source/blend.cpp

   1 #include <msp/gl/extensions/ext_blend_minmax.h>
   2 #include <msp/gl/extensions/ext_blend_subtract.h>
   3 #include <msp/strings/format.h>
   4 #include "blend.h"
   5
   6 using namespace std;
   7
   8 namespace Msp {
   9 namespace GL {
  10
  11 Blend::Blend():
  12         eq(ADD),
  13         src_factor(ONE),
  14         dst_factor(ZERO)
  15 { }
  16
  17 Blend::Blend(BlendFactor sf, BlendFactor df):
  18         eq(ADD),
  19         src_factor(sf),
  20         dst_factor(df)
  21 { }
  22
  23 Blend::Blend(BlendEquation e, BlendFactor sf, BlendFactor df):
  24         eq(e),
  25         src_factor(sf),
  26         dst_factor(df)
  27 {
  28         if(eq==MIN || eq==MAX)
  29                 static Require _req(EXT_blend_minmax);
  30         else if(eq==SUBTRACT || eq==REVERSE_SUBTRACT)
  31                 static Require _req(EXT_blend_subtract);
  32 }
  33
  34 void Blend::bind() const
  35 {
  36         if(set_current(this))
  37         {
  38                 glEnable(GL_BLEND);
  39                 if(EXT_blend_minmax)
  40                         glBlendEquation(eq);
  41                 glBlendFunc(src_factor, dst_factor);
  42         }
  43 }
  44
  45 void Blend::unbind()
  46 {
  47         if(set_current(0))
  48                 glDisable(GL_BLEND);
  49 }
  50
  51 const Blend &Blend::alpha()
  52 {
  53         static Blend blend(SRC_ALPHA, ONE_MINUS_SRC_ALPHA);
  54         return blend;
  55 }
  56
  57 const Blend &Blend::additive()
  58 {
  59         static Blend blend(ONE, ONE);
  60         return blend;
  61 }
  62
  63 const Blend &Blend::additive_alpha()
  64 {
  65         static Blend blend(SRC_ALPHA, ONE);
  66         return blend;
  67 }
  68
  69 void operator>>(const LexicalConverter &conv, BlendFactor &factor)
  70 {
  71         const string &str = conv.get();
  72         if(str=="ZERO")
  73                 factor = ZERO;
  74         else if(str=="ONE")
  75                 factor = ONE;
  76         else if(str=="SRC_COLOR")
  77                 factor = SRC_COLOR;
  78         else if(str=="ONE_MINUS_SRC_COLOR")
  79                 factor = ONE_MINUS_SRC_COLOR;
  80         else if(str=="SRC_ALPHA")
  81                 factor = SRC_ALPHA;
  82         else if(str=="ONE_MINUS_SRC_ALPHA")
  83                 factor = ONE_MINUS_SRC_ALPHA;
  84         else if(str=="DST_COLOR")
  85                 factor = DST_COLOR;
  86         else if(str=="ONE_MINUS_DST_COLOR")
  87                 factor = ONE_MINUS_DST_COLOR;
  88         else if(str=="DST_ALPHA")
  89                 factor = DST_ALPHA;
  90         else if(str=="ONE_MINUS_DST_ALPHA")
  91                 factor = ONE_MINUS_DST_ALPHA;
  92         else if(str=="CONSTANT_COLOR")
  93                 factor = CONSTANT_COLOR;
  94         else if(str=="ONE_MINUS_CONSTANT_COLOR")
  95                 factor = ONE_MINUS_CONSTANT_COLOR;
  96         else if(str=="CONSTANT_ALPHA")
  97                 factor = CONSTANT_ALPHA;
  98         else if(str=="ONE_MINUS_CONSTANT_ALPHA")
  99                 factor = ONE_MINUS_CONSTANT_ALPHA;
 100         else
 101                 throw lexical_error(format("conversion of '%s' to BlendFactor", str));
 102 }
 103
 104 void operator<<(LexicalConverter &conv, BlendFactor factor)
 105 {
 106         switch(factor)
 107         {
 108         case ZERO: conv.result("ZERO"); break;
 109         case ONE: conv.result("ONE"); break;
 110         case SRC_COLOR: conv.result("SRC_COLOR"); break;
 111         case ONE_MINUS_SRC_COLOR: conv.result("ONE_MINUS_SRC_COLOR"); break;
 112         case SRC_ALPHA: conv.result("SRC_ALPHA"); break;
 113         case ONE_MINUS_SRC_ALPHA: conv.result("ONE_MINUS_SRC_ALPHA"); break;
 114         case DST_COLOR: conv.result("DST_COLOR"); break;
 115         case ONE_MINUS_DST_COLOR: conv.result("ONE_MINUS_DST_COLOR"); break;
 116         case DST_ALPHA: conv.result("DST_ALPHA"); break;
 117         case ONE_MINUS_DST_ALPHA: conv.result("ONE_MINUS_DST_ALPHA"); break;
 118         case CONSTANT_COLOR: conv.result("CONSTANT_COLOR"); break;
 119         case ONE_MINUS_CONSTANT_COLOR: conv.result("ONE_MINUS_CONSTANT_COLOR"); break;
 120         case CONSTANT_ALPHA: conv.result("CONSTANT_ALPHA"); break;
 121         case ONE_MINUS_CONSTANT_ALPHA: conv.result("ONE_MINUS_CONSTANT_ALPHA"); break;
 122         default: conv.result(format("BlendFactor(%#x)", static_cast<int>(factor)));
 123         }
 124 }
 125
 126 } // namespace GL
 127 } // namespace Msp