/ShaderLang.h"
 #include <algorithm>
 #include "mozilla/Services.h"
 #include "nsIObserverService.h"
 using namespace mozilla;
 /**
  * Return the block size for format.
  */
 static void
 BlockSizeFor(GLenum format, GLint* blockWidth, GLint* blockHeight)
 {
     MOZ_ASSERT(blockWidth && blockHeight);
     switch (format) {
     case LOCAL_GL_ATC_RGB:
     case LOCAL_GL_ATC_RGBA_EXPLICIT_ALPHA:
     case LOCAL_GL_ATC_RGBA_INTERPOLATED_ALPHA:
     case LOCAL_GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
     case LOCAL_GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
     case LOCAL_GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
     case LOCAL_GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
         if (blockWidth)
             *blockWidth = 4;
         if (blockHeight)
             *blockHeight = 4;
         break;
     case LOCAL_GL_ETC1_RGB8_OES:
         // 4x4 blocks, but no 4-multiple requirement.
     default:
         break;
     }
 }
 /**
  * Return the displayable name for the texture function that is the
  * source for validation.
  */
 static const char*
 InfoFrom(WebGLTexImageFunc func)
 {
     // TODO: Account for dimensions (WebGL 2)
     switch (func) {
     case WebGLTexImageFunc::TexImage:        return "texImage2D";
     case WebGLTexImageFunc::TexSubImage:     return "texSubImage2D";
     case WebGLTexImageFunc::CopyTexImage:    return "copyTexImage2D";
     case WebGLTexImageFunc::CopyTexSubImage: return "copyTexSubImage2D";
     case WebGLTexImageFunc::CompTexImage:    return "compressedTexImage2D";
     case WebGLTexImageFunc::CompTexSubImage: return "compressedTexSubImage2D";
     default:
         MOZ_ASSERT(false, "Missing case for WebGLTexImageSource");
         return "(error)";
     }
 }
 /**
  * Return displayable name for GLenum.
  * This version is like gl::GLenumToStr but with out the GL_ prefix to
  * keep consistency with how errors are reported from WebGL.
  */
 static const char*
 NameFrom(GLenum glenum)
 {
     switch (glenum) {
 #define XX(x) case LOCAL_GL_##x: return #x
         XX(ALPHA);
         XX(ATC_RGB);
         XX(ATC_RGBA_EXPLICIT_ALPHA);
         XX(ATC_RGBA_INTERPOLATED_ALPHA);
         XX(COMPRESSED_RGBA_PVRTC_2BPPV1);
         XX(COMPRESSED_RGBA_PVRTC_4BPPV1);
         XX(COMPRESSED_RGBA_S3TC_DXT1_EXT);
         XX(COMPRESSED_RGBA_S3TC_DXT3_EXT);
         XX(COMPRESSED_RGBA_S3TC_DXT5_EXT);
         XX(COMPRESSED_RGB_PVRTC_2BPPV1);
         XX(COMPRESSED_RGB_PVRTC_4BPPV1);
         XX(COMPRESSED_RGB_S3TC_DXT1_EXT);
         XX(DEPTH_COMPONENT);
         XX(DEPTH_COMPONENT16);
         XX(DEPTH_COMPONENT32);
         XX(DEPTH_STENCIL);
         XX(DEPTH24_STENCIL8);
         XX(ETC1_RGB8_OES);
         XX(FLOAT);
         XX(HALF_FLOAT);
         XX(LUMINANCE);
         XX(LUMINANCE_ALPHA);
         XX(RGB);
         XX(RGB16F);
         XX(RGB32F);
         XX(RGBA);
         XX(RGBA16F);
         XX(RGBA32F);
         XX(SRGB);
         XX(SRGB_ALPHA);
         XX(TEXTURE_2D);
         XX(TEXTURE_3D);
         XX(TEXTURE_CUBE_MAP);
         XX(TEXTURE_CUBE_MAP_NEGATIVE_X);
         XX(TEXTURE_CUBE_MAP_NEGATIVE_Y);
         XX(TEXTURE_CUBE_MAP_NEGATIVE_Z);
         XX(TEXTURE_CUBE_MAP_POSITIVE_X);
         XX(TEXTURE_CUBE_MAP_POSITIVE_Y);
         XX(TEXTURE_CUBE_MAP_POSITIVE_Z);
         XX(UNSIGNED_BYTE);
         XX(UNSIGNED_INT);
         XX(UNSIGNED_INT_24_8);
         XX(UNSIGNED_SHORT);
         XX(UNSIGNED_SHORT_4_4_4_4);
         XX(UNSIGNED_SHORT_5_5_5_1);
         XX(UNSIGNED_SHORT_5_6_5);
 #undef XX
     }
     return nullptr;
 }
 /**
  * Same as ErrorInvalidEnum but uses NameFrom to print displayable
  * name for \a glenum.
  */
 static void
 ErrorInvalidEnumWithName(WebGLContext* ctx, const char* msg, GLenum glenum, WebGLTexImageFunc func)
 {
     const char* name = NameFrom(glenum);
     if (name)
         ctx->ErrorInvalidEnum("%s: %s %s", InfoFrom(func), msg, name);
     else
         ctx->ErrorInvalidEnum("%s: %s 0x%04X", InfoFrom(func), msg, glenum);
 }
 /**
  * Same as ErrorInvalidOperation but uses NameFrom to print displayable
  * name for \a glenum.
  */
 static void
 ErrorInvalidOperationWithName(WebGLContext* ctx, const char* msg, GLenum glenum,
                               WebGLTexImageFunc func)
 {
     const char* name = NameFrom(glenum);
     if (name)
         ctx->ErrorInvalidOperation("%s: %s %s", InfoFrom(func), msg, name);
     else
         ctx->ErrorInvalidOperation("%s: %s 0x%04X", InfoFrom(func), msg, glenum);
 }
 /**
  * Return true if the format is valid for source calls.
  */
 static bool
 IsAllowedFromSource(GLenum format, WebGLTexImageFunc func)
 {
     switch (format) {
     case LOCAL_GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
     case LOCAL_GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
     case LOCAL_GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
     case LOCAL_GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
     case LOCAL_GL_COMPRESSED_RGB_PVRTC_2BPPV1:
     case LOCAL_GL_COMPRESSED_RGB_PVRTC_4BPPV1:
     case LOCAL_GL_COMPRESSED_RGBA_PVRTC_2BPPV1:
     case LOCAL_GL_COMPRESSED_RGBA_PVRTC_4BPPV1:
         return (func == WebGLTexImageFunc::CompTexImage ||
                 func == WebGLTexImageFunc::CompTexSubImage);
     case LOCAL_GL_ATC_RGB:
     case LOCAL_GL_ATC_RGBA_EXPLICIT_ALPHA:
     case LOCAL_GL_ATC_RGBA_INTERPOLATED_ALPHA:
     case LOCAL_GL_ETC1_RGB8_OES:
         return func == WebGLTexImageFunc::CompTexImage;
     }
     return true;
 }
 /**
  * Returns true if func is a CopyTexImage variant.
  */
 static bool
 IsCopyFunc(WebGLTexImageFunc func)
 {
     return (func == WebGLTexImageFunc::CopyTexImage ||
             func == WebGLTexImageFunc::CopyTexSubImage);
 }
 /**
  * Returns true if func is a SubImage variant.
  */
 static bool
 IsSubFunc(WebGLTexImageFunc func)
 {
     return (func == WebGLTexImageFunc::TexSubImage ||
             func == WebGLTexImageFunc::CopyTexSubImage ||
             func == WebGLTexImageFunc::CompTexSubImage);
 }
 /**
  * returns true is target is a texture cube map target.
  */
 static bool
 IsTexImageCubemapTarget(GLenum target)
 {
     return (target >= LOCAL_GL_TEXTURE_CUBE_MAP_POSITIVE_X &&
             target <= LOCAL_GL_TEXTURE_CUBE_MAP_NEGATIVE_Z);
 }
 /*
  * Pull data out of the program, post-linking
  */
 bool
 WebGLProgram::UpdateInfo()
 {
     mIdentifierMap = nullptr;
     mIdentifierReverseMap = nullptr;
     mUniformInfoMap = nullptr;
     mAttribMaxNameLength = 0;
     for (size_t i = 0; i < mAttachedShaders.Length(); i++)
         mAttribMaxNameLength = std::max(mAttribMaxNameLength, mAttachedShaders[i]->mAttribMaxNameLength);
     GLint attribCount;
     mContext->gl->fGetProgramiv(mGLName, LOCAL_GL_ACTIVE_ATTRIBUTES, &attribCount);
     if (!mAttribsInUse.SetLength(mContext->mGLMaxVertexAttribs)) {
         mContext->ErrorOutOfMemory("updateInfo: out of memory to allocate %d attribs", mContext->mGLMaxVertexAttribs);
         return false;
     }
     for (size_t i = 0; i < mAttribsInUse.Length(); i++)
         mAttribsInUse[i] = false;
     nsAutoArrayPtr<char> nameBuf(new char[mAttribMaxNameLength]);
     for (int i = 0; i < attribCount; ++i) {
         GLint attrnamelen;
         GLint attrsize;
         GLenum attrtype;
         mContext->gl->fGetActiveAttrib(mGLName, i, mAttribMaxNameLength, &attrnamelen, &attrsize, &attrtype, nameBuf);
         if (attrnamelen > 0) {
             GLint loc = mContext->gl->fGetAttribLocation(mGLName, nameBuf);
             MOZ_ASSERT(loc >= 0, "major oops in managing the attributes of a WebGL program");
             if (loc < mContext->mGLMaxVertexAttribs) {
                 mAttribsInUse[loc] = true;
             } else {
                 mContext->GenerateWarning("program exceeds MAX_VERTEX_ATTRIBS");
                 return false;
             }
         }
     }
     if (!mUniformInfoMap) {
         mUniformInfoMap = new CStringToUniformInfoMap;
         for (size_t i = 0; i < mAttachedShaders.Length(); i++) {
             for (size_t j = 0; j < mAttachedShaders[i]->mUniforms.Length(); j++) {
                 const WebGLMappedIdentifier& uniform = mAttachedShaders[i]->mUniforms[j];
                 const WebGLUniformInfo& info = mAttachedShaders[i]->mUniformInfos[j];
                 mUniformInfoMap->Put(uniform.mapped, info);
             }
         }
     }
     mActiveAttribMap.clear();
     GLint numActiveAttrs = 0;
     mContext->gl->fGetProgramiv(mGLName, LOCAL_GL_ACTIVE_ATTRIBUTES, &numActiveAttrs);
     // Spec says the maximum attrib name length is 256 chars, so this is
     // sufficient to hold any attrib name.
     char attrName[257];
     GLint dummySize;
     GLenum dummyType;
     for (GLint i = 0; i < numActiveAttrs; i++) {
         mContext->gl->fGetActiveAttrib(mGLName, i, 257, nullptr, &dummySize,
                                        &dummyType, attrName);
         GLint attrLoc = mContext->gl->fGetAttribLocation(mGLName, attrName);
         MOZ_ASSERT(attrLoc >= 0);
         mActiveAttribMap.insert(std::make_pair(attrLoc, nsCString(attrName)));
     }
     return true;
 }
 /**
  * Return the simple base format for a given internal format.
  *
  * \return the corresponding \u base internal format (GL_ALPHA, GL_LUMINANCE,
  * GL_LUMINANCE_ALPHA, GL_RGB, GL_RGBA), or GL_NONE if invalid enum.
  */
 GLenum
 WebGLContext::BaseTexFormat(GLenum internalFormat) const
 {
     if (internalFormat == LOCAL_GL_ALPHA ||
         internalFormat == LOCAL_GL_LUMINANCE ||
         internalFormat == LOCAL_GL_LUMINANCE_ALPHA ||
         internalFormat == LOCAL_GL_RGB ||
         internalFormat == LOCAL_GL_RGBA)
     {
         return internalFormat;
     }
     if (IsExtensionEnabled(WebGLExtensionID::EXT_sRGB)) {
         if (internalFormat == LOCAL_GL_SRGB)
             return LOCAL_GL_RGB;
         if (internalFormat == LOCAL_GL_SRGB_ALPHA)
             return LOCAL_GL_RGBA;
     }
     if (IsExtensionEnabled(WebGLExtensionID::WEBGL_compressed_texture_atc)) {
         if (internalFormat == LOCAL_GL_ATC_RGB)
             return LOCAL_GL_RGB;
         if (internalFormat == LOCAL_GL_ATC_RGBA_EXPLICIT_ALPHA ||
             internalFormat == LOCAL_GL_ATC_RGBA_INTERPOLATED_ALPHA)
         {
             return LOCAL_GL_RGBA;
         }
     }
     if (IsExtensionEnabled(WebGLExtensionID::WEBGL_compressed_texture_etc1)) {
         if (internalFormat == LOCAL_GL_ETC1_RGB8_OES)
             return LOCAL_GL_RGB;
     }
     if (IsExtensionEnabled(WebGLExtensionID::WEBGL_compressed_texture_pvrtc)) {
         if (internalFormat == LOCAL_GL_COMPRESSED_RGB_PVRTC_2BPPV1 ||
             internalFormat == LOCAL_GL_COMPRESSED_RGB_PVRTC_4BPPV1)
         {
             return LOCAL_GL_RGB;
         }
         if (internalFormat == LOCAL_GL_COMPRESSED_RGBA_PVRTC_2BPPV1 ||
             internalFormat == LOCAL_GL_COMPRESSED_RGBA_PVRTC_4BPPV1)
         {
             return LOCAL_GL_RGBA;
         }
     }
     if (IsExtensionEnabled(WebGLExtensionID::WEBGL_compressed_texture_s3tc)) {
         if (internalFormat == LOCAL_GL_COMPRESSED_RGB_S3TC_DXT1_EXT)
             return LOCAL_GL_RGB;
         if (internalFormat == LOCAL_GL_COMPRESSED_RGBA_S3TC_DXT1_EXT ||
             internalFormat == LOCAL_GL_COMPRESSED_RGBA_S3TC_DXT3_EXT ||
             internalFormat == LOCAL_GL_COMPRESSED_RGBA_S3TC_DXT5_EXT)
         {
             return LOCAL_GL_RGBA;
         }
     }
     if (IsExtensionEnabled(WebGLExtensionID::WEBGL_depth_texture)) {
         if (internalFormat == LOCAL_GL_DEPTH_COMPONENT ||
             internalFormat == LOCAL_GL_DEPTH_COMPONENT16 ||
             internalFormat == LOCAL_GL_DEPTH_COMPONENT32)
         {
             return LOCAL_GL_DEPTH_COMPONENT;
         }
         if (internalFormat == LOCAL_GL_DEPTH_STENCIL ||
             internalFormat == LOCAL_GL_DEPTH24_STENCIL8)
         {
             return LOCAL_GL_DEPTH_STENCIL;
         }
     }
     MOZ_ASSERT(false, "Unhandled internalFormat");
     return LOCAL_GL_NONE;
 }
 bool WebGLContext::ValidateBlendEquationEnum(GLenum mode, const char *info)
 {
     switch (mode) {
         case LOCAL_GL_FUNC_ADD:
         case LOCAL_GL_FUNC_SUBTRACT:
         case LOCAL_GL_FUNC_REVERSE_SUBTRACT:
             return true;
         case LOCAL_GL_MIN:
         case LOCAL_GL_MAX:
             if (IsWebGL2()) {
                 // http://www.opengl.org/registry/specs/EXT/blend_minmax.txt
                 return true;
             }
             break;
         default:
             break;
     }
     ErrorInvalidEnumInfo(info, mode);
     return false;
 }
 bool WebGLContext::ValidateBlendFuncDstEnum(GLenum factor, const char *info)
 {
     switch (factor) {
         case LOCAL_GL_ZERO:
         case LOCAL_GL_ONE:
         case LOCAL_GL_SRC_COLOR:
         case LOCAL_GL_ONE_MINUS_SRC_COLOR:
         case LOCAL_GL_DST_COLOR:
         case LOCAL_GL_ONE_MINUS_DST_COLOR:
         case LOCAL_GL_SRC_ALPHA:
         case LOCAL_GL_ONE_MINUS_SRC_ALPHA:
         case LOCAL_GL_DST_ALPHA:
         case LOCAL_GL_ONE_MINUS_DST_ALPHA:
         case LOCAL_GL_CONSTANT_COLOR:
         case LOCAL_GL_ONE_MINUS_CONSTANT_COLOR:
         case LOCAL_GL_CONSTANT_ALPHA:
         case LOCAL_GL_ONE_MINUS_CONSTANT_ALPHA:
             return true;
         default:
             ErrorInvalidEnumInfo(info, factor);
             return false;
     }
 }
 bool WebGLContext::ValidateBlendFuncSrcEnum(GLenum factor, const char *info)
 {
     if (factor == LOCAL_GL_SRC_ALPHA_SATURATE)
         return true;
     else
         return ValidateBlendFuncDstEnum(factor, info);
 }
 bool WebGLContext::ValidateBlendFuncEnumsCompatibility(GLenum sfactor, GLenum dfactor, const char *info)
 {
     bool sfactorIsConstantColor = sfactor == LOCAL_GL_CONSTANT_COLOR ||
                                     sfactor == LOCAL_GL_ONE_MINUS_CONSTANT_COLOR;
     bool sfactorIsConstantAlpha = sfactor == LOCAL_GL_CONSTANT_ALPHA ||
                                     sfactor == LOCAL_GL_ONE_MINUS_CONSTANT_ALPHA;
     bool dfactorIsConstantColor = dfactor == LOCAL_GL_CONSTANT_COLOR ||
                                     dfactor == LOCAL_GL_ONE_MINUS_CONSTANT_COLOR;
     bool dfactorIsConstantAlpha = dfactor == LOCAL_GL_CONSTANT_ALPHA ||
                                     dfactor == LOCAL_GL_ONE_MINUS_CONSTANT_ALPHA;
     if ( (sfactorIsConstantColor && dfactorIsConstantAlpha) ||
          (dfactorIsConstantColor && sfactorIsConstantAlpha) ) {
         ErrorInvalidOperation("%s are mutually incompatible, see section 6.8 in the WebGL 1.0 spec", info);
         return false;
     } else {
         return true;
     }
 }
 bool WebGLContext::ValidateTextureTargetEnum(GLenum target, const char *info)
 {
     switch (target) {
         case LOCAL_GL_TEXTURE_2D:
         case LOCAL_GL_TEXTURE_CUBE_MAP:
             return true;
         default:
             ErrorInvalidEnumInfo(info, target);
             return false;
     }
 }
 bool WebGLContext::ValidateComparisonEnum(GLenum target, const char *info)
 {
     switch (target) {
         case LOCAL_GL_NEVER:
         case LOCAL_GL_LESS:
         case LOCAL_GL_LEQUAL:
         case LOCAL_GL_GREATER:
         case LOCAL_GL_GEQUAL:
         case LOCAL_GL_EQUAL:
         case LOCAL_GL_NOTEQUAL:
         case LOCAL_GL_ALWAYS:
             return true;
         default:
             ErrorInvalidEnumInfo(info, target);
             return false;
     }
 }
 bool WebGLContext::ValidateStencilOpEnum(GLenum action, const char *info)
 {
     switch (action) {
         case LOCAL_GL_KEEP:
         case LOCAL_GL_ZERO:
         case LOCAL_GL_REPLACE:
         case LOCAL_GL_INCR:
         case LOCAL_GL_INCR_WRAP:
         case LOCAL_GL_DECR:
         case LOCAL_GL_DECR_WRAP:
         case LOCAL_GL_INVERT:
             return true;
         default:
             ErrorInvalidEnumInfo(info, action);
             return false;
     }
 }
 bool WebGLContext::ValidateFaceEnum(GLenum face, const char *info)
 {
     switch (face) {
         case LOCAL_GL_FRONT:
         case LOCAL_GL_BACK:
         case LOCAL_GL_FRONT_AND_BACK:
             return true;
         default:
             ErrorInvalidEnumInfo(info, face);
             return false;
     }
 }
 bool WebGLContext::ValidateDrawModeEnum(GLenum mode, const char *info)
 {
     switch (mode) {
         case LOCAL_GL_TRIANGLES:
         case LOCAL_GL_TRIANGLE_STRIP:
         case LOCAL_GL_TRIANGLE_FAN:
         case LOCAL_GL_POINTS:
         case LOCAL_GL_LINE_STRIP:
         case LOCAL_GL_LINE_LOOP:
         case LOCAL_GL_LINES:
             return true;
         default:
             ErrorInvalidEnumInfo(info, mode);
             return false;
     }
 }
 bool WebGLContext::ValidateGLSLVariableName(const nsAString& name, const char *info)
 {
     if (name.IsEmpty())
         return false;
     const uint32_t maxSize = 256;
     if (name.Length() > maxSize) {
         ErrorInvalidValue("%s: identifier is %d characters long, exceeds the maximum allowed length of %d characters",
                           info, name.Length(), maxSize);
         return false;
     }
     if (!ValidateGLSLString(name, info)) {
         return false;
     }
     nsString prefix1 = NS_LITERAL_STRING("webgl_");
     nsString prefix2 = NS_LITERAL_STRING("_webgl_");
     if (Substring(name, 0, prefix1.Length()).Equals(prefix1) ||
         Substring(name, 0, prefix2.Length()).Equals(prefix2))
     {
         ErrorInvalidOperation("%s: string contains a reserved GLSL prefix", info);
         return false;
     }
     return true;
 }
 bool WebGLContext::ValidateGLSLString(const nsAString& string, const char *info)
 {
     for (uint32_t i = 0; i < string.Length(); ++i) {
         if (!ValidateGLSLCharacter(string.CharAt(i))) {
              ErrorInvalidValue("%s: string contains the illegal character '%d'", info, string.CharAt(i));
              return false;
         }
     }
     return true;
 }
 /**
  * Return true if format is a valid texture image format for source,
  * taking into account enabled WebGL extensions.
  */
 bool
 WebGLContext::ValidateTexImageFormat(GLenum format, WebGLTexImageFunc func)
 {
     /* Core WebGL texture formats */
     if (format == LOCAL_GL_ALPHA ||
         format == LOCAL_GL_RGB ||
         format == LOCAL_GL_RGBA ||
         format == LOCAL_GL_LUMINANCE ||
         format == LOCAL_GL_LUMINANCE_ALPHA)
     {
         return true;
     }
     /* Only core formats are valid for CopyTex(Sub)?Image */
     // TODO: Revisit this once color_buffer_(half_)?float lands
     if (IsCopyFunc(func)) {
         ErrorInvalidEnumWithName(this, "invalid format", format, func);
         return false;
     }
     /* WEBGL_depth_texture added formats */
     if (format == LOCAL_GL_DEPTH_COMPONENT ||
         format == LOCAL_GL_DEPTH_STENCIL)
     {
         bool validFormat = IsExtensionEnabled(WebGLExtensionID::WEBGL_depth_texture);
         if (!validFormat)
             ErrorInvalidEnum("%s: invalid format %s: need WEBGL_depth_texture enabled",
                              InfoFrom(func), NameFrom(format));
         return validFormat;
     }
     /* EXT_sRGB added formats */
     if (format == LOCAL_GL_SRGB ||
         format == LOCAL_GL_SRGB_ALPHA)
     {
         bool validFormat = IsExtensionEnabled(WebGLExtensionID::EXT_sRGB);
         if (!validFormat)
             ErrorInvalidEnum("%s: invalid format %s: need EXT_sRGB enabled",
                              InfoFrom(func), NameFrom(format));
         return validFormat;
     }
     /* WEBGL_compressed_texture_atc added formats */
     if (format == LOCAL_GL_ATC_RGB ||
         format == LOCAL_GL_ATC_RGBA_EXPLICIT_ALPHA ||
         format == LOCAL_GL_ATC_RGBA_INTERPOLATED_ALPHA)
     {
         bool validFormat = IsExtensionEnabled(WebGLExtensionID::WEBGL_compressed_texture_atc);
         if (!validFormat)
             ErrorInvalidEnum("%s: invalid format %s: need WEBGL_compressed_texture_atc enabled",
                              InfoFrom(func), NameFrom(format));
         return validFormat;
     }
     // WEBGL_compressed_texture_etc1
     if (format == LOCAL_GL_ETC1_RGB8_OES) {
         bool validFormat = IsExtensionEnabled(WebGLExtensionID::WEBGL_compressed_texture_etc1);
         if (!validFormat)
             ErrorInvalidEnum("%s: invalid format %s: need WEBGL_compressed_texture_etc1 enabled",
                              InfoFrom(func), NameFrom(format));
         return validFormat;
     }
     if (format == LOCAL_GL_COMPRESSED_RGB_PVRTC_2BPPV1 ||
         format == LOCAL_GL_COMPRESSED_RGB_PVRTC_4BPPV1 ||
         format == LOCAL_GL_COMPRESSED_RGBA_PVRTC_2BPPV1 ||
         format == LOCAL_GL_COMPRESSED_RGBA_PVRTC_4BPPV1)
     {
         bool validFormat = IsExtensionEnabled(WebGLExtensionID::WEBGL_compressed_texture_pvrtc);
         if (!validFormat)
             ErrorInvalidEnum("%s: invalid format %s: need WEBGL_compressed_texture_pvrtc enabled",
                              InfoFrom(func), NameFrom(format));
         return validFormat;
     }
     if (format == LOCAL_GL_COMPRESSED_RGB_S3TC_DXT1_EXT ||
         format == LOCAL_GL_COMPRESSED_RGBA_S3TC_DXT1_EXT ||
         format == LOCAL_GL_COMPRESSED_RGBA_S3TC_DXT3_EXT ||
         format == LOCAL_GL_COMPRESSED_RGBA_S3TC_DXT5_EXT)
     {
         bool validFormat = IsExtensionEnabled(WebGLExtensionID::WEBGL_compressed_texture_s3tc);
         if (!validFormat)
             ErrorInvalidEnum("%s: invalid format %s: need WEBGL_compressed_texture_s3tc enabled",
                              InfoFrom(func), NameFrom(format));
         return validFormat;
     }
     ErrorInvalidEnumWithName(this, "invalid format", format, func);
     return false;
 }
 /**
  * Check if the given texture target is valid for TexImage.
  */
 bool
 WebGLContext::ValidateTexImageTarget(GLuint dims, GLenum target, WebGLTexImageFunc func)
 {
     switch (dims) {
     case 2:
         if (target == LOCAL_GL_TEXTURE_2D ||
             IsTexImageCubemapTarget(target))
         {
             return true;
         }
         ErrorInvalidEnumWithName(this, "invalid target", target, func);
         return false;
     default:
         MOZ_ASSERT(false, "ValidateTexImageTarget: Invalid dims");
     }
     return false;
 }
 /**
  * Return true if type is a valid texture image type for source,
  * taking into account enabled WebGL extensions.
  */
 bool
 WebGLContext::ValidateTexImageType(GLenum type, WebGLTexImageFunc func)
 {
     /* Core WebGL texture types */
     if (type == LOCAL_GL_UNSIGNED_BYTE ||
         type == LOCAL_GL_UNSIGNED_SHORT_5_6_5 ||
         type == LOCAL_GL_UNSIGNED_SHORT_4_4_4_4 ||
         type == LOCAL_GL_UNSIGNED_SHORT_5_5_5_1)
     {
         return true;
     }
     /* OES_texture_float added types */
     if (type == LOCAL_GL_FLOAT) {
         bool validType = IsExtensionEnabled(WebGLExtensionID::OES_texture_float);
         if (!validType)
             ErrorInvalidEnum("%s: invalid type %s: need OES_texture_float enabled",
                              InfoFrom(func), NameFrom(type));
         return validType;
     }
     /* OES_texture_half_float add types */
     if (type == LOCAL_GL_HALF_FLOAT_OES) {
         bool validType = IsExtensionEnabled(WebGLExtensionID::OES_texture_half_float);
         if (!validType)
             ErrorInvalidEnum("%s: invalid type %s: need OES_texture_half_float enabled",
                              InfoFrom(func), NameFrom(type));
         return validType;
     }
     /* WEBGL_depth_texture added types */
     if (type == LOCAL_GL_UNSIGNED_SHORT ||
         type == LOCAL_GL_UNSIGNED_INT ||
         type == LOCAL_GL_UNSIGNED_INT_24_8)
     {
         bool validType = IsExtensionEnabled(WebGLExtensionID::WEBGL_depth_texture);
         if (!validType)
             ErrorInvalidEnum("%s: invalid type %s: need WEBGL_depth_texture enabled",
                              InfoFrom(func), NameFrom(type));
         return validType;
     }
     ErrorInvalidEnumWithName(this, "invalid type", type, func);
     return false;
 }
 /**
  * Validate texture image sizing extra constraints for
  * CompressedTex(Sub)?Image.
  */
 // TODO: WebGL 2
 bool
 WebGLContext::ValidateCompTexImageSize(GLenum target, GLint level, GLenum format,
                                        GLint xoffset, GLint yoffset,
                                        GLsizei width, GLsizei height,
                                        GLsizei levelWidth, GLsizei levelHeight,
                                        WebGLTexImageFunc func)
 {
     // Negative parameters must already have been handled above
     MOZ_ASSERT(xoffset >= 0 && yoffset >= 0 &&
                width >= 0 && height >= 0);
     if (xoffset + width > (GLint) levelWidth) {
         ErrorInvalidValue("%s: xoffset + width must be <= levelWidth", InfoFrom(func));
         return false;
     }
     if (yoffset + height > (GLint) levelHeight) {
         ErrorInvalidValue("%s: yoffset + height must be <= levelHeight", InfoFrom(func));
         return false;
     }
     GLint blockWidth = 1;
     GLint blockHeight = 1;
     BlockSizeFor(format, &blockWidth, &blockHeight);
     /* If blockWidth || blockHeight != 1, then the compressed format
      * had block-based constraints to be checked. (For example, PVRTC is compressed but
      * isn't a block-based format)
      */
     if (blockWidth != 1 || blockHeight != 1) {
         /* offsets must be multiple of block size */
         if (xoffset % blockWidth != 0) {
             ErrorInvalidOperation("%s: xoffset must be multiple of %d",
                                   InfoFrom(func), blockWidth);
             return false;
         }
         if (yoffset % blockHeight != 0) {
             ErrorInvalidOperation("%s: yoffset must be multiple of %d",
                                   InfoFrom(func), blockHeight);
             return false;
         }
         /* The size must be a multiple of blockWidth and blockHeight,
          * or must be using offset+size that exactly hits the edge.
          * Important for small mipmap levels.
          */
         /* https://www.khronos.org/registry/webgl/extensions/WEBGL_compressed_texture_s3tc/
          * "When level equals zero width and height must be a multiple of 4. When
          *  level is greater than 0 width and height must be 0, 1, 2 or a multiple of 4.
          *  If they are not an INVALID_OPERATION error is generated."
          */
         if (level == 0) {
             if (width % blockWidth != 0) {
                 ErrorInvalidOperation("%s: width of level 0 must be multple of %d",
                                       InfoFrom(func), blockWidth);
                 return false;
             }
             if (height % blockHeight != 0) {
                 ErrorInvalidOperation("%s: height of level 0 must be multipel of %d",
                                       InfoFrom(func), blockHeight);
                 return false;
             }
         }
         else if (level > 0) {
             if (width % blockWidth != 0 && width > 2) {
                 ErrorInvalidOperation("%s: width of level %d must be multiple"
                                       " of %d or 0, 1, 2",
                                       InfoFrom(func), level, blockWidth);
                 return false;
             }
             if (height % blockHeight != 0 && height > 2) {
                 ErrorInvalidOperation("%s: height of level %d must be multiple"
                                       " of %d or 0, 1, 2",
                                       InfoFrom(func), level, blockHeight);
                 return false;
             }
         }
         if (IsSubFunc(func)) {
             if ((xoffset % blockWidth) != 0) {
                 ErrorInvalidOperation("%s: xoffset must be multiple of %d",
                                       InfoFrom(func), blockWidth);
                 return false;
             }
             if (yoffset % blockHeight != 0) {
                 ErrorInvalidOperation("%s: yoffset must be multiple of %d",
                                       InfoFrom(func), blockHeight);
                 return false;
             }
         }
     }
     switch (format) {
     case LOCAL_GL_COMPRESSED_RGB_PVRTC_4BPPV1:
     case LOCAL_GL_COMPRESSED_RGB_PVRTC_2BPPV1:
     case LOCAL_GL_COMPRESSED_RGBA_PVRTC_4BPPV1:
     case LOCAL_GL_COMPRESSED_RGBA_PVRTC_2BPPV1:
         if (!is_pot_assuming_nonnegative(width) ||
             !is_pot_assuming_nonnegative(height))
         {
             ErrorInvalidValue("%s: width and height must be powers of two",
                               InfoFrom(func));
             return false;
         }
     }
     return true;
 }
 /**
  * Return true if the enough data is present to satisfy compressed
  * texture format constraints.
  */
 bool
 WebGLContext::ValidateCompTexImageDataSize(GLint level, GLenum format,
                                            GLsizei width, GLsizei height,
                                            uint32_t byteLength, WebGLTexImageFunc func)
 {
     // negative width and height must already have been handled above
     MOZ_ASSERT(width >= 0 && height >= 0);
     CheckedUint32 required_byteLength = 0;
     switch (format) {
         case LOCAL_GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
         case LOCAL_GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
         case LOCAL_GL_ATC_RGB:
         case LOCAL_GL_ETC1_RGB8_OES:
         {
             required_byteLength = ((CheckedUint32(width) + 3) / 4) * ((CheckedUint32(height) + 3) / 4) * 8;
             break;
         }
         case LOCAL_GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
         case LOCAL_GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
         case LOCAL_GL_ATC_RGBA_EXPLICIT_ALPHA:
         case LOCAL_GL_ATC_RGBA_INTERPOLATED_ALPHA:
         {
             required_byteLength = ((CheckedUint32(width) + 3) / 4) * ((CheckedUint32(height) + 3) / 4) * 16;
             break;
         }
         case LOCAL_GL_COMPRESSED_RGB_PVRTC_4BPPV1:
         case LOCAL_GL_COMPRESSED_RGBA_PVRTC_4BPPV1:
         {
             required_byteLength = CheckedUint32(std::max(width, 8)) * CheckedUint32(std::max(height, 8)) / 2;
             break;
         }
         case LOCAL_GL_COMPRESSED_RGB_PVRTC_2BPPV1:
         case LOCAL_GL_COMPRESSED_RGBA_PVRTC_2BPPV1:
         {
             required_byteLength = CheckedUint32(std::max(width, 16)) * CheckedUint32(std::max(height, 8)) / 4;
             break;
         }
     }
     if (!required_byteLength.isValid() || required_byteLength.value() != byteLength) {
         ErrorInvalidValue("%s: data size does not match dimensions", InfoFrom(func));
         return false;
     }
     return true;
 }
 /**
  * Validate the width, height, and depth of a texture image, \return
  * true is valid, false otherwise.
  * Used by all the (Compressed|Copy)?Tex(Sub)?Image functions.
  * Target and level must have been validated before calling.
  */
 bool
 WebGLContext::ValidateTexImageSize(GLenum target, GLint level,
                                    GLint width, GLint height, GLint depth,
                                    WebGLTexImageFunc func)
 {
     MOZ_ASSERT(level >= 0, "level should already be validated");
     /* Bug 966630: maxTextureSize >> level runs into "undefined"
      * behaviour depending on ISA. For example, on Intel shifts
      * amounts are mod 64 (in 64-bit mode on 64-bit dest) and mod 32
      * otherwise. This means 16384 >> 0x10000001 == 8192 which isn't
      * what would be expected. Make the required behaviour explicit by
      * clamping to a shift of 31 bits if level is greater than that
      * ammount. This will give 0 that if (!maxAllowedSize) is
      * expecting.
      */
     if (level > 31)
         level = 31;
     const GLuint maxTexImageSize = MaxTextureSizeForTarget(target) >> level;
     const bool isCubemapTarget = IsTexImageCubemapTarget(target);
     const bool isSub = IsSubFunc(func);
     if (!isSub && isCubemapTarget && (width != height)) {
         /* GL ES Version 2.0.25 - 3.7.1 Texture Image Specification
          *   "When the target parameter to TexImage2D is one of the
          *   six cube map two-dimensional image targets, the error
          *   INVALID_VALUE is generated if the width and height
          *   parameters are not equal."
          */
         ErrorInvalidValue("%s: for cube map, width must equal height", InfoFrom(func));
         return false;
     }
     if (target == LOCAL_GL_TEXTURE_2D || isCubemapTarget)
     {
         /* GL ES Version 2.0.25 - 3.7.1 Texture Image Specification
          *   "If wt and ht are the specified image width and height,
          *   and if either wt or ht are less than zero, then the error
          *   INVALID_VALUE is generated."
          */
         if (width < 0) {
             ErrorInvalidValue("%s: width must be >= 0", InfoFrom(func));
             return false;
         }
         if (height < 0) {
             ErrorInvalidValue("%s: height must be >= 0", InfoFrom(func));
             return false;
         }
         /* GL ES Version 2.0.25 - 3.7.1 Texture Image Specification
          *   "The maximum allowable width and height of a
          *   two-dimensional texture image must be at least 2**(k−lod)
          *   for image arrays of level zero through k, where k is the
          *   log base 2 of MAX_TEXTURE_SIZE. and lod is the
          *   level-of-detail of the image array. It may be zero for
          *   image arrays of any level-of-detail greater than k. The
          *   error INVALID_VALUE is generated if the specified image
          *   is too large to be stored under any conditions.
          */
         if (width > (int) maxTexImageSize) {
             ErrorInvalidValue("%s: the maximum width for level %d is %u",
                               InfoFrom(func), level, maxTexImageSize);
             return false;
         }
         if (height > (int) maxTexImageSize) {
             ErrorInvalidValue("%s: tex maximum height for level %d is %u",
                               InfoFrom(func), level, maxTexImageSize);
             return false;
         }
         /* GL ES Version 2.0.25 - 3.7.1 Texture Image Specification
          *   "If level is greater than zero, and either width or
          *   height is not a power-of-two, the error INVALID_VALUE is
          *   generated."
          */
         if (level > 0) {
             if (!is_pot_assuming_nonnegative(width)) {
                 ErrorInvalidValue("%s: level >= 0, width of %d must be a power of two.",
                                   InfoFrom(func), width);
                 return false;
             }
             if (!is_pot_assuming_nonnegative(height)) {
                 ErrorInvalidValue("%s: level >= 0, height of %d must be a power of two.",
                                   InfoFrom(func), height);
                 return false;
             }
         }
     }
     // TODO: WebGL 2
     if (target == LOCAL_GL_TEXTURE_3D) {
         if (depth < 0) {
             ErrorInvalidValue("%s: depth must be >= 0", InfoFrom(func));
             return false;
         }
         if (!is_pot_assuming_nonnegative(depth)) {
             ErrorInvalidValue("%s: level >= 0, depth of %d must be a power of two.",
                               InfoFrom(func), depth);
             return false;
         }
     }
     return true;
 }
 /**
  * Validate texture image sizing for Tex(Sub)?Image variants.
  */
 // TODO: WebGL 2. Update this to handle 3D textures.
 bool
 WebGLContext::ValidateTexSubImageSize(GLint xoffset, GLint yoffset, GLint /*zoffset*/,
                                       GLsizei width, GLsizei height, GLsizei /*depth*/,
                                       GLsizei baseWidth, GLsizei baseHeight, GLsizei /*baseDepth*/,
                                       WebGLTexImageFunc func)
 {
     /* GL ES Version 2.0.25 - 3.7.1 Texture Image Specification
      *   "Taking wt and ht to be the specified width and height of the
      *   texture array, and taking x, y, w, and h to be the xoffset,
      *   yoffset, width, and height argument values, any of the
      *   following relationships generates the error INVALID_VALUE:
      *       x < 0
      *       x + w > wt
      *       y < 0
      *       y + h > ht"
      */
     if (xoffset < 0) {
         ErrorInvalidValue("%s: xoffset must be >= 0", InfoFrom(func));
         return false;
     }
     if (yoffset < 0) {
         ErrorInvalidValue("%s: yoffset must be >= 0", InfoFrom(func));
         return false;
     }
     if (!CanvasUtils::CheckSaneSubrectSize(xoffset, yoffset, width, height, baseWidth, baseHeight)) {
         ErrorInvalidValue("%s: subtexture rectangle out-of-bounds", InfoFrom(func));
         return false;
     }
     return true;
 }
 /**
  * Return the bits per texel for format & type combination.
  * Assumes that format & type are a valid combination as checked with
  * ValidateTexImageFormatAndType().
  */
 uint32_t
 WebGLContext::GetBitsPerTexel(GLenum format, GLenum type)
 {
     // If there is no defined format or type, we're not taking up any memory
     if (!format || !type) {
         return 0;
     }
     /* Known fixed-sized types */
     if (type == LOCAL_GL_UNSIGNED_SHORT_4_4_4_4 ||
         type == LOCAL_GL_UNSIGNED_SHORT_5_5_5_1 ||
         type == LOCAL_GL_UNSIGNED_SHORT_5_6_5)
     {
         return 16;
     }
     if (type == LOCAL_GL_UNSIGNED_INT_24_8)
         return 32;
     int bitsPerComponent = 0;
     switch (type) {
     case LOCAL_GL_UNSIGNED_BYTE:
         bitsPerComponent = 8;
         break;
     case LOCAL_GL_HALF_FLOAT:
     case LOCAL_GL_HALF_FLOAT_OES:
     case LOCAL_GL_UNSIGNED_SHORT:
         bitsPerComponent = 16;
         break;
     case LOCAL_GL_FLOAT:
     case LOCAL_GL_UNSIGNED_INT:
         bitsPerComponent = 32;
         break;
     default:
         MOZ_ASSERT(false, "Unhandled type.");
         break;
     }
     switch (format) {
         // Uncompressed formats
     case LOCAL_GL_ALPHA:
     case LOCAL_GL_LUMINANCE:
     case LOCAL_GL_DEPTH_COMPONENT:
     case LOCAL_GL_DEPTH_STENCIL:
         return 1 * bitsPerComponent;
     case LOCAL_GL_LUMINANCE_ALPHA:
         return 2 * bitsPerComponent;
     case LOCAL_GL_RGB:
     case LOCAL_GL_RGB32F:
     case LOCAL_GL_SRGB_EXT:
         return 3 * bitsPerComponent;
     case LOCAL_GL_RGBA:
     case LOCAL_GL_RGBA32F:
     case LOCAL_GL_SRGB_ALPHA_EXT:
         return 4 * bitsPerComponent;
         // Compressed formats
     case LOCAL_GL_COMPRESSED_RGB_PVRTC_2BPPV1:
     case LOCAL_GL_COMPRESSED_RGBA_PVRTC_2BPPV1:
         return 2;
     case LOCAL_GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
     case LOCAL_GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
     case LOCAL_GL_ATC_RGB:
     case LOCAL_GL_COMPRESSED_RGB_PVRTC_4BPPV1:
     case LOCAL_GL_COMPRESSED_RGBA_PVRTC_4BPPV1:
     case LOCAL_GL_ETC1_RGB8_OES:
         return 4;
     case LOCAL_GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
     case LOCAL_GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
     case LOCAL_GL_ATC_RGBA_EXPLICIT_ALPHA:
     case LOCAL_GL_ATC_RGBA_INTERPOLATED_ALPHA:
         return 8;
     default:
         break;
     }
     MOZ_ASSERT(false, "Unhandled format+type combo.");
     return 0;
 }
 /**
  * Perform validation of format/type combinations for TexImage variants.
  * Returns true if the format/type is a valid combination, false otherwise.
  */
 bool
 WebGLContext::ValidateTexImageFormatAndType(GLenum format, GLenum type, WebGLTexImageFunc func)
 {
     if (!ValidateTexImageFormat(format, func) ||
         !ValidateTexImageType(type, func))
     {
         return false;
     }
     bool validCombo = false;
     switch (format) {
     case LOCAL_GL_ALPHA:
     case LOCAL_GL_LUMINANCE:
     case LOCAL_GL_LUMINANCE_ALPHA:
         validCombo = (type == LOCAL_GL_UNSIGNED_BYTE ||
                       type == LOCAL_GL_HALF_FLOAT ||
                       type == LOCAL_GL_HALF_FLOAT_OES ||
                       type == LOCAL_GL_FLOAT);
         break;
     case LOCAL_GL_RGB:
     case LOCAL_GL_SRGB:
         validCombo = (type == LOCAL_GL_UNSIGNED_BYTE ||
                       type == LOCAL_GL_UNSIGNED_SHORT_5_6_5 ||
                       type == LOCAL_GL_HALF_FLOAT ||
                       type == LOCAL_GL_HALF_FLOAT_OES ||
                       type == LOCAL_GL_FLOAT);
         break;
     case LOCAL_GL_RGBA:
     case LOCAL_GL_SRGB_ALPHA:
         validCombo = (type == LOCAL_GL_UNSIGNED_BYTE ||
                       type == LOCAL_GL_UNSIGNED_SHORT_4_4_4_4 ||
                       type == LOCAL_GL_UNSIGNED_SHORT_5_5_5_1 ||
                       type == LOCAL_GL_HALF_FLOAT ||
                       type == LOCAL_GL_HALF_FLOAT_OES ||
                       type == LOCAL_GL_FLOAT);
         break;
     case LOCAL_GL_DEPTH_COMPONENT:
         validCombo = (type == LOCAL_GL_UNSIGNED_SHORT ||
                       type == LOCAL_GL_UNSIGNED_INT);
         break;
     case LOCAL_GL_DEPTH_STENCIL:
         validCombo = (type == LOCAL_GL_UNSIGNED_INT_24_8);
         break;
     case LOCAL_GL_ATC_RGB:
     case LOCAL_GL_ATC_RGBA_EXPLICIT_ALPHA:
     case LOCAL_GL_ATC_RGBA_INTERPOLATED_ALPHA:
     case LOCAL_GL_ETC1_RGB8_OES:
     case LOCAL_GL_COMPRESSED_RGB_PVRTC_2BPPV1:
     case LOCAL_GL_COMPRESSED_RGB_PVRTC_4BPPV1:
     case LOCAL_GL_COMPRESSED_RGBA_PVRTC_2BPPV1:
     case LOCAL_GL_COMPRESSED_RGBA_PVRTC_4BPPV1:
     case LOCAL_GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
     case LOCAL_GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
     case LOCAL_GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
     case LOCAL_GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
         validCombo = (type == LOCAL_GL_UNSIGNED_BYTE);
         break;
     default:
         // Only valid formats should be passed to the switch stmt.
         MOZ_ASSERT(false, "Unexpected format and type combo. How'd this happen?");
         validCombo = false;
         // Fall through to return an InvalidOperations. This will alert us to the
         // unexpected case that needs fixing in builds without asserts.
     }
     if (!validCombo)
         ErrorInvalidOperation("%s: invalid combination of format %s and type %s",
                               InfoFrom(func), NameFrom(format), NameFrom(type));
     return validCombo;
 }
 /**
  * Return true if format, type and jsArrayType are a valid combination.
  * Also returns the size for texel of format and type (in bytes) via
  * \a texelSize.
  *
  * It is assumed that type has previously been validated.
  */
 bool
 WebGLContext::ValidateTexInputData(GLenum type, int jsArrayType, WebGLTexImageFunc func)
 {
     bool validInput = false;
     const char invalidTypedArray[] = "%s: invalid typed array type for given texture data type";
     // First, we check for packed types
     switch (type) {
     case LOCAL_GL_UNSIGNED_BYTE:
         validInput = (jsArrayType == -1 || jsArrayType == js::ArrayBufferView::TYPE_UINT8);
         break;
         // TODO: WebGL spec doesn't allow half floats to specified as UInt16.
     case LOCAL_GL_HALF_FLOAT:
     case LOCAL_GL_HALF_FLOAT_OES:
         validInput = (jsArrayType == -1);
         break;
     case LOCAL_GL_UNSIGNED_SHORT:
     case LOCAL_GL_UNSIGNED_SHORT_4_4_4_4:
     case LOCAL_GL_UNSIGNED_SHORT_5_5_5_1:
     case LOCAL_GL_UNSIGNED_SHORT_5_6_5:
         validInput = (jsArrayType == -1 || jsArrayType == js::ArrayBufferView::TYPE_UINT16);
         break;
     case LOCAL_GL_UNSIGNED_INT:
     case LOCAL_GL_UNSIGNED_INT_24_8:
         validInput = (jsArrayType == -1 || jsArrayType == js::ArrayBufferView::TYPE_UINT32);
         break;
     case LOCAL_GL_FLOAT:
         validInput = (jsArrayType == -1 || jsArrayType == js::ArrayBufferView::TYPE_FLOAT32);
         break;
     default:
         break;
     }
     if (!validInput)
         ErrorInvalidOperation(invalidTypedArray, InfoFrom(func));
     return validInput;
 }
 /**
  * Test the gl(Copy|Compressed)?Tex[Sub]?Image[23]() parameters for errors.
  * Verifies each of the parameters against the WebGL standard and enabled extensions.
  */
 // TODO: Texture dims is here for future expansion in WebGL 2.0
 bool
 WebGLContext::ValidateTexImage(GLuint dims, GLenum target,
                                GLint level, GLint internalFormat,
                                GLint xoffset, GLint yoffset, GLint zoffset,
                                GLint width, GLint height, GLint depth,
                                GLint border, GLenum format, GLenum type,
                                WebGLTexImageFunc func)
 {
     const char* info = InfoFrom(func);
     /* Check target */
     if (!ValidateTexImageTarget(dims, target, func))
         return false;
     /* Check level */
     if (level < 0) {
         ErrorInvalidValue("%s: level must be >= 0", info);
         return false;
     }
     /* Check border */
     if (border != 0) {
         ErrorInvalidValue("%s: border must be 0", info);
         return false;
     }
     /* Check incoming image format and type */
     if (!ValidateTexImageFormatAndType(format, type, func))
         return false;
     /* WebGL and OpenGL ES 2.0 impose additional restrictions on the
      * combinations of format, internalFormat, and type that can be
      * used.  Formats and types that require additional extensions
      * (e.g., GL_FLOAT requires GL_OES_texture_float) are filtered
      * elsewhere.
      */
     if ((GLint) format != internalFormat) {
         ErrorInvalidOperation("%s: format does not match internalformat", info);
         return false;
     }
     /* check internalFormat */
     // TODO: Not sure if this is a bit of over kill.
     if (BaseTexFormat(internalFormat) == LOCAL_GL_NONE) {
         MOZ_ASSERT(false);
         ErrorInvalidValue("%s:", info);
         return false;
     }
     /* Check texture image size */
     if (!ValidateTexImageSize(target, level, width, height, 0, func))
         return false;
     /* 5.14.8 Texture objects - WebGL Spec.
      *   "If an attempt is made to call these functions with no
      *    WebGLTexture bound (see above), an INVALID_OPERATION error
      *    is generated."
      */
     WebGLTexture* tex = activeBoundTextureForTarget(target);
     if (!tex) {
         ErrorInvalidOperation("%s: no texture is bound to target %s",
                               info, NameFrom(target));
         return false;
     }
     if (IsSubFunc(func)) {
         if (!tex->HasImageInfoAt(target, level)) {
             ErrorInvalidOperation("%s: no texture image previously defined for target %s at level %d",
                                   info, NameFrom(target), level);
             return false;
         }
         const WebGLTexture::ImageInfo& imageInfo = tex->ImageInfoAt(target, level);
         if (!ValidateTexSubImageSize(xoffset, yoffset, zoffset,
                                      width, height, depth,
                                      imageInfo.Width(), imageInfo.Height(), 0,
                                      func))
         {
             return false;
         }
         /* Require the format and type to match that of the existing
          * texture as created
          */
         if (imageInfo.WebGLFormat() != format ||
             imageInfo.WebGLType() != type)
         {
             ErrorInvalidOperation("%s: format or type doesn't match the existing texture",
                                   info);
             return false;
         }
     }
     /* Additional checks for depth textures */
     if (format == LOCAL_GL_DEPTH_COMPONENT ||
         format == LOCAL_GL_DEPTH_STENCIL)
     {
         if (func == WebGLTexImageFunc::TexSubImage || IsCopyFunc(func)) {
             ErrorInvalidOperationWithName(this, "called with format/internalformat",
                                           format, func);
             return false;
         }
         if (func == WebGLTexImageFunc::TexImage &&
             target != LOCAL_GL_TEXTURE_2D)
         {
             ErrorInvalidOperation("%s: with format of %s target must be TEXTURE_2D",
                                   info, NameFrom(format));
             return false;
         }
         if (func == WebGLTexImageFunc::TexImage && level != 0) {
             ErrorInvalidOperation("%s: with format of %s target, level must be 0",
                                   info, NameFrom(format));
             return false;
         }
     }
     /* Additional checks for compressed textures */
     if (!IsAllowedFromSource(format, func)) {
         ErrorInvalidOperation("%s: Invalid format %s for this operation",
                               info, NameFrom(format));
         return false;
     }
     /* Parameters are OK */
     return true;
 }
 bool
 WebGLContext::ValidateUniformLocation(const char* info, WebGLUniformLocation *location_object)
 {
     if (!ValidateObjectAllowNull(info, location_object))
         return false;
     if (!location_object)
         return false;
     /* the need to check specifically for !mCurrentProgram here is explained in bug 657556 */
     if (!mCurrentProgram) {
         ErrorInvalidOperation("%s: no program is currently bound", info);
         return false;
     }
     if (mCurrentProgram != location_object->Program()) {
         ErrorInvalidOperation("%s: this uniform location doesn't correspond to the current program", info);
         return false;
     }
     if (mCurrentProgram->Generation() != location_object->ProgramGeneration()) {
         ErrorInvalidOperation("%s: This uniform location is obsolete since the program has been relinked", info);
         return false;
     }
     return true;
 }
 bool
 WebGLContext::ValidateSamplerUniformSetter(const char* info, WebGLUniformLocation *location, GLint value)
 {
     if (location->Info().type != SH_SAMPLER_2D &&
         location->Info().type != SH_SAMPLER_CUBE)
     {
         return true;
     }
     if (value >= 0 && value < mGLMaxTextureUnits)
         return true;
     ErrorInvalidValue("%s: this uniform location is a sampler, but %d is not a valid texture unit",
                       info, value);
     return false;
 }
 bool
 WebGLContext::ValidateAttribArraySetter(const char* name, uint32_t cnt, uint32_t arrayLength)
 {
     if (IsContextLost()) {
         return false;
     }
     if (arrayLength < cnt) {
         ErrorInvalidOperation("%s: array must be >= %d elements", name, cnt);
         return false;
     }
     return true;
 }
 bool
 WebGLContext::ValidateUniformArraySetter(const char* name, uint32_t expectedElemSize, WebGLUniformLocation *location_object,
                                          GLint& location, uint32_t& numElementsToUpload, uint32_t arrayLength)
 {
     if (IsContextLost())
         return false;
     if (!ValidateUniformLocation(name, location_object))
         return false;
     location = location_object->Location();
     uint32_t uniformElemSize = location_object->ElementSize();
     if (expectedElemSize != uniformElemSize) {
         ErrorInvalidOperation("%s: this function expected a uniform of element size %d,"
                               " got a uniform of element size %d", name,
                               expectedElemSize,
                               uniformElemSize);
         return false;
     }
     if (arrayLength == 0 ||
         arrayLength % expectedElemSize)
     {
         ErrorInvalidValue("%s: expected an array of length a multiple"
                           " of %d, got an array of length %d", name,
                           expectedElemSize,
                           arrayLength);
         return false;
     }
     const WebGLUniformInfo& info = location_object->Info();
     if (!info.isArray &&
         arrayLength != expectedElemSize) {
         ErrorInvalidOperation("%s: expected an array of length exactly"
                               " %d (since this uniform is not an array"
                               " uniform), got an array of length %d", name,
                               expectedElemSize,
                               arrayLength);
         return false;
     }
     numElementsToUpload =
         std::min(info.arraySize, arrayLength / expectedElemSize);
     return true;
 }
 bool
 WebGLContext::ValidateUniformMatrixArraySetter(const char* name, int dim, WebGLUniformLocation *location_object,
                                               GLint& location, uint32_t& numElementsToUpload, uint32_t arrayLength,
                                               WebGLboolean aTranspose)
 {
     uint32_t expectedElemSize = (dim)*(dim);
     if (IsContextLost())
         return false;
     if (!ValidateUniformLocation(name, location_object))
         return false;
     location = location_object->Location();
     uint32_t uniformElemSize = location_object->ElementSize();
     if (expectedElemSize != uniformElemSize) {
         ErrorInvalidOperation("%s: this function expected a uniform of element size %d,"
                               " got a uniform of element size %d", name,
                               expectedElemSize,
                               uniformElemSize);
         return false;
     }
     if (arrayLength == 0 ||
         arrayLength % expectedElemSize)
     {
         ErrorInvalidValue("%s: expected an array of length a multiple"
                           " of %d, got an array of length %d", name,
                           expectedElemSize,
                           arrayLength);
         return false;
     }
     const WebGLUniformInfo& info = location_object->Info();
     if (!info.isArray &&
         arrayLength != expectedElemSize) {
         ErrorInvalidOperation("%s: expected an array of length exactly"
                               " %d (since this uniform is not an array"
                               " uniform), got an array of length %d", name,
                               expectedElemSize,
                               arrayLength);
         return false;
     }
     if (aTranspose) {
         ErrorInvalidValue("%s: transpose must be FALSE as per the "
                           "OpenGL ES 2.0 spec", name);
         return false;
     }
     numElementsToUpload =
         std::min(info.arraySize, arrayLength / (expectedElemSize));
     return true;
 }
 bool
 WebGLContext::ValidateUniformSetter(const char* name, WebGLUniformLocation *location_object, GLint& location)
 {
     if (IsContextLost())
         return false;
     if (!ValidateUniformLocation(name, location_object))
         return false;
     location = location_object->Location();
     return true;
 }
 bool WebGLContext::ValidateAttribIndex(GLuint index, const char *info)
 {
     return mBoundVertexArray->EnsureAttrib(index, info);
 }
 bool WebGLContext::ValidateStencilParamsForDrawCall()
 {
   const char *msg = "%s set different front and back stencil %s. Drawing in this configuration is not allowed.";
   if (mStencilRefFront != mStencilRefBack) {
       ErrorInvalidOperation(msg, "stencilFuncSeparate", "reference values");
       return false;
   }
   if (mStencilValueMaskFront != mStencilValueMaskBack) {
       ErrorInvalidOperation(msg, "stencilFuncSeparate", "value masks");
       return false;
   }
   if (mStencilWriteMaskFront != mStencilWriteMaskBack) {
       ErrorInvalidOperation(msg, "stencilMaskSeparate", "write masks");
       return false;
   }
   return true;
 }
 static inline int32_t floorPOT(int32_t x)
 {
     MOZ_ASSERT(x > 0);
     int32_t pot = 1;
     while (pot < 0x40000000) {
         if (x < pot*2)
             break;
         pot *= 2;
     }
     return pot;
 }
 bool
 WebGLContext::InitAndValidateGL()
 {
     if (!gl) return false;
     GLenum error = gl->fGetError();
     if (error != LOCAL_GL_NO_ERROR) {
         GenerateWarning("GL error 0x%x occurred during OpenGL context initialization, before WebGL initialization!", error);
         return false;
     }
     mMinCapability = Preferences::GetBool("webgl.min_capability_mode", false);
     mDisableExtensions = Preferences::GetBool("webgl.disable-extensions", false);
     mLoseContextOnHeapMinimize = Preferences::GetBool("webgl.lose-context-on-heap-minimize", false);
     mCanLoseContextInForeground = Preferences::GetBool("webgl.can-lose-context-in-foreground", true);
     if (MinCapabilityMode()) {
       mDisableFragHighP = true;
     }
     // These are the default values, see 6.2 State tables in the
     // OpenGL ES 2.0.25 spec.
     mColorWriteMask[0] = 1;
     mColorWriteMask[1] = 1;
     mColorWriteMask[2] = 1;
     mColorWriteMask[3] = 1;
     mDepthWriteMask = 1;
     mColorClearValue[0] = 0.f;
     mColorClearValue[1] = 0.f;
     mColorClearValue[2] = 0.f;
     mColorClearValue[3] = 0.f;
     mDepthClearValue = 1.f;
     mStencilClearValue = 0;
     mStencilRefFront = 0;
     mStencilRefBack = 0;
     mStencilValueMaskFront = 0xffffffff;
     mStencilValueMaskBack  = 0xffffffff;
     mStencilWriteMaskFront = 0xffffffff;
     mStencilWriteMaskBack  = 0xffffffff;
     // Bindings, etc.
     mActiveTexture = 0;
     mEmitContextLostErrorOnce = true;
     mWebGLError = LOCAL_GL_NO_ERROR;
     mUnderlyingGLError = LOCAL_GL_NO_ERROR;
     mBound2DTextures.Clear();
     mBoundCubeMapTextures.Clear();
     mBoundArrayBuffer = nullptr;
     mBoundTransformFeedbackBuffer = nullptr;
     mCurrentProgram = nullptr;
     mBoundFramebuffer = nullptr;
     mBoundRenderbuffer = nullptr;
     MakeContextCurrent();
     // on desktop OpenGL, we always keep vertex attrib 0 array enabled
     if (!gl->IsGLES()) {
         gl->fEnableVertexAttribArray(0);
     }
     if (MinCapabilityMode()) {
         mGLMaxVertexAttribs = MINVALUE_GL_MAX_VERTEX_ATTRIBS;
     } else {
         gl->fGetIntegerv(LOCAL_GL_MAX_VERTEX_ATTRIBS, &mGLMaxVertexAttribs);
     }
     if (mGLMaxVertexAttribs < 8) {
         GenerateWarning("GL_MAX_VERTEX_ATTRIBS: %d is < 8!", mGLMaxVertexAttribs);
         return false;
     }
     // Note: GL_MAX_TEXTURE_UNITS is fixed at 4 for most desktop hardware,
     // even though the hardware supports much more.  The
     // GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS value is the accurate value.
     if (MinCapabilityMode()) {
         mGLMaxTextureUnits = MINVALUE_GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS;
     } else {
         gl->fGetIntegerv(LOCAL_GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS, &mGLMaxTextureUnits);
     }
     if (mGLMaxTextureUnits < 8) {
         GenerateWarning("GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS: %d is < 8!", mGLMaxTextureUnits);
         return false;
     }
     mBound2DTextures.SetLength(mGLMaxTextureUnits);
     mBoundCubeMapTextures.SetLength(mGLMaxTextureUnits);
     if (MinCapabilityMode()) {
         mGLMaxTextureSize = MINVALUE_GL_MAX_TEXTURE_SIZE;
         mGLMaxCubeMapTextureSize = MINVALUE_GL_MAX_CUBE_MAP_TEXTURE_SIZE;
         mGLMaxRenderbufferSize = MINVALUE_GL_MAX_RENDERBUFFER_SIZE;
         mGLMaxTextureImageUnits = MINVALUE_GL_MAX_TEXTURE_IMAGE_UNITS;
         mGLMaxVertexTextureImageUnits = MINVALUE_GL_MAX_VERTEX_TEXTURE_IMAGE_UNITS;
     } else {
         gl->fGetIntegerv(LOCAL_GL_MAX_TEXTURE_SIZE, &mGLMaxTextureSize);
         gl->fGetIntegerv(LOCAL_GL_MAX_CUBE_MAP_TEXTURE_SIZE, &mGLMaxCubeMapTextureSize);
         gl->fGetIntegerv(LOCAL_GL_MAX_RENDERBUFFER_SIZE, &mGLMaxRenderbufferSize);
         gl->fGetIntegerv(LOCAL_GL_MAX_TEXTURE_IMAGE_UNITS, &mGLMaxTextureImageUnits);
         gl->fGetIntegerv(LOCAL_GL_MAX_VERTEX_TEXTURE_IMAGE_UNITS, &mGLMaxVertexTextureImageUnits);
     }
     mGLMaxTextureSize = floorPOT(mGLMaxTextureSize);
     mGLMaxRenderbufferSize = floorPOT(mGLMaxRenderbufferSize);
     if (MinCapabilityMode()) {
         mGLMaxFragmentUniformVectors = MINVALUE_GL_MAX_FRAGMENT_UNIFORM_VECTORS;
         mGLMaxVertexUniformVectors = MINVALUE_GL_MAX_VERTEX_UNIFORM_VECTORS;
         mGLMaxVaryingVectors = MINVALUE_GL_MAX_VARYING_VECTORS;
     } else {
         if (gl->IsSupported(gl::GLFeature::ES2_compatibility)) {
             gl->fGetIntegerv(LOCAL_GL_MAX_FRAGMENT_UNIFORM_VECTORS, &mGLMaxFragmentUniformVectors);
             gl->fGetIntegerv(LOCAL_GL_MAX_VERTEX_UNIFORM_VECTORS, &mGLMaxVertexUniformVectors);
             gl->fGetIntegerv(LOCAL_GL_MAX_VARYING_VECTORS, &mGLMaxVaryingVectors);
         } else {
             gl->fGetIntegerv(LOCAL_GL_MAX_FRAGMENT_UNIFORM_COMPONENTS, &mGLMaxFragmentUniformVectors);
             mGLMaxFragmentUniformVectors /= 4;
             gl->fGetIntegerv(LOCAL_GL_MAX_VERTEX_UNIFORM_COMPONENTS, &mGLMaxVertexUniformVectors);
             mGLMaxVertexUniformVectors /= 4;
             // we are now going to try to read GL_MAX_VERTEX_OUTPUT_COMPONENTS and GL_MAX_FRAGMENT_INPUT_COMPONENTS,
             // however these constants only entered the OpenGL standard at OpenGL 3.2. So we will try reading,
             // and check OpenGL error for INVALID_ENUM.
             // before we start, we check that no error already occurred, to prevent hiding it in our subsequent error handling
             error = gl->GetAndClearError();
             if (error != LOCAL_GL_NO_ERROR) {
                 GenerateWarning("GL error 0x%x occurred during WebGL context initialization!", error);
                 return false;
             }
             // On the public_webgl list, "problematic GetParameter pnames" thread, the following formula was given:
             //   mGLMaxVaryingVectors = min (GL_MAX_VERTEX_OUTPUT_COMPONENTS, GL_MAX_FRAGMENT_INPUT_COMPONENTS) / 4
             GLint maxVertexOutputComponents,
                   minFragmentInputComponents;
             gl->fGetIntegerv(LOCAL_GL_MAX_VERTEX_OUTPUT_COMPONENTS, &maxVertexOutputComponents);
             gl->fGetIntegerv(LOCAL_GL_MAX_FRAGMENT_INPUT_COMPONENTS, &minFragmentInputComponents);
             error = gl->GetAndClearError();
             switch (error) {
                 case LOCAL_GL_NO_ERROR:
                     mGLMaxVaryingVectors = std::min(maxVertexOutputComponents, minFragmentInputComponents) / 4;
                     break;
                 case LOCAL_GL_INVALID_ENUM:
                     mGLMaxVaryingVectors = 16; // = 64/4, 64 is the min value for maxVertexOutputComponents in OpenGL 3.2 spec
                     break;
                 default:
                     GenerateWarning("GL error 0x%x occurred during WebGL context initialization!", error);
                     return false;
             }
         }
     }
     // Always 1 for GLES2
     mMaxFramebufferColorAttachments = 1;
     if (!gl->IsGLES()) {
         // gl_PointSize is always available in ES2 GLSL, but has to be
         // specifically enabled on desktop GLSL.
         gl->fEnable(LOCAL_GL_VERTEX_PROGRAM_POINT_SIZE);
         // gl_PointCoord is always available in ES2 GLSL and in newer desktop GLSL versions, but apparently
         // not in OpenGL 2 and apparently not (due to a driver bug) on certain NVIDIA setups. See:
         //   http://www.opengl.org/discussion_boards/ubbthreads.php?ubb=showflat&Number=261472
         // Note that this used to cause crashes on old ATI drivers... hopefully not a significant
         // problem anymore. See bug 602183.
         gl->fEnable(LOCAL_GL_POINT_SPRITE);
     }
 #ifdef XP_MACOSX
     if (gl->WorkAroundDriverBugs() &&
         gl->Vendor() == gl::GLVendor::ATI) {
         // The Mac ATI driver, in all known OSX version up to and including 10.8,
         // renders points sprites upside-down. Apple bug 11778921
         gl->fPointParameterf(LOCAL_GL_POINT_SPRITE_COORD_ORIGIN, LOCAL_GL_LOWER_LEFT);
     }
 #endif
     // Check the shader validator pref
     NS_ENSURE_TRUE(Preferences::GetRootBranch(), false);
     mShaderValidation =
         Preferences::GetBool("webgl.shader_validator", mShaderValidation);
     // initialize shader translator
     if (mShaderValidation) {
         if (!ShInitialize()) {
             GenerateWarning("GLSL translator initialization failed!");
             return false;
         }
     }
     // Mesa can only be detected with the GL_VERSION string, of the form "2.1 Mesa 7.11.0"
     mIsMesa = strstr((const char *)(gl->fGetString(LOCAL_GL_VERSION)), "Mesa");
     // notice that the point of calling GetAndClearError here is not only to check for error,
     // it is also to reset the error flags so that a subsequent WebGL getError call will give the correct result.
     error = gl->GetAndClearError();
     if (error != LOCAL_GL_NO_ERROR) {
         GenerateWarning("GL error 0x%x occurred during WebGL context initialization!", error);
         return false;
     }
     if (IsWebGL2() &&
         !InitWebGL2())
     {
         // Todo: Bug 898404: Only allow WebGL2 on GL>=3.0 on desktop GL.
         return false;
     }
     mMemoryPressureObserver
         = new WebGLMemoryPressureObserver(this);
     nsCOMPtr<nsIObserverService> observerService
         = mozilla::services::GetObserverService();
     if (observerService) {
         observerService->AddObserver(mMemoryPressureObserver,
                                      "memory-pressure",
                                      false);
     }
     mDefaultVertexArray = new WebGLVertexArray(this);
     mDefaultVertexArray->mAttribs.SetLength(mGLMaxVertexAttribs);
     mBoundVertexArray = mDefaultVertexArray;
     return true;
 }

The Tor Browser / annotate

content/canvas/src/WebGLContextValidate.cpp@deefc01c0e14 (annotated)

content/canvas/src/WebGLContextValidate.cpp