src/mesa/swrast/s_chan.h

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 2011  VMware, Inc.  All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included
  14  * in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  22  * OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 /**
  26  * Types, macros, etc for the GLchan datatype.
  27  * The swrast module is kind of hard-coded for 8bpp color channels but
  28  * may be recompiled to use 16- or 32-bit color channels.  But that
  29  * feature is seldom used and is likely broken in various ways.
  30  */
  31
  32 #ifndef U_CHAN_H
  33 #define U_CHAN_H
  34
  35
  36 #include "main/config.h"
  37
  38
  39 /**
  40  * Default bits per color channel:  8, 16 or 32
  41  */
  42 #ifndef CHAN_BITS
  43 #define CHAN_BITS 8
  44 #endif
  45
  46
  47 /**
  48  * Color channel data type.
  49  */
  50 #if CHAN_BITS == 8
  51    typedef GLubyte GLchan;
  52 #define CHAN_MAX 255
  53 #define CHAN_MAXF 255.0F
  54 #define CHAN_TYPE GL_UNSIGNED_BYTE
  55 #elif CHAN_BITS == 16
  56    typedef GLushort GLchan;
  57 #define CHAN_MAX 65535
  58 #define CHAN_MAXF 65535.0F
  59 #define CHAN_TYPE GL_UNSIGNED_SHORT
  60 #elif CHAN_BITS == 32
  61    typedef GLfloat GLchan;
  62 #define CHAN_MAX 1.0
  63 #define CHAN_MAXF 1.0F
  64 #define CHAN_TYPE GL_FLOAT
  65 #else
  66 #error "illegal number of color channel bits"
  67 #endif
  68
  69
  70 #if CHAN_BITS == 8
  71
  72 #define CHAN_TO_UBYTE(c)  (c)
  73 #define CHAN_TO_USHORT(c) (((c) << 8) | (c))
  74 #define CHAN_TO_SHORT(c)  (((c) << 7) | ((c) >> 1))
  75 #define CHAN_TO_FLOAT(c)  UBYTE_TO_FLOAT(c)
  76
  77 #define CLAMPED_FLOAT_TO_CHAN(c, f)    CLAMPED_FLOAT_TO_UBYTE(c, f)
  78 #define UNCLAMPED_FLOAT_TO_CHAN(c, f)  UNCLAMPED_FLOAT_TO_UBYTE(c, f)
  79
  80 #define COPY_CHAN4(DST, SRC)  COPY_4UBV(DST, SRC)
  81
  82 #elif CHAN_BITS == 16
  83
  84 #define CHAN_TO_UBYTE(c)  ((c) >> 8)
  85 #define CHAN_TO_USHORT(c) (c)
  86 #define CHAN_TO_SHORT(c)  ((c) >> 1)
  87 #define CHAN_TO_FLOAT(c)  ((GLfloat) ((c) * (1.0 / CHAN_MAXF)))
  88
  89 #define CLAMPED_FLOAT_TO_CHAN(c, f)    CLAMPED_FLOAT_TO_USHORT(c, f)
  90 #define UNCLAMPED_FLOAT_TO_CHAN(c, f)  UNCLAMPED_FLOAT_TO_USHORT(c, f)
  91
  92 #define COPY_CHAN4(DST, SRC)  COPY_4V(DST, SRC)
  93
  94 #elif CHAN_BITS == 32
  95
  96 #define CHAN_TO_UBYTE(c)  FLOAT_TO_UBYTE(c)
  97 #define CHAN_TO_USHORT(c) ((GLushort) (SATURATE((c)) * 65535.0))
  98 #define CHAN_TO_SHORT(c)  ((GLshort) (SATURATE((c)) * 32767.0))
  99 #define CHAN_TO_FLOAT(c)  (c)
 100
 101 #define CLAMPED_FLOAT_TO_CHAN(c, f)  c = (f)
 102 #define UNCLAMPED_FLOAT_TO_CHAN(c, f)      c = (f)
 103
 104 #define COPY_CHAN4(DST, SRC)  COPY_4V(DST, SRC)
 105
 106 #else
 107
 108 #error unexpected CHAN_BITS size
 109
 110 #endif
 111
 112
 113 /**
 114  * Convert 4 floats to GLchan values.
 115  * \param dst pointer to destination GLchan[4] array.
 116  * \param f pointer to source GLfloat[4] array.
 117  */
 118 #define UNCLAMPED_FLOAT_TO_RGBA_CHAN(dst, f)    \
 119 do {                                            \
 120    UNCLAMPED_FLOAT_TO_CHAN((dst)[0], (f)[0]);   \
 121    UNCLAMPED_FLOAT_TO_CHAN((dst)[1], (f)[1]);   \
 122    UNCLAMPED_FLOAT_TO_CHAN((dst)[2], (f)[2]);   \
 123    UNCLAMPED_FLOAT_TO_CHAN((dst)[3], (f)[3]);   \
 124 } while (0)
 125
 126
 127
 128 #endif /* U_CHAN_H */