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#include "ui/gfx/transform.h"
19
20namespace gfx {
21
22SkRect RectToSkRect(const Rect& rect) {
23  SkRect r;
24  r.iset(rect.x(), rect.y(), rect.right(), rect.bottom());
25  return r;
26}
27
28SkIRect RectToSkIRect(const Rect& rect) {
29  return SkIRect::MakeXYWH(rect.x(), rect.y(), rect.width(), rect.height());
30}
31
32Rect SkIRectToRect(const SkIRect& rect) {
33  return Rect(rect.x(), rect.y(), rect.width(), rect.height());
34}
35
36SkRect RectFToSkRect(const RectF& rect) {
37  return SkRect::MakeXYWH(SkFloatToScalar(rect.x()),
38                          SkFloatToScalar(rect.y()),
39                          SkFloatToScalar(rect.width()),
40                          SkFloatToScalar(rect.height()));
41}
42
43RectF SkRectToRectF(const SkRect& rect) {
44  return RectF(SkScalarToFloat(rect.x()),
45               SkScalarToFloat(rect.y()),
46               SkScalarToFloat(rect.width()),
47               SkScalarToFloat(rect.height()));
48}
49
50void TransformToFlattenedSkMatrix(const gfx::Transform& transform,
51                                  SkMatrix* flattened) {
52  // Convert from 4x4 to 3x3 by dropping the third row and column.
53  flattened->set(0, SkMScalarToScalar(transform.matrix().get(0, 0)));
54  flattened->set(1, SkMScalarToScalar(transform.matrix().get(0, 1)));
55  flattened->set(2, SkMScalarToScalar(transform.matrix().get(0, 3)));
56  flattened->set(3, SkMScalarToScalar(transform.matrix().get(1, 0)));
57  flattened->set(4, SkMScalarToScalar(transform.matrix().get(1, 1)));
58  flattened->set(5, SkMScalarToScalar(transform.matrix().get(1, 3)));
59  flattened->set(6, SkMScalarToScalar(transform.matrix().get(3, 0)));
60  flattened->set(7, SkMScalarToScalar(transform.matrix().get(3, 1)));
61  flattened->set(8, SkMScalarToScalar(transform.matrix().get(3, 3)));
62}
63
64skia::RefPtr<SkShader> CreateImageRepShader(const gfx::ImageSkiaRep& image_rep,
65                                            SkShader::TileMode tile_mode,
66                                            const SkMatrix& local_matrix) {
67  return CreateImageRepShaderForScale(image_rep, tile_mode, local_matrix,
68                                      image_rep.scale());
69}
70
71skia::RefPtr<SkShader> CreateImageRepShaderForScale(
72    const gfx::ImageSkiaRep& image_rep,
73    SkShader::TileMode tile_mode,
74    const SkMatrix& local_matrix,
75    SkScalar scale) {
76  // Unscale matrix by |scale| such that the bitmap is drawn at the
77  // correct density.
78  // Convert skew and translation to pixel coordinates.
79  // Thus, for |bitmap_scale| = 2:
80  //   x scale = 2, x translation = 1 DIP,
81  // should be converted to
82  //   x scale = 1, x translation = 2 pixels.
83  SkMatrix shader_scale = local_matrix;
84  shader_scale.preScale(scale, scale);
85  shader_scale.setScaleX(local_matrix.getScaleX() / scale);
86  shader_scale.setScaleY(local_matrix.getScaleY() / scale);
87
88  skia::RefPtr<SkShader> shader = skia::AdoptRef(SkShader::CreateBitmapShader(
89      image_rep.sk_bitmap(), tile_mode, tile_mode, &shader_scale));
90  return shader;
91}
92
93skia::RefPtr<SkShader> CreateGradientShader(int start_point,
94                                            int end_point,
95                                            SkColor start_color,
96                                            SkColor end_color) {
97  SkColor grad_colors[2] = { start_color, end_color};
98  SkPoint grad_points[2];
99  grad_points[0].iset(0, start_point);
100  grad_points[1].iset(0, end_point);
101
102  return skia::AdoptRef(SkGradientShader::CreateLinear(
103      grad_points, grad_colors, NULL, 2, SkShader::kRepeat_TileMode));
104}
105
106static SkScalar RadiusToSigma(double radius) {
107  // This captures historically what skia did under the hood. Now skia accepts
108  // sigma, not radius, so we perform the conversion.
109  return radius > 0 ? SkDoubleToScalar(0.57735f * radius + 0.5) : 0;
110}
111
112skia::RefPtr<SkDrawLooper> CreateShadowDrawLooper(
113    const std::vector<ShadowValue>& shadows) {
114  if (shadows.empty())
115    return skia::RefPtr<SkDrawLooper>();
116
117  SkLayerDrawLooper::Builder looper_builder;
118
119  looper_builder.addLayer();  // top layer of the original.
120
121  SkLayerDrawLooper::LayerInfo layer_info;
122  layer_info.fPaintBits |= SkLayerDrawLooper::kMaskFilter_Bit;
123  layer_info.fPaintBits |= SkLayerDrawLooper::kColorFilter_Bit;
124  layer_info.fColorMode = SkXfermode::kSrc_Mode;
125
126  for (size_t i = 0; i < shadows.size(); ++i) {
127    const ShadowValue& shadow = shadows[i];
128
129    layer_info.fOffset.set(SkIntToScalar(shadow.x()),
130                           SkIntToScalar(shadow.y()));
131
132    // SkBlurMaskFilter's blur radius defines the range to extend the blur from
133    // original mask, which is half of blur amount as defined in ShadowValue.
134    skia::RefPtr<SkMaskFilter> blur_mask = skia::AdoptRef(
135        SkBlurMaskFilter::Create(kNormal_SkBlurStyle,
136                                 RadiusToSigma(shadow.blur() / 2),
137                                 SkBlurMaskFilter::kHighQuality_BlurFlag));
138    skia::RefPtr<SkColorFilter> color_filter = skia::AdoptRef(
139        SkColorFilter::CreateModeFilter(shadow.color(),
140                                        SkXfermode::kSrcIn_Mode));
141
142    SkPaint* paint = looper_builder.addLayer(layer_info);
143    paint->setMaskFilter(blur_mask.get());
144    paint->setColorFilter(color_filter.get());
145  }
146
147  return skia::AdoptRef<SkDrawLooper>(looper_builder.detachLooper());
148}
149
150bool BitmapsAreEqual(const SkBitmap& bitmap1, const SkBitmap& bitmap2) {
151  void* addr1 = NULL;
152  void* addr2 = NULL;
153  size_t size1 = 0;
154  size_t size2 = 0;
155
156  bitmap1.lockPixels();
157  addr1 = bitmap1.getAddr32(0, 0);
158  size1 = bitmap1.getSize();
159  bitmap1.unlockPixels();
160
161  bitmap2.lockPixels();
162  addr2 = bitmap2.getAddr32(0, 0);
163  size2 = bitmap2.getSize();
164  bitmap2.unlockPixels();
165
166  return (size1 == size2) && (0 == memcmp(addr1, addr2, bitmap1.getSize()));
167}
168
169void ConvertSkiaToRGBA(const unsigned char* skia,
170                       int pixel_width,
171                       unsigned char* rgba) {
172  int total_length = pixel_width * 4;
173  for (int i = 0; i < total_length; i += 4) {
174    const uint32_t pixel_in = *reinterpret_cast<const uint32_t*>(&skia[i]);
175
176    // Pack the components here.
177    int alpha = SkGetPackedA32(pixel_in);
178    if (alpha != 0 && alpha != 255) {
179      SkColor unmultiplied = SkUnPreMultiply::PMColorToColor(pixel_in);
180      rgba[i + 0] = SkColorGetR(unmultiplied);
181      rgba[i + 1] = SkColorGetG(unmultiplied);
182      rgba[i + 2] = SkColorGetB(unmultiplied);
183      rgba[i + 3] = alpha;
184    } else {
185      rgba[i + 0] = SkGetPackedR32(pixel_in);
186      rgba[i + 1] = SkGetPackedG32(pixel_in);
187      rgba[i + 2] = SkGetPackedB32(pixel_in);
188      rgba[i + 3] = alpha;
189    }
190  }
191}
192
193}  // namespace gfx
194