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gecko-dev/dom/canvas/WebGLContext.cpp

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/* -*- 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 "WebGLContextLossHandler.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 "GLBlitHelper.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 "ImageContainer.h"
#include "gfxContext.h"
#include "gfxPattern.h"
#include "gfxPrefs.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 "nsIDOMEvent.h"
#include "mozilla/Services.h"
#include "mozilla/dom/WebGLRenderingContextBinding.h"
#include "mozilla/dom/BindingUtils.h"
#include "mozilla/dom/HTMLVideoElement.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
#include <queue>
using namespace mozilla;
using namespace mozilla::dom;
using namespace mozilla::gfx;
using namespace mozilla::gl;
using namespace mozilla::layers;
WebGLObserver::WebGLObserver(WebGLContext* aContext)
: mContext(aContext)
{
}
WebGLObserver::~WebGLObserver()
{
}
void
WebGLObserver::Destroy()
{
UnregisterMemoryPressureEvent();
UnregisterVisibilityChangeEvent();
mContext = nullptr;
}
void
WebGLObserver::RegisterVisibilityChangeEvent()
{
if (!mContext) {
return;
}
HTMLCanvasElement* canvasElement = mContext->GetCanvas();
MOZ_ASSERT(canvasElement);
if (canvasElement) {
nsIDocument* document = canvasElement->OwnerDoc();
document->AddSystemEventListener(NS_LITERAL_STRING("visibilitychange"),
this,
true,
false);
}
}
void
WebGLObserver::UnregisterVisibilityChangeEvent()
{
if (!mContext) {
return;
}
HTMLCanvasElement* canvasElement = mContext->GetCanvas();
if (canvasElement) {
nsIDocument* document = canvasElement->OwnerDoc();
document->RemoveSystemEventListener(NS_LITERAL_STRING("visibilitychange"),
this,
true);
}
}
void
WebGLObserver::RegisterMemoryPressureEvent()
{
if (!mContext) {
return;
}
nsCOMPtr<nsIObserverService> observerService =
mozilla::services::GetObserverService();
MOZ_ASSERT(observerService);
if (observerService) {
observerService->AddObserver(this, "memory-pressure", false);
}
}
void
WebGLObserver::UnregisterMemoryPressureEvent()
{
if (!mContext) {
return;
}
nsCOMPtr<nsIObserverService> observerService =
mozilla::services::GetObserverService();
// Do not assert on observerService here. This might be triggered by
// the cycle collector at a late enough time, that XPCOM services are
// no longer available. See bug 1029504.
if (observerService) {
observerService->RemoveObserver(this, "memory-pressure");
}
}
NS_IMETHODIMP
WebGLObserver::Observe(nsISupports* aSubject,
const char* aTopic,
const char16_t* aSomeData)
{
if (!mContext || strcmp(aTopic, "memory-pressure")) {
return NS_OK;
}
bool wantToLoseContext = mContext->mLoseContextOnMemoryPressure;
if (!mContext->mCanLoseContextInForeground &&
ProcessPriorityManager::CurrentProcessIsForeground())
{
wantToLoseContext = false;
}
if (wantToLoseContext) {
mContext->ForceLoseContext();
}
return NS_OK;
}
NS_IMETHODIMP
WebGLObserver::HandleEvent(nsIDOMEvent* aEvent)
{
nsAutoString type;
aEvent->GetType(type);
if (!mContext || !type.EqualsLiteral("visibilitychange")) {
return NS_OK;
}
HTMLCanvasElement* canvasElement = mContext->GetCanvas();
MOZ_ASSERT(canvasElement);
if (canvasElement && !canvasElement->OwnerDoc()->Hidden()) {
mContext->ForceRestoreContext();
}
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)
, mNeedsFakeNoAlpha(false)
{
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;
mGLMaxTextureSizeLog2 = 0;
mGLMaxCubeMapTextureSize = 0;
mGLMaxCubeMapTextureSizeLog2 = 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;
mContextLossHandler = new WebGLContextLossHandler(this);
mContextStatus = ContextNotLost;
mLoseContextOnMemoryPressure = false;
mCanLoseContextInForeground = true;
mRestoreWhenVisible = false;
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;
}
mContextObserver = new WebGLObserver(this);
MOZ_RELEASE_ASSERT(mContextObserver, "Can't alloc WebGLContextObserver");
mLastUseIndex = 0;
InvalidateBufferFetching();
mBackbufferNeedsClear = true;
mDisableFragHighP = false;
mDrawCallsSinceLastFlush = 0;
}
WebGLContext::~WebGLContext()
{
RemovePostRefreshObserver();
mContextObserver->Destroy();
DestroyResourcesAndContext();
WebGLMemoryTracker::RemoveWebGLContext(this);
mContextLossHandler->DisableTimer();
mContextLossHandler = nullptr;
}
void
WebGLContext::DestroyResourcesAndContext()
{
mContextObserver->UnregisterMemoryPressureEvent();
if (!gl)
return;
gl->MakeCurrent();
mBound2DTextures.Clear();
mBoundCubeMapTextures.Clear();
mBound3DTextures.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<JS::Value> 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();
}
// Don't do antialiasing if we've disabled MSAA.
if (!gfxPrefs::MSAALevel()) {
newOpts.antialias = false;
}
#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
/* So there are a number of points of failure here. We might fail based
* on EGL vs. WGL, or we might fail to alloc a too-large size, or we
* might not be able to create a context with a certain combo of context
* creation attribs.
*
* We don't want to test the complete fallback matrix. (for now, at
* least) Instead, attempt creation in this order:
* 1. By platform API. (e.g. EGL vs. WGL)
* 2. By context creation attribs.
* 3. By size.
*
* That is, try to create headless contexts based on the platform API.
* Next, create dummy-sized backbuffers for the contexts with the right
* caps. Finally, resize the backbuffer to an acceptable size given the
* requested size.
*/
static bool
IsFeatureInBlacklist(const nsCOMPtr<nsIGfxInfo>& gfxInfo, int32_t feature)
{
int32_t status;
if (!NS_SUCCEEDED(gfxInfo->GetFeatureStatus(feature, &status)))
return false;
return status != nsIGfxInfo::FEATURE_STATUS_OK;
}
static already_AddRefed<GLContext>
CreateHeadlessNativeGL(bool forceEnabled,
const nsCOMPtr<nsIGfxInfo>& gfxInfo,
WebGLContext* webgl)
{
if (!forceEnabled &&
IsFeatureInBlacklist(gfxInfo, nsIGfxInfo::FEATURE_WEBGL_OPENGL))
{
webgl->GenerateWarning("Refused to create native OpenGL context"
" because of blacklisting.");
return nullptr;
}
nsRefPtr<GLContext> gl = gl::GLContextProvider::CreateHeadless();
if (!gl) {
webgl->GenerateWarning("Error during native OpenGL init.");
return nullptr;
}
MOZ_ASSERT(!gl->IsANGLE());
return gl.forget();
}
// Note that we have a separate call for ANGLE and EGL, even though
// right now, we get ANGLE implicitly by using EGL on Windows.
// Eventually, we want to be able to pick ANGLE-EGL or native EGL.
static already_AddRefed<GLContext>
CreateHeadlessANGLE(bool forceEnabled,
const nsCOMPtr<nsIGfxInfo>& gfxInfo,
WebGLContext* webgl)
{
nsRefPtr<GLContext> gl;
#ifdef XP_WIN
if (!forceEnabled &&
IsFeatureInBlacklist(gfxInfo, nsIGfxInfo::FEATURE_WEBGL_ANGLE))
{
webgl->GenerateWarning("Refused to create ANGLE OpenGL context"
" because of blacklisting.");
return nullptr;
}
gl = gl::GLContextProviderEGL::CreateHeadless();
if (!gl) {
webgl->GenerateWarning("Error during ANGLE OpenGL init.");
return nullptr;
}
MOZ_ASSERT(gl->IsANGLE());
#endif
return gl.forget();
}
static already_AddRefed<GLContext>
CreateHeadlessEGL(bool forceEnabled,
const nsCOMPtr<nsIGfxInfo>& gfxInfo,
WebGLContext* webgl)
{
nsRefPtr<GLContext> gl;
#ifdef ANDROID
gl = gl::GLContextProviderEGL::CreateHeadless();
if (!gl) {
webgl->GenerateWarning("Error during EGL OpenGL init.");
return nullptr;
}
MOZ_ASSERT(!gl->IsANGLE());
#endif
return gl.forget();
}
static already_AddRefed<GLContext>
CreateHeadlessGL(bool forceEnabled,
const nsCOMPtr<nsIGfxInfo>& gfxInfo,
WebGLContext* webgl)
{
bool preferEGL = PR_GetEnv("MOZ_WEBGL_PREFER_EGL");
bool disableANGLE = Preferences::GetBool("webgl.disable-angle", false);
if (PR_GetEnv("MOZ_WEBGL_FORCE_OPENGL")) {
disableANGLE = true;
}
nsRefPtr<GLContext> gl;
if (preferEGL)
gl = CreateHeadlessEGL(forceEnabled, gfxInfo, webgl);
if (!gl && !disableANGLE)
gl = CreateHeadlessANGLE(forceEnabled, gfxInfo, webgl);
if (!gl)
gl = CreateHeadlessNativeGL(forceEnabled, gfxInfo, webgl);
return gl.forget();
}
// Try to create a dummy offscreen with the given caps.
static bool
CreateOffscreenWithCaps(GLContext* gl, const SurfaceCaps& caps)
{
gfx::IntSize dummySize(16, 16);
return gl->InitOffscreen(dummySize, caps);
}
static void
PopulateCapFallbackQueue(const SurfaceCaps& baseCaps,
std::queue<SurfaceCaps>* fallbackCaps)
{
fallbackCaps->push(baseCaps);
// Dropping antialias drops our quality, but not our correctness.
// The user basically doesn't have to handle if this fails, they
// just get reduced quality.
if (baseCaps.antialias) {
SurfaceCaps nextCaps(baseCaps);
nextCaps.antialias = false;
PopulateCapFallbackQueue(nextCaps, fallbackCaps);
}
// If we have to drop one of depth or stencil, we'd prefer to keep
// depth. However, the client app will need to handle if this
// doesn't work.
if (baseCaps.stencil) {
SurfaceCaps nextCaps(baseCaps);
nextCaps.stencil = false;
PopulateCapFallbackQueue(nextCaps, fallbackCaps);
}
if (baseCaps.depth) {
SurfaceCaps nextCaps(baseCaps);
nextCaps.depth = false;
PopulateCapFallbackQueue(nextCaps, fallbackCaps);
}
}
static bool
CreateOffscreen(GLContext* gl,
const WebGLContextOptions& options,
const nsCOMPtr<nsIGfxInfo>& gfxInfo,
WebGLContext* webgl,
layers::ISurfaceAllocator* surfAllocator)
{
SurfaceCaps baseCaps;
baseCaps.color = true;
baseCaps.alpha = options.alpha;
baseCaps.antialias = options.antialias;
baseCaps.depth = options.depth;
baseCaps.premultAlpha = options.premultipliedAlpha;
baseCaps.preserve = options.preserveDrawingBuffer;
baseCaps.stencil = options.stencil;
if (!baseCaps.alpha)
baseCaps.premultAlpha = true;
if (gl->IsANGLE()) {
// We can't use no-alpha formats on ANGLE yet because of:
// https://code.google.com/p/angleproject/issues/detail?id=764
baseCaps.alpha = true;
}
// we should really have this behind a
// |gfxPlatform::GetPlatform()->GetScreenDepth() == 16| check, but
// for now it's just behind a pref for testing/evaluation.
baseCaps.bpp16 = Preferences::GetBool("webgl.prefer-16bpp", false);
#ifdef MOZ_WIDGET_GONK
baseCaps.surfaceAllocator = surfAllocator;
#endif
// Done with baseCaps construction.
bool forceAllowAA = Preferences::GetBool("webgl.msaa-force", false);
if (!forceAllowAA &&
IsFeatureInBlacklist(gfxInfo, nsIGfxInfo::FEATURE_WEBGL_MSAA))
{
webgl->GenerateWarning("Disallowing antialiased backbuffers due"
" to blacklisting.");
baseCaps.antialias = false;
}
std::queue<SurfaceCaps> fallbackCaps;
PopulateCapFallbackQueue(baseCaps, &fallbackCaps);
bool created = false;
while (!fallbackCaps.empty()) {
SurfaceCaps& caps = fallbackCaps.front();
created = CreateOffscreenWithCaps(gl, caps);
if (created)
break;
fallbackCaps.pop();
}
return created;
}
bool
WebGLContext::CreateOffscreenGL(bool forceEnabled)
{
nsCOMPtr<nsIGfxInfo> gfxInfo = do_GetService("@mozilla.org/gfx/info;1");
layers::ISurfaceAllocator* surfAllocator = nullptr;
#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) {
surfAllocator = static_cast<layers::ISurfaceAllocator*>(forwarder);
}
}
}
#endif
gl = CreateHeadlessGL(forceEnabled, gfxInfo, this);
do {
if (!gl)
break;
if (!CreateOffscreen(gl, mOptions, gfxInfo, this, surfAllocator))
break;
if (!InitAndValidateGL())
break;
return true;
} while (false);
gl = nullptr;
return false;
}
// Fallback for resizes:
bool
WebGLContext::ResizeBackbuffer(uint32_t requestedWidth, uint32_t requestedHeight)
{
uint32_t width = requestedWidth;
uint32_t height = requestedHeight;
bool resized = false;
while (width || height) {
width = width ? width : 1;
height = height ? height : 1;
gfx::IntSize curSize(width, height);
if (gl->ResizeOffscreen(curSize)) {
resized = true;
break;
}
width /= 2;
height /= 2;
}
if (!resized)
return false;
mWidth = gl->OffscreenSize().width;
mHeight = gl->OffscreenSize().height;
MOZ_ASSERT((uint32_t)mWidth == width);
MOZ_ASSERT((uint32_t)mHeight == height);
if (width != requestedWidth ||
height != requestedHeight)
{
GenerateWarning("Requested size %dx%d was too large, but resize"
" to %dx%d succeeded.",
requestedWidth, requestedHeight,
width, height);
}
return true;
}
NS_IMETHODIMP
WebGLContext::SetDimensions(int32_t sWidth, int32_t sHeight)
{
// Early error return cases
if (!GetCanvas())
return NS_ERROR_FAILURE;
if (sWidth < 0 || sHeight < 0) {
GenerateWarning("Canvas size is too large (seems like a negative value wrapped)");
return NS_ERROR_OUT_OF_MEMORY;
}
uint32_t width = sWidth;
uint32_t height = sHeight;
// Early success return cases
GetCanvas()->InvalidateCanvas();
// 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) {
if ((uint32_t)mWidth == width &&
(uint32_t)mHeight == height)
{
return NS_OK;
}
if (IsContextLost())
return NS_OK;
MakeContextCurrent();
// If we've already drawn, we should commit the current buffer.
PresentScreenBuffer();
// ResizeOffscreen scraps the current prod buffer before making a new one.
if (!ResizeBackbuffer(width, height)) {
GenerateWarning("WebGL context failed to resize.");
ForceLoseContext();
return NS_OK;
}
// everything's good, we're done here
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();
// 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()) {
GenerateWarning("Too many WebGL contexts created this run.");
return NS_ERROR_FAILURE; // exit without changing the value of mGeneration
}
// Get some prefs for some preferred/overriden things
NS_ENSURE_TRUE(Preferences::GetRootBranch(), NS_ERROR_FAILURE);
bool disabled = Preferences::GetBool("webgl.disabled", false);
if (disabled) {
GenerateWarning("WebGL creation is disabled, and so disallowed here.");
return NS_ERROR_FAILURE;
}
// Alright, now let's start trying.
bool forceEnabled = Preferences::GetBool("webgl.force-enabled", false);
ScopedGfxFeatureReporter reporter("WebGL", forceEnabled);
if (!CreateOffscreenGL(forceEnabled)) {
GenerateWarning("WebGL creation failed.");
return NS_ERROR_FAILURE;
}
MOZ_ASSERT(gl);
if (!ResizeBackbuffer(width, height)) {
GenerateWarning("Initializing WebGL backbuffer failed.");
return NS_ERROR_FAILURE;
}
#ifdef DEBUG
if (gl->DebugMode()) {
printf_stderr("--- WebGL context created: %p\n", gl.get());
}
#endif
mResetLayer = true;
mOptionsFrozen = true;
// increment the generation number
++mGeneration;
// Update our internal stuff:
if (gl->WorkAroundDriverBugs()) {
if (!mOptions.alpha && gl->Caps().alpha) {
mNeedsFakeNoAlpha = true;
}
}
// Update mOptions.
mOptions.depth = gl->Caps().depth;
mOptions.stencil = gl->Caps().stencil;
mOptions.antialias = gl->Caps().antialias;
MakeContextCurrent();
gl->fViewport(0, 0, mWidth, mHeight);
mViewportWidth = mWidth;
mViewportHeight = mHeight;
// 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);
MOZ_ASSERT_IF(!mNeedsFakeNoAlpha, gl->Caps().alpha == mOptions.alpha);
MOZ_ASSERT_IF(mNeedsFakeNoAlpha, !mOptions.alpha && gl->Caps().alpha);
MOZ_ASSERT(gl->Caps().depth == mOptions.depth);
MOZ_ASSERT(gl->Caps().stencil == mOptions.stencil);
MOZ_ASSERT(gl->Caps().antialias == mOptions.antialias);
MOZ_ASSERT(gl->Caps().preserve == mOptions.preserveDrawingBuffer);
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<WebGLContext*>(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<WebGLContext*>(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<WebGLContext*>(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<SourceSurface> snapshot =
GetSurfaceSnapshot(mOptions.premultipliedAlpha ? nullptr : &premult);
if (!snapshot) {
return;
}
MOZ_ASSERT(mOptions.premultipliedAlpha || !premult, "We must get unpremult when we ask for it!");
RefPtr<DataSourceSurface> 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<imgIEncoder> encoder = do_CreateInstance(enccid.get());
if (!encoder) {
return NS_ERROR_FAILURE;
}
nsAutoArrayPtr<uint8_t> 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<uint64_t> 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:
explicit 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<WebGLContextUserData*>(data);
HTMLCanvasElement* canvas = userdata->mContent;
WebGLContext* context = static_cast<WebGLContext*>(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<WebGLContextUserData*>(aData);
HTMLCanvasElement *canvas = userdata->mContent;
WebGLContext *context = static_cast<WebGLContext*>(canvas->GetContextAtIndex(0));
// Mark ourselves as no longer invalidated.
context->MarkContextClean();
context->UpdateLastUseIndex();
}
private:
nsRefPtr<HTMLCanvasElement> mContent;
};
} // end namespace mozilla
already_AddRefed<layers::CanvasLayer>
WebGLContext::GetCanvasLayer(nsDisplayListBuilder* aBuilder,
CanvasLayer *aOldLayer,
LayerManager *aManager)
{
if (IsContextLost())
return nullptr;
if (!mResetLayer && aOldLayer &&
aOldLayer->HasUserData(&gWebGLLayerUserData)) {
nsRefPtr<layers::CanvasLayer> ret = aOldLayer;
return ret.forget();
}
nsRefPtr<CanvasLayer> 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() || !data.mHasAlpha;
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<dom::WebGLContextAttributes> &retval)
{
retval.SetNull();
if (IsContextLost())
return;
dom::WebGLContextAttributes& result = retval.SetValue();
result.mAlpha.Construct(mOptions.alpha);
result.mDepth = mOptions.depth;
result.mStencil = mOptions.stencil;
result.mAntialias = mOptions.antialias;
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);
if (mNeedsFakeNoAlpha) {
gl->fClearColor(0.0f, 0.0f, 0.0f, 1.0f);
} else {
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;
}
MOZ_ASSERT(!mBackbufferNeedsClear);
gl->MakeCurrent();
GLScreenBuffer* screen = gl->Screen();
MOZ_ASSERT(screen);
if (!screen->PublishFrame(screen->Size())) {
ForceLoseContext();
return false;
}
if (!mOptions.preserveDrawingBuffer) {
mBackbufferNeedsClear = true;
}
mShouldPresent = false;
return true;
}
void
WebGLContext::DummyFramebufferOperation(const char *info)
{
FBStatus 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;
}
void
WebGLContext::RunContextLossTimer()
{
mContextLossHandler->RunTimer();
}
class UpdateContextLossStatusTask : public nsRunnable
{
nsRefPtr<WebGLContext> mContext;
public:
explicit UpdateContextLossStatusTask(WebGLContext* aContext)
: mContext(aContext)
{
}
NS_IMETHOD Run() {
mContext->UpdateContextLossStatus();
return NS_OK;
}
};
void
WebGLContext::EnqueueUpdateContextLossStatus()
{
nsCOMPtr<nsIRunnable> 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;
MOZ_ASSERT(gl); // Shouldn't be missing gl if we're NotLost.
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<nsIDOMHTMLCanvasElement*>(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;
// Restore when the app is visible
if (mRestoreWhenVisible)
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.
mContextLossHandler->RunTimer();
return;
}
// Revival!
mContextStatus = ContextNotLost;
nsContentUtils::DispatchTrustedEvent(mCanvasElement->OwnerDoc(),
static_cast<nsIDOMHTMLCanvasElement*>(mCanvasElement),
NS_LITERAL_STRING("webglcontextrestored"),
true,
true);
mEmitContextLostErrorOnce = true;
return;
}
}
void
WebGLContext::ForceLoseContext(bool simulateLosing)
{
printf_stderr("WebGL(%p)::ForceLoseContext\n", this);
MOZ_ASSERT(!IsContextLost());
mContextStatus = ContextLostAwaitingEvent;
mContextLostErrorSet = false;
// Burn it all!
DestroyResourcesAndContext();
mLastLossWasSimulated = simulateLosing;
// Register visibility change observer to defer the context restoring.
// Restore the context when the app is visible.
if (mRestoreWhenVisible && !mLastLossWasSimulated) {
mContextObserver->RegisterVisibilityChangeEvent();
}
// 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'.
mContextObserver->UnregisterVisibilityChangeEvent();
// Queue up a task, since we know the status changed.
EnqueueUpdateContextLossStatus();
}
void
WebGLContext::MakeContextCurrent() const { gl->MakeCurrent(); }
mozilla::TemporaryRef<mozilla::gfx::SourceSurface>
WebGLContext::GetSurfaceSnapshot(bool* aPremultAlpha)
{
if (!gl)
return nullptr;
bool hasAlpha = mOptions.alpha;
SurfaceFormat surfFormat = hasAlpha ? SurfaceFormat::B8G8R8A8
: SurfaceFormat::B8G8R8X8;
RefPtr<DataSourceSurface> surf;
surf = Factory::CreateDataSourceSurfaceWithStride(IntSize(mWidth, mHeight),
surfFormat,
mWidth * 4);
if (NS_WARN_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, surf);
}
}
RefPtr<DrawTarget> dt =
Factory::CreateDrawTarget(BackendType::CAIRO,
IntSize(mWidth, mHeight),
SurfaceFormat::B8G8R8A8);
if (!dt) {
return nullptr;
}
dt->SetTransform(Matrix::Translation(0.0, mHeight).PreScale(1.0, -1.0));
dt->DrawSurface(surf,
Rect(0, 0, mWidth, mHeight),
Rect(0, 0, mWidth, mHeight),
DrawSurfaceOptions(),
DrawOptions(1.0f, CompositionOp::OP_SOURCE));
return dt->Snapshot();
}
void
WebGLContext::DidRefresh()
{
if (gl) {
gl->FlushIfHeavyGLCallsSinceLastFlush();
}
}
bool WebGLContext::TexImageFromVideoElement(const TexImageTarget texImageTarget, GLint level,
GLenum internalformat, GLenum format, GLenum type,
mozilla::dom::Element& elt)
{
if (type == LOCAL_GL_HALF_FLOAT_OES) {
type = LOCAL_GL_HALF_FLOAT;
}
if (!ValidateTexImageFormatAndType(format, type,
WebGLTexImageFunc::TexImage, WebGLTexDimensions::Tex2D))
{
return false;
}
HTMLVideoElement* video = HTMLVideoElement::FromContentOrNull(&elt);
if (!video) {
return false;
}
uint16_t readyState;
if (NS_SUCCEEDED(video->GetReadyState(&readyState)) &&
readyState < nsIDOMHTMLMediaElement::HAVE_CURRENT_DATA)
{
//No frame inside, just return
return false;
}
// If it doesn't have a principal, just bail
nsCOMPtr<nsIPrincipal> principal = video->GetCurrentPrincipal();
if (!principal) {
return false;
}
mozilla::layers::ImageContainer* container = video->GetImageContainer();
if (!container) {
return false;
}
if (video->GetCORSMode() == CORS_NONE) {
bool subsumes;
nsresult rv = mCanvasElement->NodePrincipal()->Subsumes(principal, &subsumes);
if (NS_FAILED(rv) || !subsumes) {
GenerateWarning("It is forbidden to load a WebGL texture from a cross-domain element that has not been validated with CORS. "
"See https://developer.mozilla.org/en/WebGL/Cross-Domain_Textures");
return false;
}
}
gl->MakeCurrent();
nsRefPtr<mozilla::layers::Image> srcImage = container->LockCurrentImage();
WebGLTexture* tex = activeBoundTextureForTexImageTarget(texImageTarget);
const WebGLTexture::ImageInfo& info = tex->ImageInfoAt(texImageTarget, 0);
bool dimensionsMatch = info.Width() == srcImage->GetSize().width &&
info.Height() == srcImage->GetSize().height;
if (!dimensionsMatch) {
// we need to allocation
gl->fTexImage2D(texImageTarget.get(), level, internalformat, srcImage->GetSize().width, srcImage->GetSize().height, 0, format, type, nullptr);
}
bool ok = gl->BlitHelper()->BlitImageToTexture(srcImage.get(), srcImage->GetSize(), tex->GLName(), texImageTarget.get(), mPixelStoreFlipY);
if (ok) {
TexInternalFormat effectiveinternalformat =
EffectiveInternalFormatFromInternalFormatAndType(internalformat, type);
MOZ_ASSERT(effectiveinternalformat != LOCAL_GL_NONE);
tex->SetImageInfo(texImageTarget, level, srcImage->GetSize().width, srcImage->GetSize().height, 1,
effectiveinternalformat, WebGLImageDataStatus::InitializedImageData);
tex->Bind(TexImageTargetToTexTarget(texImageTarget));
}
srcImage = nullptr;
container->UnlockCurrentImage();
return ok;
}
////////////////////////////////////////////////////////////////////////////////
WebGLContext::ScopedMaskWorkaround::ScopedMaskWorkaround(WebGLContext& webgl)
: mWebGL(webgl)
, mNeedsChange(NeedsChange(webgl))
{
if (mNeedsChange) {
mWebGL.gl->fColorMask(mWebGL.mColorWriteMask[0],
mWebGL.mColorWriteMask[1],
mWebGL.mColorWriteMask[2],
false);
}
}
WebGLContext::ScopedMaskWorkaround::~ScopedMaskWorkaround()
{
if (mNeedsChange) {
mWebGL.gl->fColorMask(mWebGL.mColorWriteMask[0],
mWebGL.mColorWriteMask[1],
mWebGL.mColorWriteMask[2],
mWebGL.mColorWriteMask[3]);
}
}
////////////////////////////////////////////////////////////////////////////////
// XPCOM goop
NS_IMPL_CYCLE_COLLECTING_ADDREF(WebGLContext)
NS_IMPL_CYCLE_COLLECTING_RELEASE(WebGLContext)
NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(WebGLContext,
mCanvasElement,
mExtensions,
mBound2DTextures,
mBoundCubeMapTextures,
mBound3DTextures,
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
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