skia_util.cc revision 2a99a7e74a7f215066514fe81d2bfa6639d9eddd 
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 "ui/gfx/skia_util.h"
6
7#include "third_party/skia/include/core/SkBitmap.h"
8#include "third_party/skia/include/core/SkColorFilter.h"
9#include "third_party/skia/include/core/SkColorPriv.h"
10#include "third_party/skia/include/core/SkUnPreMultiply.h"
11#include "third_party/skia/include/effects/SkBlurMaskFilter.h"
12#include "third_party/skia/include/effects/SkGradientShader.h"
13#include "third_party/skia/include/effects/SkLayerDrawLooper.h"
14#include "ui/gfx/image/image_skia_rep.h"
15#include "ui/gfx/rect.h"
16#include "ui/gfx/rect_f.h"
17#include "ui/gfx/shadow_value.h"
18
19namespace gfx {
20
21SkRect RectToSkRect(const Rect& rect) {
22  SkRect r;
23  r.iset(rect.x(), rect.y(), rect.right(), rect.bottom());
24  return r;
25}
26
27SkIRect RectToSkIRect(const Rect& rect) {
28  return SkIRect::MakeXYWH(rect.x(), rect.y(), rect.width(), rect.height());
29}
30
31Rect SkIRectToRect(const SkIRect& rect) {
32  return Rect(rect.x(), rect.y(), rect.width(), rect.height());
33}
34
35SkRect RectFToSkRect(const RectF& rect) {
36  return SkRect::MakeXYWH(SkFloatToScalar(rect.x()),
37                          SkFloatToScalar(rect.y()),
38                          SkFloatToScalar(rect.width()),
39                          SkFloatToScalar(rect.height()));
40}
41
42RectF SkRectToRectF(const SkRect& rect) {
43  return RectF(SkScalarToFloat(rect.x()),
44               SkScalarToFloat(rect.y()),
45               SkScalarToFloat(rect.width()),
46               SkScalarToFloat(rect.height()));
47}
48
49
50skia::RefPtr<SkShader> CreateImageRepShader(const gfx::ImageSkiaRep& image_rep,
51                                            SkShader::TileMode tile_mode,
52                                            const SkMatrix& local_matrix) {
53  skia::RefPtr<SkShader> shader = skia::AdoptRef(SkShader::CreateBitmapShader(
54      image_rep.sk_bitmap(), tile_mode, tile_mode));
55  SkScalar scale_x = local_matrix.getScaleX();
56  SkScalar scale_y = local_matrix.getScaleY();
57  SkScalar bitmap_scale = SkFloatToScalar(image_rep.GetScale());
58
59  // Unscale matrix by |bitmap_scale| such that the bitmap is drawn at the
60  // correct density.
61  // Convert skew and translation to pixel coordinates.
62  // Thus, for |bitmap_scale| = 2:
63  //   x scale = 2, x translation = 1 DIP,
64  // should be converted to
65  //   x scale = 1, x translation = 2 pixels.
66  SkMatrix shader_scale = local_matrix;
67  shader_scale.preScale(bitmap_scale, bitmap_scale);
68  shader_scale.setScaleX(SkScalarDiv(scale_x, bitmap_scale));
69  shader_scale.setScaleY(SkScalarDiv(scale_y, bitmap_scale));
70
71  shader->setLocalMatrix(shader_scale);
72  return shader;
73}
74
75skia::RefPtr<SkShader> CreateGradientShader(int start_point,
76                                            int end_point,
77                                            SkColor start_color,
78                                            SkColor end_color) {
79  SkColor grad_colors[2] = { start_color, end_color};
80  SkPoint grad_points[2];
81  grad_points[0].iset(0, start_point);
82  grad_points[1].iset(0, end_point);
83
84  return skia::AdoptRef(SkGradientShader::CreateLinear(
85      grad_points, grad_colors, NULL, 2, SkShader::kRepeat_TileMode));
86}
87
88skia::RefPtr<SkDrawLooper> CreateShadowDrawLooper(
89    const std::vector<ShadowValue>& shadows) {
90  if (shadows.empty())
91    return skia::RefPtr<SkDrawLooper>();
92
93  skia::RefPtr<SkLayerDrawLooper> looper =
94      skia::AdoptRef(new SkLayerDrawLooper);
95
96  looper->addLayer();  // top layer of the original.
97
98  SkLayerDrawLooper::LayerInfo layer_info;
99  layer_info.fPaintBits |= SkLayerDrawLooper::kMaskFilter_Bit;
100  layer_info.fPaintBits |= SkLayerDrawLooper::kColorFilter_Bit;
101  layer_info.fColorMode = SkXfermode::kSrc_Mode;
102
103  for (size_t i = 0; i < shadows.size(); ++i) {
104    const ShadowValue& shadow = shadows[i];
105
106    layer_info.fOffset.set(SkIntToScalar(shadow.x()),
107                           SkIntToScalar(shadow.y()));
108
109    // SkBlurMaskFilter's blur radius defines the range to extend the blur from
110    // original mask, which is half of blur amount as defined in ShadowValue.
111    skia::RefPtr<SkMaskFilter> blur_mask = skia::AdoptRef(
112        SkBlurMaskFilter::Create(SkDoubleToScalar(shadow.blur() / 2),
113                                 SkBlurMaskFilter::kNormal_BlurStyle,
114                                 SkBlurMaskFilter::kHighQuality_BlurFlag));
115    skia::RefPtr<SkColorFilter> color_filter = skia::AdoptRef(
116        SkColorFilter::CreateModeFilter(shadow.color(),
117                                        SkXfermode::kSrcIn_Mode));
118
119    SkPaint* paint = looper->addLayer(layer_info);
120    paint->setMaskFilter(blur_mask.get());
121    paint->setColorFilter(color_filter.get());
122  }
123
124  return looper;
125}
126
127bool BitmapsAreEqual(const SkBitmap& bitmap1, const SkBitmap& bitmap2) {
128  void* addr1 = NULL;
129  void* addr2 = NULL;
130  size_t size1 = 0;
131  size_t size2 = 0;
132
133  bitmap1.lockPixels();
134  addr1 = bitmap1.getAddr32(0, 0);
135  size1 = bitmap1.getSize();
136  bitmap1.unlockPixels();
137
138  bitmap2.lockPixels();
139  addr2 = bitmap2.getAddr32(0, 0);
140  size2 = bitmap2.getSize();
141  bitmap2.unlockPixels();
142
143  return (size1 == size2) && (0 == memcmp(addr1, addr2, bitmap1.getSize()));
144}
145
146void ConvertSkiaToRGBA(const unsigned char* skia,
147                       int pixel_width,
148                       unsigned char* rgba) {
149  int total_length = pixel_width * 4;
150  for (int i = 0; i < total_length; i += 4) {
151    const uint32_t pixel_in = *reinterpret_cast<const uint32_t*>(&skia[i]);
152
153    // Pack the components here.
154    int alpha = SkGetPackedA32(pixel_in);
155    if (alpha != 0 && alpha != 255) {
156      SkColor unmultiplied = SkUnPreMultiply::PMColorToColor(pixel_in);
157      rgba[i + 0] = SkColorGetR(unmultiplied);
158      rgba[i + 1] = SkColorGetG(unmultiplied);
159      rgba[i + 2] = SkColorGetB(unmultiplied);
160      rgba[i + 3] = alpha;
161    } else {
162      rgba[i + 0] = SkGetPackedR32(pixel_in);
163      rgba[i + 1] = SkGetPackedG32(pixel_in);
164      rgba[i + 2] = SkGetPackedB32(pixel_in);
165      rgba[i + 3] = alpha;
166    }
167  }
168}
169
170}  // namespace gfx
171