source/blend.h

   1 /* $Id$
   2
   3 This file is part of libmspgl
   4 Copyright © 2008, 2010  Mikko Rasa, Mikkosoft Productions
   5 Distributed under the LGPL
   6 */
   7
   8 #ifndef MSP_GL_BLEND_H_
   9 #define MSP_GL_BLEND_H_
  10
  11 #include "bindable.h"
  12 #include "gl.h"
  13
  14 namespace Msp {
  15 namespace GL {
  16
  17 enum BlendEquation
  18 {
  19         ADD              = GL_FUNC_ADD,
  20         SUBTRACT         = GL_FUNC_SUBTRACT,
  21         REVERSE_SUBTRACT = GL_FUNC_REVERSE_SUBTRACT,
  22         MIN              = GL_MIN,
  23         MAX              = GL_MAX
  24 };
  25
  26 enum BlendFactor
  27 {
  28         ZERO = GL_ZERO,
  29         ONE = GL_ONE,
  30         SRC_COLOR = GL_SRC_COLOR,
  31         ONE_MINUS_SRC_COLOR = GL_ONE_MINUS_SRC_COLOR,
  32         SRC_ALPHA = GL_SRC_ALPHA,
  33         ONE_MINUS_SRC_ALPHA = GL_ONE_MINUS_SRC_ALPHA,
  34         DST_COLOR = GL_DST_COLOR,
  35         ONE_MINUS_DST_COLOR = GL_ONE_MINUS_DST_COLOR,
  36         DST_ALPHA = GL_DST_ALPHA,
  37         ONE_MINUS_DST_ALPHA = GL_ONE_MINUS_DST_ALPHA,
  38         CONSTANT_COLOR = GL_CONSTANT_COLOR,
  39         ONE_MINUS_CONSTANT_COLOR = GL_ONE_MINUS_CONSTANT_COLOR,
  40         CONSTANT_ALPHA = GL_CONSTANT_ALPHA,
  41         ONE_MINUS_CONSTANT_ALPHA = GL_ONE_MINUS_CONSTANT_ALPHA
  42 };
  43
  44 /**
  45 Blends incoming fragments with those already in the framebuffer.
  46 */
  47 class Blend: public Bindable<Blend>
  48 {
  49 private:
  50         BlendEquation eq;
  51         BlendFactor src_factor;
  52         BlendFactor dst_factor;
  53
  54 public:
  55         Blend();
  56         Blend(BlendFactor, BlendFactor);
  57         Blend(BlendEquation, BlendFactor, BlendFactor);
  58
  59         void bind() const;
  60
  61         static void unbind();
  62
  63         static const Blend &alpha();
  64 };
  65
  66 } // namespace GL
  67 } // namespace Msp
  68
  69 #endif