Rewrite PictureSet with TURBO!

This changes how partial invals are done by adding a hybrid mode.

What we used to do is generate a SkPicture for the new area. This
SkPicture would possibly be larger than the actual inval, depending
on various merge rules (more SkPictures == slower to draw a tile)

The new code rewrites PictureSet entirely, preserving many of the old rules
but cleans up the code and adds the concept of a "PrerenderedInval". This is
a partial inval that WebKit has rasterized. By having WebKit produce both
a SkPicture and a SkBitmap, we avoid needing to play back the picture and
avoid overdrawing. We take this SkBitmap, and simply update the front
textures with it. This gives us full partial invals through the entire
system without hitting any driver bugs, and with minimal copies. And while
the SkPicture may be larger than the inval, the SkBitmap that is rasterized
is not - it matches the area webkit has said is dirty.

Change-Id: Ieb7ecc9db0d4f679102fda004a43399f9b319ebc

7 files changed, 134 insertions, 53 deletions

diff --git a/Source/WebCore/platform/graphics/android/layers/LayerAndroid.cpp b/Source/WebCore/platform/graphics/android/layers/LayerAndroid.cpp
index 69c597f..535d211 100644
--- a/Source/WebCore/platform/graphics/android/layers/LayerAndroid.cpp
+++ b/Source/WebCore/platform/graphics/android/layers/LayerAndroid.cpp
@@ -20,6 +20,7 @@
 #include "MediaLayer.h"
 #include "ParseCanvas.h"
 #include "PictureLayerContent.h"
+#include "PrerenderedInval.h"
 #include "SkBitmapRef.h"
 #include "SkDrawFilter.h"
 #include "SkPaint.h"
@@ -524,6 +525,20 @@ void LayerAndroid::setContent(LayerContent* content)
     m_content = content;
 }
 
+bool LayerAndroid::canUpdateWithBlit()
+{
+    if (!m_content || !m_scale)
+        return false;
+    PrerenderedInval* prerendered = m_content->prerenderForRect(m_dirtyRegion.getBounds());
+    if (!prerendered)
+        return false;
+    // Check that the scales are "close enough" to produce the same rects
+    FloatRect screenArea = prerendered->screenArea;
+    screenArea.scale(1 / m_scale);
+    IntRect enclosingDocArea = enclosingIntRect(screenArea);
+    return enclosingDocArea == prerendered->area;
+}
+
 bool LayerAndroid::needsTexture()
 {
     return m_content && !m_content->isEmpty();
diff --git a/Source/WebCore/platform/graphics/android/layers/LayerAndroid.h b/Source/WebCore/platform/graphics/android/layers/LayerAndroid.h
index 4f94698..ca833f7 100644
--- a/Source/WebCore/platform/graphics/android/layers/LayerAndroid.h
+++ b/Source/WebCore/platform/graphics/android/layers/LayerAndroid.h
@@ -185,6 +185,9 @@ public:
 
     LayerContent* content() { return m_content; }
     void setContent(LayerContent* content);
+    // Check to see if the dirty area of this layer can be updated with a blit
+    // from the prerender instead of needing to generate tiles from the LayerContent
+    bool canUpdateWithBlit();
 
     void addAnimation(PassRefPtr<AndroidAnimation> anim);
     void removeAnimationsForProperty(AnimatedPropertyID property);
diff --git a/Source/WebCore/platform/graphics/android/layers/LayerContent.h b/Source/WebCore/platform/graphics/android/layers/LayerContent.h
index 97bc32a..2cd90a90 100644
--- a/Source/WebCore/platform/graphics/android/layers/LayerContent.h
+++ b/Source/WebCore/platform/graphics/android/layers/LayerContent.h
@@ -26,6 +26,7 @@
 #ifndef LayerContent_h
 #define LayerContent_h
 
+#include "IntRect.h"
 #include "SkRefCnt.h"
 #include <utils/threads.h>
 
@@ -35,14 +36,18 @@ class SkWStream;
 
 namespace WebCore {
 
+class PrerenderedInval;
+
 class LayerContent : public SkRefCnt {
 public:
     virtual int width() = 0;
     virtual int height() = 0;
-    virtual bool isEmpty() = 0;
+    virtual bool isEmpty() { return !width() || !height(); }
     virtual void checkForOptimisations() = 0;
     virtual bool hasText() = 0;
     virtual void draw(SkCanvas* canvas) = 0;
+    virtual PrerenderedInval* prerenderForRect(const IntRect& dirty) { return 0; }
+    virtual void clearPrerenders() { };
 
     virtual void serialize(SkWStream* stream) = 0;
 
diff --git a/Source/WebCore/platform/graphics/android/layers/PicturePileLayerContent.cpp b/Source/WebCore/platform/graphics/android/layers/PicturePileLayerContent.cpp
new file mode 100644
index 0000000..b648e72
--- /dev/null
+++ b/Source/WebCore/platform/graphics/android/layers/PicturePileLayerContent.cpp
@@ -0,0 +1,41 @@
+#include "config.h"
+#include "PicturePileLayerContent.h"
+
+#include "SkCanvas.h"
+#include "SkPicture.h"
+
+namespace WebCore {
+
+PicturePileLayerContent::PicturePileLayerContent(const PicturePile& picturePile)
+    : m_picturePile(picturePile)
+{
+}
+
+void PicturePileLayerContent::draw(SkCanvas* canvas)
+{
+    android::Mutex::Autolock lock(m_drawLock);
+    m_picturePile.draw(canvas);
+}
+
+void PicturePileLayerContent::serialize(SkWStream* stream)
+{
+    if (!stream)
+       return;
+    SkPicture picture;
+    draw(picture.beginRecording(width(), height(),
+                                SkPicture::kUsePathBoundsForClip_RecordingFlag));
+    picture.endRecording();
+    picture.serialize(stream);
+}
+
+PrerenderedInval* PicturePileLayerContent::prerenderForRect(const IntRect& dirty)
+{
+    return m_picturePile.prerenderedInvalForArea(dirty);
+}
+
+void PicturePileLayerContent::clearPrerenders()
+{
+    m_picturePile.clearPrerenders();
+}
+
+} // namespace WebCore
diff --git a/Source/WebCore/platform/graphics/android/layers/PictureSetLayerContent.h b/Source/WebCore/platform/graphics/android/layers/PicturePileLayerContent.h
index 61fc3f4..4216617 100644
--- a/Source/WebCore/platform/graphics/android/layers/PictureSetLayerContent.h
+++ b/Source/WebCore/platform/graphics/android/layers/PicturePileLayerContent.h
@@ -23,31 +23,31 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef PictureSetLayerContent_h
-#define PictureSetLayerContent_h
+#ifndef PicturePileLayerContent_h
+#define PicturePileLayerContent_h
 
 #include "LayerContent.h"
-#include "PictureSet.h"
+#include "PicturePile.h"
 
 namespace WebCore {
 
-class PictureSetLayerContent : public LayerContent {
+class PicturePileLayerContent : public LayerContent {
 public:
-    PictureSetLayerContent(const android::PictureSet& pictureSet);
-    ~PictureSetLayerContent();
+    PicturePileLayerContent(const PicturePile& picturePile);
 
-    virtual int width() { return m_pictureSet.width(); }
-    virtual int height() { return m_pictureSet.height(); }
-    virtual bool isEmpty() { return m_pictureSet.isEmpty(); }
+    virtual int width() { return m_picturePile.size().width(); }
+    virtual int height() { return m_picturePile.size().height(); }
     virtual void checkForOptimisations() {}
     virtual bool hasText() { return true; }
     virtual void draw(SkCanvas* canvas);
     virtual void serialize(SkWStream* stream);
+    virtual PrerenderedInval* prerenderForRect(const IntRect& dirty);
+    virtual void clearPrerenders();
 
 private:
-    android::PictureSet m_pictureSet;
+    PicturePile m_picturePile;
 };
 
 } // WebCore
 
-#endif // PictureLayerContent_h
+#endif // PicturePileLayerContent_h
diff --git a/Source/WebCore/platform/graphics/android/layers/PictureSetLayerContent.cpp b/Source/WebCore/platform/graphics/android/layers/PictureSetLayerContent.cpp
deleted file mode 100644
index 8b72b0a..0000000
--- a/Source/WebCore/platform/graphics/android/layers/PictureSetLayerContent.cpp
+++ /dev/null
@@ -1,41 +0,0 @@
-#include "config.h"
-#include "PictureSetLayerContent.h"
-
-#include "SkCanvas.h"
-#include "SkPicture.h"
-
-namespace WebCore {
-
-PictureSetLayerContent::PictureSetLayerContent(const android::PictureSet& pictureSet)
-{
-    m_pictureSet.set(pictureSet);
-}
-
-PictureSetLayerContent::~PictureSetLayerContent()
-{
-    m_pictureSet.clear();
-}
-
-void PictureSetLayerContent::draw(SkCanvas* canvas)
-{
-    if (m_pictureSet.isEmpty())
-        return;
-
-    android::Mutex::Autolock lock(m_drawLock);
-    SkRect r = SkRect::MakeWH(width(), height());
-    canvas->clipRect(r);
-    m_pictureSet.draw(canvas);
-}
-
-void PictureSetLayerContent::serialize(SkWStream* stream)
-{
-    if (!stream)
-           return;
-    SkPicture picture;
-    draw(picture.beginRecording(m_pictureSet.width(), m_pictureSet.height(),
-                                SkPicture::kUsePathBoundsForClip_RecordingFlag));
-    picture.endRecording();
-    picture.serialize(stream);
-}
-
-} // namespace WebCore
diff --git a/Source/WebCore/platform/graphics/android/layers/PrerenderedInval.h b/Source/WebCore/platform/graphics/android/layers/PrerenderedInval.h
new file mode 100644
index 0000000..91f385d
--- /dev/null
+++ b/Source/WebCore/platform/graphics/android/layers/PrerenderedInval.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright 2012, The Android Open Source Project
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef PrerenderedInval_h
+#define PrerenderedInval_h
+
+#include "IntRect.h"
+#include "SkBitmap.h"
+
+#include <wtf/PassRefPtr.h>
+#include <wtf/RefCounted.h>
+#include <wtf/ThreadSafeRefCounted.h>
+
+namespace WebCore {
+
+class PrerenderedInval : public ThreadSafeRefCounted<PrerenderedInval> {
+    WTF_MAKE_NONCOPYABLE(PrerenderedInval);
+public:
+    SkBitmap bitmap;
+    IntRect area;
+    IntRect screenArea;
+
+    static PassRefPtr<PrerenderedInval> create(const IntRect& ir)
+    {
+        return adoptRef(new PrerenderedInval(ir));
+    }
+
+private:
+    PrerenderedInval(const IntRect& ir)
+        : area(ir)
+    {}
+};
+
+} // namespace WebCore
+
+#endif // PrerenderedInval_h