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// Copyright 2011 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/resources/content_layer_updater.h"
#include "base/debug/trace_event.h"
#include "cc/resources/layer_painter.h"
#include "third_party/skia/include/core/SkCanvas.h"
#include "third_party/skia/include/core/SkRect.h"
#include "third_party/skia/include/core/SkScalar.h"
#include "ui/gfx/geometry/rect_conversions.h"
#include "ui/gfx/geometry/rect_f.h"
#include "ui/gfx/skia_util.h"
namespace cc {
ContentLayerUpdater::ContentLayerUpdater(scoped_ptr<LayerPainter> painter,
int layer_id)
: layer_id_(layer_id),
layer_is_opaque_(false),
layer_fills_bounds_completely_(false),
painter_(painter.Pass()),
background_color_(SK_ColorTRANSPARENT) {
}
ContentLayerUpdater::~ContentLayerUpdater() {}
void ContentLayerUpdater::PaintContents(SkCanvas* canvas,
const gfx::Size& layer_content_size,
const gfx::Rect& paint_rect,
float contents_width_scale,
float contents_height_scale) {
TRACE_EVENT0("cc", "ContentLayerUpdater::PaintContents");
if (!canvas)
return;
canvas->save();
canvas->translate(SkIntToScalar(-paint_rect.x()),
SkIntToScalar(-paint_rect.y()));
// The |canvas| backing should be sized to hold the |paint_rect|.
DCHECK_EQ(paint_rect.width(), canvas->getBaseLayerSize().width());
DCHECK_EQ(paint_rect.height(), canvas->getBaseLayerSize().height());
const bool is_scaled =
contents_width_scale != 1.f || contents_height_scale != 1.f;
if (is_scaled && (layer_is_opaque_ || layer_fills_bounds_completely_)) {
// Even if completely covered, for rasterizations that touch the edge of the
// layer, we also need to raster the background color underneath the last
// texel (since the paint won't cover it).
//
// The final texel of content may only be partially covered by a
// rasterization; this rect represents the content rect that is fully
// covered by content.
const gfx::Rect layer_content_rect = gfx::Rect(layer_content_size);
gfx::Rect deflated_layer_content_rect = layer_content_rect;
deflated_layer_content_rect.Inset(0, 0, 1, 1);
if (!layer_content_rect.Contains(deflated_layer_content_rect)) {
// Drawing at most 1 x 1 x (canvas width + canvas height) texels is 2-3X
// faster than clearing, so special case this.
DCHECK_LE(paint_rect.right(), layer_content_rect.right());
DCHECK_LE(paint_rect.bottom(), layer_content_rect.bottom());
canvas->save();
canvas->clipRect(gfx::RectToSkRect(layer_content_rect),
SkRegion::kReplace_Op);
canvas->clipRect(gfx::RectToSkRect(deflated_layer_content_rect),
SkRegion::kDifference_Op);
canvas->drawColor(background_color_, SkXfermode::kSrc_Mode);
canvas->restore();
}
}
gfx::Rect layer_rect;
if (is_scaled) {
canvas->scale(SkFloatToScalar(contents_width_scale),
SkFloatToScalar(contents_height_scale));
// NOTE: this may go beyond the bounds of the layer, but that shouldn't
// cause problems (anything beyond the layer is clipped out).
layer_rect = gfx::ScaleToEnclosingRect(
paint_rect, 1.f / contents_width_scale, 1.f / contents_height_scale);
} else {
layer_rect = paint_rect;
}
SkRect layer_sk_rect = SkRect::MakeXYWH(
layer_rect.x(), layer_rect.y(), layer_rect.width(), layer_rect.height());
canvas->clipRect(layer_sk_rect);
// If the layer has opaque contents or will fill the bounds completely there
// is no need to clear the canvas before painting.
if (!layer_is_opaque_ && !layer_fills_bounds_completely_) {
TRACE_EVENT0("cc", "Clear");
canvas->drawColor(SK_ColorTRANSPARENT, SkXfermode::kSrc_Mode);
}
painter_->Paint(canvas, layer_rect);
canvas->restore();
paint_rect_ = paint_rect;
}
void ContentLayerUpdater::SetOpaque(bool opaque) {
layer_is_opaque_ = opaque;
}
void ContentLayerUpdater::SetFillsBoundsCompletely(bool fills_bounds) {
layer_fills_bounds_completely_ = fills_bounds;
}
void ContentLayerUpdater::SetBackgroundColor(SkColor background_color) {
background_color_ = background_color;
}
} // namespace cc
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