src/mesa/main/colormac.h

   1 /* $Id: colormac.h,v 1.2 2000/10/29 18:12:14 brianp Exp $ */
   2
   3 /*
   4  * Mesa 3-D graphics library
   5  * Version:  3.5
   6  *
   7  * Copyright (C) 1999-2000  Brian Paul   All Rights Reserved.
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a
  10  * copy of this software and associated documentation files (the "Software"),
  11  * to deal in the Software without restriction, including without limitation
  12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  13  * and/or sell copies of the Software, and to permit persons to whom the
  14  * Software is furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included
  17  * in all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  22  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  23  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  24  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  */
  26
  27
  28
  29 /*
  30  * Color-related macros
  31  */
  32
  33 #ifndef COLORMAC_H
  34 #define COLORMAC_H
  35
  36
  37 #include "glheader.h"
  38 #include "config.h"
  39 #include "macros.h"
  40 #include "mmath.h"
  41
  42
  43
  44 /*
  45  * Integer / float conversion for colors, normals, etc.
  46  */
  47
  48 #define BYTE_TO_UBYTE(b)   (b < 0 ? 0 : (GLubyte) b)
  49 #define SHORT_TO_UBYTE(s)  (s < 0 ? 0 : (GLubyte) (s >> 7))
  50 #define USHORT_TO_UBYTE(s)              (GLubyte) (s >> 8)
  51 #define INT_TO_UBYTE(i)    (i < 0 ? 0 : (GLubyte) (i >> 23))
  52 #define UINT_TO_UBYTE(i)                (GLubyte) (i >> 24)
  53
  54 /* Convert GLfloat in [0.0,1.0] to GLubyte in [0,255] */
  55 #define FLOAT_TO_UBYTE(X)       ((GLubyte) (GLint) (((X)) * 255.0F))
  56
  57
  58 /* Convert GLbyte in [-128,127] to GLfloat in [-1.0,1.0] */
  59 #define BYTE_TO_FLOAT(B)        ((2.0F * (B) + 1.0F) * (1.0F/255.0F))
  60
  61 /* Convert GLfloat in [-1.0,1.0] to GLbyte in [-128,127] */
  62 #define FLOAT_TO_BYTE(X)        ( (((GLint) (255.0F * (X))) - 1) / 2 )
  63
  64
  65 /* Convert GLushort in [0,65536] to GLfloat in [0.0,1.0] */
  66 #define USHORT_TO_FLOAT(S)      ((GLfloat) (S) * (1.0F / 65535.0F))
  67
  68 /* Convert GLfloat in [0.0,1.0] to GLushort in [0,65536] */
  69 #define FLOAT_TO_USHORT(X)      ((GLushort) (GLint) ((X) * 65535.0F))
  70
  71
  72 /* Convert GLshort in [-32768,32767] to GLfloat in [-1.0,1.0] */
  73 #define SHORT_TO_FLOAT(S)       ((2.0F * (S) + 1.0F) * (1.0F/65535.0F))
  74
  75 /* Convert GLfloat in [0.0,1.0] to GLshort in [-32768,32767] */
  76 #define FLOAT_TO_SHORT(X)       ( (((GLint) (65535.0F * (X))) - 1) / 2 )
  77
  78
  79 /* Convert GLuint in [0,4294967295] to GLfloat in [0.0,1.0] */
  80 #define UINT_TO_FLOAT(U)        ((GLfloat) (U) * (1.0F / 4294967295.0F))
  81
  82 /* Convert GLfloat in [0.0,1.0] to GLuint in [0,4294967295] */
  83 #define FLOAT_TO_UINT(X)        ((GLuint) ((X) * 4294967295.0))
  84
  85
  86 /* Convert GLint in [-2147483648,2147483647] to GLfloat in [-1.0,1.0] */
  87 #define INT_TO_FLOAT(I)         ((2.0F * (I) + 1.0F) * (1.0F/4294967294.0F))
  88
  89 /* Convert GLfloat in [-1.0,1.0] to GLint in [-2147483648,2147483647] */
  90 /* causes overflow:
  91 #define FLOAT_TO_INT(X)         ( (((GLint) (4294967294.0F * (X))) - 1) / 2 )
  92 */
  93 /* a close approximation: */
  94 #define FLOAT_TO_INT(X)         ( (GLint) (2147483647.0 * (X)) )
  95
  96
  97
  98 #if CHAN_BITS == 8
  99
 100 #define BYTE_TO_CHAN(b)   ((b) < 0 ? 0 : (GLchan) (b))
 101 #define UBYTE_TO_CHAN(b)  (b)
 102 #define SHORT_TO_CHAN(s)  ((s) < 0 ? 0 : (GLchan) ((s) >> 7))
 103 #define USHORT_TO_CHAN(s) ((GLchan) ((s) >> 8))
 104 #define INT_TO_CHAN(i)    ((i) < 0 ? 0 : (GLchan) ((i) >> 23))
 105 #define UINT_TO_CHAN(i)   ((GLchan) ((i) >> 24))
 106
 107 #define CHAN_TO_FLOAT(c)  UBYTE_TO_FLOAT(c)
 108
 109 #define FLOAT_COLOR_TO_CHAN(c, f) FLOAT_COLOR_TO_UBYTE_COLOR(c, f)
 110
 111 #define COPY_CHAN4(DST, SRC)  COPY_4UBV(DST, SRC)
 112
 113 #define CHAN_PRODUCT(a, b)  ( (GLubyte) (((GLint)(a) * ((GLint)(b) + 1)) >> 8) )
 114
 115 #elif CHAN_BITS == 16
 116
 117 #define BYTE_TO_CHAN(b)   ((b) < 0 ? 0 : (GLchan) ((b) * 516))
 118 #define UBYTE_TO_CHAN(b)  ((GLchan) (((b) << 8) | (b)))
 119 #define SHORT_TO_CHAN(s)  ((s) < 0 ? 0 : (GLchan) (s))
 120 #define USHORT_TO_CHAN(s) (s)
 121 #define INT_TO_CHAN(i)    ((i) < 0 ? 0 : (GLchan) ((i) >> 15))
 122 #define UINT_TO_CHAN(i)   ((GLchan) ((i) >> 16))
 123
 124 #define CHAN_TO_FLOAT(c)  ((GLfloat) ((c) * (1.0 / CHAN_MAXF)))
 125
 126 #define FLOAT_COLOR_TO_CHAN(c, f) \
 127         c = ((GLchan) FloatToInt(CLAMP(f, 0.0F, 1.0F) * CHAN_MAXF + 0.5F))
 128
 129 #define COPY_CHAN4(DST, SRC)  COPY_4V(DST, SRC)
 130
 131 #define CHAN_PRODUCT(a, b)  ( (GLchan) ((((GLint) (a)) * ((GLint) (b))) / 65535) )
 132
 133 #elif CHAN_BITS == 32
 134
 135 /* XXX floating-point color channels not fully thought-out */
 136 #define BYTE_TO_CHAN(b)   ((GLfloat) ((b) * (1.0F / 127.0F)))
 137 #define UBYTE_TO_CHAN(b)  ((GLfloat) ((b) * (1.0F / 255.0F)))
 138 #define SHORT_TO_CHAN(s)  ((GLfloat) ((s) * (1.0F / 32767.0F)))
 139 #define USHORT_TO_CHAN(s) ((GLfloat) ((s) * (1.0F / 65535.0F)))
 140 #define INT_TO_CHAN(i)    ((GLfloat) ((i) * (1.0F / 2147483647.0F)))
 141 #define UINT_TO_CHAN(i)   ((GLfloat) ((i) * (1.0F / 4294967295.0F)))
 142
 143 #define CHAN_TO_FLOAT(c)  (c)
 144
 145 #define FLOAT_COLOR_TO_CHAN(c, f)  c = f
 146
 147 #define COPY_CHAN4(DST, SRC)  COPY_4V(DST, SRC)
 148
 149 #define CHAN_PRODUCT(a, b)    ((a) * (b))
 150
 151 #else
 152
 153 #error unexpected CHAN_BITS size
 154
 155 #endif
 156
 157
 158 #define FLOAT_RGB_TO_CHAN_RGB(dst, f)           \
 159 do {                                            \
 160    FLOAT_COLOR_TO_CHAN(dst[0], f[0]);           \
 161    FLOAT_COLOR_TO_CHAN(dst[1], f[1]);           \
 162    FLOAT_COLOR_TO_CHAN(dst[2], f[2]);           \
 163 } while(0)
 164
 165 #define FLOAT_RGBA_TO_CHAN_RGBA(c, f)           \
 166 do {                                            \
 167    FLOAT_COLOR_TO_CHAN(c[0], f[0]);             \
 168    FLOAT_COLOR_TO_CHAN(c[1], f[1]);             \
 169    FLOAT_COLOR_TO_CHAN(c[2], f[2]);             \
 170    FLOAT_COLOR_TO_CHAN(c[3], f[3]);             \
 171 } while(0)
 172
 173
 174 #if CHAN_BITS == 32
 175
 176 #define FLOAT_TO_CHAN(f)   (f)
 177 #define DOUBLE_TO_CHAN(f)  ((GLfloat) (f))
 178 #define UNCLAMPED_FLOAT_TO_CHAN(f)   (f)
 179 #define UNCLAMPED_DOUBLE_TO_CHAN(f)  ((GLfloat) (f))
 180
 181 #else
 182
 183 #define FLOAT_TO_CHAN(f)   ( (GLchan) FloatToInt((f) * CHAN_MAXF + 0.5F) )
 184 #define DOUBLE_TO_CHAN(f)  ( (GLchan) FloatToInt((f) * CHAN_MAXF + 0.5F) )
 185
 186 #define UNCLAMPED_FLOAT_TO_CHAN(f)   \
 187    ( (GLchan) FloatToInt( CLAMP(f, 0.0, 1.0) * CHAN_MAXF + 0.5F) )
 188
 189 #define UNCLAMPED_DOUBLE_TO_CHAN(f)  \
 190    ( (GLchan) FloatToInt( CLAMP(f, 0.0, 1.0) * CHAN_MAXF + 0.5F) )
 191
 192 #endif
 193
 194
 195 #endif /* COLORMAC_H */