1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "content/browser/renderer_host/backing_store_aura.h"
6
7#include "content/browser/renderer_host/dip_util.h"
8#include "content/browser/renderer_host/render_process_host_impl.h"
9#include "content/public/browser/render_widget_host.h"
10#include "skia/ext/platform_canvas.h"
11#include "third_party/skia/include/core/SkCanvas.h"
12#include "ui/gfx/canvas.h"
13#include "ui/gfx/image/image_skia.h"
14#include "ui/gfx/rect.h"
15#include "ui/gfx/rect_conversions.h"
16#include "ui/gfx/size_conversions.h"
17#include "ui/gfx/vector2d_conversions.h"
18
19namespace {
20
21gfx::Size ToPixelSize(gfx::Size dipSize, float scale) {
22  return gfx::ToCeiledSize(gfx::ScaleSize(dipSize, scale));
23}
24
25}  // namespace
26
27
28namespace content {
29
30// Assume that somewhere along the line, someone will do width * height * 4
31// with signed numbers. If the maximum value is 2**31, then 2**31 / 4 =
32// 2**29 and floor(sqrt(2**29)) = 23170.
33
34// Max height and width for layers
35static const int kMaxVideoLayerSize = 23170;
36
37BackingStoreAura::BackingStoreAura(RenderWidgetHost* widget,
38                                   const gfx::Size& size)
39    : BackingStore(widget, size) {
40  device_scale_factor_ =
41      ui::GetScaleFactorScale(GetScaleFactorForView(widget->GetView()));
42  gfx::Size pixel_size = ToPixelSize(size, device_scale_factor_);
43  bitmap_.setConfig(SkBitmap::kARGB_8888_Config,
44      pixel_size.width(), pixel_size.height());
45  bitmap_.allocPixels();
46  canvas_.reset(new SkCanvas(bitmap_));
47}
48
49BackingStoreAura::~BackingStoreAura() {
50}
51
52void BackingStoreAura::SkiaShowRect(const gfx::Point& point,
53                                    gfx::Canvas* canvas) {
54  gfx::ImageSkia image = gfx::ImageSkia(gfx::ImageSkiaRep(bitmap_,
55      ui::GetScaleFactorFromScale(device_scale_factor_)));
56  canvas->DrawImageInt(image, point.x(), point.y());
57}
58
59void BackingStoreAura::ScaleFactorChanged(float device_scale_factor) {
60  if (device_scale_factor == device_scale_factor_)
61    return;
62
63  gfx::Size old_pixel_size = ToPixelSize(size(), device_scale_factor_);
64  device_scale_factor_ = device_scale_factor;
65
66  gfx::Size pixel_size = ToPixelSize(size(), device_scale_factor_);
67  SkBitmap new_bitmap;
68  new_bitmap.setConfig(SkBitmap::kARGB_8888_Config,
69      pixel_size.width(), pixel_size.height());
70  new_bitmap.allocPixels();
71  scoped_ptr<SkCanvas> new_canvas(new SkCanvas(new_bitmap));
72
73  // Copy old contents; a low-res flash is better than a black flash.
74  SkPaint copy_paint;
75  copy_paint.setXfermodeMode(SkXfermode::kSrc_Mode);
76  SkIRect src_rect = SkIRect::MakeWH(old_pixel_size.width(),
77                                     old_pixel_size.height());
78  SkRect dst_rect = SkRect::MakeWH(pixel_size.width(), pixel_size.height());
79  new_canvas.get()->drawBitmapRect(bitmap_, &src_rect, dst_rect, &copy_paint);
80
81  canvas_.swap(new_canvas);
82  bitmap_ = new_bitmap;
83}
84
85size_t BackingStoreAura::MemorySize() {
86  // NOTE: The computation may be different when the canvas is a subrectangle of
87  // a larger bitmap.
88  return ToPixelSize(size(), device_scale_factor_).GetArea() * 4;
89}
90
91void BackingStoreAura::PaintToBackingStore(
92    RenderProcessHost* process,
93    TransportDIB::Id bitmap,
94    const gfx::Rect& bitmap_rect,
95    const std::vector<gfx::Rect>& copy_rects,
96    float scale_factor,
97    const base::Closure& completion_callback,
98    bool* scheduled_completion_callback) {
99  *scheduled_completion_callback = false;
100  if (bitmap_rect.IsEmpty())
101    return;
102
103  gfx::Rect pixel_bitmap_rect = gfx::ToEnclosingRect(
104      gfx::ScaleRect(bitmap_rect, scale_factor));
105
106  const int width = pixel_bitmap_rect.width();
107  const int height = pixel_bitmap_rect.height();
108
109  if (width <= 0 || width > kMaxVideoLayerSize ||
110      height <= 0 || height > kMaxVideoLayerSize)
111    return;
112
113  TransportDIB* dib = process->GetTransportDIB(bitmap);
114  if (!dib)
115    return;
116
117  SkPaint copy_paint;
118  copy_paint.setXfermodeMode(SkXfermode::kSrc_Mode);
119
120  SkBitmap sk_bitmap;
121  sk_bitmap.setConfig(SkBitmap::kARGB_8888_Config, width, height);
122  sk_bitmap.setPixels(dib->memory());
123  for (size_t i = 0; i < copy_rects.size(); i++) {
124    const gfx::Rect pixel_copy_rect = gfx::ToEnclosingRect(
125        gfx::ScaleRect(copy_rects[i], scale_factor));
126    int x = pixel_copy_rect.x() - pixel_bitmap_rect.x();
127    int y = pixel_copy_rect.y() - pixel_bitmap_rect.y();
128    SkIRect srcrect = SkIRect::MakeXYWH(x, y,
129        pixel_copy_rect.width(),
130        pixel_copy_rect.height());
131
132    const gfx::Rect pixel_copy_dst_rect = gfx::ToEnclosingRect(
133        gfx::ScaleRect(copy_rects[i], device_scale_factor_));
134    SkRect dstrect = SkRect::MakeXYWH(
135        SkIntToScalar(pixel_copy_dst_rect.x()),
136        SkIntToScalar(pixel_copy_dst_rect.y()),
137        SkIntToScalar(pixel_copy_dst_rect.width()),
138        SkIntToScalar(pixel_copy_dst_rect.height()));
139    canvas_.get()->drawBitmapRect(sk_bitmap, &srcrect, dstrect, &copy_paint);
140  }
141}
142
143void BackingStoreAura::ScrollBackingStore(const gfx::Vector2d& delta,
144                                          const gfx::Rect& clip_rect,
145                                          const gfx::Size& view_size) {
146  gfx::Rect pixel_rect = gfx::ToEnclosingRect(
147      gfx::ScaleRect(clip_rect, device_scale_factor_));
148  gfx::Vector2d pixel_delta = gfx::ToFlooredVector2d(
149      gfx::ScaleVector2d(delta, device_scale_factor_));
150
151  int x = std::min(pixel_rect.x(), pixel_rect.x() - pixel_delta.x());
152  int y = std::min(pixel_rect.y(), pixel_rect.y() - pixel_delta.y());
153  int w = pixel_rect.width() + abs(pixel_delta.x());
154  int h = pixel_rect.height() + abs(pixel_delta.y());
155  SkIRect rect = SkIRect::MakeXYWH(x, y, w, h);
156  bitmap_.scrollRect(&rect, pixel_delta.x(), pixel_delta.y());
157}
158
159bool BackingStoreAura::CopyFromBackingStore(const gfx::Rect& rect,
160                                            skia::PlatformBitmap* output) {
161  const int width =
162      std::min(size().width(), rect.width()) * device_scale_factor_;
163  const int height =
164      std::min(size().height(), rect.height()) * device_scale_factor_;
165  if (!output->Allocate(width, height, true))
166    return false;
167
168  SkIRect skrect = SkIRect::MakeXYWH(rect.x(), rect.y(), width, height);
169  SkBitmap b;
170  if (!canvas_->readPixels(skrect, &b))
171    return false;
172  SkCanvas(output->GetBitmap()).writePixels(b, rect.x(), rect.y());
173  return true;
174}
175
176}  // namespace content
177