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/quad_f.h"
  15 #include "ui/gfx/geometry/rect.h"
  16 #include "ui/gfx/geometry/rect_f.h"
  17 #include "ui/gfx/image/image_skia_rep.h"
  18 #include "ui/gfx/shadow_value.h"
  19 #include "ui/gfx/transform.h"
  20
  21 namespace gfx {
  22
  23 SkRect RectToSkRect(const Rect& rect) {
  24   SkRect r;
  25   r.iset(rect.x(), rect.y(), rect.right(), rect.bottom());
  26   return r;
  27 }
  28
  29 SkIRect RectToSkIRect(const Rect& rect) {
  30   return SkIRect::MakeXYWH(rect.x(), rect.y(), rect.width(), rect.height());
  31 }
  32
  33 Rect SkIRectToRect(const SkIRect& rect) {
  34   return Rect(rect.x(), rect.y(), rect.width(), rect.height());
  35 }
  36
  37 SkRect RectFToSkRect(const RectF& rect) {
  38   return SkRect::MakeXYWH(SkFloatToScalar(rect.x()),
  39                           SkFloatToScalar(rect.y()),
  40                           SkFloatToScalar(rect.width()),
  41                           SkFloatToScalar(rect.height()));
  42 }
  43
  44 RectF SkRectToRectF(const SkRect& rect) {
  45   return RectF(SkScalarToFloat(rect.x()),
  46                SkScalarToFloat(rect.y()),
  47                SkScalarToFloat(rect.width()),
  48                SkScalarToFloat(rect.height()));
  49 }
  50
  51 SkSize SizeFToSkSize(const SizeF& size) {
  52   return SkSize::Make(SkFloatToScalar(size.width()),
  53                       SkFloatToScalar(size.height()));
  54 }
  55
  56 SizeF SkSizeToSizeF(const SkSize& size) {
  57   return SizeF(SkScalarToFloat(size.width()), SkScalarToFloat(size.height()));
  58 }
  59
  60 void TransformToFlattenedSkMatrix(const gfx::Transform& transform,
  61                                   SkMatrix* flattened) {
  62   // Convert from 4x4 to 3x3 by dropping the third row and column.
  63   flattened->set(0, SkMScalarToScalar(transform.matrix().get(0, 0)));
  64   flattened->set(1, SkMScalarToScalar(transform.matrix().get(0, 1)));
  65   flattened->set(2, SkMScalarToScalar(transform.matrix().get(0, 3)));
  66   flattened->set(3, SkMScalarToScalar(transform.matrix().get(1, 0)));
  67   flattened->set(4, SkMScalarToScalar(transform.matrix().get(1, 1)));
  68   flattened->set(5, SkMScalarToScalar(transform.matrix().get(1, 3)));
  69   flattened->set(6, SkMScalarToScalar(transform.matrix().get(3, 0)));
  70   flattened->set(7, SkMScalarToScalar(transform.matrix().get(3, 1)));
  71   flattened->set(8, SkMScalarToScalar(transform.matrix().get(3, 3)));
  72 }
  73
  74 skia::RefPtr<SkShader> CreateImageRepShader(const gfx::ImageSkiaRep& image_rep,
  75                                             SkShader::TileMode tile_mode,
  76                                             const SkMatrix& local_matrix) {
  77   return CreateImageRepShaderForScale(image_rep, tile_mode, local_matrix,
  78                                       image_rep.scale());
  79 }
  80
  81 skia::RefPtr<SkShader> CreateImageRepShaderForScale(
  82     const gfx::ImageSkiaRep& image_rep,
  83     SkShader::TileMode tile_mode,
  84     const SkMatrix& local_matrix,
  85     SkScalar scale) {
  86   // Unscale matrix by |scale| such that the bitmap is drawn at the
  87   // correct density.
  88   // Convert skew and translation to pixel coordinates.
  89   // Thus, for |bitmap_scale| = 2:
  90   //   x scale = 2, x translation = 1 DIP,
  91   // should be converted to
  92   //   x scale = 1, x translation = 2 pixels.
  93   SkMatrix shader_scale = local_matrix;
  94   shader_scale.preScale(scale, scale);
  95   shader_scale.setScaleX(local_matrix.getScaleX() / scale);
  96   shader_scale.setScaleY(local_matrix.getScaleY() / scale);
  97
  98   skia::RefPtr<SkShader> shader = skia::AdoptRef(SkShader::CreateBitmapShader(
  99       image_rep.sk_bitmap(), tile_mode, tile_mode, &shader_scale));
 100   return shader;
 101 }
 102
 103 skia::RefPtr<SkShader> CreateGradientShader(int start_point,
 104                                             int end_point,
 105                                             SkColor start_color,
 106                                             SkColor end_color) {
 107   SkColor grad_colors[2] = { start_color, end_color};
 108   SkPoint grad_points[2];
 109   grad_points[0].iset(0, start_point);
 110   grad_points[1].iset(0, end_point);
 111
 112   return skia::AdoptRef(SkGradientShader::CreateLinear(
 113       grad_points, grad_colors, NULL, 2, SkShader::kRepeat_TileMode));
 114 }
 115
 116 static SkScalar RadiusToSigma(double radius) {
 117   // This captures historically what skia did under the hood. Now skia accepts
 118   // sigma, not radius, so we perform the conversion.
 119   return radius > 0 ? SkDoubleToScalar(0.57735f * radius + 0.5) : 0;
 120 }
 121
 122 skia::RefPtr<SkDrawLooper> CreateShadowDrawLooper(
 123     const std::vector<ShadowValue>& shadows) {
 124   if (shadows.empty())
 125     return skia::RefPtr<SkDrawLooper>();
 126
 127   SkLayerDrawLooper::Builder looper_builder;
 128
 129   looper_builder.addLayer();  // top layer of the original.
 130
 131   SkLayerDrawLooper::LayerInfo layer_info;
 132   layer_info.fPaintBits |= SkLayerDrawLooper::kMaskFilter_Bit;
 133   layer_info.fPaintBits |= SkLayerDrawLooper::kColorFilter_Bit;
 134   layer_info.fColorMode = SkXfermode::kSrc_Mode;
 135
 136   for (size_t i = 0; i < shadows.size(); ++i) {
 137     const ShadowValue& shadow = shadows[i];
 138
 139     layer_info.fOffset.set(SkIntToScalar(shadow.x()),
 140                            SkIntToScalar(shadow.y()));
 141
 142     // SkBlurMaskFilter's blur radius defines the range to extend the blur from
 143     // original mask, which is half of blur amount as defined in ShadowValue.
 144     skia::RefPtr<SkMaskFilter> blur_mask = skia::AdoptRef(
 145         SkBlurMaskFilter::Create(kNormal_SkBlurStyle,
 146                                  RadiusToSigma(shadow.blur() / 2),
 147                                  SkBlurMaskFilter::kHighQuality_BlurFlag));
 148     skia::RefPtr<SkColorFilter> color_filter = skia::AdoptRef(
 149         SkColorFilter::CreateModeFilter(shadow.color(),
 150                                         SkXfermode::kSrcIn_Mode));
 151
 152     SkPaint* paint = looper_builder.addLayer(layer_info);
 153     paint->setMaskFilter(blur_mask.get());
 154     paint->setColorFilter(color_filter.get());
 155   }
 156
 157   return skia::AdoptRef<SkDrawLooper>(looper_builder.detachLooper());
 158 }
 159
 160 bool BitmapsAreEqual(const SkBitmap& bitmap1, const SkBitmap& bitmap2) {
 161   void* addr1 = NULL;
 162   void* addr2 = NULL;
 163   size_t size1 = 0;
 164   size_t size2 = 0;
 165
 166   bitmap1.lockPixels();
 167   addr1 = bitmap1.getAddr32(0, 0);
 168   size1 = bitmap1.getSize();
 169   bitmap1.unlockPixels();
 170
 171   bitmap2.lockPixels();
 172   addr2 = bitmap2.getAddr32(0, 0);
 173   size2 = bitmap2.getSize();
 174   bitmap2.unlockPixels();
 175
 176   return (size1 == size2) && (0 == memcmp(addr1, addr2, bitmap1.getSize()));
 177 }
 178
 179 void ConvertSkiaToRGBA(const unsigned char* skia,
 180                        int pixel_width,
 181                        unsigned char* rgba) {
 182   int total_length = pixel_width * 4;
 183   for (int i = 0; i < total_length; i += 4) {
 184     const uint32_t pixel_in = *reinterpret_cast<const uint32_t*>(&skia[i]);
 185
 186     // Pack the components here.
 187     SkAlpha alpha = SkGetPackedA32(pixel_in);
 188     if (alpha != 0 && alpha != 255) {
 189       SkColor unmultiplied = SkUnPreMultiply::PMColorToColor(pixel_in);
 190       rgba[i + 0] = SkColorGetR(unmultiplied);
 191       rgba[i + 1] = SkColorGetG(unmultiplied);
 192       rgba[i + 2] = SkColorGetB(unmultiplied);
 193       rgba[i + 3] = alpha;
 194     } else {
 195       rgba[i + 0] = SkGetPackedR32(pixel_in);
 196       rgba[i + 1] = SkGetPackedG32(pixel_in);
 197       rgba[i + 2] = SkGetPackedB32(pixel_in);
 198       rgba[i + 3] = alpha;
 199     }
 200   }
 201 }
 202
 203 void QuadFToSkPoints(const gfx::QuadF& quad, SkPoint points[4]) {
 204   points[0] = SkPoint::Make(quad.p1().x(), quad.p1().y());
 205   points[1] = SkPoint::Make(quad.p2().x(), quad.p2().y());
 206   points[2] = SkPoint::Make(quad.p3().x(), quad.p3().y());
 207   points[3] = SkPoint::Make(quad.p4().x(), quad.p4().y());
 208 }
 209
 210 }  // namespace gfx