Handle simple SkImageShaders

cc/playback/image_hijack_canvas.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/playback/image_hijack_canvas.h"
 
 #include "base/optional.h"
 #include "cc/playback/discardable_image_map.h"
 #include "cc/tiles/image_decode_controller.h"
+#include "third_party/skia/include/core/SkPath.h"
 
 namespace cc {
 namespace {
 
 SkIRect RoundOutRect(const SkRect& rect) {
   SkIRect result;
   rect.roundOut(&result);
   return result;
 }
 
@@ skipping 11 matching lines @@
                     matrix),
         decoded_draw_image_(
             image_decode_controller_->GetDecodedImageForDraw(draw_image_)) {
     DCHECK(draw_image_.image()->isLazyGenerated());
     if (paint) {
       decoded_paint_ = *paint;
       decoded_paint_->setFilterQuality(decoded_draw_image_.filter_quality());
     }
   }
 
+  ScopedDecodedImageLock(ScopedDecodedImageLock&& from)
+      : image_decode_controller_(from.image_decode_controller_),
+        draw_image_(std::move(from.draw_image_)),
+        decoded_draw_image_(std::move(from.decoded_draw_image_)),
+        decoded_paint_(std::move(from.decoded_paint_)) {
+    from.image_decode_controller_ = nullptr;
+  }
+
   ~ScopedDecodedImageLock() {
-    image_decode_controller_->DrawWithImageFinished(draw_image_,
-                                                    decoded_draw_image_);
+    if (image_decode_controller_) {
+      image_decode_controller_->DrawWithImageFinished(draw_image_,
+                                                      decoded_draw_image_);
+    }
   }
 
   const DecodedDrawImage& decoded_image() const { return decoded_draw_image_; }
   const SkPaint* decoded_paint() const {
     return decoded_paint_ ? &decoded_paint_.value() : nullptr;
   }
 
  private:
   ImageDecodeController* image_decode_controller_;
   DrawImage draw_image_;
   DecodedDrawImage decoded_draw_image_;
   base::Optional<SkPaint> decoded_paint_;
 };
 
+// Encapsulates a ScopedDecodedImageLock and an SkPaint. Use of this class
+// ensures that the ScopedDecodedImageLock outlives the dependent SkPaint.
+class ScopedImagePaint {
+ public:
+  // Tries to create a ScopedImagePaint for the provided SkPaint. If a
+  // the SkPaint does not contain an image that we support replacing,
+  // an empty base::Optional will be returned.
+  static base::Optional<ScopedImagePaint> TryCreate(
+      ImageDecodeController* image_decode_controller,
+      const SkMatrix& ctm,
+      const SkPaint& paint) {
+    SkShader* shader = paint.getShader();
+    if (!shader)
+      return base::Optional<ScopedImagePaint>();
+
+    SkMatrix matrix;
+    SkShader::TileMode xy[2];
+    SkImage* image = shader->isAImage(&matrix, xy);
+    if (!image)
+      return base::Optional<ScopedImagePaint>();
+
+    ScopedDecodedImageLock scoped_lock(
+        image_decode_controller, sk_ref_sp(image),
+        SkRect::MakeIWH(image->width(), image->height()), ctm, &paint);
+    const DecodedDrawImage& decoded_image = scoped_lock.decoded_image();
+    if (!decoded_image.image())
+      return base::Optional<ScopedImagePaint>();
+
+    bool need_scale = !decoded_image.is_scale_adjustment_identity();
+    if (need_scale) {
+      matrix.preScale(1.f / (decoded_image.scale_adjustment().width()),

[vmpstr, 2016/11/29 01:00:03]

nit: no need for brackets

[ericrk, 2016/11/29 21:46:05]

Done.

+                      1.f / (decoded_image.scale_adjustment().height()));
+    }
+    SkPaint scratch_paint = paint;
+    scratch_paint.setShader(
+        decoded_image.image()->makeShader(xy[0], xy[1], &matrix));
+    return ScopedImagePaint(std::move(scoped_lock), std::move(scratch_paint));
+  }
+
+  const SkPaint& paint() { return paint_; }
+
+ private:
+  ScopedImagePaint(ScopedDecodedImageLock lock, SkPaint paint)
+      : lock_(std::move(lock)), paint_(std::move(paint)) {}
+
+  ScopedDecodedImageLock lock_;
+  SkPaint paint_;
+};
+
 }  // namespace
 
 ImageHijackCanvas::ImageHijackCanvas(
     int width,
     int height,
     ImageDecodeController* image_decode_controller)
     : SkNWayCanvas(width, height),
       image_decode_controller_(image_decode_controller) {}
 
 void ImageHijackCanvas::onDrawPicture(const SkPicture* picture,
@@ skipping 71 matching lines @@
     float x_scale = decoded_image.scale_adjustment().width();
     float y_scale = decoded_image.scale_adjustment().height();
     adjusted_src = SkRect::MakeXYWH(
         adjusted_src.x() * x_scale, adjusted_src.y() * y_scale,
         adjusted_src.width() * x_scale, adjusted_src.height() * y_scale);
   }
   SkNWayCanvas::onDrawImageRect(decoded_image.image().get(), &adjusted_src, dst,
                                 decoded_paint, constraint);
 }
 
+void ImageHijackCanvas::onDrawRect(const SkRect& r, const SkPaint& paint) {
+  base::Optional<ScopedImagePaint> image_paint = ScopedImagePaint::TryCreate(
+      image_decode_controller_, getTotalMatrix(), paint);
+  if (!image_paint.has_value()) {
+    SkNWayCanvas::onDrawRect(r, paint);
+    return;
+  }
+  SkNWayCanvas::onDrawRect(r, image_paint.value().paint());
+}
+
+void ImageHijackCanvas::onDrawPath(const SkPath& path, const SkPaint& paint) {
+  base::Optional<ScopedImagePaint> image_paint = ScopedImagePaint::TryCreate(
+      image_decode_controller_, getTotalMatrix(), paint);
+  if (!image_paint.has_value()) {
+    SkNWayCanvas::onDrawPath(path, paint);
+    return;
+  }
+  SkNWayCanvas::onDrawPath(path, image_paint.value().paint());
+}
+
+void ImageHijackCanvas::onDrawOval(const SkRect& r, const SkPaint& paint) {
+  base::Optional<ScopedImagePaint> image_paint = ScopedImagePaint::TryCreate(
+      image_decode_controller_, getTotalMatrix(), paint);
+  if (!image_paint.has_value()) {
+    SkNWayCanvas::onDrawOval(r, paint);
+    return;
+  }
+  SkNWayCanvas::onDrawOval(r, image_paint.value().paint());
+}
+
+void ImageHijackCanvas::onDrawArc(const SkRect& r,
+                                  SkScalar start_angle,
+                                  SkScalar sweep_angle,
+                                  bool use_center,
+                                  const SkPaint& paint) {
+  base::Optional<ScopedImagePaint> image_paint = ScopedImagePaint::TryCreate(
+      image_decode_controller_, getTotalMatrix(), paint);
+  if (!image_paint.has_value()) {
+    SkNWayCanvas::onDrawArc(r, start_angle, sweep_angle, use_center, paint);
+    return;
+  }
+  SkNWayCanvas::onDrawArc(r, start_angle, sweep_angle, use_center,
+                          image_paint.value().paint());
+}
+
+void ImageHijackCanvas::onDrawRRect(const SkRRect& rr, const SkPaint& paint) {
+  base::Optional<ScopedImagePaint> image_paint = ScopedImagePaint::TryCreate(
+      image_decode_controller_, getTotalMatrix(), paint);
+  if (!image_paint.has_value()) {
+    SkNWayCanvas::onDrawRRect(rr, paint);
+    return;
+  }
+  SkNWayCanvas::onDrawRRect(rr, image_paint.value().paint());
+}
+
 void ImageHijackCanvas::onDrawImageNine(const SkImage* image,
                                         const SkIRect& center,
                                         const SkRect& dst,
                                         const SkPaint* paint) {
   // No cc embedder issues image nine calls.
   NOTREACHED();
 }
 
 }  // namespace cc