Smart layer invalidation for LCD text.

When LCD text needs to be disabled for a layer, we can invalidate just the tiles containing text.
This only works with impl-side painting where it is very cheap to mark tiles that have text.

BUG=181245


Review URL: https://chromiumcodereview.appspot.com/13726013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@192936 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 145 insertions, 2 deletions

diff --git a/skia/ext/analysis_canvas.cc b/skia/ext/analysis_canvas.cc
index 93580b0..0af76f2 100644
--- a/skia/ext/analysis_canvas.cc
+++ b/skia/ext/analysis_canvas.cc
@@ -96,8 +96,8 @@ AnalysisDevice::AnalysisDevice(const SkBitmap& bm)
   , isForcedNotSolid_(false)
   , isForcedNotTransparent_(false)
   , isSolidColor_(false)
-  , isTransparent_(false) {
-
+  , isTransparent_(false)
+  , hasText_(false) {
 }
 
 AnalysisDevice::~AnalysisDevice() {
@@ -118,6 +118,10 @@ bool AnalysisDevice::isTransparent() const {
   return isTransparent_;
 }
 
+bool AnalysisDevice::hasText() const {
+  return hasText_;
+}
+
 void AnalysisDevice::setForceNotSolid(bool flag) {
   isForcedNotSolid_ = flag;
   if (isForcedNotSolid_)
@@ -181,6 +185,7 @@ void AnalysisDevice::clear(SkColor color) {
   estimatedCost_ += kUnknownExpensiveCost;
 
   isTransparent_ = (!isForcedNotTransparent_ && SkColorGetA(color) == 0);
+  hasText_ = false;
 
   if (!isForcedNotSolid_ && SkColorGetA(color) == 255) {
     isSolidColor_ = true;
@@ -246,6 +251,7 @@ void AnalysisDevice::drawRect(const SkDraw& draw, const SkRect& rect,
       !isForcedNotTransparent_ &&
       xferMode == SkXfermode::kClear_Mode) {
     isTransparent_ = true;
+    hasText_ = false;
   }
   else if (paint.getAlpha() != 0 ||
            xferMode != SkXfermode::kSrc_Mode) {
@@ -262,6 +268,7 @@ void AnalysisDevice::drawRect(const SkDraw& draw, const SkRect& rect,
       doesCoverCanvas) {
     isSolidColor_ = true;
     color_ = paint.getColor();
+    hasText_ = false;
   }
   else {
     isSolidColor_ = false;
@@ -346,6 +353,7 @@ void AnalysisDevice::drawText(const SkDraw&, const void* text, size_t len,
   }
   isSolidColor_ = false;
   isTransparent_ = false;
+  hasText_ = true;
 }
 
 void AnalysisDevice::drawPosText(const SkDraw& draw, const void* text,
@@ -361,6 +369,7 @@ void AnalysisDevice::drawPosText(const SkDraw& draw, const void* text,
   }
   isSolidColor_ = false;
   isTransparent_ = false;
+  hasText_ = true;
 }
 
 void AnalysisDevice::drawTextOnPath(const SkDraw&, const void* text,
@@ -374,6 +383,7 @@ void AnalysisDevice::drawTextOnPath(const SkDraw&, const void* text,
   }
   isSolidColor_ = false;
   isTransparent_ = false;
+  hasText_ = true;
 }
 
 #ifdef SK_BUILD_FOR_ANDROID
@@ -388,6 +398,7 @@ void AnalysisDevice::drawPosTextOnPath(const SkDraw& draw, const void* text,
   }
   isSolidColor_ = false;
   isTransparent_ = false;
+  hasText_ = true;
 }
 #endif
 
@@ -441,6 +452,10 @@ bool AnalysisCanvas::isTransparent() const {
   return (static_cast<AnalysisDevice*>(getDevice()))->isTransparent();
 }
 
+bool AnalysisCanvas::hasText() const {
+  return (static_cast<AnalysisDevice*>(getDevice()))->hasText();
+}
+
 int AnalysisCanvas::getEstimatedCost() const {
   return (static_cast<AnalysisDevice*>(getDevice()))->getEstimatedCost();
 }
diff --git a/skia/ext/analysis_canvas.h b/skia/ext/analysis_canvas.h
index 3c2daaf..4ebf793 100644
--- a/skia/ext/analysis_canvas.h
+++ b/skia/ext/analysis_canvas.h
@@ -35,6 +35,7 @@ class SK_API AnalysisCanvas : public SkCanvas {
   bool isCheap() const;
   bool getColorIfSolid(SkColor* color) const;
   bool isTransparent() const;
+  bool hasText() const;
   void consumeLazyPixelRefs(LazyPixelRefList* pixelRefs);
 
   // Returns the estimated cost of drawing, in arbitrary units.
@@ -76,6 +77,7 @@ class SK_API AnalysisDevice : public SkDevice {
   int getEstimatedCost() const;
   bool getColorIfSolid(SkColor* color) const;
   bool isTransparent() const;
+  bool hasText() const;
   void consumeLazyPixelRefs(LazyPixelRefList* pixelRefs);
 
   void setForceNotSolid(bool flag);
@@ -144,6 +146,7 @@ class SK_API AnalysisDevice : public SkDevice {
   bool isSolidColor_;
   SkColor color_;
   bool isTransparent_;
+  bool hasText_;
   IdSet existingPixelRefIDs_;
   LazyPixelRefList lazyPixelRefs_;
 };
diff --git a/skia/ext/analysis_canvas_unittest.cc b/skia/ext/analysis_canvas_unittest.cc
index 46c9645..a8a9d0d 100644
--- a/skia/ext/analysis_canvas_unittest.cc
+++ b/skia/ext/analysis_canvas_unittest.cc
@@ -454,4 +454,129 @@ TEST(AnalysisCanvasTest, PixelRefsFromPaint) {
   }
 }
 
+TEST(AnalysisCanvasTest, HasText) {
+  int width = 200;
+  int height = 100;
+
+  SkBitmap bitmap;
+  bitmap.setConfig(SkBitmap::kNo_Config, width, height);
+
+  const char* text = "A";
+  size_t byteLength = 1;
+
+  SkPoint point = SkPoint::Make(SkIntToScalar(25), SkIntToScalar(25));
+  SkPath path;
+  path.moveTo(point);
+  path.lineTo(SkIntToScalar(75), SkIntToScalar(75));
+
+  SkPaint paint;
+  paint.setColor(SK_ColorGRAY);
+  paint.setTextSize(SkIntToScalar(10));
+
+  {
+    skia::AnalysisDevice device(bitmap);
+    skia::AnalysisCanvas canvas(&device);
+    // Test after initialization.
+    EXPECT_FALSE(canvas.hasText());
+    // Test drawing anything other than text.
+    canvas.drawRect(SkRect::MakeWH(width/2, height), paint);
+    EXPECT_FALSE(canvas.hasText());
+  }
+  {
+    // Test SkCanvas::drawText.
+    skia::AnalysisDevice device(bitmap);
+    skia::AnalysisCanvas canvas(&device);
+    canvas.drawText(text, byteLength, point.fX, point.fY, paint);
+    EXPECT_TRUE(canvas.hasText());
+  }
+  {
+    // Test SkCanvas::drawPosText.
+    skia::AnalysisDevice device(bitmap);
+    skia::AnalysisCanvas canvas(&device);
+    canvas.drawPosText(text, byteLength, &point, paint);
+    EXPECT_TRUE(canvas.hasText());
+  }
+  {
+    // Test SkCanvas::drawPosTextH.
+    skia::AnalysisDevice device(bitmap);
+    skia::AnalysisCanvas canvas(&device);
+    canvas.drawPosTextH(text, byteLength, &point.fX, point.fY, paint);
+    EXPECT_TRUE(canvas.hasText());
+  }
+  {
+    // Test SkCanvas::drawTextOnPathHV.
+    skia::AnalysisDevice device(bitmap);
+    skia::AnalysisCanvas canvas(&device);
+    canvas.drawTextOnPathHV(text, byteLength, path, point.fX, point.fY, paint);
+    EXPECT_TRUE(canvas.hasText());
+  }
+  {
+    // Test SkCanvas::drawTextOnPath.
+    skia::AnalysisDevice device(bitmap);
+    skia::AnalysisCanvas canvas(&device);
+    canvas.drawTextOnPath(text, byteLength, path, NULL, paint);
+    EXPECT_TRUE(canvas.hasText());
+  }
+  {
+    // Text under opaque rect.
+    skia::AnalysisDevice device(bitmap);
+    skia::AnalysisCanvas canvas(&device);
+    canvas.drawText(text, byteLength, point.fX, point.fY, paint);
+    EXPECT_TRUE(canvas.hasText());
+    canvas.drawRect(SkRect::MakeWH(width, height), paint);
+    EXPECT_FALSE(canvas.hasText());
+  }
+  {
+    // Text under translucent rect.
+    skia::AnalysisDevice device(bitmap);
+    skia::AnalysisCanvas canvas(&device);
+    canvas.drawText(text, byteLength, point.fX, point.fY, paint);
+    EXPECT_TRUE(canvas.hasText());
+    SkPaint translucentPaint;
+    translucentPaint.setColor(0x88FFFFFF);
+    canvas.drawRect(SkRect::MakeWH(width, height), translucentPaint);
+    EXPECT_TRUE(canvas.hasText());
+  }
+  {
+    // Text under rect in clear mode.
+    skia::AnalysisDevice device(bitmap);
+    skia::AnalysisCanvas canvas(&device);
+    canvas.drawText(text, byteLength, point.fX, point.fY, paint);
+    EXPECT_TRUE(canvas.hasText());
+    SkPaint clearModePaint;
+    clearModePaint.setXfermodeMode(SkXfermode::kClear_Mode);
+    canvas.drawRect(SkRect::MakeWH(width, height), clearModePaint);
+    EXPECT_FALSE(canvas.hasText());
+  }
+  {
+    // Clear.
+    skia::AnalysisDevice device(bitmap);
+    skia::AnalysisCanvas canvas(&device);
+    canvas.drawText(text, byteLength, point.fX, point.fY, paint);
+    EXPECT_TRUE(canvas.hasText());
+    canvas.clear(SK_ColorGRAY);
+    EXPECT_FALSE(canvas.hasText());
+  }
+  {
+    // Text inside clip region.
+    skia::AnalysisDevice device(bitmap);
+    skia::AnalysisCanvas canvas(&device);
+    canvas.clipRect(SkRect::MakeWH(100, 100));
+    canvas.drawText(text, byteLength, point.fX, point.fY, paint);
+    EXPECT_TRUE(canvas.hasText());
+  }
+  {
+    // Text outside clip region.
+    skia::AnalysisDevice device(bitmap);
+    skia::AnalysisCanvas canvas(&device);
+    canvas.clipRect(SkRect::MakeXYWH(100, 0, 100, 100));
+    canvas.drawText(text, byteLength, point.fX, point.fY, paint);
+    // Analysis device does not do any clipping.
+    // So even when text is outside the clip region,
+    // it is marked as having the text.
+    // TODO(alokp): We may be able to do some trivial rejection.
+    EXPECT_TRUE(canvas.hasText());
+  }
+}
+
 }  // namespace skia