nsdfont/src/ColorBlender.h

   1 /*\r
   2  *      Kimikage NScripter Plugins Project\r
   3  *\r
   4  *      This software is distributed under a MIT-style license.\r
   5  *      See license.txt for more information.\r
   6  */\r
   7 \r
   8 #pragma once\r
   9 #include "Color.h"\r
  10 \r
  11 namespace nsdfont\r
  12 {\r
  13         class ColorBlender\r
  14         {\r
  15         private:\r
  16                 class Table\r
  17                 {\r
  18                 protected:\r
  19                         unsigned char table[256*256];\r
  20                 public:\r
  21                         inline unsigned int operator[]( size_t i ) const\r
  22                         {\r
  23                                 return static_cast<unsigned int>( table[i] );\r
  24                         }\r
  25                 };\r
  26                 \r
  27                 /**\r
  28                  *      \8fæ\8eZ\83e\81[\83u\83\8b.\r
  29                  */\r
  30                 class MulTable : public Table\r
  31                 {\r
  32                 public:\r
  33                         MulTable();\r
  34                 };\r
  35                 /**\r
  36                  *      \8f\9c\8eZ\83e\81[\83u\83\8b.\r
  37                  */\r
  38                 class DivTable : public Table\r
  39                 {\r
  40                 public:\r
  41                         DivTable();\r
  42                 };\r
  43 \r
  44                 static const MulTable mulTable;\r
  45                 static const DivTable divTable;\r
  46         public:\r
  47                 ColorBlender( void );\r
  48 \r
  49                 ~ColorBlender( void );\r
  50 \r
  51                 /**\r
  52                  *      \8fæ\8eZ\r
  53                  */\r
  54                 static inline unsigned int mul( const unsigned int v1, const unsigned int v2 )\r
  55                 {\r
  56                         const size_t i = v1 + (v2 << 8);\r
  57                         return mulTable[i];\r
  58                 }\r
  59                 \r
  60                 /**\r
  61                  *      \83X\83N\83\8a\81[\83\93(\94½\93]\8fæ\8eZ)\r
  62                  */\r
  63                 static inline unsigned int scr( const unsigned int v1, const unsigned int v2 )\r
  64                 {\r
  65                         const size_t i = (v1 + (v2 << 8)) ^ 0xFFFF;\r
  66                         return mulTable[i] ^ 0xFF;\r
  67                 }\r
  68 \r
  69                 static inline unsigned int div( const unsigned int numerator, const unsigned int divider )\r
  70                 {\r
  71                         const size_t i = numerator + (divider << 8);\r
  72                         return divTable[i];\r
  73                 }\r
  74                 \r
  75                 static inline Color blend( const Color &c1, const Color &c2, unsigned int rate )\r
  76                 {\r
  77                         const unsigned int inv = 255 - rate;\r
  78                         const unsigned int newA = mul( c1.getA(), inv ) + mul( c2.getA(), rate );\r
  79                         const unsigned int newR = mul( c1.getR(), inv ) + mul( c2.getR(), rate );\r
  80                         const unsigned int newG = mul( c1.getG(), inv ) + mul( c2.getG(), rate );\r
  81                         const unsigned int newB = mul( c1.getB(), inv ) + mul( c2.getB(), rate );\r
  82                         return Color( newR, newG, newB, newA );\r
  83                 }\r
  84                 \r
  85                 static inline Color interpolate( const Color &c1, const Color &c2, double rate )\r
  86                 {\r
  87                         const unsigned int r = static_cast<unsigned int>( 255 * rate );\r
  88                         return blend( c1, c2, r );\r
  89                 }\r
  90 \r
  91                 static inline Color interpolateHsv( const Color &c1, const Color &c2, double rate )\r
  92                 {\r
  93                         const unsigned int r = static_cast<unsigned int>( 255 * rate );\r
  94                         return blend( c1, c2, r );\r
  95                 }\r
  96 \r
  97                 \r
  98                 /**\r
  99                  *      2\82Â\82Ì\90F\82ð\8fd\82Ë\8d\87\82í\82¹\82½\90F\82ð\90¶\90¬\82·\82é.\r
 100                  *      @param back     \89º\91w\82Ì\90F\r
 101                  *      @param fore \91O\96Ê\82Ì\90F\r
 102                  *      @return \8fd\82Ë\8d\87\82í\82¹\82½\90F\r
 103                  */\r
 104                 static inline Color merge( const Color &back, const Color &fore )\r
 105                 {\r
 106                         // C = blend( blend( C0, C1, A1), C2, A2 )\r
 107                         //   = blend( C0*(1-A1) + C1*A1, C2, A2 )\r
 108                         //   = C0*(1-A1)*(1-A2) + C1*A1*(1-A2) + C2*A2\r
 109                         //   = blend( C0, {C1*A1*(1-A2) + C2*A2}/{1-(1-A1)*(1-A2)}, 1-(1-A1)*(1-A2) )\r
 110                         //       = blend( C0, {C1*A1 + C2*A2 - C1*A1*A2}/scr(A1,A2), scr(A1,A2) )\r
 111                         const unsigned int backA = back.getA();\r
 112                         if ( backA == 0 ) return Color( fore );\r
 113                         const unsigned int foreA = fore.getA();\r
 114                         if ( foreA == 0 ) return Color( back );\r
 115                         const unsigned int mulA = mul( backA, foreA );\r
 116 \r
 117                         const unsigned int backR = back.getR();\r
 118                         const unsigned int foreR = fore.getR();\r
 119                         const unsigned int newR = mul( backR, backA ) + mul( foreR, foreA )\r
 120                                                                                 - mul( backR, mulA );\r
 121                         const unsigned int backG = back.getG();\r
 122                         const unsigned int foreG = fore.getG();\r
 123                         const unsigned int newG = mul( backG, backA ) + mul( foreG, foreA )\r
 124                                                                                 - mul( backG, mulA ); \r
 125                         const unsigned int backB = back.getB();\r
 126                         const unsigned int foreB = fore.getB();\r
 127                         const unsigned int newB = mul( backB, backA ) + mul( foreB, foreA )\r
 128                                                                                 -mul(  backB, mulA );\r
 129                         const unsigned int newA = scr( backA, foreA );\r
 130                         return Color( div( newR, newA ), \r
 131                                                   div( newG, newA ),\r
 132                                                   div( newB, newA ), newA );\r
 133                 }\r
 134         };\r
 135 }