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
  18 {
  19         BLEND = GL_BLEND
  20 };
  21
  22 enum BlendEquation
  23 {
  24         ADD              = GL_FUNC_ADD,
  25         SUBTRACT         = GL_FUNC_SUBTRACT,
  26         REVERSE_SUBTRACT = GL_FUNC_REVERSE_SUBTRACT,
  27         MIN              = GL_MIN,
  28         MAX              = GL_MAX
  29 };
  30
  31 enum BlendFactor
  32 {
  33         ZERO = GL_ZERO,
  34         ONE = GL_ONE,
  35         SRC_COLOR = GL_SRC_COLOR,
  36         ONE_MINUS_SRC_COLOR = GL_ONE_MINUS_SRC_COLOR,
  37         SRC_ALPHA = GL_SRC_ALPHA,
  38         ONE_MINUS_SRC_ALPHA = GL_ONE_MINUS_SRC_ALPHA,
  39         DST_COLOR = GL_DST_COLOR,
  40         ONE_MINUS_DST_COLOR = GL_ONE_MINUS_DST_COLOR,
  41         DST_ALPHA = GL_DST_ALPHA,
  42         ONE_MINUS_DST_ALPHA = GL_ONE_MINUS_DST_ALPHA,
  43         CONSTANT_COLOR = GL_CONSTANT_COLOR,
  44         ONE_MINUS_CONSTANT_COLOR = GL_ONE_MINUS_CONSTANT_COLOR,
  45         CONSTANT_ALPHA = GL_CONSTANT_ALPHA,
  46         ONE_MINUS_CONSTANT_ALPHA = GL_ONE_MINUS_CONSTANT_ALPHA
  47 };
  48
  49 /**
  50 Blends incoming fragments with those already in the framebuffer.
  51 */
  52 class Blend: public Bindable<Blend>
  53 {
  54 private:
  55         BlendEquation eq;
  56         BlendFactor src_factor;
  57         BlendFactor dst_factor;
  58
  59 public:
  60         Blend();
  61         Blend(BlendFactor, BlendFactor);
  62         Blend(BlendEquation, BlendFactor, BlendFactor);
  63
  64         void bind() const;
  65
  66         static const Blend &alpha();
  67         static void unbind();
  68 };
  69
  70 void blend_equation(BlendEquation eq);
  71 void blend_func(BlendFactor src, BlendFactor dst);
  72
  73 } // namespace GL
  74 } // namespace Msp
  75
  76 #endif