Bug 1164970 - Implement failIfMajorPerformanceCaveat. r=jgilbert, r=ehsan

--HG--
extra : rebase_source : c609118df9618795a1c84a7f5749979ad8f9aa68

dom/canvas/WebGLContext.cpp

@@ -194,6 +194,7 @@ WebGLContextOptions::WebGLContextOptions()
     , premultipliedAlpha(true)
     , antialias(true)
     , preserveDrawingBuffer(false)
+    , failIfMajorPerformanceCaveat(false)
 {
     // Set default alpha state based on preference.
     if (Preferences::GetBool("webgl.default-no-alpha", false))
@@ -431,6 +432,7 @@ WebGLContext::SetContextOptions(JSContext* cx, JS::Handle<JS::Value> options)
     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();
@@ -500,6 +502,30 @@ IsFeatureInBlacklist(const nsCOMPtr<nsIGfxInfo>& gfxInfo, int32_t feature)
     return status != nsIGfxInfo::FEATURE_STATUS_OK;
 }
 
+static bool
+HasAcceleratedLayers(const nsCOMPtr<nsIGfxInfo>& gfxInfo)
+{
+    int32_t status;
+
+    gfxInfo->GetFeatureStatus(nsIGfxInfo::FEATURE_DIRECT3D_9_LAYERS, &status);
+    if (status)
+        return true;
+    gfxInfo->GetFeatureStatus(nsIGfxInfo::FEATURE_DIRECT3D_10_LAYERS, &status);
+    if (status)
+        return true;
+    gfxInfo->GetFeatureStatus(nsIGfxInfo::FEATURE_DIRECT3D_10_1_LAYERS, &status);
+    if (status)
+        return true;
+    gfxInfo->GetFeatureStatus(nsIGfxInfo::FEATURE_DIRECT3D_11_LAYERS, &status);
+    if (status)
+        return true;
+    gfxInfo->GetFeatureStatus(nsIGfxInfo::FEATURE_OPENGL_LAYERS, &status);
+    if (status)
+        return true;
+
+    return false;
+}
+
 static already_AddRefed<GLContext>
 CreateHeadlessNativeGL(bool forceEnabled, const nsCOMPtr<nsIGfxInfo>& gfxInfo,
                        bool requireCompatProfile, WebGLContext* webgl)
@@ -569,7 +595,6 @@ CreateHeadlessEGL(bool forceEnabled, bool requireCompatProfile,
     return gl.forget();
 }
 
-
 static already_AddRefed<GLContext>
 CreateHeadlessGL(bool forceEnabled, const nsCOMPtr<nsIGfxInfo>& gfxInfo,
                  WebGLContext* webgl)
@@ -873,6 +898,18 @@ WebGLContext::SetDimensions(int32_t signedWidth, int32_t signedHeight)
         return NS_ERROR_FAILURE;
     }
 
+    nsCOMPtr<nsIGfxInfo> gfxInfo = do_GetService("@mozilla.org/gfx/info;1");
+    bool failIfMajorPerformanceCaveat =
+                    !gfxPrefs::WebGLDisableFailIfMajorPerformanceCaveat() &&
+                    !HasAcceleratedLayers(gfxInfo);
+    if (failIfMajorPerformanceCaveat) {
+        Nullable<dom::WebGLContextAttributes> contextAttributes;
+        this->GetContextAttributes(contextAttributes);
+        if (contextAttributes.Value().mFailIfMajorPerformanceCaveat) {
+            return NS_ERROR_FAILURE;
+        }
+    }
+
     // Alright, now let's start trying.
     bool forceEnabled = Preferences::GetBool("webgl.force-enabled", false);
     ScopedGfxFeatureReporter reporter("WebGL", forceEnabled);
@@ -1255,6 +1292,7 @@ WebGLContext::GetContextAttributes(Nullable<dom::WebGLContextAttributes>& retval
     result.mAntialias = mOptions.antialias;
     result.mPremultipliedAlpha = mOptions.premultipliedAlpha;
     result.mPreserveDrawingBuffer = mOptions.preserveDrawingBuffer;
+    result.mFailIfMajorPerformanceCaveat = mOptions.failIfMajorPerformanceCaveat;
 }
 
 /* [noscript] DOMString mozGetUnderlyingParamString(in GLenum pname); */

dom/canvas/WebGLContext.h

@@ -128,6 +128,7 @@ struct WebGLContextOptions
     bool premultipliedAlpha;
     bool antialias;
     bool preserveDrawingBuffer;
+    bool failIfMajorPerformanceCaveat;
 };
 
 // From WebGLContextUtils

dom/webidl/WebGLRenderingContext.webidl

@@ -41,6 +41,7 @@ dictionary WebGLContextAttributes {
     boolean antialias = true;
     boolean premultipliedAlpha = true;
     boolean preserveDrawingBuffer = false;
+    boolean failIfMajorPerformanceCaveat = false;
 };
 
 interface WebGLBuffer {

gfx/thebes/gfxPrefs.h

@@ -368,6 +368,8 @@ private:
   DECL_GFX_PREF(Live, "ui.click_hold_context_menus.delay",     UiClickHoldContextMenusDelay, int32_t, 500);
   DECL_GFX_PREF(Once, "webgl.angle.force-d3d11",               WebGLANGLEForceD3D11, bool, false);
   DECL_GFX_PREF(Once, "webgl.angle.try-d3d11",                 WebGLANGLETryD3D11, bool, false);
+  DECL_GFX_PREF(Live, "webgl.disable-fail-if-major-performance-caveat",
+                WebGLDisableFailIfMajorPerformanceCaveat, bool, false);
   DECL_GFX_PREF(Once, "webgl.force-layers-readback",           WebGLForceLayersReadback, bool, false);
 
   // WARNING:

modules/libpref/init/all.js

@@ -4001,6 +4001,7 @@ pref("webgl.enable-draft-extensions", false);
 pref("webgl.enable-privileged-extensions", false);
 pref("webgl.bypass-shader-validation", false);
 pref("webgl.enable-prototype-webgl2", false);
+pref("webgl.disable-fail-if-major-performance-caveat", false);
 pref("gl.require-hardware", false);
 
 #ifdef XP_WIN