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 #ifndef UI_GFX_SKBITMAP_OPERATIONS_H_ 6 #define UI_GFX_SKBITMAP_OPERATIONS_H_ 7 8 #include "base/gtest_prod_util.h" 9 #include "ui/gfx/color_utils.h" 10 #include "ui/gfx/gfx_export.h" 11 #include "ui/gfx/shadow_value.h" 12 13 class SkBitmap; 14 15 class GFX_EXPORT SkBitmapOperations { 16 public: 17 // Enum for use in rotating images (must be in 90 degree increments), 18 // see: Rotate. 19 enum RotationAmount { 20 ROTATION_90_CW, 21 ROTATION_180_CW, 22 ROTATION_270_CW, 23 }; 24 25 // Create a bitmap that is an inverted image of the passed in image. 26 // Each color becomes its inverse in the color wheel. So (255, 15, 0) becomes 27 // (0, 240, 255). The alpha value is not inverted. 28 static SkBitmap CreateInvertedBitmap(const SkBitmap& image); 29 30 // Create a bitmap that is a blend of two others. The alpha argument 31 // specifies the opacity of the second bitmap. The provided bitmaps must 32 // use have the kARGB_8888_Config config and be of equal dimensions. 33 static SkBitmap CreateBlendedBitmap(const SkBitmap& first, 34 const SkBitmap& second, 35 double alpha); 36 37 // Create a bitmap that is the original bitmap masked out by the mask defined 38 // in the alpha bitmap. The images must use the kARGB_8888_Config config and 39 // be of equal dimensions. 40 static SkBitmap CreateMaskedBitmap(const SkBitmap& first, 41 const SkBitmap& alpha); 42 43 // We create a button background image by compositing the color and image 44 // together, then applying the mask. This is a highly specialized composite 45 // operation that is the equivalent of drawing a background in |color|, 46 // tiling |image| over the top, and then masking the result out with |mask|. 47 // The images must use kARGB_8888_Config config. 48 static SkBitmap CreateButtonBackground(SkColor color, 49 const SkBitmap& image, 50 const SkBitmap& mask); 51 52 // Shift a bitmap's HSL values. The shift values are in the range of 0-1, 53 // with the option to specify -1 for 'no change'. The shift values are 54 // defined as: 55 // hsl_shift[0] (hue): The absolute hue value for the image - 0 and 1 map 56 // to 0 and 360 on the hue color wheel (red). 57 // hsl_shift[1] (saturation): A saturation shift for the image, with the 58 // following key values: 59 // 0 = remove all color. 60 // 0.5 = leave unchanged. 61 // 1 = fully saturate the image. 62 // hsl_shift[2] (lightness): A lightness shift for the image, with the 63 // following key values: 64 // 0 = remove all lightness (make all pixels black). 65 // 0.5 = leave unchanged. 66 // 1 = full lightness (make all pixels white). 67 static SkBitmap CreateHSLShiftedBitmap(const SkBitmap& bitmap, 68 const color_utils::HSL& hsl_shift); 69 70 // Create a bitmap that is cropped from another bitmap. This is special 71 // because it tiles the original bitmap, so your coordinates can extend 72 // outside the bounds of the original image. 73 static SkBitmap CreateTiledBitmap(const SkBitmap& bitmap, 74 int src_x, int src_y, 75 int dst_w, int dst_h); 76 77 // Iteratively downsamples by 2 until the bitmap is no smaller than the 78 // input size. The normal use of this is to downsample the bitmap "close" to 79 // the final size, and then use traditional resampling on the result. 80 // Because the bitmap will be closer to the final size, it will be faster, 81 // and linear interpolation will generally work well as a second step. 82 static SkBitmap DownsampleByTwoUntilSize(const SkBitmap& bitmap, 83 int min_w, int min_h); 84 85 // Makes a bitmap half has large in each direction by averaging groups of 86 // 4 pixels. This is one step in generating a mipmap. 87 static SkBitmap DownsampleByTwo(const SkBitmap& bitmap); 88 89 // Unpremultiplies all pixels in |bitmap|. You almost never want to call 90 // this, as |SkBitmap|s are always premultiplied by conversion. Call this 91 // only if you will pass the bitmap's data into a system function that 92 // doesn't expect premultiplied colors. 93 static SkBitmap UnPreMultiply(const SkBitmap& bitmap); 94 95 // Transpose the pixels in |bitmap| by swapping x and y. 96 static SkBitmap CreateTransposedBitmap(const SkBitmap& bitmap); 97 98 // Create a bitmap by combining alpha channel of |bitmap| and color |c|. 99 // The image must use the kARGB_8888_Config config. 100 static SkBitmap CreateColorMask(const SkBitmap& bitmap, SkColor c); 101 102 // Create a bitmap with drop shadow added to |bitmap|. |shadows| defines 103 // the shadows to add. The created bitmap would be padded to have enough space 104 // for shadows and have original bitmap in the center. The image must use the 105 // kARGB_8888_Config config. 106 static SkBitmap CreateDropShadow(const SkBitmap& bitmap, 107 const gfx::ShadowValues& shadows); 108 109 // Rotates the given source bitmap clockwise by the requested amount. 110 static SkBitmap Rotate(const SkBitmap& source, RotationAmount rotation); 111 112 private: 113 SkBitmapOperations(); // Class for scoping only. 114 115 FRIEND_TEST_ALL_PREFIXES(SkBitmapOperationsTest, DownsampleByTwo); 116 FRIEND_TEST_ALL_PREFIXES(SkBitmapOperationsTest, DownsampleByTwoSmall); 117 }; 118 119 #endif // UI_GFX_SKBITMAP_OPERATIONS_H_ 120