src/ui/gfx/skia_util.cc

   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
  20 namespace gfx {
  21
  22 SkRect RectToSkRect(const Rect& rect) {
  23   SkRect r;
  24   r.iset(rect.x(), rect.y(), rect.right(), rect.bottom());
  25   return r;
  26 }
  27
  28 SkIRect RectToSkIRect(const Rect& rect) {
  29   return SkIRect::MakeXYWH(rect.x(), rect.y(), rect.width(), rect.height());
  30 }
  31
  32 Rect SkIRectToRect(const SkIRect& rect) {
  33   return Rect(rect.x(), rect.y(), rect.width(), rect.height());
  34 }
  35
  36 SkRect 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
  43 RectF SkRectToRectF(const SkRect& rect) {
  44   return RectF(SkScalarToFloat(rect.x()),
  45                SkScalarToFloat(rect.y()),
  46                SkScalarToFloat(rect.width()),
  47                SkScalarToFloat(rect.height()));
  48 }
  49
  50 void 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
  64 skia::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
  71 skia::RefPtr<SkShader> CreateImageRepShaderForScale(
  72     const gfx::ImageSkiaRep& image_rep,
  73     SkShader::TileMode tile_mode,
  74     const SkMatrix& local_matrix,
  75     SkScalar scale) {
  76   skia::RefPtr<SkShader> shader = skia::AdoptRef(SkShader::CreateBitmapShader(
  77       image_rep.sk_bitmap(), tile_mode, tile_mode));
  78   SkScalar scale_x = local_matrix.getScaleX();
  79   SkScalar scale_y = local_matrix.getScaleY();
  80
  81   // Unscale matrix by |scale| such that the bitmap is drawn at the
  82   // correct density.
  83   // Convert skew and translation to pixel coordinates.
  84   // Thus, for |bitmap_scale| = 2:
  85   //   x scale = 2, x translation = 1 DIP,
  86   // should be converted to
  87   //   x scale = 1, x translation = 2 pixels.
  88   SkMatrix shader_scale = local_matrix;
  89   shader_scale.preScale(scale, scale);
  90   shader_scale.setScaleX(SkScalarDiv(scale_x, scale));
  91   shader_scale.setScaleY(SkScalarDiv(scale_y, scale));
  92
  93   shader->setLocalMatrix(shader_scale);
  94   return shader;
  95 }
  96
  97 skia::RefPtr<SkShader> CreateGradientShader(int start_point,
  98                                             int end_point,
  99                                             SkColor start_color,
 100                                             SkColor end_color) {
 101   SkColor grad_colors[2] = { start_color, end_color};
 102   SkPoint grad_points[2];
 103   grad_points[0].iset(0, start_point);
 104   grad_points[1].iset(0, end_point);
 105
 106   return skia::AdoptRef(SkGradientShader::CreateLinear(
 107       grad_points, grad_colors, NULL, 2, SkShader::kRepeat_TileMode));
 108 }
 109
 110 static SkScalar RadiusToSigma(double radius) {
 111   // This captures historically what skia did under the hood. Now skia accepts
 112   // sigma, not radius, so we perform the conversion.
 113   return radius > 0 ? SkDoubleToScalar(0.57735f * radius + 0.5) : 0;
 114 }
 115
 116 skia::RefPtr<SkDrawLooper> CreateShadowDrawLooper(
 117     const std::vector<ShadowValue>& shadows) {
 118   if (shadows.empty())
 119     return skia::RefPtr<SkDrawLooper>();
 120
 121   SkLayerDrawLooper::Builder looper_builder;
 122
 123   looper_builder.addLayer();  // top layer of the original.
 124
 125   SkLayerDrawLooper::LayerInfo layer_info;
 126   layer_info.fPaintBits |= SkLayerDrawLooper::kMaskFilter_Bit;
 127   layer_info.fPaintBits |= SkLayerDrawLooper::kColorFilter_Bit;
 128   layer_info.fColorMode = SkXfermode::kSrc_Mode;
 129
 130   for (size_t i = 0; i < shadows.size(); ++i) {
 131     const ShadowValue& shadow = shadows[i];
 132
 133     layer_info.fOffset.set(SkIntToScalar(shadow.x()),
 134                            SkIntToScalar(shadow.y()));
 135
 136     // SkBlurMaskFilter's blur radius defines the range to extend the blur from
 137     // original mask, which is half of blur amount as defined in ShadowValue.
 138     skia::RefPtr<SkMaskFilter> blur_mask = skia::AdoptRef(
 139         SkBlurMaskFilter::Create(kNormal_SkBlurStyle,
 140                                  RadiusToSigma(shadow.blur() / 2),
 141                                  SkBlurMaskFilter::kHighQuality_BlurFlag));
 142     skia::RefPtr<SkColorFilter> color_filter = skia::AdoptRef(
 143         SkColorFilter::CreateModeFilter(shadow.color(),
 144                                         SkXfermode::kSrcIn_Mode));
 145
 146     SkPaint* paint = looper_builder.addLayer(layer_info);
 147     paint->setMaskFilter(blur_mask.get());
 148     paint->setColorFilter(color_filter.get());
 149   }
 150
 151   return skia::AdoptRef<SkDrawLooper>(looper_builder.detachLooper());
 152 }
 153
 154 bool BitmapsAreEqual(const SkBitmap& bitmap1, const SkBitmap& bitmap2) {
 155   void* addr1 = NULL;
 156   void* addr2 = NULL;
 157   size_t size1 = 0;
 158   size_t size2 = 0;
 159
 160   bitmap1.lockPixels();
 161   addr1 = bitmap1.getAddr32(0, 0);
 162   size1 = bitmap1.getSize();
 163   bitmap1.unlockPixels();
 164
 165   bitmap2.lockPixels();
 166   addr2 = bitmap2.getAddr32(0, 0);
 167   size2 = bitmap2.getSize();
 168   bitmap2.unlockPixels();
 169
 170   return (size1 == size2) && (0 == memcmp(addr1, addr2, bitmap1.getSize()));
 171 }
 172
 173 void ConvertSkiaToRGBA(const unsigned char* skia,
 174                        int pixel_width,
 175                        unsigned char* rgba) {
 176   int total_length = pixel_width * 4;
 177   for (int i = 0; i < total_length; i += 4) {
 178     const uint32_t pixel_in = *reinterpret_cast<const uint32_t*>(&skia[i]);
 179
 180     // Pack the components here.
 181     int alpha = SkGetPackedA32(pixel_in);
 182     if (alpha != 0 && alpha != 255) {
 183       SkColor unmultiplied = SkUnPreMultiply::PMColorToColor(pixel_in);
 184       rgba[i + 0] = SkColorGetR(unmultiplied);
 185       rgba[i + 1] = SkColorGetG(unmultiplied);
 186       rgba[i + 2] = SkColorGetB(unmultiplied);
 187       rgba[i + 3] = alpha;
 188     } else {
 189       rgba[i + 0] = SkGetPackedR32(pixel_in);
 190       rgba[i + 1] = SkGetPackedG32(pixel_in);
 191       rgba[i + 2] = SkGetPackedB32(pixel_in);
 192       rgba[i + 3] = alpha;
 193     }
 194   }
 195 }
 196
 197 }  // namespace gfx