/* -*- 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 "WebGL1Context.h" #include "WebGLObjectModel.h" #include "WebGLExtensions.h" #include "WebGLContextUtils.h" #include "WebGLBuffer.h" #include "WebGLVertexAttribData.h" #include "WebGLMemoryTracker.h" #include "WebGLFramebuffer.h" #include "WebGLVertexArray.h" #include "WebGLQuery.h" #include "AccessCheck.h" #include "nsIConsoleService.h" #include "nsServiceManagerUtils.h" #include "nsIClassInfoImpl.h" #include "nsContentUtils.h" #include "nsIXPConnect.h" #include "nsError.h" #include "nsIGfxInfo.h" #include "nsIWidget.h" #include "nsIVariant.h" #include "ImageEncoder.h" #include "gfxContext.h" #include "gfxPattern.h" #include "gfxUtils.h" #include "CanvasUtils.h" #include "nsDisplayList.h" #include "GLContextProvider.h" #include "GLContext.h" #include "ScopedGLHelpers.h" #include "GLReadTexImageHelper.h" #include "gfxCrashReporterUtils.h" #include "nsSVGEffects.h" #include "prenv.h" #include "mozilla/Preferences.h" #include "mozilla/Services.h" #include "mozilla/Telemetry.h" #include "nsIObserverService.h" #include "mozilla/Services.h" #include "mozilla/dom/WebGLRenderingContextBinding.h" #include "mozilla/dom/BindingUtils.h" #include "mozilla/dom/ImageData.h" #include "mozilla/ProcessPriorityManager.h" #include "mozilla/EnumeratedArrayCycleCollection.h" #include "Layers.h" #ifdef MOZ_WIDGET_GONK #include "mozilla/layers/ShadowLayers.h" #endif using namespace mozilla; using namespace mozilla::dom; using namespace mozilla::gfx; using namespace mozilla::gl; using namespace mozilla::layers; NS_IMETHODIMP WebGLMemoryPressureObserver::Observe(nsISupports* aSubject, const char* aTopic, const char16_t* aSomeData) { if (strcmp(aTopic, "memory-pressure")) return NS_OK; bool wantToLoseContext = true; if (!mContext->mCanLoseContextInForeground && ProcessPriorityManager::CurrentProcessIsForeground()) { wantToLoseContext = false; } else if (!nsCRT::strcmp(aSomeData, MOZ_UTF16("heap-minimize"))) { wantToLoseContext = mContext->mLoseContextOnHeapMinimize; } if (wantToLoseContext) { mContext->ForceLoseContext(); } return NS_OK; } WebGLContextOptions::WebGLContextOptions() : alpha(true), depth(true), stencil(false), premultipliedAlpha(true), antialias(true), preserveDrawingBuffer(false) { // Set default alpha state based on preference. if (Preferences::GetBool("webgl.default-no-alpha", false)) alpha = false; } WebGLContext::WebGLContext() : gl(nullptr) { SetIsDOMBinding(); mGeneration = 0; mInvalidated = false; mShouldPresent = true; mResetLayer = true; mOptionsFrozen = false; mActiveTexture = 0; mPixelStoreFlipY = false; mPixelStorePremultiplyAlpha = false; mPixelStoreColorspaceConversion = BROWSER_DEFAULT_WEBGL; mShaderValidation = true; mFakeBlackStatus = WebGLContextFakeBlackStatus::NotNeeded; mVertexAttrib0Vector[0] = 0; mVertexAttrib0Vector[1] = 0; mVertexAttrib0Vector[2] = 0; mVertexAttrib0Vector[3] = 1; mFakeVertexAttrib0BufferObjectVector[0] = 0; mFakeVertexAttrib0BufferObjectVector[1] = 0; mFakeVertexAttrib0BufferObjectVector[2] = 0; mFakeVertexAttrib0BufferObjectVector[3] = 1; mFakeVertexAttrib0BufferObjectSize = 0; mFakeVertexAttrib0BufferObject = 0; mFakeVertexAttrib0BufferStatus = WebGLVertexAttrib0Status::Default; mViewportX = 0; mViewportY = 0; mViewportWidth = 0; mViewportHeight = 0; mScissorTestEnabled = 0; mDitherEnabled = 1; mRasterizerDiscardEnabled = 0; // OpenGL ES 3.0 spec p244 // initialize some GL values: we're going to get them from the GL and use them as the sizes of arrays, // so in case glGetIntegerv leaves them uninitialized because of a GL bug, we would have very weird crashes. mGLMaxVertexAttribs = 0; mGLMaxTextureUnits = 0; mGLMaxTextureSize = 0; mGLMaxCubeMapTextureSize = 0; mGLMaxRenderbufferSize = 0; mGLMaxTextureImageUnits = 0; mGLMaxVertexTextureImageUnits = 0; mGLMaxVaryingVectors = 0; mGLMaxFragmentUniformVectors = 0; mGLMaxVertexUniformVectors = 0; mGLMaxColorAttachments = 1; mGLMaxDrawBuffers = 1; mGLMaxTransformFeedbackSeparateAttribs = 0; // See OpenGL ES 2.0.25 spec, 6.2 State Tables, table 6.13 mPixelStorePackAlignment = 4; mPixelStoreUnpackAlignment = 4; WebGLMemoryTracker::AddWebGLContext(this); mAllowContextRestore = true; mLastLossWasSimulated = false; mContextLossTimerRunning = false; mRunContextLossTimerAgain = false; mContextRestorer = do_CreateInstance("@mozilla.org/timer;1"); mContextStatus = ContextNotLost; mLoseContextOnHeapMinimize = false; mCanLoseContextInForeground = true; mAlreadyGeneratedWarnings = 0; mAlreadyWarnedAboutFakeVertexAttrib0 = false; mAlreadyWarnedAboutViewportLargerThanDest = false; mMaxWarnings = Preferences::GetInt("webgl.max-warnings-per-context", 32); if (mMaxWarnings < -1) { GenerateWarning("webgl.max-warnings-per-context size is too large (seems like a negative value wrapped)"); mMaxWarnings = 0; } mLastUseIndex = 0; InvalidateBufferFetching(); mBackbufferNeedsClear = true; mDisableFragHighP = false; mDrawCallsSinceLastFlush = 0; } WebGLContext::~WebGLContext() { DestroyResourcesAndContext(); WebGLMemoryTracker::RemoveWebGLContext(this); TerminateContextLossTimer(); mContextRestorer = nullptr; } void WebGLContext::DestroyResourcesAndContext() { if (mMemoryPressureObserver) { nsCOMPtr observerService = mozilla::services::GetObserverService(); if (observerService) { observerService->RemoveObserver(mMemoryPressureObserver, "memory-pressure"); } mMemoryPressureObserver = nullptr; } if (!gl) return; gl->MakeCurrent(); mBound2DTextures.Clear(); mBoundCubeMapTextures.Clear(); mBoundArrayBuffer = nullptr; mBoundTransformFeedbackBuffer = nullptr; mCurrentProgram = nullptr; mBoundFramebuffer = nullptr; mActiveOcclusionQuery = nullptr; mBoundRenderbuffer = nullptr; mBoundVertexArray = nullptr; mDefaultVertexArray = nullptr; while (!mTextures.isEmpty()) mTextures.getLast()->DeleteOnce(); while (!mVertexArrays.isEmpty()) mVertexArrays.getLast()->DeleteOnce(); while (!mBuffers.isEmpty()) mBuffers.getLast()->DeleteOnce(); while (!mRenderbuffers.isEmpty()) mRenderbuffers.getLast()->DeleteOnce(); while (!mFramebuffers.isEmpty()) mFramebuffers.getLast()->DeleteOnce(); while (!mShaders.isEmpty()) mShaders.getLast()->DeleteOnce(); while (!mPrograms.isEmpty()) mPrograms.getLast()->DeleteOnce(); while (!mQueries.isEmpty()) mQueries.getLast()->DeleteOnce(); mBlackOpaqueTexture2D = nullptr; mBlackOpaqueTextureCubeMap = nullptr; mBlackTransparentTexture2D = nullptr; mBlackTransparentTextureCubeMap = nullptr; if (mFakeVertexAttrib0BufferObject) { gl->fDeleteBuffers(1, &mFakeVertexAttrib0BufferObject); } // disable all extensions except "WEBGL_lose_context". see bug #927969 // spec: http://www.khronos.org/registry/webgl/specs/latest/1.0/#5.15.2 for (size_t i = 0; i < size_t(WebGLExtensionID::Max); ++i) { WebGLExtensionID extension = WebGLExtensionID(i); if (!IsExtensionEnabled(extension) || (extension == WebGLExtensionID::WEBGL_lose_context)) continue; mExtensions[extension]->MarkLost(); mExtensions[extension] = nullptr; } // We just got rid of everything, so the context had better // have been going away. #ifdef DEBUG if (gl->DebugMode()) { printf_stderr("--- WebGL context destroyed: %p\n", gl.get()); } #endif gl = nullptr; } void WebGLContext::Invalidate() { if (mInvalidated) return; if (!mCanvasElement) return; nsSVGEffects::InvalidateDirectRenderingObservers(mCanvasElement); mInvalidated = true; mCanvasElement->InvalidateCanvasContent(nullptr); } // // nsICanvasRenderingContextInternal // NS_IMETHODIMP WebGLContext::SetContextOptions(JSContext* aCx, JS::Handle aOptions) { if (aOptions.isNullOrUndefined() && mOptionsFrozen) { return NS_OK; } WebGLContextAttributes attributes; NS_ENSURE_TRUE(attributes.Init(aCx, aOptions), NS_ERROR_UNEXPECTED); WebGLContextOptions newOpts; newOpts.stencil = attributes.mStencil; newOpts.depth = attributes.mDepth; newOpts.premultipliedAlpha = attributes.mPremultipliedAlpha; newOpts.antialias = attributes.mAntialias; newOpts.preserveDrawingBuffer = attributes.mPreserveDrawingBuffer; if (attributes.mAlpha.WasPassed()) { newOpts.alpha = attributes.mAlpha.Value(); } // enforce that if stencil is specified, we also give back depth newOpts.depth |= newOpts.stencil; #if 0 GenerateWarning("aaHint: %d stencil: %d depth: %d alpha: %d premult: %d preserve: %d\n", newOpts.antialias ? 1 : 0, newOpts.stencil ? 1 : 0, newOpts.depth ? 1 : 0, newOpts.alpha ? 1 : 0, newOpts.premultipliedAlpha ? 1 : 0, newOpts.preserveDrawingBuffer ? 1 : 0); #endif if (mOptionsFrozen && newOpts != mOptions) { // Error if the options are already frozen, and the ones that were asked for // aren't the same as what they were originally. return NS_ERROR_FAILURE; } mOptions = newOpts; return NS_OK; } #ifdef DEBUG int32_t WebGLContext::GetWidth() const { return mWidth; } int32_t WebGLContext::GetHeight() const { return mHeight; } #endif NS_IMETHODIMP WebGLContext::SetDimensions(int32_t width, int32_t height) { // Early error return cases if (width < 0 || height < 0) { GenerateWarning("Canvas size is too large (seems like a negative value wrapped)"); return NS_ERROR_OUT_OF_MEMORY; } if (!GetCanvas()) return NS_ERROR_FAILURE; // Early success return cases GetCanvas()->InvalidateCanvas(); if (gl && mWidth == width && mHeight == height) return NS_OK; // Zero-sized surfaces can cause problems. if (width == 0) { width = 1; } if (height == 0) { height = 1; } // If we already have a gl context, then we just need to resize it if (gl) { MakeContextCurrent(); // If we've already drawn, we should commit the current buffer. PresentScreenBuffer(); // ResizeOffscreen scraps the current prod buffer before making a new one. gl->ResizeOffscreen(gfx::IntSize(width, height)); // Doesn't matter if it succeeds (soft-fail) // It's unlikely that we'll get a proper-sized context if we recreate if we didn't on resize // everything's good, we're done here mWidth = gl->OffscreenSize().width; mHeight = gl->OffscreenSize().height; mResetLayer = true; mBackbufferNeedsClear = true; return NS_OK; } // End of early return cases. // At this point we know that we're not just resizing an existing context, // we are initializing a new context. // if we exceeded either the global or the per-principal limit for WebGL contexts, // lose the oldest-used context now to free resources. Note that we can't do that // in the WebGLContext constructor as we don't have a canvas element yet there. // Here is the right place to do so, as we are about to create the OpenGL context // and that is what can fail if we already have too many. LoseOldestWebGLContextIfLimitExceeded(); // Get some prefs for some preferred/overriden things NS_ENSURE_TRUE(Preferences::GetRootBranch(), NS_ERROR_FAILURE); #ifdef XP_WIN bool preferEGL = Preferences::GetBool("webgl.prefer-egl", false); bool preferOpenGL = Preferences::GetBool("webgl.prefer-native-gl", false); #endif bool forceEnabled = Preferences::GetBool("webgl.force-enabled", false); bool disabled = Preferences::GetBool("webgl.disabled", false); bool prefer16bit = Preferences::GetBool("webgl.prefer-16bpp", false); ScopedGfxFeatureReporter reporter("WebGL", forceEnabled); if (disabled) return NS_ERROR_FAILURE; // We're going to create an entirely new context. If our // generation is not 0 right now (that is, if this isn't the first // context we're creating), we may have to dispatch a context lost // event. // If incrementing the generation would cause overflow, // don't allow it. Allowing this would allow us to use // resource handles created from older context generations. if (!(mGeneration + 1).isValid()) return NS_ERROR_FAILURE; // exit without changing the value of mGeneration SurfaceCaps caps; caps.color = true; caps.alpha = mOptions.alpha; caps.depth = mOptions.depth; caps.stencil = mOptions.stencil; // we should really have this behind a // |gfxPlatform::GetPlatform()->GetScreenDepth() == 16| check, but // for now it's just behind a pref for testing/evaluation. caps.bpp16 = prefer16bit; caps.preserve = mOptions.preserveDrawingBuffer; #ifdef MOZ_WIDGET_GONK nsIWidget *docWidget = nsContentUtils::WidgetForDocument(mCanvasElement->OwnerDoc()); if (docWidget) { layers::LayerManager *layerManager = docWidget->GetLayerManager(); if (layerManager) { // XXX we really want "AsSurfaceAllocator" here for generality layers::ShadowLayerForwarder *forwarder = layerManager->AsShadowForwarder(); if (forwarder) { caps.surfaceAllocator = static_cast(forwarder); } } } #endif bool forceMSAA = Preferences::GetBool("webgl.msaa-force", false); int32_t status; nsCOMPtr gfxInfo = do_GetService("@mozilla.org/gfx/info;1"); if (mOptions.antialias && gfxInfo && NS_SUCCEEDED(gfxInfo->GetFeatureStatus(nsIGfxInfo::FEATURE_WEBGL_MSAA, &status))) { if (status == nsIGfxInfo::FEATURE_NO_INFO || forceMSAA) { caps.antialias = true; } } #ifdef XP_WIN if (PR_GetEnv("MOZ_WEBGL_PREFER_EGL")) { preferEGL = true; } #endif // Ask GfxInfo about what we should use bool useOpenGL = true; #ifdef XP_WIN bool useANGLE = true; #endif if (gfxInfo && !forceEnabled) { if (NS_SUCCEEDED(gfxInfo->GetFeatureStatus(nsIGfxInfo::FEATURE_WEBGL_OPENGL, &status))) { if (status != nsIGfxInfo::FEATURE_NO_INFO) { useOpenGL = false; } } #ifdef XP_WIN if (NS_SUCCEEDED(gfxInfo->GetFeatureStatus(nsIGfxInfo::FEATURE_WEBGL_ANGLE, &status))) { if (status != nsIGfxInfo::FEATURE_NO_INFO) { useANGLE = false; } } #endif } #ifdef XP_WIN // allow forcing GL and not EGL/ANGLE if (PR_GetEnv("MOZ_WEBGL_FORCE_OPENGL")) { preferEGL = false; useANGLE = false; useOpenGL = true; } #endif gfxIntSize size(width, height); #ifdef XP_WIN // if we want EGL, try it now if (!gl && (preferEGL || useANGLE) && !preferOpenGL) { gl = gl::GLContextProviderEGL::CreateOffscreen(size, caps); if (!gl || !InitAndValidateGL()) { GenerateWarning("Error during ANGLE OpenGL ES initialization"); return NS_ERROR_FAILURE; } } #endif // try the default provider, whatever that is if (!gl && useOpenGL) { gl = gl::GLContextProvider::CreateOffscreen(size, caps); if (gl && !InitAndValidateGL()) { GenerateWarning("Error during OpenGL initialization"); return NS_ERROR_FAILURE; } } if (!gl) { GenerateWarning("Can't get a usable WebGL context"); return NS_ERROR_FAILURE; } #ifdef DEBUG if (gl->DebugMode()) { printf_stderr("--- WebGL context created: %p\n", gl.get()); } #endif mWidth = width; mHeight = height; mViewportWidth = width; mViewportHeight = height; mResetLayer = true; mOptionsFrozen = true; // increment the generation number ++mGeneration; #if 0 if (mGeneration > 0) { // XXX dispatch context lost event } #endif MakeContextCurrent(); // Make sure that we clear this out, otherwise // we'll end up displaying random memory gl->fBindFramebuffer(LOCAL_GL_FRAMEBUFFER, 0); AssertCachedBindings(); AssertCachedState(); // Clear immediately, because we need to present the cleared initial // buffer. mBackbufferNeedsClear = true; ClearBackbufferIfNeeded(); mShouldPresent = true; MOZ_ASSERT(gl->Caps().color == caps.color); MOZ_ASSERT(gl->Caps().alpha == caps.alpha); MOZ_ASSERT(gl->Caps().depth == caps.depth || !gl->Caps().depth); MOZ_ASSERT(gl->Caps().stencil == caps.stencil || !gl->Caps().stencil); MOZ_ASSERT(gl->Caps().antialias == caps.antialias || !gl->Caps().antialias); MOZ_ASSERT(gl->Caps().preserve == caps.preserve); AssertCachedBindings(); AssertCachedState(); reporter.SetSuccessful(); return NS_OK; } void WebGLContext::ClearBackbufferIfNeeded() { if (!mBackbufferNeedsClear) return; #ifdef DEBUG gl->MakeCurrent(); GLuint fb = 0; gl->GetUIntegerv(LOCAL_GL_FRAMEBUFFER_BINDING, &fb); MOZ_ASSERT(fb == 0); #endif ClearScreen(); mBackbufferNeedsClear = false; } void WebGLContext::LoseOldestWebGLContextIfLimitExceeded() { #ifdef MOZ_GFX_OPTIMIZE_MOBILE // some mobile devices can't have more than 8 GL contexts overall const size_t kMaxWebGLContextsPerPrincipal = 2; const size_t kMaxWebGLContexts = 4; #else const size_t kMaxWebGLContextsPerPrincipal = 16; const size_t kMaxWebGLContexts = 32; #endif MOZ_ASSERT(kMaxWebGLContextsPerPrincipal < kMaxWebGLContexts); // it's important to update the index on a new context before losing old contexts, // otherwise new unused contexts would all have index 0 and we couldn't distinguish older ones // when choosing which one to lose first. UpdateLastUseIndex(); WebGLMemoryTracker::ContextsArrayType &contexts = WebGLMemoryTracker::Contexts(); // quick exit path, should cover a majority of cases if (contexts.Length() <= kMaxWebGLContextsPerPrincipal) { return; } // note that here by "context" we mean "non-lost context". See the check for // IsContextLost() below. Indeed, the point of this function is to maybe lose // some currently non-lost context. uint64_t oldestIndex = UINT64_MAX; uint64_t oldestIndexThisPrincipal = UINT64_MAX; const WebGLContext *oldestContext = nullptr; const WebGLContext *oldestContextThisPrincipal = nullptr; size_t numContexts = 0; size_t numContextsThisPrincipal = 0; for(size_t i = 0; i < contexts.Length(); ++i) { // don't want to lose ourselves. if (contexts[i] == this) continue; if (contexts[i]->IsContextLost()) continue; if (!contexts[i]->GetCanvas()) { // Zombie context: the canvas is already destroyed, but something else // (typically the compositor) is still holding on to the context. // Killing zombies is a no-brainer. const_cast(contexts[i])->LoseContext(); continue; } numContexts++; if (contexts[i]->mLastUseIndex < oldestIndex) { oldestIndex = contexts[i]->mLastUseIndex; oldestContext = contexts[i]; } nsIPrincipal *ourPrincipal = GetCanvas()->NodePrincipal(); nsIPrincipal *theirPrincipal = contexts[i]->GetCanvas()->NodePrincipal(); bool samePrincipal; nsresult rv = ourPrincipal->Equals(theirPrincipal, &samePrincipal); if (NS_SUCCEEDED(rv) && samePrincipal) { numContextsThisPrincipal++; if (contexts[i]->mLastUseIndex < oldestIndexThisPrincipal) { oldestIndexThisPrincipal = contexts[i]->mLastUseIndex; oldestContextThisPrincipal = contexts[i]; } } } if (numContextsThisPrincipal > kMaxWebGLContextsPerPrincipal) { GenerateWarning("Exceeded %d live WebGL contexts for this principal, losing the " "least recently used one.", kMaxWebGLContextsPerPrincipal); MOZ_ASSERT(oldestContextThisPrincipal); // if we reach this point, this can't be null const_cast(oldestContextThisPrincipal)->LoseContext(); } else if (numContexts > kMaxWebGLContexts) { GenerateWarning("Exceeded %d live WebGL contexts, losing the least recently used one.", kMaxWebGLContexts); MOZ_ASSERT(oldestContext); // if we reach this point, this can't be null const_cast(oldestContext)->LoseContext(); } } void WebGLContext::GetImageBuffer(uint8_t** aImageBuffer, int32_t* aFormat) { *aImageBuffer = nullptr; *aFormat = 0; // Use GetSurfaceSnapshot() to make sure that appropriate y-flip gets applied bool premult; RefPtr snapshot = GetSurfaceSnapshot(mOptions.premultipliedAlpha ? nullptr : &premult); if (!snapshot) { return; } MOZ_ASSERT(mOptions.premultipliedAlpha || !premult, "We must get unpremult when we ask for it!"); RefPtr dataSurface = snapshot->GetDataSurface(); DataSourceSurface::MappedSurface map; if (!dataSurface->Map(DataSourceSurface::MapType::READ, &map)) { return; } static const fallible_t fallible = fallible_t(); uint8_t* imageBuffer = new (fallible) uint8_t[mWidth * mHeight * 4]; if (!imageBuffer) { dataSurface->Unmap(); return; } memcpy(imageBuffer, map.mData, mWidth * mHeight * 4); dataSurface->Unmap(); int32_t format = imgIEncoder::INPUT_FORMAT_HOSTARGB; if (!mOptions.premultipliedAlpha) { // We need to convert to INPUT_FORMAT_RGBA, otherwise // we are automatically considered premult, and unpremult'd. // Yes, it is THAT silly. // Except for different lossy conversions by color, // we could probably just change the label, and not change the data. gfxUtils::ConvertBGRAtoRGBA(imageBuffer, mWidth * mHeight * 4); format = imgIEncoder::INPUT_FORMAT_RGBA; } *aImageBuffer = imageBuffer; *aFormat = format; } NS_IMETHODIMP WebGLContext::GetInputStream(const char* aMimeType, const char16_t* aEncoderOptions, nsIInputStream **aStream) { NS_ASSERTION(gl, "GetInputStream on invalid context?"); if (!gl) return NS_ERROR_FAILURE; nsCString enccid("@mozilla.org/image/encoder;2?type="); enccid += aMimeType; nsCOMPtr encoder = do_CreateInstance(enccid.get()); if (!encoder) { return NS_ERROR_FAILURE; } nsAutoArrayPtr imageBuffer; int32_t format = 0; GetImageBuffer(getter_Transfers(imageBuffer), &format); if (!imageBuffer) { return NS_ERROR_FAILURE; } return ImageEncoder::GetInputStream(mWidth, mHeight, imageBuffer, format, encoder, aEncoderOptions, aStream); } void WebGLContext::UpdateLastUseIndex() { static CheckedInt sIndex = 0; sIndex++; // should never happen with 64-bit; trying to handle this would be riskier than // not handling it as the handler code would never get exercised. if (!sIndex.isValid()) { NS_RUNTIMEABORT("Can't believe it's been 2^64 transactions already!"); } mLastUseIndex = sIndex.value(); } static uint8_t gWebGLLayerUserData; namespace mozilla { class WebGLContextUserData : public LayerUserData { public: WebGLContextUserData(HTMLCanvasElement *aContent) : mContent(aContent) {} /* PreTransactionCallback gets called by the Layers code every time the * WebGL canvas is going to be composited. */ static void PreTransactionCallback(void* data) { WebGLContextUserData* userdata = static_cast(data); HTMLCanvasElement* canvas = userdata->mContent; WebGLContext* context = static_cast(canvas->GetContextAtIndex(0)); // Present our screenbuffer, if needed. context->PresentScreenBuffer(); context->mDrawCallsSinceLastFlush = 0; } /** DidTransactionCallback gets called by the Layers code everytime the WebGL canvas gets composite, * so it really is the right place to put actions that have to be performed upon compositing */ static void DidTransactionCallback(void* aData) { WebGLContextUserData *userdata = static_cast(aData); HTMLCanvasElement *canvas = userdata->mContent; WebGLContext *context = static_cast(canvas->GetContextAtIndex(0)); // Mark ourselves as no longer invalidated. context->MarkContextClean(); context->UpdateLastUseIndex(); } private: nsRefPtr mContent; }; } // end namespace mozilla already_AddRefed WebGLContext::GetCanvasLayer(nsDisplayListBuilder* aBuilder, CanvasLayer *aOldLayer, LayerManager *aManager) { if (IsContextLost()) return nullptr; if (!mResetLayer && aOldLayer && aOldLayer->HasUserData(&gWebGLLayerUserData)) { nsRefPtr ret = aOldLayer; return ret.forget(); } nsRefPtr canvasLayer = aManager->CreateCanvasLayer(); if (!canvasLayer) { NS_WARNING("CreateCanvasLayer returned null!"); return nullptr; } WebGLContextUserData *userData = nullptr; if (aBuilder->IsPaintingToWindow()) { // Make the layer tell us whenever a transaction finishes (including // the current transaction), so we can clear our invalidation state and // start invalidating again. We need to do this for the layer that is // being painted to a window (there shouldn't be more than one at a time, // and if there is, flushing the invalidation state more often than // necessary is harmless). // The layer will be destroyed when we tear down the presentation // (at the latest), at which time this userData will be destroyed, // releasing the reference to the element. // The userData will receive DidTransactionCallbacks, which flush the // the invalidation state to indicate that the canvas is up to date. userData = new WebGLContextUserData(mCanvasElement); canvasLayer->SetDidTransactionCallback( WebGLContextUserData::DidTransactionCallback, userData); canvasLayer->SetPreTransactionCallback( WebGLContextUserData::PreTransactionCallback, userData); } canvasLayer->SetUserData(&gWebGLLayerUserData, userData); CanvasLayer::Data data; data.mGLContext = gl; data.mSize = nsIntSize(mWidth, mHeight); data.mHasAlpha = gl->Caps().alpha; data.mIsGLAlphaPremult = IsPremultAlpha(); canvasLayer->Initialize(data); uint32_t flags = gl->Caps().alpha ? 0 : Layer::CONTENT_OPAQUE; canvasLayer->SetContentFlags(flags); canvasLayer->Updated(); mResetLayer = false; return canvasLayer.forget(); } void WebGLContext::GetContextAttributes(Nullable &retval) { retval.SetNull(); if (IsContextLost()) return; dom::WebGLContextAttributes& result = retval.SetValue(); const PixelBufferFormat& format = gl->GetPixelFormat(); result.mAlpha.Construct(format.alpha > 0); result.mDepth = format.depth > 0; result.mStencil = format.stencil > 0; result.mAntialias = format.samples > 1; result.mPremultipliedAlpha = mOptions.premultipliedAlpha; result.mPreserveDrawingBuffer = mOptions.preserveDrawingBuffer; } /* [noscript] DOMString mozGetUnderlyingParamString(in GLenum pname); */ NS_IMETHODIMP WebGLContext::MozGetUnderlyingParamString(uint32_t pname, nsAString& retval) { if (IsContextLost()) return NS_OK; retval.SetIsVoid(true); MakeContextCurrent(); switch (pname) { case LOCAL_GL_VENDOR: case LOCAL_GL_RENDERER: case LOCAL_GL_VERSION: case LOCAL_GL_SHADING_LANGUAGE_VERSION: case LOCAL_GL_EXTENSIONS: { const char *s = (const char *) gl->fGetString(pname); retval.Assign(NS_ConvertASCIItoUTF16(nsDependentCString(s))); } break; default: return NS_ERROR_INVALID_ARG; } return NS_OK; } void WebGLContext::ClearScreen() { bool colorAttachmentsMask[WebGLContext::kMaxColorAttachments] = {false}; MakeContextCurrent(); ScopedBindFramebuffer autoFB(gl, 0); GLbitfield clearMask = LOCAL_GL_COLOR_BUFFER_BIT; if (mOptions.depth) clearMask |= LOCAL_GL_DEPTH_BUFFER_BIT; if (mOptions.stencil) clearMask |= LOCAL_GL_STENCIL_BUFFER_BIT; colorAttachmentsMask[0] = true; ForceClearFramebufferWithDefaultValues(clearMask, colorAttachmentsMask); } void WebGLContext::ForceClearFramebufferWithDefaultValues(GLbitfield mask, const bool colorAttachmentsMask[kMaxColorAttachments]) { MakeContextCurrent(); bool initializeColorBuffer = 0 != (mask & LOCAL_GL_COLOR_BUFFER_BIT); bool initializeDepthBuffer = 0 != (mask & LOCAL_GL_DEPTH_BUFFER_BIT); bool initializeStencilBuffer = 0 != (mask & LOCAL_GL_STENCIL_BUFFER_BIT); bool drawBuffersIsEnabled = IsExtensionEnabled(WebGLExtensionID::WEBGL_draw_buffers); bool shouldOverrideDrawBuffers = false; GLenum currentDrawBuffers[WebGLContext::kMaxColorAttachments]; // Fun GL fact: No need to worry about the viewport here, glViewport is just // setting up a coordinates transformation, it doesn't affect glClear at all. AssertCachedState(); // Can't check cached bindings, as we could // have a different FB bound temporarily. // Prepare GL state for clearing. gl->fDisable(LOCAL_GL_SCISSOR_TEST); if (initializeColorBuffer) { if (drawBuffersIsEnabled) { GLenum drawBuffersCommand[WebGLContext::kMaxColorAttachments] = { LOCAL_GL_NONE }; for(int32_t i = 0; i < mGLMaxDrawBuffers; i++) { GLint temp; gl->fGetIntegerv(LOCAL_GL_DRAW_BUFFER0 + i, &temp); currentDrawBuffers[i] = temp; if (colorAttachmentsMask[i]) { drawBuffersCommand[i] = LOCAL_GL_COLOR_ATTACHMENT0 + i; } if (currentDrawBuffers[i] != drawBuffersCommand[i]) shouldOverrideDrawBuffers = true; } // calling draw buffers can cause resolves on adreno drivers so // we try to avoid calling it if (shouldOverrideDrawBuffers) gl->fDrawBuffers(mGLMaxDrawBuffers, drawBuffersCommand); } gl->fColorMask(1, 1, 1, 1); gl->fClearColor(0.0f, 0.0f, 0.0f, 0.0f); } if (initializeDepthBuffer) { gl->fDepthMask(1); gl->fClearDepth(1.0f); } if (initializeStencilBuffer) { // "The clear operation always uses the front stencil write mask // when clearing the stencil buffer." gl->fStencilMaskSeparate(LOCAL_GL_FRONT, 0xffffffff); gl->fStencilMaskSeparate(LOCAL_GL_BACK, 0xffffffff); gl->fClearStencil(0); } if (mRasterizerDiscardEnabled) { gl->fDisable(LOCAL_GL_RASTERIZER_DISCARD); } // Do the clear! gl->fClear(mask); // And reset! if (mScissorTestEnabled) gl->fEnable(LOCAL_GL_SCISSOR_TEST); if (mRasterizerDiscardEnabled) { gl->fEnable(LOCAL_GL_RASTERIZER_DISCARD); } // Restore GL state after clearing. if (initializeColorBuffer) { if (shouldOverrideDrawBuffers) { gl->fDrawBuffers(mGLMaxDrawBuffers, currentDrawBuffers); } gl->fColorMask(mColorWriteMask[0], mColorWriteMask[1], mColorWriteMask[2], mColorWriteMask[3]); gl->fClearColor(mColorClearValue[0], mColorClearValue[1], mColorClearValue[2], mColorClearValue[3]); } if (initializeDepthBuffer) { gl->fDepthMask(mDepthWriteMask); gl->fClearDepth(mDepthClearValue); } if (initializeStencilBuffer) { gl->fStencilMaskSeparate(LOCAL_GL_FRONT, mStencilWriteMaskFront); gl->fStencilMaskSeparate(LOCAL_GL_BACK, mStencilWriteMaskBack); gl->fClearStencil(mStencilClearValue); } } // For an overview of how WebGL compositing works, see: // https://wiki.mozilla.org/Platform/GFX/WebGL/Compositing bool WebGLContext::PresentScreenBuffer() { if (IsContextLost()) { return false; } if (!mShouldPresent) { return false; } gl->MakeCurrent(); MOZ_ASSERT(!mBackbufferNeedsClear); if (!gl->PublishFrame()) { this->ForceLoseContext(); return false; } if (!mOptions.preserveDrawingBuffer) { mBackbufferNeedsClear = true; } mShouldPresent = false; return true; } void WebGLContext::DummyFramebufferOperation(const char *info) { GLenum status = CheckFramebufferStatus(LOCAL_GL_FRAMEBUFFER); if (status != LOCAL_GL_FRAMEBUFFER_COMPLETE) ErrorInvalidFramebufferOperation("%s: incomplete framebuffer", info); } static bool CheckContextLost(GLContext* gl, bool* out_isGuilty) { MOZ_ASSERT(gl); MOZ_ASSERT(out_isGuilty); bool isEGL = gl->GetContextType() == gl::GLContextType::EGL; GLenum resetStatus = LOCAL_GL_NO_ERROR; if (gl->HasRobustness()) { gl->MakeCurrent(); resetStatus = gl->fGetGraphicsResetStatus(); } else if (isEGL) { // Simulate a ARB_robustness guilty context loss for when we // get an EGL_CONTEXT_LOST error. It may not actually be guilty, // but we can't make any distinction. if (!gl->MakeCurrent(true) && gl->IsContextLost()) { resetStatus = LOCAL_GL_UNKNOWN_CONTEXT_RESET_ARB; } } if (resetStatus == LOCAL_GL_NO_ERROR) { *out_isGuilty = false; return false; } // Assume guilty unless we find otherwise! bool isGuilty = true; switch (resetStatus) { case LOCAL_GL_INNOCENT_CONTEXT_RESET_ARB: // Either nothing wrong, or not our fault. isGuilty = false; break; case LOCAL_GL_GUILTY_CONTEXT_RESET_ARB: NS_WARNING("WebGL content on the page definitely caused the graphics" " card to reset."); break; case LOCAL_GL_UNKNOWN_CONTEXT_RESET_ARB: NS_WARNING("WebGL content on the page might have caused the graphics" " card to reset"); // If we can't tell, assume guilty. break; default: MOZ_ASSERT(false, "Unreachable."); // If we do get here, let's pretend to be guilty as an escape plan. break; } if (isGuilty) { NS_WARNING("WebGL context on this page is considered guilty, and will" " not be restored."); } *out_isGuilty = isGuilty; return true; } bool WebGLContext::TryToRestoreContext() { if (NS_FAILED(SetDimensions(mWidth, mHeight))) return false; return true; } class UpdateContextLossStatusTask : public nsRunnable { WebGLContext* const mContext; public: UpdateContextLossStatusTask(WebGLContext* context) : mContext(context) { } NS_IMETHOD Run() { mContext->UpdateContextLossStatus(); return NS_OK; } }; void WebGLContext::EnqueueUpdateContextLossStatus() { nsCOMPtr task = new UpdateContextLossStatusTask(this); NS_DispatchToCurrentThread(task); } // We use this timer for many things. Here are the things that it is activated for: // 1) If a script is using the MOZ_WEBGL_lose_context extension. // 2) If we are using EGL and _NOT ANGLE_, we query periodically to see if the // CONTEXT_LOST_WEBGL error has been triggered. // 3) If we are using ANGLE, or anything that supports ARB_robustness, query the // GPU periodically to see if the reset status bit has been set. // In all of these situations, we use this timer to send the script context lost // and restored events asynchronously. For example, if it triggers a context loss, // the webglcontextlost event will be sent to it the next time the robustness timer // fires. // Note that this timer mechanism is not used unless one of these 3 criteria // are met. // At a bare minimum, from context lost to context restores, it would take 3 // full timer iterations: detection, webglcontextlost, webglcontextrestored. void WebGLContext::UpdateContextLossStatus() { if (!mCanvasElement) { // the canvas is gone. That happens when the page was closed before we got // this timer event. In this case, there's nothing to do here, just don't crash. return; } if (mContextStatus == ContextNotLost) { // We don't know that we're lost, but we might be, so we need to // check. If we're guilty, don't allow restores, though. bool isGuilty = true; bool isContextLost = CheckContextLost(gl, &isGuilty); if (isContextLost) { if (isGuilty) mAllowContextRestore = false; ForceLoseContext(); } // Fall through. } if (mContextStatus == ContextLostAwaitingEvent) { // The context has been lost and we haven't yet triggered the // callback, so do that now. bool useDefaultHandler; nsContentUtils::DispatchTrustedEvent(mCanvasElement->OwnerDoc(), static_cast(mCanvasElement), NS_LITERAL_STRING("webglcontextlost"), true, true, &useDefaultHandler); // We sent the callback, so we're just 'regular lost' now. mContextStatus = ContextLost; // If we're told to use the default handler, it means the script // didn't bother to handle the event. In this case, we shouldn't // auto-restore the context. if (useDefaultHandler) mAllowContextRestore = false; // Fall through. } if (mContextStatus == ContextLost) { // Context is lost, and we've already sent the callback. We // should try to restore the context if we're both allowed to, // and supposed to. // Are we allowed to restore the context? if (!mAllowContextRestore) return; // If we're only simulated-lost, we shouldn't auto-restore, and // instead we should wait for restoreContext() to be called. if (mLastLossWasSimulated) return; ForceRestoreContext(); return; } if (mContextStatus == ContextLostAwaitingRestore) { // Context is lost, but we should try to restore it. if (!mAllowContextRestore) { // We might decide this after thinking we'd be OK restoring // the context, so downgrade. mContextStatus = ContextLost; return; } if (!TryToRestoreContext()) { // Failed to restore. Try again later. RunContextLossTimer(); return; } // Revival! mContextStatus = ContextNotLost; nsContentUtils::DispatchTrustedEvent(mCanvasElement->OwnerDoc(), static_cast(mCanvasElement), NS_LITERAL_STRING("webglcontextrestored"), true, true); mEmitContextLostErrorOnce = true; return; } } void WebGLContext::ForceLoseContext() { printf_stderr("WebGL(%p)::ForceLoseContext\n", this); MOZ_ASSERT(!IsContextLost()); mContextStatus = ContextLostAwaitingEvent; mContextLostErrorSet = false; mLastLossWasSimulated = false; // Burn it all! DestroyResourcesAndContext(); // Queue up a task, since we know the status changed. EnqueueUpdateContextLossStatus(); } void WebGLContext::ForceRestoreContext() { printf_stderr("WebGL(%p)::ForceRestoreContext\n", this); mContextStatus = ContextLostAwaitingRestore; mAllowContextRestore = true; // Hey, you did say 'force'. // Queue up a task, since we know the status changed. EnqueueUpdateContextLossStatus(); } void WebGLContext::MakeContextCurrent() const { gl->MakeCurrent(); } mozilla::TemporaryRef WebGLContext::GetSurfaceSnapshot(bool* aPremultAlpha) { if (!gl) return nullptr; RefPtr surf = Factory::CreateDataSourceSurfaceWithStride(IntSize(mWidth, mHeight), SurfaceFormat::B8G8R8A8, mWidth * 4); if (!surf) { return nullptr; } gl->MakeCurrent(); { ScopedBindFramebuffer autoFB(gl, 0); ClearBackbufferIfNeeded(); ReadPixelsIntoDataSurface(gl, surf); } if (aPremultAlpha) { *aPremultAlpha = true; } bool srcPremultAlpha = mOptions.premultipliedAlpha; if (!srcPremultAlpha) { if (aPremultAlpha) { *aPremultAlpha = false; } else { gfxUtils::PremultiplyDataSurface(surf); } } RefPtr dt = Factory::CreateDrawTarget(BackendType::CAIRO, IntSize(mWidth, mHeight), SurfaceFormat::B8G8R8A8); if (!dt) { return nullptr; } Matrix m; m.Translate(0.0, mHeight); m.Scale(1.0, -1.0); dt->SetTransform(m); dt->DrawSurface(surf, Rect(0, 0, mWidth, mHeight), Rect(0, 0, mWidth, mHeight), DrawSurfaceOptions(), DrawOptions(1.0f, CompositionOp::OP_SOURCE)); return dt->Snapshot(); } // // XPCOM goop // NS_IMPL_CYCLE_COLLECTING_ADDREF(WebGLContext) NS_IMPL_CYCLE_COLLECTING_RELEASE(WebGLContext) NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(WebGLContext, mCanvasElement, mExtensions, mBound2DTextures, mBoundCubeMapTextures, mBoundArrayBuffer, mBoundTransformFeedbackBuffer, mCurrentProgram, mBoundFramebuffer, mBoundRenderbuffer, mBoundVertexArray, mDefaultVertexArray, mActiveOcclusionQuery, mActiveTransformFeedbackQuery) NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(WebGLContext) NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY NS_INTERFACE_MAP_ENTRY(nsIDOMWebGLRenderingContext) NS_INTERFACE_MAP_ENTRY(nsICanvasRenderingContextInternal) NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference) // If the exact way we cast to nsISupports here ever changes, fix our // ToSupports() method. NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIDOMWebGLRenderingContext) NS_INTERFACE_MAP_END