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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 <queue>
#include "AccessCheck.h"
#include "gfxContext.h"
#include "gfxCrashReporterUtils.h"
#include "gfxPattern.h"
#include "gfxPrefs.h"
#include "gfxUtils.h"
#include "GLBlitHelper.h"
#include "GLContext.h"
#include "GLContextProvider.h"
#include "GLReadTexImageHelper.h"
#include "GLScreenBuffer.h"
#include "ImageContainer.h"
#include "ImageEncoder.h"
#include "Layers.h"
#include "LayerUserData.h"
#include "mozilla/dom/BindingUtils.h"
#include "mozilla/dom/Event.h"
#include "mozilla/dom/HTMLVideoElement.h"
#include "mozilla/dom/ImageData.h"
#include "mozilla/EnumeratedArrayCycleCollection.h"
#include "mozilla/Preferences.h"
#include "mozilla/ProcessPriorityManager.h"
#include "mozilla/Services.h"
#include "mozilla/Telemetry.h"
#include "nsContentUtils.h"
#include "nsDisplayList.h"
#include "nsError.h"
#include "nsIClassInfoImpl.h"
#include "nsIConsoleService.h"
#include "nsIDOMEvent.h"
#include "nsIGfxInfo.h"
#include "nsIObserverService.h"
#include "nsIVariant.h"
#include "nsIWidget.h"
#include "nsIXPConnect.h"
#include "nsServiceManagerUtils.h"
#include "nsSVGEffects.h"
#include "prenv.h"
#include "ScopedGLHelpers.h"
#ifdef MOZ_WIDGET_GONK
#include "mozilla/layers/ShadowLayers.h"
#endif
// Local
#include "CanvasUtils.h"
#include "WebGL1Context.h"
#include "WebGLActiveInfo.h"
#include "WebGLBuffer.h"
#include "WebGLContextLossHandler.h"
#include "WebGLContextUtils.h"
#include "WebGLExtensions.h"
#include "WebGLFramebuffer.h"
#include "WebGLMemoryTracker.h"
#include "WebGLObjectModel.h"
#include "WebGLProgram.h"
#include "WebGLQuery.h"
#include "WebGLSampler.h"
#include "WebGLShader.h"
#include "WebGLTransformFeedback.h"
#include "WebGLVertexArray.h"
#include "WebGLVertexAttribData.h"
// Generated
#include "mozilla/dom/WebGLRenderingContextBinding.h"
namespace mozilla {
using namespace mozilla::dom;
using namespace mozilla::gfx;
using namespace mozilla::gl;
using namespace mozilla::layers;
WebGLContextOptions::WebGLContextOptions()
: alpha(true)
, depth(true)
, stencil(false)
, premultipliedAlpha(true)
, antialias(true)
, preserveDrawingBuffer(false)
, failIfMajorPerformanceCaveat(false)
{
// Set default alpha state based on preference.
if (gfxPrefs::WebGLDefaultNoAlpha())
alpha = false;
}
/*static*/ const uint32_t WebGLContext::kMinMaxColorAttachments = 4;
/*static*/ const uint32_t WebGLContext::kMinMaxDrawBuffers = 4;
WebGLContext::WebGLContext()
: WebGLContextUnchecked(nullptr)
, mBypassShaderValidation(false)
, mGLMaxSamples(1)
, mNeedsFakeNoAlpha(false)
, mNeedsFakeNoDepth(false)
, mNeedsFakeNoStencil(false)
{
mGeneration = 0;
mInvalidated = false;
mCapturedFrameInvalidated = false;
mShouldPresent = true;
mResetLayer = true;
mOptionsFrozen = false;
mActiveTexture = 0;
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;
mDitherEnabled = 1;
mRasterizerDiscardEnabled = 0; // OpenGL ES 3.0 spec p244
mScissorTestEnabled = 0;
mDepthTestEnabled = 0;
mStencilTestEnabled = 0;
if (NS_IsMainThread()) {
// XXX mtseng: bug 709490, not thread safe
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 = gfxPrefs::WebGLMaxWarningsPerContext();
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()
{
RemovePostRefreshObserver();
DestroyResourcesAndContext();
if (NS_IsMainThread()) {
// XXX mtseng: bug 709490, not thread safe
WebGLMemoryTracker::RemoveWebGLContext(this);
}
mContextLossHandler->DisableTimer();
mContextLossHandler = nullptr;
}
void
WebGLContext::DestroyResourcesAndContext()
{
if (!gl)
return;
gl->MakeCurrent();
mBound2DTextures.Clear();
mBoundCubeMapTextures.Clear();
mBound3DTextures.Clear();
mBound2DArrayTextures.Clear();
mBoundSamplers.Clear();
mBoundArrayBuffer = nullptr;
mBoundCopyReadBuffer = nullptr;
mBoundCopyWriteBuffer = nullptr;
mBoundPixelPackBuffer = nullptr;
mBoundPixelUnpackBuffer = nullptr;
mBoundTransformFeedbackBuffer = nullptr;
mBoundUniformBuffer = nullptr;
mCurrentProgram = nullptr;
mActiveProgramLinkInfo = nullptr;
mBoundDrawFramebuffer = nullptr;
mBoundReadFramebuffer = nullptr;
mActiveOcclusionQuery = nullptr;
mBoundRenderbuffer = nullptr;
mBoundVertexArray = nullptr;
mDefaultVertexArray = nullptr;
mBoundTransformFeedback = nullptr;
mDefaultTransformFeedback = nullptr;
mBoundTransformFeedbackBuffers.Clear();
mBoundUniformBuffers.Clear();
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();
while (!mSamplers.isEmpty())
mSamplers.getLast()->DeleteOnce();
while (!mTransformFeedbacks.isEmpty())
mTransformFeedbacks.getLast()->DeleteOnce();
mFakeBlack_2D_0000 = nullptr;
mFakeBlack_2D_0001 = nullptr;
mFakeBlack_CubeMap_0000 = nullptr;
mFakeBlack_CubeMap_0001 = nullptr;
mFakeBlack_3D_0000 = nullptr;
mFakeBlack_3D_0001 = nullptr;
mFakeBlack_2D_Array_0000 = nullptr;
mFakeBlack_2D_Array_0001 = 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 (!mCanvasElement)
return;
mCapturedFrameInvalidated = true;
if (mInvalidated)
return;
nsSVGEffects::InvalidateDirectRenderingObservers(mCanvasElement);
mInvalidated = true;
mCanvasElement->InvalidateCanvasContent(nullptr);
}
void
WebGLContext::OnVisibilityChange()
{
if (!IsContextLost()) {
return;
}
if (!mRestoreWhenVisible || mLastLossWasSimulated) {
return;
}
ForceRestoreContext();
}
void
WebGLContext::OnMemoryPressure()
{
bool shouldLoseContext = mLoseContextOnMemoryPressure;
if (!mCanLoseContextInForeground &&
ProcessPriorityManager::CurrentProcessIsForeground())
{
shouldLoseContext = false;
}
if (shouldLoseContext)
ForceLoseContext();
}
//
// nsICanvasRenderingContextInternal
//
NS_IMETHODIMP
WebGLContext::SetContextOptions(JSContext* cx, JS::Handle<JS::Value> options,
ErrorResult& aRvForDictionaryInit)
{
if (options.isNullOrUndefined() && mOptionsFrozen)
return NS_OK;
WebGLContextAttributes attributes;
if (!attributes.Init(cx, options)) {
aRvForDictionaryInit.Throw(NS_ERROR_UNEXPECTED);
return 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;
newOpts.failIfMajorPerformanceCaveat = attributes.mFailIfMajorPerformanceCaveat;
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;
}
int32_t
WebGLContext::GetWidth() const
{
return mWidth;
}
int32_t
WebGLContext::GetHeight() const
{
return mHeight;
}
/* 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(gfxUtils::ThreadSafeGetFeatureStatus(gfxInfo, feature, &status)))
return false;
return status != nsIGfxInfo::FEATURE_STATUS_OK;
}
static bool
HasAcceleratedLayers(const nsCOMPtr<nsIGfxInfo>& gfxInfo)
{
int32_t status;
gfxUtils::ThreadSafeGetFeatureStatus(gfxInfo,
nsIGfxInfo::FEATURE_DIRECT3D_9_LAYERS,
&status);
if (status)
return true;
gfxUtils::ThreadSafeGetFeatureStatus(gfxInfo,
nsIGfxInfo::FEATURE_DIRECT3D_10_LAYERS,
&status);
if (status)
return true;
gfxUtils::ThreadSafeGetFeatureStatus(gfxInfo,
nsIGfxInfo::FEATURE_DIRECT3D_10_1_LAYERS,
&status);
if (status)
return true;
gfxUtils::ThreadSafeGetFeatureStatus(gfxInfo,
nsIGfxInfo::FEATURE_DIRECT3D_11_LAYERS,
&status);
if (status)
return true;
gfxUtils::ThreadSafeGetFeatureStatus(gfxInfo,
nsIGfxInfo::FEATURE_OPENGL_LAYERS,
&status);
if (status)
return true;
return false;
}
static void
PopulateCapFallbackQueue(const gl::SurfaceCaps& baseCaps,
std::queue<gl::SurfaceCaps>* out_fallbackCaps)
{
out_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) {
gl::SurfaceCaps nextCaps(baseCaps);
nextCaps.antialias = false;
PopulateCapFallbackQueue(nextCaps, out_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) {
gl::SurfaceCaps nextCaps(baseCaps);
nextCaps.stencil = false;
PopulateCapFallbackQueue(nextCaps, out_fallbackCaps);
}
if (baseCaps.depth) {
gl::SurfaceCaps nextCaps(baseCaps);
nextCaps.depth = false;
PopulateCapFallbackQueue(nextCaps, out_fallbackCaps);
}
}
static gl::SurfaceCaps
BaseCaps(const WebGLContextOptions& options, WebGLContext* webgl)
{
gl::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;
// 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 = gfxPrefs::WebGLPrefer16bpp();
#ifdef MOZ_WIDGET_GONK
do {
auto canvasElement = webgl->GetCanvas();
if (!canvasElement)
break;
auto ownerDoc = canvasElement->OwnerDoc();
nsIWidget* docWidget = nsContentUtils::WidgetForDocument(ownerDoc);
if (!docWidget)
break;
layers::LayerManager* layerManager = docWidget->GetLayerManager();
if (!layerManager)
break;
// XXX we really want "AsSurfaceAllocator" here for generality
layers::ShadowLayerForwarder* forwarder = layerManager->AsShadowForwarder();
if (!forwarder)
break;
baseCaps.surfaceAllocator = static_cast<layers::ISurfaceAllocator*>(forwarder);
} while (false);
#endif
// Done with baseCaps construction.
bool forceAllowAA = gfxPrefs::WebGLForceMSAA();
nsCOMPtr<nsIGfxInfo> gfxInfo = services::GetGfxInfo();
if (!forceAllowAA &&
IsFeatureInBlacklist(gfxInfo, nsIGfxInfo::FEATURE_WEBGL_MSAA))
{
webgl->GenerateWarning("Disallowing antialiased backbuffers due"
" to blacklisting.");
baseCaps.antialias = false;
}
return baseCaps;
}
////////////////////////////////////////
static already_AddRefed<gl::GLContext>
CreateGLWithEGL(const gl::SurfaceCaps& caps, gl::CreateContextFlags flags,
WebGLContext* webgl)
{
RefPtr<GLContext> gl;
#ifndef XP_MACOSX // Mac doesn't have GLContextProviderEGL.
gfx::IntSize dummySize(16, 16);
gl = gl::GLContextProviderEGL::CreateOffscreen(dummySize, caps,
flags);
if (!gl) {
webgl->GenerateWarning("Error during EGL OpenGL init.");
return nullptr;
}
if (gl->IsANGLE())
return nullptr;
#endif // XP_MACOSX
return gl.forget();
}
static already_AddRefed<GLContext>
CreateGLWithANGLE(const gl::SurfaceCaps& caps, gl::CreateContextFlags flags,
WebGLContext* webgl)
{
RefPtr<GLContext> gl;
#ifdef XP_WIN
gfx::IntSize dummySize(16, 16);
gl = gl::GLContextProviderEGL::CreateOffscreen(dummySize, caps, flags);
if (!gl) {
webgl->GenerateWarning("Error during ANGLE OpenGL init.");
return nullptr;
}
if (!gl->IsANGLE())
return nullptr;
#endif
return gl.forget();
}
static already_AddRefed<gl::GLContext>
CreateGLWithDefault(const gl::SurfaceCaps& caps, gl::CreateContextFlags flags,
WebGLContext* webgl)
{
nsCOMPtr<nsIGfxInfo> gfxInfo = services::GetGfxInfo();
if (!(flags & CreateContextFlags::FORCE_ENABLE_HARDWARE) &&
IsFeatureInBlacklist(gfxInfo, nsIGfxInfo::FEATURE_WEBGL_OPENGL))
{
webgl->GenerateWarning("Refused to create native OpenGL context because of"
" blacklisting.");
return nullptr;
}
gfx::IntSize dummySize(16, 16);
RefPtr<GLContext> gl = gl::GLContextProvider::CreateOffscreen(dummySize, caps, flags);
if (!gl) {
webgl->GenerateWarning("Error during native OpenGL init.");
return nullptr;
}
if (gl->IsANGLE())
return nullptr;
return gl.forget();
}
////////////////////////////////////////
bool
WebGLContext::CreateAndInitGLWith(FnCreateGL_T fnCreateGL,
const gl::SurfaceCaps& baseCaps,
gl::CreateContextFlags flags)
{
MOZ_ASSERT(!gl);
std::queue<gl::SurfaceCaps> fallbackCaps;
PopulateCapFallbackQueue(baseCaps, &fallbackCaps);
gl = nullptr;
while (!fallbackCaps.empty()) {
gl::SurfaceCaps& caps = fallbackCaps.front();
gl = fnCreateGL(caps, flags, this);
if (gl)
break;
fallbackCaps.pop();
}
if (!gl)
return false;
if (!InitAndValidateGL()) {
gl = nullptr;
return false;
}
return true;
}
bool
WebGLContext::CreateAndInitGL(bool forceEnabled)
{
bool preferEGL = PR_GetEnv("MOZ_WEBGL_PREFER_EGL");
bool disableANGLE = gfxPrefs::WebGLDisableANGLE();
if (PR_GetEnv("MOZ_WEBGL_FORCE_OPENGL"))
disableANGLE = true;
gl::CreateContextFlags flags = gl::CreateContextFlags::NONE;
if (forceEnabled) flags |= gl::CreateContextFlags::FORCE_ENABLE_HARDWARE;
if (!IsWebGL2()) flags |= gl::CreateContextFlags::REQUIRE_COMPAT_PROFILE;
if (IsWebGL2()) flags |= gl::CreateContextFlags::PREFER_ES3;
const gl::SurfaceCaps baseCaps = BaseCaps(mOptions, this);
MOZ_ASSERT(!gl);
if (preferEGL) {
if (CreateAndInitGLWith(CreateGLWithEGL, baseCaps, flags))
return true;
}
MOZ_ASSERT(!gl);
if (!disableANGLE) {
if (CreateAndInitGLWith(CreateGLWithANGLE, baseCaps, flags))
return true;
}
MOZ_ASSERT(!gl);
if (CreateAndInitGLWith(CreateGLWithDefault, baseCaps, flags))
return true;
MOZ_ASSERT(!gl);
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 signedWidth, int32_t signedHeight)
{
if (signedWidth < 0 || signedHeight < 0) {
GenerateWarning("Canvas size is too large (seems like a negative value wrapped)");
return NS_ERROR_OUT_OF_MEMORY;
}
uint32_t width = signedWidth;
uint32_t height = signedHeight;
// Early success return cases
// May have a OffscreenCanvas instead of an HTMLCanvasElement
if (GetCanvas())
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();
if (IsContextLost()) {
GenerateWarning("WebGL context was lost due to swap failure.");
return NS_OK;
}
// 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
}
// increment the generation number - Do this early because later
// in CreateOffscreenGL(), "default" objects are created that will
// pick up the old generation.
++mGeneration;
bool disabled = gfxPrefs::WebGLDisabled();
// TODO: When we have software webgl support we should use that instead.
disabled |= gfxPlatform::InSafeMode();
if (disabled) {
GenerateWarning("WebGL creation is disabled, and so disallowed here.");
return NS_ERROR_FAILURE;
}
nsCOMPtr<nsIGfxInfo> gfxInfo = services::GetGfxInfo();
bool failIfMajorPerformanceCaveat =
!gfxPrefs::WebGLDisableFailIfMajorPerformanceCaveat() &&
!HasAcceleratedLayers(gfxInfo);
if (failIfMajorPerformanceCaveat) {
dom::Nullable<dom::WebGLContextAttributes> contextAttributes;
this->GetContextAttributes(contextAttributes);
if (contextAttributes.Value().mFailIfMajorPerformanceCaveat) {
return NS_ERROR_FAILURE;
}
}
// Alright, now let's start trying.
bool forceEnabled = gfxPrefs::WebGLForceEnabled();
ScopedGfxFeatureReporter reporter("WebGL", forceEnabled);
MOZ_ASSERT(!gl);
if (!CreateAndInitGL(forceEnabled)) {
GenerateWarning("WebGL creation failed.");
return NS_ERROR_FAILURE;
}
MOZ_ASSERT(gl);
MOZ_ASSERT_IF(mOptions.alpha, gl->Caps().alpha);
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;
// Update our internal stuff:
if (gl->WorkAroundDriverBugs()) {
if (!mOptions.alpha && gl->Caps().alpha)
mNeedsFakeNoAlpha = true;
if (!mOptions.depth && gl->Caps().depth)
mNeedsFakeNoDepth = true;
if (!mOptions.stencil && gl->Caps().stencil)
mNeedsFakeNoStencil = true;
}
// Update mOptions.
if (!gl->Caps().depth)
mOptions.depth = false;
if (!gl->Caps().stencil)
mOptions.stencil = false;
mOptions.antialias = gl->Caps().antialias;
MakeContextCurrent();
gl->fViewport(0, 0, mWidth, mHeight);
mViewportWidth = mWidth;
mViewportHeight = mHeight;
gl->fScissor(0, 0, mWidth, 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_IF(!mNeedsFakeNoDepth, gl->Caps().depth == mOptions.depth);
MOZ_ASSERT_IF(mNeedsFakeNoDepth, !mOptions.depth && gl->Caps().depth);
MOZ_ASSERT_IF(!mNeedsFakeNoStencil, gl->Caps().stencil == mOptions.stencil);
MOZ_ASSERT_IF(mNeedsFakeNoStencil, !mOptions.stencil && gl->Caps().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);
if (!NS_IsMainThread()) {
// XXX mtseng: bug 709490, WebGLMemoryTracker is not thread safe.
return;
}
// 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();
}
}
UniquePtr<uint8_t[]>
WebGLContext::GetImageBuffer(int32_t* out_format)
{
*out_format = 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 nullptr;
}
MOZ_ASSERT(mOptions.premultipliedAlpha || !premult, "We must get unpremult when we ask for it!");
RefPtr<DataSourceSurface> dataSurface = snapshot->GetDataSurface();
return gfxUtils::GetImageBuffer(dataSurface, mOptions.premultipliedAlpha,
out_format);
}
NS_IMETHODIMP
WebGLContext::GetInputStream(const char* mimeType,
const char16_t* encoderOptions,
nsIInputStream** out_stream)
{
NS_ASSERTION(gl, "GetInputStream on invalid context?");
if (!gl)
return NS_ERROR_FAILURE;
// Use GetSurfaceSnapshot() to make sure that appropriate y-flip gets applied
bool premult;
RefPtr<SourceSurface> snapshot =
GetSurfaceSnapshot(mOptions.premultipliedAlpha ? nullptr : &premult);
if (!snapshot)
return NS_ERROR_FAILURE;
MOZ_ASSERT(mOptions.premultipliedAlpha || !premult, "We must get unpremult when we ask for it!");
RefPtr<DataSourceSurface> dataSurface = snapshot->GetDataSurface();
return gfxUtils::GetInputStream(dataSurface, mOptions.premultipliedAlpha, mimeType,
encoderOptions, out_stream);
}
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;
class WebGLContextUserData : public LayerUserData
{
public:
explicit WebGLContextUserData(HTMLCanvasElement* canvas)
: mCanvas(canvas)
{}
/* 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->mCanvas;
WebGLContext* webgl = static_cast<WebGLContext*>(canvas->GetContextAtIndex(0));
// Present our screenbuffer, if needed.
webgl->PresentScreenBuffer();
webgl->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* data) {
WebGLContextUserData* userdata = static_cast<WebGLContextUserData*>(data);
HTMLCanvasElement* canvas = userdata->mCanvas;
WebGLContext* webgl = static_cast<WebGLContext*>(canvas->GetContextAtIndex(0));
// Mark ourselves as no longer invalidated.
webgl->MarkContextClean();
webgl->UpdateLastUseIndex();
}
private:
RefPtr<HTMLCanvasElement> mCanvas;
};
already_AddRefed<layers::Layer>
WebGLContext::GetCanvasLayer(nsDisplayListBuilder* builder,
Layer* oldLayer,
LayerManager* manager)
{
if (IsContextLost())
return nullptr;
if (!mResetLayer && oldLayer &&
oldLayer->HasUserData(&gWebGLLayerUserData)) {
RefPtr<layers::Layer> ret = oldLayer;
return ret.forget();
}
RefPtr<CanvasLayer> canvasLayer = manager->CreateCanvasLayer();
if (!canvasLayer) {
NS_WARNING("CreateCanvasLayer returned null!");
return nullptr;
}
WebGLContextUserData* userData = nullptr;
if (builder->IsPaintingToWindow() && mCanvasElement) {
// 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();
}
layers::LayersBackend
WebGLContext::GetCompositorBackendType() const
{
if (mCanvasElement) {
return mCanvasElement->GetCompositorBackendType();
} else if (mOffscreenCanvas) {
return mOffscreenCanvas->GetCompositorBackendType();
}
return LayersBackend::LAYERS_NONE;
}
void
WebGLContext::Commit()
{
if (mOffscreenCanvas) {
mOffscreenCanvas->CommitFrameToCompositor();
}
}
void
WebGLContext::GetCanvas(Nullable<dom::OwningHTMLCanvasElementOrOffscreenCanvas>& retval)
{
if (mCanvasElement) {
MOZ_RELEASE_ASSERT(!mOffscreenCanvas);
if (mCanvasElement->IsInNativeAnonymousSubtree()) {
retval.SetNull();
} else {
retval.SetValue().SetAsHTMLCanvasElement() = mCanvasElement;
}
} else if (mOffscreenCanvas) {
retval.SetValue().SetAsOffscreenCanvas() = mOffscreenCanvas;
} else {
retval.SetNull();
}
}
void
WebGLContext::GetContextAttributes(dom::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;
result.mFailIfMajorPerformanceCaveat = mOptions.failIfMajorPerformanceCaveat;
}
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()
{
MakeContextCurrent();
ScopedBindFramebuffer autoFB(gl, 0);
const bool changeDrawBuffers = (mDefaultFB_DrawBuffer0 != LOCAL_GL_BACK);
if (changeDrawBuffers) {
const GLenum back = LOCAL_GL_BACK;
gl->fDrawBuffers(1, &back);
}
GLbitfield bufferBits = LOCAL_GL_COLOR_BUFFER_BIT;
if (mOptions.depth)
bufferBits |= LOCAL_GL_DEPTH_BUFFER_BIT;
if (mOptions.stencil)
bufferBits |= LOCAL_GL_STENCIL_BUFFER_BIT;
ForceClearFramebufferWithDefaultValues(bufferBits, mNeedsFakeNoAlpha);
if (changeDrawBuffers) {
gl->fDrawBuffers(1, &mDefaultFB_DrawBuffer0);
}
}
void
WebGLContext::ForceClearFramebufferWithDefaultValues(GLbitfield clearBits,
bool fakeNoAlpha)
{
MakeContextCurrent();
const bool initializeColorBuffer = bool(clearBits & LOCAL_GL_COLOR_BUFFER_BIT);
const bool initializeDepthBuffer = bool(clearBits & LOCAL_GL_DEPTH_BUFFER_BIT);
const bool initializeStencilBuffer = bool(clearBits & LOCAL_GL_STENCIL_BUFFER_BIT);
// 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) {
gl->fColorMask(1, 1, 1, 1);
if (fakeNoAlpha) {
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(clearBits);
// 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) {
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::DummyReadFramebufferOperation(const char* funcName)
{
if (!mBoundReadFramebuffer)
return; // Infallible.
nsCString fbStatusInfo;
const auto status = mBoundReadFramebuffer->CheckFramebufferStatus(&fbStatusInfo);
if (status != LOCAL_GL_FRAMEBUFFER_COMPLETE) {
nsCString errorText("Incomplete framebuffer");
if (fbStatusInfo.Length()) {
errorText += ": ";
errorText += fbStatusInfo;
}
ErrorInvalidFramebufferOperation("%s: %s.", funcName, errorText.BeginReading());
}
}
static bool
CheckContextLost(GLContext* gl, bool* const 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 nsCancelableRunnable
{
RefPtr<WebGLContext> mWebGL;
public:
explicit UpdateContextLossStatusTask(WebGLContext* webgl)
: mWebGL(webgl)
{
}
NS_IMETHOD Run() {
if (mWebGL)
mWebGL->UpdateContextLossStatus();
return NS_OK;
}
NS_IMETHOD Cancel() {
mWebGL = nullptr;
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 && !mOffscreenCanvas) {
// 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;
if (mCanvasElement) {
nsContentUtils::DispatchTrustedEvent(
mCanvasElement->OwnerDoc(),
static_cast<nsIDOMHTMLCanvasElement*>(mCanvasElement),
NS_LITERAL_STRING("webglcontextlost"),
true,
true,
&useDefaultHandler);
} else {
// OffscreenCanvas case
RefPtr<Event> event = new Event(mOffscreenCanvas, nullptr, nullptr);
event->InitEvent(NS_LITERAL_STRING("webglcontextlost"), true, true);
event->SetTrusted(true);
mOffscreenCanvas->DispatchEvent(event, &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;
if (mCanvasElement) {
nsContentUtils::DispatchTrustedEvent(
mCanvasElement->OwnerDoc(),
static_cast<nsIDOMHTMLCanvasElement*>(mCanvasElement),
NS_LITERAL_STRING("webglcontextrestored"),
true,
true);
} else {
RefPtr<Event> event = new Event(mOffscreenCanvas, nullptr, nullptr);
event->InitEvent(NS_LITERAL_STRING("webglcontextrestored"), true, true);
event->SetTrusted(true);
bool unused;
mOffscreenCanvas->DispatchEvent(event, &unused);
}
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;
// 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();
}
already_AddRefed<mozilla::gfx::SourceSurface>
WebGLContext::GetSurfaceSnapshot(bool* out_premultAlpha)
{
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();
// TODO: Save, override, then restore glReadBuffer if present.
ReadPixelsIntoDataSurface(gl, surf);
}
if (out_premultAlpha) {
*out_premultAlpha = true;
}
bool srcPremultAlpha = mOptions.premultipliedAlpha;
if (!srcPremultAlpha) {
if (out_premultAlpha) {
*out_premultAlpha = false;
} else if(hasAlpha) {
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::ValidateCurFBForRead(const char* funcName,
const webgl::FormatUsageInfo** const out_format,
uint32_t* const out_width, uint32_t* const out_height)
{
if (!mBoundReadFramebuffer) {
ClearBackbufferIfNeeded();
// FIXME - here we're assuming that the default framebuffer is backed by
// UNSIGNED_BYTE that might not always be true, say if we had a 16bpp default
// framebuffer.
auto effFormat = mOptions.alpha ? webgl::EffectiveFormat::RGBA8
: webgl::EffectiveFormat::RGB8;
*out_format = mFormatUsage->GetUsage(effFormat);
MOZ_ASSERT(*out_format);
*out_width = mWidth;
*out_height = mHeight;
return true;
}
return mBoundReadFramebuffer->ValidateForRead(funcName, out_format, out_width,
out_height);
}
////////////////////////////////////////////////////////////////////////////////
WebGLContext::ScopedMaskWorkaround::ScopedMaskWorkaround(WebGLContext& webgl)
: mWebGL(webgl)
, mFakeNoAlpha(ShouldFakeNoAlpha(webgl))
, mFakeNoDepth(ShouldFakeNoDepth(webgl))
, mFakeNoStencil(ShouldFakeNoStencil(webgl))
{
if (mFakeNoAlpha) {
mWebGL.gl->fColorMask(mWebGL.mColorWriteMask[0],
mWebGL.mColorWriteMask[1],
mWebGL.mColorWriteMask[2],
false);
}
if (mFakeNoDepth) {
mWebGL.gl->fDisable(LOCAL_GL_DEPTH_TEST);
}
if (mFakeNoStencil) {
mWebGL.gl->fDisable(LOCAL_GL_STENCIL_TEST);
}
}
WebGLContext::ScopedMaskWorkaround::~ScopedMaskWorkaround()
{
if (mFakeNoAlpha) {
mWebGL.gl->fColorMask(mWebGL.mColorWriteMask[0],
mWebGL.mColorWriteMask[1],
mWebGL.mColorWriteMask[2],
mWebGL.mColorWriteMask[3]);
}
if (mFakeNoDepth) {
mWebGL.gl->fEnable(LOCAL_GL_DEPTH_TEST);
}
if (mFakeNoStencil) {
mWebGL.gl->fEnable(LOCAL_GL_STENCIL_TEST);
}
}
////////////////////////////////////////
ScopedUnpackReset::ScopedUnpackReset(WebGLContext* webgl)
: ScopedGLWrapper<ScopedUnpackReset>(webgl->gl)
, mWebGL(webgl)
{
if (mWebGL->mPixelStore_UnpackAlignment != 4) mGL->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT, 4);
if (mWebGL->IsWebGL2()) {
if (mWebGL->mPixelStore_UnpackRowLength != 0) mGL->fPixelStorei(LOCAL_GL_UNPACK_ROW_LENGTH , 0);
if (mWebGL->mPixelStore_UnpackImageHeight != 0) mGL->fPixelStorei(LOCAL_GL_UNPACK_IMAGE_HEIGHT, 0);
if (mWebGL->mPixelStore_UnpackSkipPixels != 0) mGL->fPixelStorei(LOCAL_GL_UNPACK_SKIP_PIXELS , 0);
if (mWebGL->mPixelStore_UnpackSkipRows != 0) mGL->fPixelStorei(LOCAL_GL_UNPACK_SKIP_ROWS , 0);
if (mWebGL->mPixelStore_UnpackSkipImages != 0) mGL->fPixelStorei(LOCAL_GL_UNPACK_SKIP_IMAGES , 0);
if (mWebGL->mBoundPixelUnpackBuffer) mGL->fBindBuffer(LOCAL_GL_PIXEL_UNPACK_BUFFER, 0);
}
}
void
ScopedUnpackReset::UnwrapImpl()
{
mGL->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT, mWebGL->mPixelStore_UnpackAlignment);
if (mWebGL->IsWebGL2()) {
mGL->fPixelStorei(LOCAL_GL_UNPACK_ROW_LENGTH , mWebGL->mPixelStore_UnpackRowLength );
mGL->fPixelStorei(LOCAL_GL_UNPACK_IMAGE_HEIGHT, mWebGL->mPixelStore_UnpackImageHeight);
mGL->fPixelStorei(LOCAL_GL_UNPACK_SKIP_PIXELS , mWebGL->mPixelStore_UnpackSkipPixels );
mGL->fPixelStorei(LOCAL_GL_UNPACK_SKIP_ROWS , mWebGL->mPixelStore_UnpackSkipRows );
mGL->fPixelStorei(LOCAL_GL_UNPACK_SKIP_IMAGES , mWebGL->mPixelStore_UnpackSkipImages );
GLuint pbo = 0;
if (mWebGL->mBoundPixelUnpackBuffer) {
pbo = mWebGL->mBoundPixelUnpackBuffer->mGLName;
}
mGL->fBindBuffer(LOCAL_GL_PIXEL_UNPACK_BUFFER, pbo);
}
}
////////////////////////////////////////
void
Intersect(uint32_t srcSize, int32_t dstStartInSrc, uint32_t dstSize,
uint32_t* const out_intStartInSrc, uint32_t* const out_intStartInDst,
uint32_t* const out_intSize)
{
// Only >0 if dstStartInSrc is >0:
// 0 3 // src coords
// | [========] // dst box
// ^--^
*out_intStartInSrc = std::max<int32_t>(0, dstStartInSrc);
// Only >0 if dstStartInSrc is <0:
//-6 0 // src coords
// [=====|==] // dst box
// ^-----^
*out_intStartInDst = std::max<int32_t>(0, 0 - dstStartInSrc);
int32_t intEndInSrc = std::min<int32_t>(srcSize, dstStartInSrc + dstSize);
*out_intSize = std::max<int32_t>(0, intEndInSrc - *out_intStartInSrc);
}
static bool
ZeroTexImageWithClear(WebGLContext* webgl, GLContext* gl, TexImageTarget target,
GLuint tex, uint32_t level, const webgl::FormatUsageInfo* usage,
uint32_t width, uint32_t height)
{
MOZ_ASSERT(gl->IsCurrent());
ScopedFramebuffer scopedFB(gl);
ScopedBindFramebuffer scopedBindFB(gl, scopedFB.FB());
const auto format = usage->format;
GLenum attachPoint = 0;
GLbitfield clearBits = 0;
if (format->isColorFormat) {
attachPoint = LOCAL_GL_COLOR_ATTACHMENT0;
clearBits = LOCAL_GL_COLOR_BUFFER_BIT;
}
if (format->hasDepth) {
attachPoint = LOCAL_GL_DEPTH_ATTACHMENT;
clearBits |= LOCAL_GL_DEPTH_BUFFER_BIT;
}
if (format->hasStencil) {
attachPoint = (format->hasDepth ? LOCAL_GL_DEPTH_STENCIL_ATTACHMENT
: LOCAL_GL_STENCIL_ATTACHMENT);
clearBits |= LOCAL_GL_STENCIL_BUFFER_BIT;
}
MOZ_RELEASE_ASSERT(attachPoint && clearBits);
{
gl::GLContext::LocalErrorScope errorScope(*gl);
gl->fFramebufferTexture2D(LOCAL_GL_FRAMEBUFFER, attachPoint, target.get(), tex,
level);
if (errorScope.GetError()) {
MOZ_ASSERT(false);
return false;
}
}
auto status = gl->fCheckFramebufferStatus(LOCAL_GL_FRAMEBUFFER);
if (status != LOCAL_GL_FRAMEBUFFER_COMPLETE)
return false;
{
gl::GLContext::LocalErrorScope errorScope(*gl);
const bool fakeNoAlpha = false;
webgl->ForceClearFramebufferWithDefaultValues(clearBits, fakeNoAlpha);
if (errorScope.GetError()) {
MOZ_ASSERT(false);
return false;
}
}
return true;
}
bool
ZeroTextureData(WebGLContext* webgl, const char* funcName, bool respecifyTexture,
GLuint tex, TexImageTarget target, uint32_t level,
const webgl::FormatUsageInfo* usage, uint32_t xOffset, uint32_t yOffset,
uint32_t zOffset, uint32_t width, uint32_t height, uint32_t depth)
{
// This has two usecases:
// 1. Lazy zeroing of uninitialized textures:
// a. Before draw, when FakeBlack isn't viable. (TexStorage + Draw*)
// b. Before partial upload. (TexStorage + TexSubImage)
// 2. Zero subrects from out-of-bounds blits. (CopyTex(Sub)Image)
// We have no sympathy for any of these cases.
// "Doctor, it hurts when I do this!" "Well don't do that!"
webgl->GenerateWarning("%s: This operation requires zeroing texture data. This is"
" slow.",
funcName);
gl::GLContext* gl = webgl->GL();
gl->MakeCurrent();
auto compression = usage->format->compression;
if (compression) {
MOZ_RELEASE_ASSERT(!xOffset && !yOffset && !zOffset);
MOZ_RELEASE_ASSERT(!respecifyTexture);
auto sizedFormat = usage->format->sizedFormat;
MOZ_RELEASE_ASSERT(sizedFormat);
const auto fnSizeInBlocks = [](CheckedUint32 pixels, uint8_t pixelsPerBlock) {
return RoundUpToMultipleOf(pixels, pixelsPerBlock) / pixelsPerBlock;
};
const auto widthBlocks = fnSizeInBlocks(width, compression->blockWidth);
const auto heightBlocks = fnSizeInBlocks(height, compression->blockHeight);
CheckedUint32 checkedByteCount = compression->bytesPerBlock;
checkedByteCount *= widthBlocks;
checkedByteCount *= heightBlocks;
checkedByteCount *= depth;
if (!checkedByteCount.isValid())
return false;
const size_t byteCount = checkedByteCount.value();
UniqueBuffer zeros = calloc(1, byteCount);
if (!zeros)
return false;
ScopedUnpackReset scopedReset(webgl);
gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT, 1); // Don't bother with striding it
// well.
GLenum error = DoCompressedTexSubImage(gl, target.get(), level, xOffset, yOffset,
zOffset, width, height, depth, sizedFormat,
byteCount, zeros.get());
if (error)
return false;
return true;
}
const auto driverUnpackInfo = usage->idealUnpack;
MOZ_RELEASE_ASSERT(driverUnpackInfo);
if (usage->isRenderable && depth == 1 &&
!xOffset && !yOffset && !zOffset)
{
// While we would like to skip the extra complexity of trying to zero with an FB
// clear, ANGLE_depth_texture requires this.
do {
if (respecifyTexture) {
const auto error = DoTexImage(gl, target, level, driverUnpackInfo, width,
height, depth, nullptr);
if (error)
break;
}
if (ZeroTexImageWithClear(webgl, gl, target, tex, level, usage, width,
height))
{
return true;
}
} while (false);
}
const webgl::PackingInfo packing = driverUnpackInfo->ToPacking();
const auto bytesPerPixel = webgl::BytesPerPixel(packing);
CheckedUint32 checkedByteCount = bytesPerPixel;
checkedByteCount *= width;
checkedByteCount *= height;
checkedByteCount *= depth;
if (!checkedByteCount.isValid())
return false;
const size_t byteCount = checkedByteCount.value();
UniqueBuffer zeros = calloc(1, byteCount);
if (!zeros)
return false;
ScopedUnpackReset scopedReset(webgl);
gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT, 1); // Don't bother with striding it well.
GLenum error;
if (respecifyTexture) {
MOZ_RELEASE_ASSERT(!xOffset && !yOffset && !zOffset);
error = DoTexImage(gl, target, level, driverUnpackInfo, width, height, depth,
zeros.get());
} else {
error = DoTexSubImage(gl, target, level, xOffset, yOffset, zOffset, width, height,
depth, packing, zeros.get());
}
if (error)
return false;
return true;
}
////////////////////////////////////////////////////////////////////////////////
CheckedUint32
WebGLContext::GetUnpackSize(bool isFunc3D, uint32_t width, uint32_t height,
uint32_t depth, uint8_t bytesPerPixel)
{
if (!width || !height || !depth)
return 0;
////////////////
const auto& maybeRowLength = mPixelStore_UnpackRowLength;
const auto& maybeImageHeight = mPixelStore_UnpackImageHeight;
const auto usedPixelsPerRow = CheckedUint32(mPixelStore_UnpackSkipPixels) + width;
const auto stridePixelsPerRow = (maybeRowLength ? CheckedUint32(maybeRowLength)
: usedPixelsPerRow);
const auto usedRowsPerImage = CheckedUint32(mPixelStore_UnpackSkipRows) + height;
const auto strideRowsPerImage = (maybeImageHeight ? CheckedUint32(maybeImageHeight)
: usedRowsPerImage);
const uint32_t skipImages = (isFunc3D ? mPixelStore_UnpackSkipImages
: 0);
const CheckedUint32 usedImages = CheckedUint32(skipImages) + depth;
////////////////
CheckedUint32 strideBytesPerRow = bytesPerPixel * stridePixelsPerRow;
strideBytesPerRow = RoundUpToMultipleOf(strideBytesPerRow,
mPixelStore_UnpackAlignment);
const CheckedUint32 strideBytesPerImage = strideBytesPerRow * strideRowsPerImage;
////////////////
CheckedUint32 usedBytesPerRow = bytesPerPixel * usedPixelsPerRow;
// Don't round this to the alignment, since alignment here is really just used for
// establishing stride, particularly in WebGL 1, where you can't set ROW_LENGTH.
CheckedUint32 totalBytes = strideBytesPerImage * (usedImages - 1);
totalBytes += strideBytesPerRow * (usedRowsPerImage - 1);
totalBytes += usedBytesPerRow;
return totalBytes;
}
////////////////////////////////////////////////////////////////////////////////
// XPCOM goop
NS_IMPL_CYCLE_COLLECTING_ADDREF(WebGLContext)
NS_IMPL_CYCLE_COLLECTING_RELEASE(WebGLContext)
NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(WebGLContext,
mCanvasElement,
mOffscreenCanvas,
mExtensions,
mBound2DTextures,
mBoundCubeMapTextures,
mBound3DTextures,
mBound2DArrayTextures,
mBoundSamplers,
mBoundArrayBuffer,
mBoundCopyReadBuffer,
mBoundCopyWriteBuffer,
mBoundPixelPackBuffer,
mBoundPixelUnpackBuffer,
mBoundTransformFeedbackBuffer,
mBoundUniformBuffer,
mCurrentProgram,
mBoundDrawFramebuffer,
mBoundReadFramebuffer,
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
} // namespace mozilla
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