native_client_sdk/src/examples/demo/flock/sprite.h

   1 // Copyright 2013 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 SPRITE_H_
   6 #define SPRITE_H_
   7
   8 #include <vector>
   9 #include "ppapi/cpp/point.h"
  10 #include "ppapi/cpp/rect.h"
  11 #include "ppapi/cpp/size.h"
  12
  13
  14 // A Sprite is a simple container of a pixel buffer.  It knows how to
  15 // composite itself to another pixel buffer of the same format.
  16 class Sprite {
  17  public:
  18   // Initialize a Sprite to use the attached pixel buffer.  The Sprite takes
  19   // ownership of the pixel buffer, deleting it in the dtor.  The pixel
  20   // buffer is assumed to be 32-bit ARGB-8-8-8-8 pixel format, with pre-
  21   // multiplied alpha.  If |row_bytes| is 0, then the number of bytes per row
  22   // is assumed to be size.width() * sizeof(uint32_t).
  23   Sprite(uint32_t* pixel_buffer, const pp::Size& size, int32_t stride = 0);
  24
  25   // Delete the pixel buffer.  It is assumed that the pixel buffer was created
  26   // using malloc().
  27   ~Sprite();
  28
  29   // Reset the internal pixel buffer to a new one.  Deletes the old pixel
  30   // buffer.  Sprite takes ownership of the new pixel buffer.  If |row_bytes|
  31   // is 0, then the number of bytes per row is assumed to be size.width() *
  32   // sizeof(uint32_t).
  33   void SetPixelBuffer(uint32_t* pixel_buffer,
  34                       const pp::Size& size,
  35                       int32_t row_bytes);
  36
  37   // Composite the section of the Sprite contained in |src_rect| into the given
  38   // pixel buffer at |dest_point|.  Performs an average of the source and
  39   // dest pixel, and all necessary clipping.
  40   void CompositeFromRectToPoint(const pp::Rect& src_rect,
  41                                 uint32_t* dest_pixel_buffer,
  42                                 const pp::Rect& dest_bounds,
  43                                 int32_t dest_row_bytes,
  44                                 const pp::Point& dest_point) const;
  45
  46   // Accessors.
  47   const pp::Size& size() const {
  48     return pixel_buffer_size_;
  49   }
  50
  51  private:
  52   uint32_t* pixel_buffer_;
  53   pp::Size pixel_buffer_size_;
  54   int32_t row_bytes_;
  55 };
  56
  57 #endif  // SPRITE_H_