Bug 1249640: Part 2 gfxPlatform simplification when it comes to accelerated canvas, using the new blocking. r=gw280

dom/canvas/CanvasRenderingContext2D.cpp

@@ -795,10 +795,16 @@ CanvasDrawObserver::FrameEnd()
     // If we don't have enough data, don't bother changing...
     if (mGPUPreferredCalls > mMinCallsBeforeDecision ||
         mSoftwarePreferredCalls > mMinCallsBeforeDecision) {
+      CanvasRenderingContext2D::RenderingMode switchToMode;
       if (mGPUPreferredCalls >= mSoftwarePreferredCalls) {
-        mCanvasContext->SwitchRenderingMode(CanvasRenderingContext2D::RenderingMode::OpenGLBackendMode);
+        switchToMode = CanvasRenderingContext2D::RenderingMode::OpenGLBackendMode;
       } else {
-        mCanvasContext->SwitchRenderingMode(CanvasRenderingContext2D::RenderingMode::SoftwareBackendMode);
+        switchToMode = CanvasRenderingContext2D::RenderingMode::SoftwareBackendMode;
+      }
+      if (switchToMode != mCanvasContext->mRenderingMode) {
+        if (!mCanvasContext->SwitchRenderingMode(switchToMode)) {
+          gfxDebug() << "Canvas acceleration failed mode switch to " << switchToMode;
+        }
       }
     }
 
@@ -968,12 +974,10 @@ CanvasRenderingContext2D::CanvasRenderingContext2D()
   sNumLivingContexts++;
 
   // The default is to use OpenGL mode
-  if (!gfxPlatform::GetPlatform()->UseAcceleratedSkiaCanvas()) {
-    mRenderingMode = RenderingMode::SoftwareBackendMode;
-  }
-
-  if (gfxPlatform::GetPlatform()->HaveChoiceOfHWAndSWCanvas()) {
+  if (gfxPlatform::GetPlatform()->UseAcceleratedCanvas()) {
     mDrawObserver = new CanvasDrawObserver(this);
+  } else {
+    mRenderingMode = RenderingMode::SoftwareBackendMode;
   }
 }
 
@@ -1208,8 +1212,7 @@ bool CanvasRenderingContext2D::SwitchRenderingMode(RenderingMode aRenderingMode)
 #ifdef USE_SKIA_GPU
   // Do not attempt to switch into GL mode if the platform doesn't allow it.
   if ((aRenderingMode == RenderingMode::OpenGLBackendMode) &&
-      (!gfxPlatform::GetPlatform()->HaveChoiceOfHWAndSWCanvas() ||
-       !gfxPlatform::GetPlatform()->UseAcceleratedSkiaCanvas())) {
+      !gfxPlatform::GetPlatform()->UseAcceleratedCanvas()) {
       return false;
   }
 
@@ -1416,7 +1419,7 @@ CanvasRenderingContext2D::EnsureTarget(RenderingMode aRenderingMode)
 
     if (layerManager) {
       if (mode == RenderingMode::OpenGLBackendMode &&
-          gfxPlatform::GetPlatform()->UseAcceleratedSkiaCanvas() &&
+          gfxPlatform::GetPlatform()->UseAcceleratedCanvas() &&
           CheckSizeForSkiaGL(size)) {
         DemoteOldestContextIfNecessary();
         mBufferProvider = nullptr;

dom/canvas/test/test_canvas.html

@@ -64,7 +64,7 @@ function IsAcceleratedSkia() {
 
   try {
     var props = Cc["@mozilla.org/gfx/info;1"].getService(SpecialPowers.Ci.nsIGfxInfo).getInfo();
-    enabled = props.AzureCanvasBackend == "skia" && props.AzureSkiaAccelerated;
+    enabled = props.AzureCanvasBackend == "skia" && props.AzureCanvasAccelerated;
   } catch(e) { }
 
   return enabled;

gfx/thebes/gfxPlatform.cpp

@@ -1207,22 +1207,24 @@ gfxPlatform::SupportsAzureContentForDrawTarget(DrawTarget* aTarget)
   return SupportsAzureContentForType(aTarget->GetBackendType());
 }
 
-bool
-gfxPlatform::UseAcceleratedSkiaCanvas()
+bool gfxPlatform::UseAcceleratedCanvas()
 {
-  return gfxPrefs::CanvasAzureAccelerated() &&
-         mPreferredCanvasBackend == BackendType::SKIA;
-}
-
-bool gfxPlatform::HaveChoiceOfHWAndSWCanvas()
-{
-  return mPreferredCanvasBackend == BackendType::SKIA;
+  // Allow acceleration on Skia if the preference is set, unless it's blocked
+  if (mPreferredCanvasBackend == BackendType::SKIA && gfxPrefs::CanvasAzureAccelerated()) {
+    nsCOMPtr<nsIGfxInfo> gfxInfo = do_GetService("@mozilla.org/gfx/info;1");
+    int32_t status;
+    return !gfxInfo ||
+      (NS_SUCCEEDED(gfxInfo->GetFeatureStatus(nsIGfxInfo::FEATURE_CANVAS2D_ACCELERATION,
+                                              &status)) &&
+       status == nsIGfxInfo::FEATURE_STATUS_OK);
+  }
+  return false;
 }
 
 void
 gfxPlatform::InitializeSkiaCacheLimits()
 {
-  if (UseAcceleratedSkiaCanvas()) {
+  if (UseAcceleratedCanvas()) {
 #ifdef USE_SKIA_GPU
     bool usingDynamicCache = gfxPrefs::CanvasSkiaGLDynamicCache();
     int cacheItemLimit = gfxPrefs::CanvasSkiaGLCacheItems();
@@ -1254,7 +1256,7 @@ SkiaGLGlue*
 gfxPlatform::GetSkiaGLGlue()
 {
 #ifdef USE_SKIA_GPU
-  if (!gfxPlatform::GetPlatform()->UseAcceleratedSkiaCanvas()) {
+  if (!UseAcceleratedCanvas()) {
     gfxCriticalNote << "Accelerated Skia canvas is disabled";
     return nullptr;
   }

gfx/thebes/gfxPlatform.h

@@ -252,15 +252,13 @@ public:
       return BackendTypeBit(aType) & mContentBackendBitmask;
     }
 
-    /// This function lets us know if the current preferences/platform
+    /// This function also 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 bool UseAcceleratedCanvas();
     virtual void InitializeSkiaCacheLimits();
 
     /// These should be used instead of directly accessing the preference,
@@ -271,7 +269,7 @@ public:
 
     virtual void GetAzureBackendInfo(mozilla::widget::InfoObject &aObj) {
       aObj.DefineProperty("AzureCanvasBackend", GetBackendName(mPreferredCanvasBackend));
-      aObj.DefineProperty("AzureSkiaAccelerated", UseAcceleratedSkiaCanvas());
+      aObj.DefineProperty("AzureCanvasAccelerated", UseAcceleratedCanvas());
       aObj.DefineProperty("AzureFallbackCanvasBackend", GetBackendName(mFallbackCanvasBackend));
       aObj.DefineProperty("AzureContentBackend", GetBackendName(mContentBackend));
     }

layout/tools/reftest/reftest.js

@@ -654,7 +654,7 @@ function BuildConditionSandbox(aURL) {
     sandbox.azureQuartz = info.AzureCanvasBackend == "quartz";
     sandbox.azureSkia = info.AzureCanvasBackend == "skia";
     sandbox.skiaContent = info.AzureContentBackend == "skia";
-    sandbox.azureSkiaGL = info.AzureSkiaAccelerated; // FIXME: assumes GL right now
+    sandbox.azureSkiaGL = info.AzureCanvasAccelerated; // FIXME: assumes GL right now
     // true if we are using the same Azure backend for rendering canvas and content
     sandbox.contentSameGfxBackendAsCanvas = info.AzureContentBackend == info.AzureCanvasBackend
                                             || (info.AzureContentBackend == "none" && info.AzureCanvasBackend == "cairo");