Bug 805028 - Use ComputeRenderIntegrity to calculate accurate checkerboard. r=kats

Use ComputeRenderIntegrity so that checkerboarding values remain accurate when
progressive tiles are enabled.

mobile/android/base/GeckoAppShell.java

@@ -249,6 +249,7 @@ public class GeckoAppShell
     public static native void scheduleComposite();
     public static native void schedulePauseComposition();
     public static native void scheduleResumeComposition(int width, int height);
+    public static native float computeRenderIntegrity();
 
     public static native SurfaceBits getSurfaceBits(Surface surface);
 

mobile/android/base/gfx/LayerRenderer.java

@@ -410,12 +410,18 @@ public class LayerRenderer implements Tabs.OnTabsChangedListener {
         // Whether a layer was updated.
         private boolean mUpdated;
         private final Rect mPageRect;
+        private final Rect mAbsolutePageRect;
 
         public Frame(ImmutableViewportMetrics metrics) {
             mFrameMetrics = metrics;
             mPageContext = createPageContext(metrics);
             mScreenContext = createScreenContext(metrics);
-            mPageRect = getPageRect();
+
+            Point origin = PointUtils.round(mFrameMetrics.getOrigin());
+            Rect pageRect = RectUtils.round(mFrameMetrics.getPageRect());
+            mAbsolutePageRect = new Rect(pageRect);
+            pageRect.offset(-origin.x, -origin.y);
+            mPageRect = pageRect;
         }
 
         private void setScissorRect() {
@@ -437,13 +443,6 @@ public class LayerRenderer implements Tabs.OnTabsChangedListener {
                             (screenSize.height - bottom) + (bottom - top));
         }
 
-        private Rect getPageRect() {
-            Point origin = PointUtils.round(mFrameMetrics.getOrigin());
-            Rect pageRect = RectUtils.round(mFrameMetrics.getPageRect());
-            pageRect.offset(-origin.x, -origin.y);
-            return pageRect;
-        }
-
         /** This function is invoked via JNI; be careful when modifying signature. */
         public void beginDrawing() {
             mFrameStartTime = SystemClock.uptimeMillis();
@@ -543,9 +542,7 @@ public class LayerRenderer implements Tabs.OnTabsChangedListener {
             mBackgroundLayer.draw(mScreenContext);
 
             /* Draw the drop shadow, if we need to. */
-            RectF untransformedPageRect = new RectF(0.0f, 0.0f, mPageRect.width(),
-                                                    mPageRect.height());
-            if (!untransformedPageRect.contains(mFrameMetrics.getViewport()))
+            if (!new RectF(mAbsolutePageRect).contains(mFrameMetrics.getViewport()))
                 mShadowLayer.draw(mPageContext);
 
             /* Draw the 'checkerboard'. We use gfx.show_checkerboard_pattern to
@@ -607,7 +604,7 @@ public class LayerRenderer implements Tabs.OnTabsChangedListener {
 
                 /* restrict the viewport to page bounds so we don't
                  * count overscroll as checkerboard */
-                if (!viewport.intersect(mPageRect)) {
+                if (!viewport.intersect(mAbsolutePageRect)) {
                     /* if the rectangles don't intersect
                        intersect() doesn't change viewport
                        so we set it to empty by hand */
@@ -615,10 +612,14 @@ public class LayerRenderer implements Tabs.OnTabsChangedListener {
                 }
                 validRegion.op(viewport, Region.Op.INTERSECT);
 
-                float checkerboard = 0.0f;
-
+                // Check if we have total checkerboarding (there's visible
+                // page area and the valid region doesn't intersect with the
+                // viewport).
                 int screenArea = viewport.width() * viewport.height();
-                if (screenArea > 0 && !(validRegion.isRect() && validRegion.getBounds().equals(viewport))) {
+                float checkerboard = (screenArea > 0 &&
+                  validRegion.quickReject(viewport)) ? 1.0f : 0.0f;
+
+                if (screenArea > 0 && checkerboard < 1.0f) {
                     validRegion.op(viewport, Region.Op.REVERSE_DIFFERENCE);
 
                     // XXX The assumption here is that a Region never has overlapping
@@ -633,6 +634,9 @@ public class LayerRenderer implements Tabs.OnTabsChangedListener {
                     }
 
                     checkerboard = checkerboardArea / (float)screenArea;
+
+                    // Add any incomplete rendering in the screen area
+                    checkerboard += (1.0 - checkerboard) * (1.0 - GeckoAppShell.computeRenderIntegrity());
                 }
 
                 PanningPerfAPI.recordCheckerboard(checkerboard);

mozglue/android/APKOpen.cpp

@@ -306,6 +306,7 @@ SHELL_WRAPPER0(bindWidgetTexture)
 SHELL_WRAPPER0(scheduleComposite)
 SHELL_WRAPPER0(schedulePauseComposition)
 SHELL_WRAPPER2(scheduleResumeComposition, jint, jint)
+SHELL_WRAPPER0_WITH_RETURN(computeRenderIntegrity, jfloat)
 SHELL_WRAPPER3_WITH_RETURN(saveMessageInSentbox, jint, jstring, jstring, jlong)
 SHELL_WRAPPER6(notifySmsSent, jint, jstring, jstring, jlong, jint, jlong)
 SHELL_WRAPPER4(notifySmsDelivered, jint, jstring, jstring, jlong)
@@ -729,6 +730,7 @@ loadGeckoLibs(const char *apkName)
   GETFUNC(scheduleComposite);
   GETFUNC(schedulePauseComposition);
   GETFUNC(scheduleResumeComposition);
+  GETFUNC(computeRenderIntegrity);
   GETFUNC(saveMessageInSentbox);
   GETFUNC(notifySmsSent);
   GETFUNC(notifySmsDelivered);

widget/android/AndroidJNI.cpp

@@ -834,6 +834,12 @@ Java_org_mozilla_gecko_GeckoAppShell_scheduleResumeComposition(JNIEnv*, jclass,
     nsWindow::ScheduleResumeComposition(width, height);
 }
 
+NS_EXPORT float JNICALL
+Java_org_mozilla_gecko_GeckoAppShell_computeRenderIntegrity(JNIEnv*, jclass)
+{
+    return nsWindow::ComputeRenderIntegrity();
+}
+
 NS_EXPORT void JNICALL
 Java_org_mozilla_gecko_GeckoAppShell_notifyFilePickerResult(JNIEnv* jenv, jclass, jstring filePath, jlong callback)
 {

widget/android/nsWindow.cpp

@@ -2283,6 +2283,20 @@ nsWindow::ScheduleResumeComposition(int width, int height)
     }
 }
 
+float
+nsWindow::ComputeRenderIntegrity()
+{
+    if (sCompositorParent) {
+        mozilla::layers::LayerManagerOGL* manager =
+          static_cast<mozilla::layers::LayerManagerOGL*>(sCompositorParent->GetLayerManager());
+        if (manager) {
+            return manager->ComputeRenderIntegrity();
+        }
+    }
+
+    return 1.f;
+}
+
 bool
 nsWindow::WidgetPaintsBackground()
 {

widget/android/nsWindow.h

@@ -156,6 +156,7 @@ public:
     static void ScheduleComposite();
     static void SchedulePauseComposition();
     static void ScheduleResumeComposition(int width, int height);
+    static float ComputeRenderIntegrity();
 
     virtual bool WidgetPaintsBackground();
 #endif