cc: Add image decode control in the compositor.

cc/playback/display_list_raster_source.cc

Index: cc/playback/display_list_raster_source.cc
diff --git a/cc/playback/display_list_raster_source.cc b/cc/playback/display_list_raster_source.cc
index cc4f7a7807d4b95b21a292c48d7440b560fbc222..c9ef9897b12d9f4a60a19c4a2f134f186fd2e3f9 100644
--- a/cc/playback/display_list_raster_source.cc
+++ b/cc/playback/display_list_raster_source.cc
@@ -8,13 +8,172 @@
 #include "cc/base/region.h"
 #include "cc/debug/debug_colors.h"
 #include "cc/playback/display_item_list.h"
+#include "cc/tiles/image_decode_controller.h"
 #include "skia/ext/analysis_canvas.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkPictureRecorder.h"
+#include "third_party/skia/include/utils/SkNWayCanvas.h"
 #include "ui/gfx/geometry/rect_conversions.h"
 
 namespace cc {
 
+namespace {
+
+SkSize ExtractScale(const SkMatrix& matrix) {
+  SkSize scale = SkSize::Make(matrix.getScaleX(), matrix.getScaleY());
+  if (matrix.getType() & SkMatrix::kAffine_Mask) {
+    if (!matrix.decomposeScale(&scale))
+      scale.set(1, 1);
+  }
+  return scale;
+}
+
+class ImageHijackCanvas : public SkNWayCanvas {
+ public:
+  ImageHijackCanvas(int width,
+                    int height,
+                    ImageDecodeController* image_decode_controller)
+      : SkNWayCanvas(width, height),
+        image_decode_controller_(image_decode_controller) {}
+
+ protected:
+  // Ensure that pictures are unpacked by this canvas, instead of being
+  // forwarded to the raster canvas.
+  void onDrawPicture(const SkPicture* picture,
+                     const SkMatrix* matrix,
+                     const SkPaint* paint) override {
+    SkCanvas::onDrawPicture(picture, matrix, paint);
+  }
+
+  void onDrawImage(const SkImage* image,
+                   SkScalar x,
+                   SkScalar y,
+                   const SkPaint* paint) override {
+    if (!image->isLazyGenerated()) {
+      SkNWayCanvas::onDrawImage(image, x, y, paint);
+      return;
+    }
+
+    SkMatrix ctm = this->getTotalMatrix();
+
+    ScopedDecodedImageLock scoped_lock(image_decode_controller_, image,
+                                       ExtractScale(ctm), paint);
+    const DecodedDrawImage& decoded_image = scoped_lock.decoded_image();
+    const SkPaint* decoded_paint = scoped_lock.decoded_paint();
+
+    SkNWayCanvas::save();
+    SkNWayCanvas::scale(1.f / (decoded_image.scale_adjustment().width()),

[reed1, 2015/10/27 17:35:07]

Is scale_adjustment = scaled_version.width / original_version ?

If so, then this makes sense (though it might be nicer to avoid the invert here
by storing the inverse division).

+                        1.f / (decoded_image.scale_adjustment().height()));
+    SkNWayCanvas::onDrawImage(decoded_image.image(), x, y, decoded_paint);
+    SkNWayCanvas::restore();
+  }
+
+  void onDrawImageRect(const SkImage* image,
+                       const SkRect* src,
+                       const SkRect& dst,
+                       const SkPaint* paint,
+                       SrcRectConstraint constraint) override {
+    if (!image->isLazyGenerated()) {
+      SkNWayCanvas::onDrawImageRect(image, src, dst, paint, constraint);
+      return;
+    }
+
+    SkMatrix ctm = this->getTotalMatrix();
+    SkRect src_storage;
+    if (!src) {
+      src_storage = SkRect::MakeIWH(image->width(), image->height());
+      src = &src_storage;
+    }
+    SkMatrix matrix;
+    matrix.setRectToRect(*src, dst, SkMatrix::kFill_ScaleToFit);
+    matrix.postConcat(ctm);
+
+    ScopedDecodedImageLock scoped_lock(image_decode_controller_, image,
+                                       ExtractScale(matrix), paint);
+    const DecodedDrawImage& decoded_image = scoped_lock.decoded_image();
+    const SkPaint* decoded_paint = scoped_lock.decoded_paint();
+
+    float x_scale = decoded_image.scale_adjustment().width();
+    float y_scale = decoded_image.scale_adjustment().height();
+    SkRect adjusted_src =
+        SkRect::MakeXYWH(src->x() * x_scale, src->y() * y_scale,
+                         src->width() * x_scale, src->height() * y_scale);
+    SkNWayCanvas::onDrawImageRect(decoded_image.image(), &adjusted_src, dst,
+                                  decoded_paint, constraint);
+  }
+
+  void onDrawImageNine(const SkImage* image,
+                       const SkIRect& center,
+                       const SkRect& dst,
+                       const SkPaint* paint) override {
+    if (!image->isLazyGenerated()) {
+      SkNWayCanvas::onDrawImageNine(image, center, dst, paint);
+      return;
+    }
+
+    SkMatrix ctm = this->getTotalMatrix();
+    ScopedDecodedImageLock scoped_lock(image_decode_controller_, image,
+                                       ExtractScale(ctm), paint);
+    const DecodedDrawImage& decoded_image = scoped_lock.decoded_image();
+    const SkPaint* decoded_paint = scoped_lock.decoded_paint();
+
+    float x_scale = decoded_image.scale_adjustment().width();
+    float y_scale = decoded_image.scale_adjustment().height();
+    SkIRect adjusted_center = SkIRect::MakeXYWH(
+        static_cast<int>(std::floor(center.x() * x_scale)),
+        static_cast<int>(std::floor(center.y() * y_scale)),
+        static_cast<int>(std::ceil(center.width() * x_scale)),
+        static_cast<int>(std::ceil(center.height() * y_scale)));
+    SkNWayCanvas::onDrawImageNine(decoded_image.image(), adjusted_center, dst,
+                                  decoded_paint);
+  }
+
+ private:
+  class ScopedDecodedImageLock {
+   public:
+    ScopedDecodedImageLock(ImageDecodeController* image_decode_controller,
+                           const SkImage* image,
+                           const SkSize& scale,
+                           const SkPaint* paint)
+        : image_decode_controller_(image_decode_controller),
+          paint_(paint),
+          draw_image_(
+              image,
+              scale,
+              paint ? paint->getFilterQuality() : kNone_SkFilterQuality),
+          decoded_draw_image_(
+              image_decode_controller_->GetDecodedImage(draw_image_)) {
+      DCHECK(image->isLazyGenerated());
+      if (paint) {
+        decoded_paint_ = *paint;
+        decoded_paint_.setFilterQuality(decoded_draw_image_.filter_quality());
+      }
+    }
+
+    ~ScopedDecodedImageLock() {
+      image_decode_controller_->DrawWithImageFinished(draw_image_);
+    }
+
+    const DecodedDrawImage& decoded_image() const {
+      return decoded_draw_image_;
+    }
+    const SkPaint* decoded_paint() const {
+      return paint_ ? &decoded_paint_ : nullptr;
+    }
+
+   private:
+    ImageDecodeController* image_decode_controller_;
+    const SkPaint* paint_;
+    DrawImage draw_image_;
+    DecodedDrawImage decoded_draw_image_;
+    SkPaint decoded_paint_;
+  };
+
+  ImageDecodeController* image_decode_controller_;
+};
+
+}  // namespace
+
 scoped_refptr<DisplayListRasterSource>
 DisplayListRasterSource::CreateFromDisplayListRecordingSource(
     const DisplayListRecordingSource* other,
@@ -38,7 +197,8 @@ DisplayListRasterSource::DisplayListRasterSource(
       clear_canvas_with_debug_color_(other->clear_canvas_with_debug_color_),
       slow_down_raster_scale_factor_for_debug_(
           other->slow_down_raster_scale_factor_for_debug_),
-      should_attempt_to_use_distance_field_text_(false) {}
+      should_attempt_to_use_distance_field_text_(false),
+      image_decode_controller_(nullptr) {}
 
 DisplayListRasterSource::DisplayListRasterSource(
     const DisplayListRasterSource* other,
@@ -56,7 +216,8 @@ DisplayListRasterSource::DisplayListRasterSource(
       slow_down_raster_scale_factor_for_debug_(
           other->slow_down_raster_scale_factor_for_debug_),
       should_attempt_to_use_distance_field_text_(
-          other->should_attempt_to_use_distance_field_text_) {}
+          other->should_attempt_to_use_distance_field_text_),
+      image_decode_controller_(other->image_decode_controller_) {}
 
 DisplayListRasterSource::~DisplayListRasterSource() {
 }
@@ -173,24 +334,29 @@ void DisplayListRasterSource::PrepareForPlaybackToCanvas(
 }
 
 void DisplayListRasterSource::RasterCommon(
-    SkCanvas* canvas,
+    SkCanvas* raster_canvas,
     SkPicture::AbortCallback* callback,
     const gfx::Rect& canvas_bitmap_rect,
     const gfx::Rect& canvas_playback_rect,
     float contents_scale) const {
-  canvas->translate(-canvas_bitmap_rect.x(), -canvas_bitmap_rect.y());
+  SkImageInfo info = raster_canvas->imageInfo();
+  ImageHijackCanvas canvas(info.width(), info.height(),
+                           image_decode_controller_);
+  canvas.addCanvas(raster_canvas);
+
+  canvas.translate(-canvas_bitmap_rect.x(), -canvas_bitmap_rect.y());
   gfx::Rect content_rect =
       gfx::ScaleToEnclosingRect(gfx::Rect(size_), contents_scale);
   content_rect.Intersect(canvas_playback_rect);
 
-  canvas->clipRect(gfx::RectToSkRect(content_rect), SkRegion::kIntersect_Op);
+  canvas.clipRect(gfx::RectToSkRect(content_rect), SkRegion::kIntersect_Op);
 
   DCHECK(display_list_.get());
   gfx::Rect canvas_target_playback_rect =
       canvas_playback_rect - canvas_bitmap_rect.OffsetFromOrigin();
   int repeat_count = std::max(1, slow_down_raster_scale_factor_for_debug_);
   for (int i = 0; i < repeat_count; ++i) {
-    display_list_->Raster(canvas, callback, canvas_target_playback_rect,
+    display_list_->Raster(&canvas, callback, canvas_target_playback_rect,
                           contents_scale);
   }
 }
@@ -300,4 +466,12 @@ DisplayListRasterSource::CreateCloneWithoutLCDText() const {
       new DisplayListRasterSource(this, can_use_lcd_text));
 }
 
+void DisplayListRasterSource::SetImageDecodeController(
+    ImageDecodeController* image_decode_controller) {
+  // This should only be set once.
+  DCHECK(image_decode_controller);
+  DCHECK(!image_decode_controller_);
+  image_decode_controller_ = image_decode_controller;
+}
+
 }  // namespace cc