pdf/draw_utils.h

   1 // Copyright (c) 2011 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 PDF_DRAW_UTILS_H_
   6 #define PDF_DRAW_UTILS_H_
   7
   8 #include <vector>
   9
  10 #include "base/basictypes.h"
  11 #include "ppapi/cpp/image_data.h"
  12 #include "ppapi/cpp/rect.h"
  13
  14 namespace chrome_pdf {
  15
  16 const uint8 kOpaqueAlpha = 0xFF;
  17 const uint8 kTransparentAlpha = 0x00;
  18
  19 void AlphaBlend(const pp::ImageData& src, const pp::Rect& src_rc,
  20                 pp::ImageData* dest, const pp::Point& dest_origin,
  21                 uint8 alpha_adjustment);
  22
  23 // Fill rectangle with gradient horizontally or vertically. Start is a color of
  24 // top-left point of the rectangle, end color is a color of
  25 // top-right (horizontal==true) or bottom-left (horizontal==false) point.
  26 void GradientFill(pp::ImageData* image,
  27                   const pp::Rect& rc,
  28                   uint32 start_color,
  29                   uint32 end_color,
  30                   bool horizontal);
  31
  32 // Fill dirty rectangle with gradient, where gradient color set for corners of
  33 // gradient rectangle. Parts of the dirty rect outside of gradient rect will
  34 // be unchanged.
  35 void GradientFill(pp::Instance* instance,
  36                   pp::ImageData* image,
  37                   const pp::Rect& dirty_rc,
  38                   const pp::Rect& gradient_rc,
  39                   uint32 start_color,
  40                   uint32 end_color,
  41                   bool horizontal,
  42                   uint8 transparency);
  43
  44 // Copy one image into another. If stretch is true, the result occupy the entire
  45 // dest_rc. If stretch is false, dest_rc.point will be used as an origin of the
  46 // result image. Copy will ignore all pixels with transparent alpha from the
  47 // source image.
  48 void CopyImage(const pp::ImageData& src, const pp::Rect& src_rc,
  49                pp::ImageData* dest, const pp::Rect& dest_rc,
  50                bool stretch);
  51
  52 // Fill in rectangle with specified color.
  53 void FillRect(pp::ImageData* image, const pp::Rect& rc, uint32 color);
  54
  55 // Shadow Matrix contains matrix for shadow rendering. To reduce amount of
  56 // calculations user may choose to cache matrix and reuse it if nothing changed.
  57 class ShadowMatrix {
  58  public:
  59   // Matrix parameters.
  60   // depth - how big matrix should be. Shadow will go smoothly across the
  61   // entire matrix from black to background color.
  62   // If factor == 1, smoothing will be linear from 0 to the end (depth),
  63   // if 0 < factor < 1, smoothing will drop faster near 0.
  64   // if factor > 1, smoothing will drop faster near the end (depth).
  65   ShadowMatrix(uint32 depth, double factor, uint32 background);
  66
  67   ~ShadowMatrix();
  68
  69   uint32 GetValue(int32 x, int32 y) const { return matrix_[y * depth_ + x]; }
  70
  71   uint32 depth() const { return depth_; }
  72   double factor() const { return factor_; }
  73   uint32 background() const { return background_; }
  74
  75  private:
  76   uint32 depth_;
  77   double factor_;
  78   uint32 background_;
  79   std::vector<uint32> matrix_;
  80 };
  81
  82 // Draw shadow on the image using provided ShadowMatrix.
  83 // shadow_rc - rectangle occupied by shadow
  84 // object_rc - rectangle that drops the shadow
  85 // clip_rc - clipping region
  86 void DrawShadow(pp::ImageData* image,
  87                 const pp::Rect& shadow_rc,
  88                 const pp::Rect& object_rc,
  89                 const pp::Rect& clip_rc,
  90                 const ShadowMatrix& matrix);
  91
  92 }  // namespace chrome_pdf
  93
  94 #endif  // PDF_DRAW_UTILS_H_