gfx/thebes/gfxPrefs.h
author Sebastian Hengst <archaeopteryx@coole-files.de>
Thu, 28 Apr 2016 10:32:25 +0200
changeset 295258 df82a308881223ce93397787ef45da2aa960737e
parent 295237 b5ab83af342ced09135b9e743a594422856f3ac9
child 295444 4dbe9e240867d9073d3e9a4529e15ed036f93852
permissions -rw-r--r--
Backed out 13 changesets (bug 1254899) for test failure in browser_Troubleshoot.js. r=backout Backed out changeset f749ee384012 (bug 1254899) Backed out changeset 1d7eeee5a5c5 (bug 1254899) Backed out changeset b5ab83af342c (bug 1254899) Backed out changeset 993906e53329 (bug 1254899) Backed out changeset e8abac801a51 (bug 1254899) Backed out changeset e9c311c68e4a (bug 1254899) Backed out changeset f8f3ae8c5cef (bug 1254899) Backed out changeset d17f98a9918a (bug 1254899) Backed out changeset 21c8a7ea2b93 (bug 1254899) Backed out changeset 64e58f9625eb (bug 1254899) Backed out changeset 2de214d5d1e0 (bug 1254899) Backed out changeset f2056259d227 (bug 1254899) Backed out changeset b805df0c8296 (bug 1254899)

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * 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_PREFS_H
#define GFX_PREFS_H

#include <cmath>                 // for M_PI
#include <stdint.h>
#include "mozilla/Assertions.h"

// First time gfxPrefs::GetSingleton() needs to be called on the main thread,
// before any of the methods accessing the values are used, but after
// the Preferences system has been initialized.

// The static methods to access the preference value are safe to call
// from any thread after that first call.

// To register a preference, you need to add a line in this file using
// the DECL_GFX_PREF macro.
//
// Update argument controls whether we read the preference value and save it
// or connect with a callback.  See UpdatePolicy enum below.
// Pref is the string with the preference name.
// Name argument is the name of the static function to create.
// Type is the type of the preference - bool, int32_t, uint32_t.
// Default is the default value for the preference.
//
// For example this line in the .h:
//   DECL_GFX_PREF(Once,"layers.dump",LayersDump,bool,false);
// means that you can call
//   bool var = gfxPrefs::LayersDump();
// from any thread, but that you will only get the preference value of
// "layers.dump" as it was set at the start of the session (subject to
// note 2 below). If the value was not set, the default would be false.
//
// In another example, this line in the .h:
//   DECL_GFX_PREF(Live,"gl.msaa-level",MSAALevel,uint32_t,2);
// means that every time you call
//   uint32_t var = gfxPrefs::MSAALevel();
// from any thread, you will get the most up to date preference value of
// "gl.msaa-level".  If the value is not set, the default would be 2.

// Note 1: Changing a preference from Live to Once is now as simple
// as changing the Update argument.  If your code worked before, it will
// keep working, and behave as if the user never changes the preference.
// Things are a bit more complicated and perhaps even dangerous when
// going from Once to Live, or indeed setting a preference to be Live
// in the first place, so be careful.  You need to be ready for the
// values changing mid execution, and if you're using those preferences
// in any setup and initialization, you may need to do extra work.

// Note 2: Prefs can be set by using the corresponding Set method. For
// example, if the accessor is Foo() then calling SetFoo(...) will update
// the preference and also change the return value of subsequent Foo() calls.
// This is true even for 'Once' prefs which otherwise do not change if the
// pref is updated after initialization.

#define DECL_GFX_PREF(Update, Pref, Name, Type, Default)                     \
public:                                                                       \
static Type Name() { MOZ_ASSERT(SingletonExists()); return GetSingleton().mPref##Name.mValue; } \
static void Set##Name(Type aVal) { MOZ_ASSERT(SingletonExists()); \
    GetSingleton().mPref##Name.Set(UpdatePolicy::Update, Get##Name##PrefName(), aVal); } \
private:                                                                      \
static const char* Get##Name##PrefName() { return Pref; }                     \
static Type Get##Name##PrefDefault() { return Default; }                      \
PrefTemplate<UpdatePolicy::Update, Type, Get##Name##PrefDefault, Get##Name##PrefName> mPref##Name

class PreferenceAccessImpl;
class gfxPrefs;
class gfxPrefs final
{
private:
  /// See Logging.h.  This lets Moz2D access preference values it owns.
  PreferenceAccessImpl* mMoz2DPrefAccess;

private:
  // Enums for the update policy.
  enum class UpdatePolicy {
    Skip, // Set the value to default, skip any Preferences calls
    Once, // Evaluate the preference once, unchanged during the session
    Live  // Evaluate the preference and set callback so it stays current/live
  };

  // Since we cannot use const char*, use a function that returns it.
  template <UpdatePolicy Update, class T, T Default(void), const char* Pref(void)>
  class PrefTemplate
  {
  public:
    PrefTemplate()
    : mValue(Default())
    {
      Register(Update, Pref());
    }
    void Register(UpdatePolicy aUpdate, const char* aPreference)
    {
      AssertMainThread();
      switch(aUpdate) {
        case UpdatePolicy::Skip:
          break;
        case UpdatePolicy::Once:
          mValue = PrefGet(aPreference, mValue);
          break;
        case UpdatePolicy::Live:
          PrefAddVarCache(&mValue,aPreference, mValue);
          break;
        default:
          MOZ_CRASH();
          break;
      }
    }
    void Set(UpdatePolicy aUpdate, const char* aPref, T aValue)
    {
      AssertMainThread();
      PrefSet(aPref, aValue);
      switch (aUpdate) {
        case UpdatePolicy::Skip:
        case UpdatePolicy::Live:
          break;
        case UpdatePolicy::Once:
          mValue = PrefGet(aPref, mValue);
          break;
        default:
          MOZ_CRASH();
          break;
      }
    }
    T mValue;
  };

  // This is where DECL_GFX_PREF for each of the preferences should go.
  // We will keep these in an alphabetical order to make it easier to see if
  // a method accessing a pref already exists. Just add yours in the list.

  // It's a short time fix, and will be removed after landing bug 1206637.
  DECL_GFX_PREF(Live, "accessibility.monoaudio.enable",        MonoAudio, bool, false);
  DECL_GFX_PREF(Live, "media.resampling.enabled",              AudioSinkResampling, bool, false);
  DECL_GFX_PREF(Live, "media.resampling.rate",                 AudioSinkResampleRate, uint32_t, 48000);
  DECL_GFX_PREF(Live, "media.forcestereo.enabled",             AudioSinkForceStereo, bool, true);

  // The apz prefs are explained in AsyncPanZoomController.cpp
  DECL_GFX_PREF(Live, "apz.allow_checkerboarding",             APZAllowCheckerboarding, bool, true);
  DECL_GFX_PREF(Live, "apz.allow_immediate_handoff",           APZAllowImmediateHandoff, bool, true);
  DECL_GFX_PREF(Live, "apz.allow_zooming",                     APZAllowZooming, bool, false);
  DECL_GFX_PREF(Live, "apz.axis_lock.breakout_angle",          APZAxisBreakoutAngle, float, float(M_PI / 8.0) /* 22.5 degrees */);
  DECL_GFX_PREF(Live, "apz.axis_lock.breakout_threshold",      APZAxisBreakoutThreshold, float, 1.0f / 32.0f);
  DECL_GFX_PREF(Live, "apz.axis_lock.direct_pan_angle",        APZAllowedDirectPanAngle, float, float(M_PI / 3.0) /* 60 degrees */);
  DECL_GFX_PREF(Live, "apz.axis_lock.lock_angle",              APZAxisLockAngle, float, float(M_PI / 6.0) /* 30 degrees */);
  DECL_GFX_PREF(Live, "apz.axis_lock.mode",                    APZAxisLockMode, int32_t, 0);
  DECL_GFX_PREF(Live, "apz.content_response_timeout",          APZContentResponseTimeout, int32_t, 300);
  DECL_GFX_PREF(Live, "apz.danger_zone_x",                     APZDangerZoneX, int32_t, 50);
  DECL_GFX_PREF(Live, "apz.danger_zone_y",                     APZDangerZoneY, int32_t, 100);
  DECL_GFX_PREF(Live, "apz.disable_for_scroll_linked_effects", APZDisableForScrollLinkedEffects, bool, false);
  DECL_GFX_PREF(Live, "apz.displayport_expiry_ms",             APZDisplayPortExpiryTime, uint32_t, 15000);
  DECL_GFX_PREF(Live, "apz.drag.enabled",                      APZDragEnabled, bool, false);
  DECL_GFX_PREF(Live, "apz.enlarge_displayport_when_clipped",  APZEnlargeDisplayPortWhenClipped, bool, false);
  DECL_GFX_PREF(Live, "apz.fling_accel_base_mult",             APZFlingAccelBaseMultiplier, float, 1.0f);
  DECL_GFX_PREF(Live, "apz.fling_accel_interval_ms",           APZFlingAccelInterval, int32_t, 500);
  DECL_GFX_PREF(Live, "apz.fling_accel_supplemental_mult",     APZFlingAccelSupplementalMultiplier, float, 1.0f);
  DECL_GFX_PREF(Once, "apz.fling_curve_function_x1",           APZCurveFunctionX1, float, 0.0f);
  DECL_GFX_PREF(Once, "apz.fling_curve_function_x2",           APZCurveFunctionX2, float, 1.0f);
  DECL_GFX_PREF(Once, "apz.fling_curve_function_y1",           APZCurveFunctionY1, float, 0.0f);
  DECL_GFX_PREF(Once, "apz.fling_curve_function_y2",           APZCurveFunctionY2, float, 1.0f);
  DECL_GFX_PREF(Live, "apz.fling_curve_threshold_inches_per_ms", APZCurveThreshold, float, -1.0f);
  DECL_GFX_PREF(Live, "apz.fling_friction",                    APZFlingFriction, float, 0.002f);
  DECL_GFX_PREF(Live, "apz.fling_stop_on_tap_threshold",       APZFlingStopOnTapThreshold, float, 0.05f);
  DECL_GFX_PREF(Live, "apz.fling_stopped_threshold",           APZFlingStoppedThreshold, float, 0.01f);
  DECL_GFX_PREF(Live, "apz.highlight_checkerboarded_areas",    APZHighlightCheckerboardedAreas, bool, false);
  DECL_GFX_PREF(Live, "apz.max_velocity_inches_per_ms",        APZMaxVelocity, float, -1.0f);
  DECL_GFX_PREF(Once, "apz.max_velocity_queue_size",           APZMaxVelocityQueueSize, uint32_t, 5);
  DECL_GFX_PREF(Live, "apz.min_skate_speed",                   APZMinSkateSpeed, float, 1.0f);
  DECL_GFX_PREF(Live, "apz.minimap.enabled",                   APZMinimap, bool, false);
  DECL_GFX_PREF(Live, "apz.minimap.visibility.enabled",        APZMinimapVisibilityEnabled, bool, false);
  DECL_GFX_PREF(Live, "apz.overscroll.enabled",                APZOverscrollEnabled, bool, false);
  DECL_GFX_PREF(Live, "apz.overscroll.min_pan_distance_ratio", APZMinPanDistanceRatio, float, 1.0f);
  DECL_GFX_PREF(Live, "apz.overscroll.spring_friction",        APZOverscrollSpringFriction, float, 0.015f);
  DECL_GFX_PREF(Live, "apz.overscroll.spring_stiffness",       APZOverscrollSpringStiffness, float, 0.001f);
  DECL_GFX_PREF(Live, "apz.overscroll.stop_distance_threshold", APZOverscrollStopDistanceThreshold, float, 5.0f);
  DECL_GFX_PREF(Live, "apz.overscroll.stop_velocity_threshold", APZOverscrollStopVelocityThreshold, float, 0.01f);
  DECL_GFX_PREF(Live, "apz.overscroll.stretch_factor",         APZOverscrollStretchFactor, float, 0.5f);
  DECL_GFX_PREF(Live, "apz.paint_skipping.enabled",            APZPaintSkipping, bool, true);
  DECL_GFX_PREF(Live, "apz.peek_messages.enabled",             APZPeekMessages, bool, true);
  DECL_GFX_PREF(Live, "apz.printtree",                         APZPrintTree, bool, false);
  DECL_GFX_PREF(Live, "apz.record_checkerboarding",            APZRecordCheckerboarding, bool, false);
  DECL_GFX_PREF(Live, "apz.test.logging_enabled",              APZTestLoggingEnabled, bool, false);
  DECL_GFX_PREF(Live, "apz.touch_move_tolerance",              APZTouchMoveTolerance, float, 0.0);
  DECL_GFX_PREF(Live, "apz.touch_start_tolerance",             APZTouchStartTolerance, float, 1.0f/4.5f);
  DECL_GFX_PREF(Live, "apz.velocity_bias",                     APZVelocityBias, float, 1.0f);
  DECL_GFX_PREF(Live, "apz.velocity_relevance_time_ms",        APZVelocityRelevanceTime, uint32_t, 150);
  DECL_GFX_PREF(Live, "apz.x_skate_highmem_adjust",            APZXSkateHighMemAdjust, float, 0.0f);
  DECL_GFX_PREF(Live, "apz.x_skate_size_multiplier",           APZXSkateSizeMultiplier, float, 1.5f);
  DECL_GFX_PREF(Live, "apz.x_stationary_size_multiplier",      APZXStationarySizeMultiplier, float, 3.0f);
  DECL_GFX_PREF(Live, "apz.y_skate_highmem_adjust",            APZYSkateHighMemAdjust, float, 0.0f);
  DECL_GFX_PREF(Live, "apz.y_skate_size_multiplier",           APZYSkateSizeMultiplier, float, 2.5f);
  DECL_GFX_PREF(Live, "apz.y_stationary_size_multiplier",      APZYStationarySizeMultiplier, float, 3.5f);
  DECL_GFX_PREF(Live, "apz.zoom_animation_duration_ms",        APZZoomAnimationDuration, int32_t, 250);

  DECL_GFX_PREF(Live, "browser.ui.zoom.force-user-scalable",   ForceUserScalable, bool, false);
  DECL_GFX_PREF(Live, "browser.viewport.desktopWidth",         DesktopViewportWidth, int32_t, 980);

  DECL_GFX_PREF(Live, "dom.ipc.plugins.asyncdrawing.enabled",  PluginAsyncDrawingEnabled, bool, false);
  DECL_GFX_PREF(Live, "dom.meta-viewport.enabled",             MetaViewportEnabled, bool, false);
  DECL_GFX_PREF(Once, "dom.vr.enabled",                        VREnabled, bool, false);
  DECL_GFX_PREF(Once, "dom.vr.oculus.enabled",                 VROculusEnabled, bool, true);
  DECL_GFX_PREF(Once, "dom.vr.oculus050.enabled",              VROculus050Enabled, bool, true);
  DECL_GFX_PREF(Once, "dom.vr.cardboard.enabled",              VRCardboardEnabled, bool, false);
  DECL_GFX_PREF(Once, "dom.vr.add-test-devices",               VRAddTestDevices, int32_t, 1);
  DECL_GFX_PREF(Live, "dom.vr.poseprediction.enabled",         VRPosePredictionEnabled, bool, false);
  DECL_GFX_PREF(Live, "dom.w3c_pointer_events.enabled",        PointerEventsEnabled, bool, false);
  DECL_GFX_PREF(Live, "dom.w3c_touch_events.enabled",          TouchEventsEnabled, int32_t, 0);

  DECL_GFX_PREF(Live, "general.smoothScroll",                  SmoothScrollEnabled, bool, true);
  DECL_GFX_PREF(Live, "general.smoothScroll.currentVelocityWeighting",
                SmoothScrollCurrentVelocityWeighting, float, 0.25);
  DECL_GFX_PREF(Live, "general.smoothScroll.durationToIntervalRatio",
                SmoothScrollDurationToIntervalRatio, int32_t, 200);
  DECL_GFX_PREF(Live, "general.smoothScroll.mouseWheel",       WheelSmoothScrollEnabled, bool, true);
  DECL_GFX_PREF(Live, "general.smoothScroll.mouseWheel.durationMaxMS",
                WheelSmoothScrollMaxDurationMs, int32_t, 400);
  DECL_GFX_PREF(Live, "general.smoothScroll.mouseWheel.durationMinMS",
                WheelSmoothScrollMinDurationMs, int32_t, 200);
  DECL_GFX_PREF(Live, "general.smoothScroll.pages",            PageSmoothScrollEnabled, bool, true);
  DECL_GFX_PREF(Live, "general.smoothScroll.pages.durationMaxMS",
                PageSmoothScrollMaxDurationMs, int32_t, 150);
  DECL_GFX_PREF(Live, "general.smoothScroll.pages.durationMinMS",
                PageSmoothScrollMinDurationMs, int32_t, 150);
  DECL_GFX_PREF(Live, "general.smoothScroll.pixels",           PixelSmoothScrollEnabled, bool, true);
  DECL_GFX_PREF(Live, "general.smoothScroll.pixels.durationMaxMS",
                PixelSmoothScrollMaxDurationMs, int32_t, 150);
  DECL_GFX_PREF(Live, "general.smoothScroll.pixels.durationMinMS",
                PixelSmoothScrollMinDurationMs, int32_t, 150);
  DECL_GFX_PREF(Live, "general.smoothScroll.stopDecelerationWeighting",
                SmoothScrollStopDecelerationWeighting, float, 0.4f);

  DECL_GFX_PREF(Once, "gfx.android.rgb16.force",               AndroidRGB16Force, bool, false);
#if defined(ANDROID)
  DECL_GFX_PREF(Once, "gfx.apitrace.enabled",                  UseApitrace, bool, false);
#endif
#if defined(RELEASE_BUILD)
  // "Skip" means this is locked to the default value in beta and release.
  DECL_GFX_PREF(Skip, "gfx.blocklist.all",                     BlocklistAll, int32_t, 0);
#else
  DECL_GFX_PREF(Once, "gfx.blocklist.all",                     BlocklistAll, int32_t, 0);
#endif
  DECL_GFX_PREF(Live, "gfx.canvas.auto_accelerate.min_calls",  CanvasAutoAccelerateMinCalls, int32_t, 4);
  DECL_GFX_PREF(Live, "gfx.canvas.auto_accelerate.min_frames", CanvasAutoAccelerateMinFrames, int32_t, 30);
  DECL_GFX_PREF(Live, "gfx.canvas.auto_accelerate.min_seconds", CanvasAutoAccelerateMinSeconds, float, 5.0f);
  DECL_GFX_PREF(Live, "gfx.canvas.azure.accelerated",          CanvasAzureAccelerated, bool, false);
  // 0x7fff is the maximum supported xlib surface size and is more than enough for canvases.
  DECL_GFX_PREF(Live, "gfx.canvas.max-size",                   MaxCanvasSize, int32_t, 0x7fff);
  DECL_GFX_PREF(Once, "gfx.canvas.skiagl.cache-items",         CanvasSkiaGLCacheItems, int32_t, 256);
  DECL_GFX_PREF(Once, "gfx.canvas.skiagl.cache-size",          CanvasSkiaGLCacheSize, int32_t, 96);
  DECL_GFX_PREF(Once, "gfx.canvas.skiagl.dynamic-cache",       CanvasSkiaGLDynamicCache, bool, false);

  DECL_GFX_PREF(Live, "gfx.color_management.enablev4",         CMSEnableV4, bool, false);
  DECL_GFX_PREF(Live, "gfx.color_management.mode",             CMSMode, int32_t,-1);
  // The zero default here should match QCMS_INTENT_DEFAULT from qcms.h
  DECL_GFX_PREF(Live, "gfx.color_management.rendering_intent", CMSRenderingIntent, int32_t, 0);

  DECL_GFX_PREF(Once, "gfx.direct2d.disabled",                 Direct2DDisabled, bool, false);
  DECL_GFX_PREF(Once, "gfx.direct2d.force-enabled",            Direct2DForceEnabled, bool, false);
  DECL_GFX_PREF(Live, "gfx.draw-color-bars",                   CompositorDrawColorBars, bool, false);
  DECL_GFX_PREF(Once, "gfx.e10s.hide-plugins-for-scroll",      HidePluginsForScroll, bool, true);
  DECL_GFX_PREF(Once, "gfx.font_rendering.directwrite.force-enabled", DirectWriteFontRenderingForceEnabled, bool, false);
  DECL_GFX_PREF(Live, "gfx.gralloc.fence-with-readpixels",     GrallocFenceWithReadPixels, bool, false);
  DECL_GFX_PREF(Live, "gfx.layerscope.enabled",                LayerScopeEnabled, bool, false);
  DECL_GFX_PREF(Live, "gfx.layerscope.port",                   LayerScopePort, int32_t, 23456);
  // Note that        "gfx.logging.level" is defined in Logging.h
  DECL_GFX_PREF(Once, "gfx.logging.crash.length",              GfxLoggingCrashLength, uint32_t, 16);
  DECL_GFX_PREF(Live, "gfx.logging.painted-pixel-count.enabled",GfxLoggingPaintedPixelCountEnabled, bool, false);
  // The maximums here are quite conservative, we can tighten them if problems show up.
  DECL_GFX_PREF(Once, "gfx.logging.texture-usage.enabled",     GfxLoggingTextureUsageEnabled, bool, false);
  DECL_GFX_PREF(Once, "gfx.logging.peak-texture-usage.enabled",GfxLoggingPeakTextureUsageEnabled, bool, false);
  DECL_GFX_PREF(Once, "gfx.max-alloc-size",                    MaxAllocSize, int32_t, (int32_t)500000000);
  DECL_GFX_PREF(Once, "gfx.max-texture-size",                  MaxTextureSize, int32_t, (int32_t)32767);
  DECL_GFX_PREF(Live, "gfx.partialpresent.force",              PartialPresent, int32_t, 0);
  DECL_GFX_PREF(Live, "gfx.perf-warnings.enabled",             PerfWarnings, bool, false);
  DECL_GFX_PREF(Live, "gfx.SurfaceTexture.detach.enabled",     SurfaceTextureDetachEnabled, bool, true);
  DECL_GFX_PREF(Live, "gfx.testing.device-reset",              DeviceResetForTesting, int32_t, 0);
  DECL_GFX_PREF(Live, "gfx.testing.device-fail",               DeviceFailForTesting, bool, false);

  DECL_GFX_PREF(Live, "gfx.content.use-native-pushlayer",      UseNativePushLayer, bool, false);

  // Disable surface sharing due to issues with compatible FBConfigs on
  // NVIDIA drivers as described in bug 1193015.
  DECL_GFX_PREF(Live, "gfx.use-glx-texture-from-pixmap",       UseGLXTextureFromPixmap, bool, false);

  // These times should be in milliseconds
  DECL_GFX_PREF(Once, "gfx.touch.resample.delay-threshold",    TouchResampleVsyncDelayThreshold, int32_t, 20);
  DECL_GFX_PREF(Once, "gfx.touch.resample.max-predict",        TouchResampleMaxPredict, int32_t, 8);
  DECL_GFX_PREF(Once, "gfx.touch.resample.min-delta",          TouchResampleMinDelta, int32_t, 2);
  DECL_GFX_PREF(Once, "gfx.touch.resample.old-touch-threshold",TouchResampleOldTouchThreshold, int32_t, 17);
  DECL_GFX_PREF(Once, "gfx.touch.resample.vsync-adjust",       TouchVsyncSampleAdjust, int32_t, 5);

  DECL_GFX_PREF(Once, "gfx.vr.mirror-textures",                VRMirrorTextures, bool, false);

  DECL_GFX_PREF(Live, "gfx.vsync.collect-scroll-transforms",   CollectScrollTransforms, bool, false);
  // On b2g, in really bad cases, I've seen up to 80 ms delays between touch events and the main thread
  // processing them. So 80 ms / 16 = 5 vsync events. Double it up just to be on the safe side, so 10.
  DECL_GFX_PREF(Once, "gfx.vsync.compositor.unobserve-count",  CompositorUnobserveCount, int32_t, 10);
  // Use vsync events generated by hardware
  DECL_GFX_PREF(Once, "gfx.work-around-driver-bugs",           WorkAroundDriverBugs, bool, true);
  DECL_GFX_PREF(Once, "gfx.screen-mirroring.enabled",          ScreenMirroringEnabled, bool, false);

  DECL_GFX_PREF(Live, "gl.msaa-level",                         MSAALevel, uint32_t, 2);
#if defined(XP_MACOSX)
  DECL_GFX_PREF(Live, "gl.multithreaded",                      GLMultithreaded, bool, false);
#endif
  DECL_GFX_PREF(Live, "gl.require-hardware",                   RequireHardwareGL, bool, false);

  DECL_GFX_PREF(Once, "image.cache.size",                      ImageCacheSize, int32_t, 5*1024*1024);
  DECL_GFX_PREF(Once, "image.cache.timeweight",                ImageCacheTimeWeight, int32_t, 500);
  DECL_GFX_PREF(Live, "image.decode-immediately.enabled",      ImageDecodeImmediatelyEnabled, bool, false);
  DECL_GFX_PREF(Live, "image.downscale-during-decode.enabled", ImageDownscaleDuringDecodeEnabled, bool, true);
  DECL_GFX_PREF(Live, "image.infer-src-animation.threshold-ms", ImageInferSrcAnimationThresholdMS, uint32_t, 2000);
  DECL_GFX_PREF(Once, "image.mem.decode_bytes_at_a_time",      ImageMemDecodeBytesAtATime, uint32_t, 200000);
  DECL_GFX_PREF(Live, "image.mem.discardable",                 ImageMemDiscardable, bool, false);
  DECL_GFX_PREF(Once, "image.mem.surfacecache.discard_factor", ImageMemSurfaceCacheDiscardFactor, uint32_t, 1);
  DECL_GFX_PREF(Once, "image.mem.surfacecache.max_size_kb",    ImageMemSurfaceCacheMaxSizeKB, uint32_t, 100 * 1024);
  DECL_GFX_PREF(Once, "image.mem.surfacecache.min_expiration_ms", ImageMemSurfaceCacheMinExpirationMS, uint32_t, 60*1000);
  DECL_GFX_PREF(Once, "image.mem.surfacecache.size_factor",    ImageMemSurfaceCacheSizeFactor, uint32_t, 64);
  DECL_GFX_PREF(Live, "image.mozsamplesize.enabled",           ImageMozSampleSizeEnabled, bool, false);
  DECL_GFX_PREF(Once, "image.multithreaded_decoding.limit",    ImageMTDecodingLimit, int32_t, -1);
  DECL_GFX_PREF(Live, "image.single-color-optimization.enabled", ImageSingleColorOptimizationEnabled, bool, true);

  DECL_GFX_PREF(Live, "layers.child-process-shutdown",         ChildProcessShutdown, bool, true);
  DECL_GFX_PREF(Once, "layers.acceleration.disabled",          LayersAccelerationDisabled, bool, false);
  DECL_GFX_PREF(Live, "layers.acceleration.draw-fps",          LayersDrawFPS, bool, false);
  DECL_GFX_PREF(Live, "layers.acceleration.draw-fps.print-histogram",  FPSPrintHistogram, bool, false);
  DECL_GFX_PREF(Live, "layers.acceleration.draw-fps.write-to-file", WriteFPSToFile, bool, false);
  DECL_GFX_PREF(Once, "layers.acceleration.force-enabled",     LayersAccelerationForceEnabled, bool, false);
  DECL_GFX_PREF(Once, "layers.allow-d3d9-fallback",            LayersAllowD3D9Fallback, bool, false);
  DECL_GFX_PREF(Once, "layers.amd-switchable-gfx.enabled",     LayersAMDSwitchableGfxEnabled, bool, false);
  DECL_GFX_PREF(Once, "layers.async-pan-zoom.enabled",         AsyncPanZoomEnabledDoNotUseDirectly, bool, true);
  DECL_GFX_PREF(Once, "layers.async-pan-zoom.separate-event-thread", AsyncPanZoomSeparateEventThread, bool, false);
  DECL_GFX_PREF(Live, "layers.bench.enabled",                  LayersBenchEnabled, bool, false);
  DECL_GFX_PREF(Once, "layers.bufferrotation.enabled",         BufferRotationEnabled, bool, true);
#ifdef MOZ_GFX_OPTIMIZE_MOBILE
  // If MOZ_GFX_OPTIMIZE_MOBILE is defined, we force component alpha off
  // and ignore the preference.
  DECL_GFX_PREF(Skip, "layers.componentalpha.enabled",         ComponentAlphaEnabled, bool, false);
#else
  // If MOZ_GFX_OPTIMIZE_MOBILE is not defined, we actually take the
  // preference value, defaulting to true.
  DECL_GFX_PREF(Once, "layers.componentalpha.enabled",         ComponentAlphaEnabled, bool, true);
#endif
  DECL_GFX_PREF(Live, "layers.composer2d.enabled",             Composer2DCompositionEnabled, bool, false);
  DECL_GFX_PREF(Once, "layers.d3d11.disable-warp",             LayersD3D11DisableWARP, bool, false);
  DECL_GFX_PREF(Once, "layers.d3d11.force-warp",               LayersD3D11ForceWARP, bool, false);
  DECL_GFX_PREF(Live, "layers.deaa.enabled",                   LayersDEAAEnabled, bool, false);
  DECL_GFX_PREF(Live, "layers.draw-bigimage-borders",          DrawBigImageBorders, bool, false);
  DECL_GFX_PREF(Live, "layers.draw-borders",                   DrawLayerBorders, bool, false);
  DECL_GFX_PREF(Live, "layers.draw-tile-borders",              DrawTileBorders, bool, false);
  DECL_GFX_PREF(Live, "layers.draw-layer-info",                DrawLayerInfo, bool, false);
  DECL_GFX_PREF(Live, "layers.dump",                           LayersDump, bool, false);
  DECL_GFX_PREF(Live, "layers.dump-texture",                   LayersDumpTexture, bool, false);
#ifdef MOZ_DUMP_PAINTING
  DECL_GFX_PREF(Live, "layers.dump-client-layers",             DumpClientLayers, bool, false);
  DECL_GFX_PREF(Live, "layers.dump-decision",                  LayersDumpDecision, bool, false);
  DECL_GFX_PREF(Live, "layers.dump-host-layers",               DumpHostLayers, bool, false);
#endif

  // 0 is "no change" for contrast, positive values increase it, negative values
  // decrease it until we hit mid gray at -1 contrast, after that it gets weird.
  DECL_GFX_PREF(Live, "layers.effect.contrast",                LayersEffectContrast, float, 0.0f);
  DECL_GFX_PREF(Live, "layers.effect.grayscale",               LayersEffectGrayscale, bool, false);
  DECL_GFX_PREF(Live, "layers.effect.invert",                  LayersEffectInvert, bool, false);
  DECL_GFX_PREF(Once, "layers.enable-tiles",                   LayersTilesEnabled, bool, false);
  DECL_GFX_PREF(Live, "layers.flash-borders",                  FlashLayerBorders, bool, false);
  DECL_GFX_PREF(Once, "layers.force-shmem-tiles",              ForceShmemTiles, bool, false);
  DECL_GFX_PREF(Live, "layers.frame-counter",                  DrawFrameCounter, bool, false);
  DECL_GFX_PREF(Once, "layers.gralloc.disable",                DisableGralloc, bool, false);
  DECL_GFX_PREF(Live, "layers.low-precision-buffer",           UseLowPrecisionBuffer, bool, false);
  DECL_GFX_PREF(Live, "layers.low-precision-opacity",          LowPrecisionOpacity, float, 1.0f);
  DECL_GFX_PREF(Live, "layers.low-precision-resolution",       LowPrecisionResolution, float, 0.25f);
  DECL_GFX_PREF(Live, "layers.max-active",                     MaxActiveLayers, int32_t, -1);
  DECL_GFX_PREF(Once, "layers.offmainthreadcomposition.force-disabled", LayersOffMainThreadCompositionForceDisabled, bool, false);
  DECL_GFX_PREF(Live, "layers.offmainthreadcomposition.frame-rate", LayersCompositionFrameRate, int32_t,-1);
  DECL_GFX_PREF(Live, "layers.orientation.sync.timeout",       OrientationSyncMillis, uint32_t, (uint32_t)0);
  DECL_GFX_PREF(Once, "layers.overzealous-gralloc-unlocking",  OverzealousGrallocUnlocking, bool, false);
  DECL_GFX_PREF(Once, "layers.prefer-d3d9",                    LayersPreferD3D9, bool, false);
  DECL_GFX_PREF(Once, "layers.prefer-opengl",                  LayersPreferOpenGL, bool, false);
  DECL_GFX_PREF(Live, "layers.progressive-paint",              ProgressivePaintDoNotUseDirectly, bool, false);
  DECL_GFX_PREF(Once, "layers.stereo-video.enabled",           StereoVideoEnabled, bool, false);

  // We allow for configurable and rectangular tile size to avoid wasting memory on devices whose
  // screen size does not align nicely to the default tile size. Although layers can be any size,
  // they are often the same size as the screen, especially for width.
  DECL_GFX_PREF(Once, "layers.tile-width",                     LayersTileWidth, int32_t, 256);
  DECL_GFX_PREF(Once, "layers.tile-height",                    LayersTileHeight, int32_t, 256);
  DECL_GFX_PREF(Once, "layers.tile-max-pool-size",             LayersTileMaxPoolSize, uint32_t, (uint32_t)50);
  DECL_GFX_PREF(Once, "layers.tile-shrink-pool-timeout",       LayersTileShrinkPoolTimeout, uint32_t, (uint32_t)1000);
  DECL_GFX_PREF(Once, "layers.tiled-drawtarget.enabled",       TiledDrawTargetEnabled, bool, false);
  DECL_GFX_PREF(Once, "layers.tiles.adjust",                   LayersTilesAdjust, bool, true);
  DECL_GFX_PREF(Once, "layers.tiles.edge-padding",             TileEdgePaddingEnabled, bool, true);
  DECL_GFX_PREF(Live, "layers.tiles.fade-in.enabled",          LayerTileFadeInEnabled, bool, false);
  DECL_GFX_PREF(Live, "layers.tiles.fade-in.duration-ms",      LayerTileFadeInDuration, uint32_t, 250);
  DECL_GFX_PREF(Live, "layers.transaction.warning-ms",         LayerTransactionWarning, uint32_t, 200);
  DECL_GFX_PREF(Once, "layers.uniformity-info",                UniformityInfo, bool, false);
  DECL_GFX_PREF(Once, "layers.use-image-offscreen-surfaces",   UseImageOffscreenSurfaces, bool, true);
  DECL_GFX_PREF(Live, "layers.single-tile.enabled",            LayersSingleTileEnabled, bool, true);

  DECL_GFX_PREF(Live, "layout.css.scroll-behavior.damping-ratio", ScrollBehaviorDampingRatio, float, 1.0f);
  DECL_GFX_PREF(Live, "layout.css.scroll-behavior.enabled",    ScrollBehaviorEnabled, bool, false);
  DECL_GFX_PREF(Live, "layout.css.scroll-behavior.spring-constant", ScrollBehaviorSpringConstant, float, 250.0f);
  DECL_GFX_PREF(Live, "layout.css.scroll-snap.prediction-max-velocity", ScrollSnapPredictionMaxVelocity, int32_t, 2000);
  DECL_GFX_PREF(Live, "layout.css.scroll-snap.prediction-sensitivity", ScrollSnapPredictionSensitivity, float, 0.750f);
  DECL_GFX_PREF(Live, "layout.css.scroll-snap.proximity-threshold", ScrollSnapProximityThreshold, int32_t, 200);
  DECL_GFX_PREF(Once, "layout.css.touch_action.enabled",       TouchActionEnabled, bool, false);
  DECL_GFX_PREF(Live, "layout.display-list.dump",              LayoutDumpDisplayList, bool, false);
  DECL_GFX_PREF(Live, "layout.display-list.dump-content",      LayoutDumpDisplayListContent, bool, false);
  DECL_GFX_PREF(Live, "layout.event-regions.enabled",          LayoutEventRegionsEnabledDoNotUseDirectly, bool, false);
  DECL_GFX_PREF(Once, "layout.frame_rate",                     LayoutFrameRate, int32_t, -1);
  DECL_GFX_PREF(Once, "layout.paint_rects_separately",         LayoutPaintRectsSeparately, bool, true);

  // This and code dependent on it should be removed once containerless scrolling looks stable.
  DECL_GFX_PREF(Once, "layout.scroll.root-frame-containers",   LayoutUseContainersForRootFrames, bool, true);

  // These affect how line scrolls from wheel events will be accelerated.
  DECL_GFX_PREF(Live, "mousewheel.acceleration.factor",        MouseWheelAccelerationFactor, int32_t, -1);
  DECL_GFX_PREF(Live, "mousewheel.acceleration.start",         MouseWheelAccelerationStart, int32_t, -1);

  // This affects whether events will be routed through APZ or not.
  DECL_GFX_PREF(Live, "mousewheel.system_scroll_override_on_root_content.enabled",
                                                               MouseWheelHasRootScrollDeltaOverride, bool, false);
  DECL_GFX_PREF(Live, "mousewheel.transaction.ignoremovedelay",MouseWheelIgnoreMoveDelayMs, int32_t, (int32_t)100);
  DECL_GFX_PREF(Live, "mousewheel.transaction.timeout",        MouseWheelTransactionTimeoutMs, int32_t, (int32_t)1500);

  DECL_GFX_PREF(Live, "nglayout.debug.widget_update_flashing", WidgetUpdateFlashing, bool, false);

  DECL_GFX_PREF(Live, "test.events.async.enabled",             TestEventsAsyncEnabled, bool, false);
  DECL_GFX_PREF(Live, "test.mousescroll",                      MouseScrollTestingEnabled, bool, false);

  DECL_GFX_PREF(Live, "ui.click_hold_context_menus.delay",     UiClickHoldContextMenusDelay, int32_t, 500);

  // WebGL (for pref access from Worker threads)
  DECL_GFX_PREF(Live, "webgl.all-angle-options",               WebGLAllANGLEOptions, bool, false);
  DECL_GFX_PREF(Live, "webgl.angle.force-d3d11",               WebGLANGLEForceD3D11, bool, false);
  DECL_GFX_PREF(Live, "webgl.angle.try-d3d11",                 WebGLANGLETryD3D11, bool, false);
  DECL_GFX_PREF(Live, "webgl.angle.force-warp",                WebGLANGLEForceWARP, bool, false);
  DECL_GFX_PREF(Live, "webgl.bypass-shader-validation",        WebGLBypassShaderValidator, bool, true);
  DECL_GFX_PREF(Live, "webgl.can-lose-context-in-foreground",  WebGLCanLoseContextInForeground, bool, true);
  DECL_GFX_PREF(Live, "webgl.default-no-alpha",                WebGLDefaultNoAlpha, bool, false);
  DECL_GFX_PREF(Live, "webgl.disable-angle",                   WebGLDisableANGLE, bool, false);
  DECL_GFX_PREF(Live, "webgl.disable-extensions",              WebGLDisableExtensions, bool, false);
  DECL_GFX_PREF(Live, "webgl.dxgl.enabled",                    WebGLDXGLEnabled, bool, false);
  DECL_GFX_PREF(Live, "webgl.dxgl.needs-finish",               WebGLDXGLNeedsFinish, bool, false);

  DECL_GFX_PREF(Live, "webgl.disable-fail-if-major-performance-caveat",
                WebGLDisableFailIfMajorPerformanceCaveat, bool, false);
  DECL_GFX_PREF(Live, "webgl.disable-DOM-blit-uploads",
                WebGLDisableDOMBlitUploads, bool, false);

  DECL_GFX_PREF(Live, "webgl.disabled",                        WebGLDisabled, bool, false);

  DECL_GFX_PREF(Live, "webgl.enable-draft-extensions",         WebGLDraftExtensionsEnabled, bool, false);
  DECL_GFX_PREF(Live, "webgl.enable-privileged-extensions",    WebGLPrivilegedExtensionsEnabled, bool, false);
  DECL_GFX_PREF(Once, "webgl.enable-prototype-webgl2",         WebGL2Enabled, bool, false);
  DECL_GFX_PREF(Live, "webgl.force-enabled",                   WebGLForceEnabled, bool, false);
  DECL_GFX_PREF(Once, "webgl.force-layers-readback",           WebGLForceLayersReadback, bool, false);
  DECL_GFX_PREF(Live, "webgl.lose-context-on-memory-pressure", WebGLLoseContextOnMemoryPressure, bool, false);
  DECL_GFX_PREF(Live, "webgl.max-warnings-per-context",        WebGLMaxWarningsPerContext, uint32_t, 32);
  DECL_GFX_PREF(Live, "webgl.min_capability_mode",             WebGLMinCapabilityMode, bool, false);
  DECL_GFX_PREF(Live, "webgl.msaa-force",                      WebGLForceMSAA, bool, false);
  DECL_GFX_PREF(Live, "webgl.prefer-16bpp",                    WebGLPrefer16bpp, bool, false);
  DECL_GFX_PREF(Live, "webgl.restore-context-when-visible",    WebGLRestoreWhenVisible, bool, true);
  DECL_GFX_PREF(Live, "webgl.allow-immediate-queries",         WebGLImmediateQueries, bool, false);

  DECL_GFX_PREF(Live, "webgl.webgl2-compat-mode",              WebGL2CompatMode, bool, false);

  DECL_GFX_PREF(Once, "media.hardware-video-decoding.force-enabled",
                                                               HardwareVideoDecodingForceEnabled, bool, false);

  // WARNING:
  // Please make sure that you've added your new preference to the list above in alphabetical order.
  // Please do not just append it to the end of the list.

public:
  // Manage the singleton:
  static gfxPrefs& GetSingleton()
  {
    MOZ_ASSERT(!sInstanceHasBeenDestroyed, "Should never recreate a gfxPrefs instance!");
    if (!sInstance) {
      sInstance = new gfxPrefs;
    }
    MOZ_ASSERT(SingletonExists());
    return *sInstance;
  }
  static void DestroySingleton();
  static bool SingletonExists();

private:
  static gfxPrefs* sInstance;
  static bool sInstanceHasBeenDestroyed;

private:
  // Creating these to avoid having to include Preferences.h in the .h
  static void PrefAddVarCache(bool*, const char*, bool);
  static void PrefAddVarCache(int32_t*, const char*, int32_t);
  static void PrefAddVarCache(uint32_t*, const char*, uint32_t);
  static void PrefAddVarCache(float*, const char*, float);
  static bool PrefGet(const char*, bool);
  static int32_t PrefGet(const char*, int32_t);
  static uint32_t PrefGet(const char*, uint32_t);
  static float PrefGet(const char*, float);
  static void PrefSet(const char* aPref, bool aValue);
  static void PrefSet(const char* aPref, int32_t aValue);
  static void PrefSet(const char* aPref, uint32_t aValue);
  static void PrefSet(const char* aPref, float aValue);

  static void AssertMainThread();

  gfxPrefs();
  ~gfxPrefs();
  gfxPrefs(const gfxPrefs&) = delete;
  gfxPrefs& operator=(const gfxPrefs&) = delete;
};

#undef DECL_GFX_PREF /* Don't need it outside of this file */

#endif /* GFX_PREFS_H */