gecko-dev/gfx/thebes/gfxPlatform.h

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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/. */
#ifndef GFX_PLATFORM_H
#define GFX_PLATFORM_H
#include "mozilla/Logging.h"
#include "mozilla/gfx/Types.h"
#include "nsTArray.h"
#include "nsString.h"
#include "nsCOMPtr.h"
#include "nsAutoPtr.h"
#include "gfxTypes.h"
#include "gfxFontFamilyList.h"
#include "gfxBlur.h"
#include "nsRect.h"
#include "qcms.h"
#include "mozilla/RefPtr.h"
#include "GfxInfoCollector.h"
#include "mozilla/layers/CompositorTypes.h"
class gfxASurface;
class gfxFont;
class gfxFontGroup;
struct gfxFontStyle;
class gfxUserFontSet;
class gfxFontEntry;
class gfxPlatformFontList;
class gfxTextRun;
class nsIURI;
class nsIAtom;
class nsIObserver;
class SRGBOverrideObserver;
class gfxTextPerfMetrics;
namespace mozilla {
namespace gl {
class SkiaGLGlue;
} // namespace gl
namespace gfx {
class DrawTarget;
class SourceSurface;
class DataSourceSurface;
class ScaledFont;
class DrawEventRecorder;
class VsyncSource;
class DeviceInitData;
inline uint32_t
BackendTypeBit(BackendType b)
{
return 1 << uint8_t(b);
}
} // namespace gfx
} // namespace mozilla
#define MOZ_PERFORMANCE_WARNING(module, ...) \
do { \
if (gfxPlatform::PerfWarnings()) { \
printf_stderr("[" module "] " __VA_ARGS__); \
} \
} while (0)
extern cairo_user_data_key_t kDrawTarget;
enum eCMSMode {
eCMSMode_Off = 0, // No color management
eCMSMode_All = 1, // Color manage everything
eCMSMode_TaggedOnly = 2, // Color manage tagged Images Only
eCMSMode_AllCount = 3
};
enum eGfxLog {
// all font enumerations, localized names, fullname/psnames, cmap loads
eGfxLog_fontlist = 0,
// timing info on font initialization
eGfxLog_fontinit = 1,
// dump text runs, font matching, system fallback for content
eGfxLog_textrun = 2,
// dump text runs, font matching, system fallback for chrome
eGfxLog_textrunui = 3,
// dump cmap coverage data as they are loaded
eGfxLog_cmapdata = 4,
// text perf data
eGfxLog_textperf = 5
};
// when searching through pref langs, max number of pref langs
const uint32_t kMaxLenPrefLangList = 32;
extern bool gANGLESupportsD3D11;
#define UNINITIALIZED_VALUE (-1)
inline const char*
GetBackendName(mozilla::gfx::BackendType aBackend)
{
switch (aBackend) {
case mozilla::gfx::BackendType::DIRECT2D:
return "direct2d";
case mozilla::gfx::BackendType::COREGRAPHICS_ACCELERATED:
return "quartz accelerated";
case mozilla::gfx::BackendType::COREGRAPHICS:
return "quartz";
case mozilla::gfx::BackendType::CAIRO:
return "cairo";
case mozilla::gfx::BackendType::SKIA:
return "skia";
case mozilla::gfx::BackendType::RECORDING:
return "recording";
case mozilla::gfx::BackendType::DIRECT2D1_1:
return "direct2d 1.1";
case mozilla::gfx::BackendType::NONE:
return "none";
}
MOZ_CRASH("Incomplete switch");
}
enum class DeviceResetReason
{
OK = 0,
HUNG,
REMOVED,
RESET,
DRIVER_ERROR,
INVALID_CALL,
OUT_OF_MEMORY,
UNKNOWN
};
class gfxPlatform {
friend class SRGBOverrideObserver;
public:
typedef mozilla::gfx::Color Color;
typedef mozilla::gfx::DataSourceSurface DataSourceSurface;
typedef mozilla::gfx::DrawTarget DrawTarget;
typedef mozilla::gfx::IntSize IntSize;
typedef mozilla::gfx::SourceSurface SourceSurface;
/**
* Return a pointer to the current active platform.
* This is a singleton; it contains mostly convenience
* functions to obtain platform-specific objects.
*/
static gfxPlatform *GetPlatform();
/**
* Returns whether or not graphics has been initialized yet. This is
* intended for Telemetry where we don't necessarily want to initialize
* graphics just to observe its state.
*/
static bool Initialized();
/**
* Shut down Thebes.
* Init() arranges for this to be called at an appropriate time.
*/
static void Shutdown();
static void InitLayersIPC();
static void ShutdownLayersIPC();
/**
* Create an offscreen surface of the given dimensions
* and image format.
*/
virtual already_AddRefed<gfxASurface>
CreateOffscreenSurface(const IntSize& aSize,
gfxImageFormat aFormat) = 0;
/**
* Beware that these methods may return DrawTargets which are not fully supported
* on the current platform and might fail silently in subtle ways. This is a massive
* potential footgun. You should only use these methods for canvas drawing really.
* Use extreme caution if you use them for content where you are not 100% sure we
* support the DrawTarget we get back.
* See SupportsAzureContentForDrawTarget.
*/
virtual already_AddRefed<DrawTarget>
CreateDrawTargetForSurface(gfxASurface *aSurface, const mozilla::gfx::IntSize& aSize);
virtual already_AddRefed<DrawTarget>
CreateDrawTargetForUpdateSurface(gfxASurface *aSurface, const mozilla::gfx::IntSize& aSize);
/*
* Creates a SourceSurface for a gfxASurface. This function does no caching,
* so the caller should cache the gfxASurface if it will be used frequently.
* The returned surface keeps a reference to aTarget, so it is OK to keep the
* surface, even if aTarget changes.
* aTarget should not keep a reference to the returned surface because that
* will cause a cycle.
*
* This function is static so that it can be accessed from
* PluginInstanceChild (where we can't call gfxPlatform::GetPlatform()
* because the prefs service can only be accessed from the main process).
*/
static already_AddRefed<SourceSurface>
GetSourceSurfaceForSurface(mozilla::gfx::DrawTarget *aTarget, gfxASurface *aSurface);
static void ClearSourceSurfaceForSurface(gfxASurface *aSurface);
static already_AddRefed<DataSourceSurface>
GetWrappedDataSourceSurface(gfxASurface *aSurface);
virtual already_AddRefed<mozilla::gfx::ScaledFont>
GetScaledFontForFont(mozilla::gfx::DrawTarget* aTarget, gfxFont *aFont);
already_AddRefed<DrawTarget>
CreateOffscreenContentDrawTarget(const mozilla::gfx::IntSize& aSize, mozilla::gfx::SurfaceFormat aFormat);
already_AddRefed<DrawTarget>
CreateOffscreenCanvasDrawTarget(const mozilla::gfx::IntSize& aSize, mozilla::gfx::SurfaceFormat aFormat);
virtual already_AddRefed<DrawTarget>
CreateDrawTargetForData(unsigned char* aData, const mozilla::gfx::IntSize& aSize,
int32_t aStride, mozilla::gfx::SurfaceFormat aFormat);
/**
* Returns true if rendering to data surfaces produces the same results as
* rendering to offscreen surfaces on this platform, making it safe to
* render content to data surfaces. This is generally false on platforms
* which use different backends for each type of DrawTarget.
*/
virtual bool CanRenderContentToDataSurface() const {
return false;
}
/**
* Returns true if we should use Azure to render content with aTarget. For
* example, it is possible that we are using Direct2D for rendering and thus
* using Azure. But we want to render to a CairoDrawTarget, in which case
* SupportsAzureContent will return true but SupportsAzureContentForDrawTarget
* will return false.
*/
bool SupportsAzureContentForDrawTarget(mozilla::gfx::DrawTarget* aTarget);
bool SupportsAzureContentForType(mozilla::gfx::BackendType aType) {
return BackendTypeBit(aType) & mContentBackendBitmask;
}
/// This function lets us know if the current preferences/platform
/// combination allows for both accelerated and not accelerated canvas
/// implementations. If it does, and other relevant preferences are
/// asking for it, we will examine the commands in the first few seconds
/// of the canvas usage, and potentially change to accelerated or
/// non-accelerated canvas.
virtual bool HaveChoiceOfHWAndSWCanvas();
virtual bool UseAcceleratedSkiaCanvas();
virtual void InitializeSkiaCacheLimits();
/// These should be used instead of directly accessing the preference,
/// as different platforms may override the behaviour.
virtual bool UseProgressivePaint();
static bool AsyncPanZoomEnabled();
virtual void GetAzureBackendInfo(mozilla::widget::InfoObject &aObj) {
aObj.DefineProperty("AzureCanvasBackend", GetBackendName(mPreferredCanvasBackend));
aObj.DefineProperty("AzureSkiaAccelerated", UseAcceleratedSkiaCanvas());
aObj.DefineProperty("AzureFallbackCanvasBackend", GetBackendName(mFallbackCanvasBackend));
aObj.DefineProperty("AzureContentBackend", GetBackendName(mContentBackend));
}
void GetApzSupportInfo(mozilla::widget::InfoObject& aObj);
// Get the default content backend that will be used with the default
// compositor. If the compositor is known when calling this function,
// GetContentBackendFor() should be called instead.
mozilla::gfx::BackendType GetDefaultContentBackend() {
return mContentBackend;
}
// Return the best content backend available that is compatible with the
// given layers backend.
virtual mozilla::gfx::BackendType GetContentBackendFor(mozilla::layers::LayersBackend aLayers) {
return mContentBackend;
}
mozilla::gfx::BackendType GetPreferredCanvasBackend() {
return mPreferredCanvasBackend;
}
mozilla::gfx::BackendType GetFallbackCanvasBackend() {
return mFallbackCanvasBackend;
}
/*
* Font bits
*/
virtual void SetupClusterBoundaries(gfxTextRun *aTextRun, const char16_t *aString);
/**
* Fill aListOfFonts with the results of querying the list of font names
* that correspond to the given language group or generic font family
* (or both, or neither).
*/
virtual nsresult GetFontList(nsIAtom *aLangGroup,
const nsACString& aGenericFamily,
nsTArray<nsString>& aListOfFonts);
int GetTileWidth();
int GetTileHeight();
void SetTileSize(int aWidth, int aHeight);
/**
* Rebuilds the any cached system font lists
*/
virtual nsresult UpdateFontList();
/**
* Create the platform font-list object (gfxPlatformFontList concrete subclass).
* This function is responsible to create the appropriate subclass of
* gfxPlatformFontList *and* to call its InitFontList() method.
*/
virtual gfxPlatformFontList *CreatePlatformFontList() {
NS_NOTREACHED("oops, this platform doesn't have a gfxPlatformFontList implementation");
return nullptr;
}
/**
* Resolving a font name to family name. The result MUST be in the result of GetFontList().
* If the name doesn't in the system, aFamilyName will be empty string, but not failed.
*/
virtual nsresult GetStandardFamilyName(const nsAString& aFontName, nsAString& aFamilyName) = 0;
/**
* Create the appropriate platform font group
*/
virtual gfxFontGroup*
CreateFontGroup(const mozilla::FontFamilyList& aFontFamilyList,
const gfxFontStyle *aStyle,
gfxTextPerfMetrics* aTextPerf,
gfxUserFontSet *aUserFontSet) = 0;
/**
* Look up a local platform font using the full font face name.
* (Needed to support @font-face src local().)
* Ownership of the returned gfxFontEntry is passed to the caller,
* who must either AddRef() or delete.
*/
virtual gfxFontEntry* LookupLocalFont(const nsAString& aFontName,
uint16_t aWeight,
int16_t aStretch,
uint8_t aStyle)
{ return nullptr; }
/**
* Activate a platform font. (Needed to support @font-face src url().)
* aFontData is a NS_Malloc'ed block that must be freed by this function
* (or responsibility passed on) when it is no longer needed; the caller
* will NOT free it.
* Ownership of the returned gfxFontEntry is passed to the caller,
* who must either AddRef() or delete.
*/
virtual gfxFontEntry* MakePlatformFont(const nsAString& aFontName,
uint16_t aWeight,
int16_t aStretch,
uint8_t aStyle,
const uint8_t* aFontData,
uint32_t aLength);
/**
* Whether to allow downloadable fonts via @font-face rules
*/
bool DownloadableFontsEnabled();
/**
* True when hinting should be enabled. This setting shouldn't
* change per gecko process, while the process is live. If so the
* results are not defined.
*
* NB: this bit is only honored by the FT2 backend, currently.
*/
virtual bool FontHintingEnabled() { return true; }
/**
* True when zooming should not require reflow, so glyph metrics and
* positioning should not be adjusted for device pixels.
* If this is TRUE, then FontHintingEnabled() should be FALSE,
* but the converse is not necessarily required; in particular,
* B2G always has FontHintingEnabled FALSE, but RequiresLinearZoom
* is only true for the browser process, not Gaia or other apps.
*
* Like FontHintingEnabled (above), this setting shouldn't
* change per gecko process, while the process is live. If so the
* results are not defined.
*
* NB: this bit is only honored by the FT2 backend, currently.
*/
virtual bool RequiresLinearZoom() { return false; }
/**
* Whether to check all font cmaps during system font fallback
*/
bool UseCmapsDuringSystemFallback();
/**
* Whether to render SVG glyphs within an OpenType font wrapper
*/
bool OpenTypeSVGEnabled();
/**
* Max character length of words in the word cache
*/
uint32_t WordCacheCharLimit();
/**
* Max number of entries in word cache
*/
uint32_t WordCacheMaxEntries();
/**
* Whether to use the SIL Graphite rendering engine
* (for fonts that include Graphite tables)
*/
bool UseGraphiteShaping();
// check whether format is supported on a platform or not (if unclear, returns true)
virtual bool IsFontFormatSupported(nsIURI *aFontURI, uint32_t aFormatFlags) { return false; }
virtual bool DidRenderingDeviceReset(DeviceResetReason* aResetReason = nullptr) { return false; }
// returns a list of commonly used fonts for a given character
// these are *possible* matches, no cmap-checking is done at this level
virtual void GetCommonFallbackFonts(uint32_t /*aCh*/, uint32_t /*aNextCh*/,
int32_t /*aRunScript*/,
nsTArray<const char*>& /*aFontList*/)
{
// platform-specific override, by default do nothing
}
// Are we in safe mode?
static bool InSafeMode();
static bool OffMainThreadCompositingEnabled();
static bool CanUseDirect3D9();
static bool CanUseDirect3D11();
virtual bool CanUseHardwareVideoDecoding();
static bool CanUseDirect3D11ANGLE();
// Returns whether or not layers acceleration should be used. This should
// only be called on the parent process.
bool ShouldUseLayersAcceleration();
// Returns a prioritized list of all available compositor backends.
void GetCompositorBackends(bool useAcceleration, nsTArray<mozilla::layers::LayersBackend>& aBackends);
/**
* Is it possible to use buffer rotation. Note that these
* check the preference, but also allow for the override to
* disable it using DisableBufferRotation.
*/
static bool BufferRotationEnabled();
static void DisableBufferRotation();
/**
* Are we going to try color management?
*/
static eCMSMode GetCMSMode();
/**
* Determines the rendering intent for color management.
*
* If the value in the pref gfx.color_management.rendering_intent is a
* valid rendering intent as defined in gfx/qcms/qcms.h, that
* value is returned. Otherwise, -1 is returned and the embedded intent
* should be used.
*
* See bug 444014 for details.
*/
static int GetRenderingIntent();
/**
* Convert a pixel using a cms transform in an endian-aware manner.
*
* Sets 'out' to 'in' if transform is nullptr.
*/
static void TransformPixel(const Color& in, Color& out, qcms_transform *transform);
/**
* Return the output device ICC profile.
*/
static qcms_profile* GetCMSOutputProfile();
/**
* Return the sRGB ICC profile.
*/
static qcms_profile* GetCMSsRGBProfile();
/**
* Return sRGB -> output device transform.
*/
static qcms_transform* GetCMSRGBTransform();
/**
* Return output -> sRGB device transform.
*/
static qcms_transform* GetCMSInverseRGBTransform();
/**
* Return sRGBA -> output device transform.
*/
static qcms_transform* GetCMSRGBATransform();
virtual void FontsPrefsChanged(const char *aPref);
int32_t GetBidiNumeralOption();
/**
* Returns a 1x1 surface that can be used to create graphics contexts
* for measuring text etc as if they will be rendered to the screen
*/
gfxASurface* ScreenReferenceSurface() { return mScreenReferenceSurface; }
mozilla::gfx::DrawTarget* ScreenReferenceDrawTarget() { return mScreenReferenceDrawTarget; }
virtual mozilla::gfx::SurfaceFormat Optimal2DFormatForContent(gfxContentType aContent);
virtual gfxImageFormat OptimalFormatForContent(gfxContentType aContent);
virtual gfxImageFormat GetOffscreenFormat()
{ return gfxImageFormat::RGB24; }
/**
* Returns a logger if one is available and logging is enabled
*/
static mozilla::LogModule* GetLog(eGfxLog aWhichLog);
int GetScreenDepth() const { return mScreenDepth; }
mozilla::gfx::IntSize GetScreenSize() const { return mScreenSize; }
/**
* Return the layer debugging options to use browser-wide.
*/
mozilla::layers::DiagnosticTypes GetLayerDiagnosticTypes();
static mozilla::gfx::IntRect FrameCounterBounds() {
int bits = 16;
int sizeOfBit = 3;
return mozilla::gfx::IntRect(0, 0, bits * sizeOfBit, sizeOfBit);
}
mozilla::gl::SkiaGLGlue* GetSkiaGLGlue();
void PurgeSkiaCache();
virtual bool IsInGonkEmulator() const { return false; }
static bool UsesOffMainThreadCompositing();
bool HasEnoughTotalSystemMemoryForSkiaGL();
/**
* Get the hardware vsync source for each platform.
* Should only exist and be valid on the parent process
*/
virtual mozilla::gfx::VsyncSource* GetHardwareVsync() {
MOZ_ASSERT(mVsyncSource != nullptr);
MOZ_ASSERT(XRE_IsParentProcess());
return mVsyncSource;
}
/**
* True if layout rendering should use ASAP mode, which means
* the refresh driver and compositor should render ASAP.
* Used for talos testing purposes
*/
static bool IsInLayoutAsapMode();
/**
* Returns the software vsync rate to use.
*/
static int GetSoftwareVsyncRate();
/**
* Returns whether or not a custom vsync rate is set.
*/
static bool ForceSoftwareVsync();
/**
* Returns the default frame rate for the refresh driver / software vsync.
*/
static int GetDefaultFrameRate();
/**
* Used to test which input types are handled via APZ.
*/
virtual bool SupportsApzWheelInput() const {
return false;
}
virtual bool SupportsApzTouchInput() const {
return false;
}
bool SupportsApzDragInput() const;
virtual void FlushContentDrawing() {}
/**
* Helper method, creates a draw target for a specific Azure backend.
* Used by CreateOffscreenDrawTarget.
*/
already_AddRefed<DrawTarget>
CreateDrawTargetForBackend(mozilla::gfx::BackendType aBackend,
const mozilla::gfx::IntSize& aSize,
mozilla::gfx::SurfaceFormat aFormat);
/**
* Wrapper around gfxPrefs::PerfWarnings().
* Extracted into a function to avoid including gfxPrefs.h from this file.
*/
static bool PerfWarnings();
void NotifyCompositorCreated(mozilla::layers::LayersBackend aBackend);
mozilla::layers::LayersBackend GetCompositorBackend() const {
return mCompositorBackend;
}
// Trigger a test-driven graphics device reset.
virtual void TestDeviceReset(DeviceResetReason aReason)
{}
// Return information on how child processes should initialize graphics
// devices. Currently this is only used on Windows.
virtual void GetDeviceInitData(mozilla::gfx::DeviceInitData* aOut);
protected:
gfxPlatform();
virtual ~gfxPlatform();
/**
* Initialized hardware vsync based on each platform.
*/
virtual already_AddRefed<mozilla::gfx::VsyncSource> CreateHardwareVsyncSource();
// Returns whether or not layers should be accelerated by default on this platform.
virtual bool AccelerateLayersByDefault();
// Returns a prioritized list of available compositor backends for acceleration.
virtual void GetAcceleratedCompositorBackends(nsTArray<mozilla::layers::LayersBackend>& aBackends);
// Returns whether or not the basic compositor is supported.
virtual bool SupportsBasicCompositor() const {
return true;
}
/**
* Initialise the preferred and fallback canvas backends
* aBackendBitmask specifies the backends which are acceptable to the caller.
* The backend used is determined by aBackendBitmask and the order specified
* by the gfx.canvas.azure.backends pref.
*/
void InitBackendPrefs(uint32_t aCanvasBitmask, mozilla::gfx::BackendType aCanvasDefault,
uint32_t aContentBitmask, mozilla::gfx::BackendType aContentDefault);
/**
* If in a child process, triggers a refresh of device preferences.
*/
void UpdateDeviceInitData();
/**
* Called when new device preferences are available.
*/
virtual void SetDeviceInitData(mozilla::gfx::DeviceInitData& aData)
{}
/**
* returns the first backend named in the pref gfx.canvas.azure.backends
* which is a component of aBackendBitmask, a bitmask of backend types
*/
static mozilla::gfx::BackendType GetCanvasBackendPref(uint32_t aBackendBitmask);
/**
* returns the first backend named in the pref gfx.content.azure.backend
* which is a component of aBackendBitmask, a bitmask of backend types
*/
static mozilla::gfx::BackendType GetContentBackendPref(uint32_t &aBackendBitmask);
/**
* Will return the first backend named in aBackendPrefName
* allowed by aBackendBitmask, a bitmask of backend types.
* It also modifies aBackendBitmask to only include backends that are
* allowed given the prefs.
*/
static mozilla::gfx::BackendType GetBackendPref(const char* aBackendPrefName,
uint32_t &aBackendBitmask);
/**
* Decode the backend enumberation from a string.
*/
static mozilla::gfx::BackendType BackendTypeForName(const nsCString& aName);
static already_AddRefed<mozilla::gfx::ScaledFont>
GetScaledFontForFontWithCairoSkia(mozilla::gfx::DrawTarget* aTarget, gfxFont* aFont);
int8_t mAllowDownloadableFonts;
int8_t mGraphiteShapingEnabled;
int8_t mOpenTypeSVGEnabled;
int8_t mBidiNumeralOption;
// whether to always search font cmaps globally
// when doing system font fallback
int8_t mFallbackUsesCmaps;
// max character limit for words in word cache
int32_t mWordCacheCharLimit;
// max number of entries in word cache
int32_t mWordCacheMaxEntries;
uint32_t mTotalSystemMemory;
// Hardware vsync source. Only valid on parent process
RefPtr<mozilla::gfx::VsyncSource> mVsyncSource;
RefPtr<mozilla::gfx::DrawTarget> mScreenReferenceDrawTarget;
private:
/**
* Start up Thebes.
*/
static void Init();
static void CreateCMSOutputProfile();
static void GetCMSOutputProfileData(void *&mem, size_t &size);
friend void RecordingPrefChanged(const char *aPrefName, void *aClosure);
virtual void GetPlatformCMSOutputProfile(void *&mem, size_t &size);
/**
* Calling this function will compute and set the ideal tile size for the
* platform. This will only have an effect in the parent process; child processes
* should be updated via SetTileSize to match the value computed in the parent.
*/
void ComputeTileSize();
/**
* This uses nsIScreenManager to determine the screen size and color depth
*/
void PopulateScreenInfo();
RefPtr<gfxASurface> mScreenReferenceSurface;
nsCOMPtr<nsIObserver> mSRGBOverrideObserver;
nsCOMPtr<nsIObserver> mFontPrefsObserver;
nsCOMPtr<nsIObserver> mMemoryPressureObserver;
// The preferred draw target backend to use for canvas
mozilla::gfx::BackendType mPreferredCanvasBackend;
// The fallback draw target backend to use for canvas, if the preferred backend fails
mozilla::gfx::BackendType mFallbackCanvasBackend;
// The backend to use for content
mozilla::gfx::BackendType mContentBackend;
// Bitmask of backend types we can use to render content
uint32_t mContentBackendBitmask;
int mTileWidth;
int mTileHeight;
mozilla::widget::GfxInfoCollector<gfxPlatform> mAzureCanvasBackendCollector;
mozilla::widget::GfxInfoCollector<gfxPlatform> mApzSupportCollector;
RefPtr<mozilla::gfx::DrawEventRecorder> mRecorder;
RefPtr<mozilla::gl::SkiaGLGlue> mSkiaGlue;
// Backend that we are compositing with. NONE, if no compositor has been
// created yet.
mozilla::layers::LayersBackend mCompositorBackend;
int32_t mScreenDepth;
mozilla::gfx::IntSize mScreenSize;
};
#endif /* GFX_PLATFORM_H */