text: /*
   * Copyright (C) 2011 Apple Inc. All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. 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 APPLE COMPUTER, INC. ``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 APPLE COMPUTER, INC. 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.
   */
  
  #include "third_party/blink/renderer/platform/graphics/crossfade_generated_image.h"
  
  #include "third_party/blink/renderer/platform/geometry/float_rect.h"
  #include "third_party/blink/renderer/platform/graphics/dark_mode_filter_helper.h"
  #include "third_party/blink/renderer/platform/graphics/graphics_context.h"
  #include "third_party/blink/renderer/platform/graphics/paint/paint_canvas.h"
  
  namespace blink {
  
  CrossfadeGeneratedImage::CrossfadeGeneratedImage(
      scoped_refptr<Image> from_image,
      scoped_refptr<Image> to_image,
      float percentage,
      const FloatSize& size)
      : GeneratedImage(size),
        from_image_(std::move(from_image)),
        to_image_(std::move(to_image)),
        percentage_(percentage) {}
  
  void CrossfadeGeneratedImage::DrawCrossfade(
      cc::PaintCanvas* canvas,
      const PaintFlags& flags,
      const ImageDrawOptions& draw_options) {
    FloatRect from_image_rect(FloatPoint(), FloatSize(from_image_->Size()));
    FloatRect to_image_rect(FloatPoint(), FloatSize(to_image_->Size()));
    FloatRect dest_rect((FloatPoint()), size_);
  
    // TODO(junov): The various effects encoded into paint should probably be
    // applied here instead of inside the layer.  This probably faulty behavior
    // was maintained in order to preserve pre-existing behavior while refactoring
    // this code.  This should be investigated further. crbug.com/472634
    PaintFlags layer_flags;
    layer_flags.setBlendMode(flags.getBlendMode());
    PaintCanvasAutoRestore ar(canvas, false);
    canvas->saveLayer(nullptr, &layer_flags);
  
    PaintFlags image_flags(flags);
    image_flags.setBlendMode(SkBlendMode::kSrcOver);
    image_flags.setColor(ScaleAlpha(flags.getColor(), 1 - percentage_));
    // TODO(junov): This code should probably be propagating the
    // RespectImageOrientationEnum from CrossfadeGeneratedImage::draw(). Code
    // was written this way during refactoring to avoid modifying existing
    // behavior, but this warrants further investigation. crbug.com/472634
    ImageDrawOptions from_draw_options(draw_options);
    from_draw_options.respect_orientation = kDoNotRespectImageOrientation;
    if (draw_options.apply_dark_mode) {
      DarkModeFilterHelper::ApplyToImageIfNeeded(*(draw_options.dark_mode_filter),
                                                 from_image_.get(), &image_flags,
                                                 from_image_rect, dest_rect);
    }
    from_image_->Draw(canvas, image_flags, dest_rect, from_image_rect,
                      from_draw_options);
    image_flags.setBlendMode(SkBlendMode::kPlus);
    image_flags.setColor(ScaleAlpha(flags.getColor(), percentage_));
    if (draw_options.apply_dark_mode) {
      DarkModeFilterHelper::ApplyToImageIfNeeded(*(draw_options.dark_mode_filter),
                                                 to_image_.get(), &image_flags,
                                                 to_image_rect, dest_rect);
    }
    to_image_->Draw(canvas, image_flags, dest_rect, to_image_rect, draw_options);
  }
  
  void CrossfadeGeneratedImage::Draw(cc::PaintCanvas* canvas,
                                     const PaintFlags& flags,
                                     const FloatRect& dst_rect,
                                     const FloatRect& src_rect,
                                     const ImageDrawOptions& draw_options) {
    // Draw nothing if either of the images hasn't loaded yet.
    if (from_image_ == Image::NullImage() || to_image_ == Image::NullImage())
      return;
  
    PaintCanvasAutoRestore ar(canvas, true);
    canvas->clipRect(dst_rect);
    canvas->concat(SkMatrix::RectToRect(src_rect, dst_rect));
    DrawCrossfade(canvas, flags, draw_options);
  }
  
  void CrossfadeGeneratedImage::DrawTile(GraphicsContext& context,
                                         const FloatRect& src_rect,
                                         const ImageDrawOptions& options) {
    // Draw nothing if either of the images hasn't loaded yet.
    if (from_image_ == Image::NullImage() || to_image_ == Image::NullImage())
      return;
    PaintFlags flags = context.FillFlags();
    flags.setBlendMode(SkBlendMode::kSrcOver);
    FloatRect dest_rect((FloatPoint()), size_);
    ImageDrawOptions draw_options;
    draw_options.sampling_options =
        context.ComputeSamplingOptions(this, dest_rect, src_rect);
    draw_options.respect_orientation = options.respect_orientation;
    DrawCrossfade(context.Canvas(), flags, draw_options);
  }
  
  }  // namespace blink
  