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/geometry/rect.h"
  15 #include "ui/gfx/geometry/rect_f.h"
  16 #include "ui/gfx/image/image_skia_rep.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 SkSize SizeFToSkSize(const SizeF& size) {
  51   return SkSize::Make(SkFloatToScalar(size.width()),
  52                       SkFloatToScalar(size.height()));
  53 }
  54
  55 SizeF SkSizeToSizeF(const SkSize& size) {
  56   return SizeF(SkScalarToFloat(size.width()), SkScalarToFloat(size.height()));
  57 }
  58
  59 void TransformToFlattenedSkMatrix(const gfx::Transform& transform,
  60                                   SkMatrix* flattened) {
  61   // Convert from 4x4 to 3x3 by dropping the third row and column.
  62   flattened->set(0, SkMScalarToScalar(transform.matrix().get(0, 0)));
  63   flattened->set(1, SkMScalarToScalar(transform.matrix().get(0, 1)));
  64   flattened->set(2, SkMScalarToScalar(transform.matrix().get(0, 3)));
  65   flattened->set(3, SkMScalarToScalar(transform.matrix().get(1, 0)));
  66   flattened->set(4, SkMScalarToScalar(transform.matrix().get(1, 1)));
  67   flattened->set(5, SkMScalarToScalar(transform.matrix().get(1, 3)));
  68   flattened->set(6, SkMScalarToScalar(transform.matrix().get(3, 0)));
  69   flattened->set(7, SkMScalarToScalar(transform.matrix().get(3, 1)));
  70   flattened->set(8, SkMScalarToScalar(transform.matrix().get(3, 3)));
  71 }
  72
  73 skia::RefPtr<SkShader> CreateImageRepShader(const gfx::ImageSkiaRep& image_rep,
  74                                             SkShader::TileMode tile_mode,
  75                                             const SkMatrix& local_matrix) {
  76   return CreateImageRepShaderForScale(image_rep, tile_mode, local_matrix,
  77                                       image_rep.scale());
  78 }
  79
  80 skia::RefPtr<SkShader> CreateImageRepShaderForScale(
  81     const gfx::ImageSkiaRep& image_rep,
  82     SkShader::TileMode tile_mode,
  83     const SkMatrix& local_matrix,
  84     SkScalar scale) {
  85   // Unscale matrix by |scale| such that the bitmap is drawn at the
  86   // correct density.
  87   // Convert skew and translation to pixel coordinates.
  88   // Thus, for |bitmap_scale| = 2:
  89   //   x scale = 2, x translation = 1 DIP,
  90   // should be converted to
  91   //   x scale = 1, x translation = 2 pixels.
  92   SkMatrix shader_scale = local_matrix;
  93   shader_scale.preScale(scale, scale);
  94   shader_scale.setScaleX(local_matrix.getScaleX() / scale);
  95   shader_scale.setScaleY(local_matrix.getScaleY() / scale);
  96
  97   skia::RefPtr<SkShader> shader = skia::AdoptRef(SkShader::CreateBitmapShader(
  98       image_rep.sk_bitmap(), tile_mode, tile_mode, &shader_scale));
  99   return shader;
 100 }
 101
 102 skia::RefPtr<SkShader> CreateGradientShader(int start_point,
 103                                             int end_point,
 104                                             SkColor start_color,
 105                                             SkColor end_color) {
 106   SkColor grad_colors[2] = { start_color, end_color};
 107   SkPoint grad_points[2];
 108   grad_points[0].iset(0, start_point);
 109   grad_points[1].iset(0, end_point);
 110
 111   return skia::AdoptRef(SkGradientShader::CreateLinear(
 112       grad_points, grad_colors, NULL, 2, SkShader::kRepeat_TileMode));
 113 }
 114
 115 static SkScalar RadiusToSigma(double radius) {
 116   // This captures historically what skia did under the hood. Now skia accepts
 117   // sigma, not radius, so we perform the conversion.
 118   return radius > 0 ? SkDoubleToScalar(0.57735f * radius + 0.5) : 0;
 119 }
 120
 121 skia::RefPtr<SkDrawLooper> CreateShadowDrawLooper(
 122     const std::vector<ShadowValue>& shadows) {
 123   if (shadows.empty())
 124     return skia::RefPtr<SkDrawLooper>();
 125
 126   SkLayerDrawLooper::Builder looper_builder;
 127
 128   looper_builder.addLayer();  // top layer of the original.
 129
 130   SkLayerDrawLooper::LayerInfo layer_info;
 131   layer_info.fPaintBits |= SkLayerDrawLooper::kMaskFilter_Bit;
 132   layer_info.fPaintBits |= SkLayerDrawLooper::kColorFilter_Bit;
 133   layer_info.fColorMode = SkXfermode::kSrc_Mode;
 134
 135   for (size_t i = 0; i < shadows.size(); ++i) {
 136     const ShadowValue& shadow = shadows[i];
 137
 138     layer_info.fOffset.set(SkIntToScalar(shadow.x()),
 139                            SkIntToScalar(shadow.y()));
 140
 141     // SkBlurMaskFilter's blur radius defines the range to extend the blur from
 142     // original mask, which is half of blur amount as defined in ShadowValue.
 143     skia::RefPtr<SkMaskFilter> blur_mask = skia::AdoptRef(
 144         SkBlurMaskFilter::Create(kNormal_SkBlurStyle,
 145                                  RadiusToSigma(shadow.blur() / 2),
 146                                  SkBlurMaskFilter::kHighQuality_BlurFlag));
 147     skia::RefPtr<SkColorFilter> color_filter = skia::AdoptRef(
 148         SkColorFilter::CreateModeFilter(shadow.color(),
 149                                         SkXfermode::kSrcIn_Mode));
 150
 151     SkPaint* paint = looper_builder.addLayer(layer_info);
 152     paint->setMaskFilter(blur_mask.get());
 153     paint->setColorFilter(color_filter.get());
 154   }
 155
 156   return skia::AdoptRef<SkDrawLooper>(looper_builder.detachLooper());
 157 }
 158
 159 bool BitmapsAreEqual(const SkBitmap& bitmap1, const SkBitmap& bitmap2) {
 160   void* addr1 = NULL;
 161   void* addr2 = NULL;
 162   size_t size1 = 0;
 163   size_t size2 = 0;
 164
 165   bitmap1.lockPixels();
 166   addr1 = bitmap1.getAddr32(0, 0);
 167   size1 = bitmap1.getSize();
 168   bitmap1.unlockPixels();
 169
 170   bitmap2.lockPixels();
 171   addr2 = bitmap2.getAddr32(0, 0);
 172   size2 = bitmap2.getSize();
 173   bitmap2.unlockPixels();
 174
 175   return (size1 == size2) && (0 == memcmp(addr1, addr2, bitmap1.getSize()));
 176 }
 177
 178 void ConvertSkiaToRGBA(const unsigned char* skia,
 179                        int pixel_width,
 180                        unsigned char* rgba) {
 181   int total_length = pixel_width * 4;
 182   for (int i = 0; i < total_length; i += 4) {
 183     const uint32_t pixel_in = *reinterpret_cast<const uint32_t*>(&skia[i]);
 184
 185     // Pack the components here.
 186     SkAlpha alpha = SkGetPackedA32(pixel_in);
 187     if (alpha != 0 && alpha != 255) {
 188       SkColor unmultiplied = SkUnPreMultiply::PMColorToColor(pixel_in);
 189       rgba[i + 0] = SkColorGetR(unmultiplied);
 190       rgba[i + 1] = SkColorGetG(unmultiplied);
 191       rgba[i + 2] = SkColorGetB(unmultiplied);
 192       rgba[i + 3] = alpha;
 193     } else {
 194       rgba[i + 0] = SkGetPackedR32(pixel_in);
 195       rgba[i + 1] = SkGetPackedG32(pixel_in);
 196       rgba[i + 2] = SkGetPackedB32(pixel_in);
 197       rgba[i + 3] = alpha;
 198     }
 199   }
 200 }
 201
 202 }  // namespace gfx