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 BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  20  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 /**
  25  * Types, macros, etc for the GLchan datatype.
  26  * The swrast module is kind of hard-coded for 8bpp color channels but
  27  * may be recompiled to use 16- or 32-bit color channels.  But that
  28  * feature is seldom used and is likely broken in various ways.
  29  */
  30
  31 #ifndef U_CHAN_H
  32 #define U_CHAN_H
  33
  34
  35 #include "main/config.h"
  36
  37
  38 /**
  39  * Default bits per color channel:  8, 16 or 32
  40  */
  41 #ifndef CHAN_BITS
  42 #define CHAN_BITS 8
  43 #endif
  44
  45
  46 /**
  47  * Color channel data type.
  48  */
  49 #if CHAN_BITS == 8
  50    typedef GLubyte GLchan;
  51 #define CHAN_MAX 255
  52 #define CHAN_MAXF 255.0F
  53 #define CHAN_TYPE GL_UNSIGNED_BYTE
  54 #elif CHAN_BITS == 16
  55    typedef GLushort GLchan;
  56 #define CHAN_MAX 65535
  57 #define CHAN_MAXF 65535.0F
  58 #define CHAN_TYPE GL_UNSIGNED_SHORT
  59 #elif CHAN_BITS == 32
  60    typedef GLfloat GLchan;
  61 #define CHAN_MAX 1.0
  62 #define CHAN_MAXF 1.0F
  63 #define CHAN_TYPE GL_FLOAT
  64 #else
  65 #error "illegal number of color channel bits"
  66 #endif
  67
  68
  69 #if CHAN_BITS == 8
  70
  71 #define CHAN_TO_UBYTE(c)  (c)
  72 #define CHAN_TO_USHORT(c) (((c) << 8) | (c))
  73 #define CHAN_TO_SHORT(c)  (((c) << 7) | ((c) >> 1))
  74 #define CHAN_TO_FLOAT(c)  UBYTE_TO_FLOAT(c)
  75
  76 #define CLAMPED_FLOAT_TO_CHAN(c, f)    CLAMPED_FLOAT_TO_UBYTE(c, f)
  77 #define UNCLAMPED_FLOAT_TO_CHAN(c, f)  UNCLAMPED_FLOAT_TO_UBYTE(c, f)
  78
  79 #define COPY_CHAN4(DST, SRC)  COPY_4UBV(DST, SRC)
  80
  81 #elif CHAN_BITS == 16
  82
  83 #define CHAN_TO_UBYTE(c)  ((c) >> 8)
  84 #define CHAN_TO_USHORT(c) (c)
  85 #define CHAN_TO_SHORT(c)  ((c) >> 1)
  86 #define CHAN_TO_FLOAT(c)  ((GLfloat) ((c) * (1.0 / CHAN_MAXF)))
  87
  88 #define CLAMPED_FLOAT_TO_CHAN(c, f)    CLAMPED_FLOAT_TO_USHORT(c, f)
  89 #define UNCLAMPED_FLOAT_TO_CHAN(c, f)  UNCLAMPED_FLOAT_TO_USHORT(c, f)
  90
  91 #define COPY_CHAN4(DST, SRC)  COPY_4V(DST, SRC)
  92
  93 #elif CHAN_BITS == 32
  94
  95 #define CHAN_TO_UBYTE(c)  FLOAT_TO_UBYTE(c)
  96 #define CHAN_TO_USHORT(c) ((GLushort) (CLAMP((c), 0.0f, 1.0f) * 65535.0))
  97 #define CHAN_TO_SHORT(c)  ((GLshort) (CLAMP((c), 0.0f, 1.0f) * 32767.0))
  98 #define CHAN_TO_FLOAT(c)  (c)
  99
 100 #define CLAMPED_FLOAT_TO_CHAN(c, f)  c = (f)
 101 #define UNCLAMPED_FLOAT_TO_CHAN(c, f)      c = (f)
 102
 103 #define COPY_CHAN4(DST, SRC)  COPY_4V(DST, SRC)
 104
 105 #else
 106
 107 #error unexpected CHAN_BITS size
 108
 109 #endif
 110
 111
 112 /**
 113  * Convert 4 floats to GLchan values.
 114  * \param dst pointer to destination GLchan[4] array.
 115  * \param f pointer to source GLfloat[4] array.
 116  */
 117 #define UNCLAMPED_FLOAT_TO_RGBA_CHAN(dst, f)    \
 118 do {                                            \
 119    UNCLAMPED_FLOAT_TO_CHAN((dst)[0], (f)[0]);   \
 120    UNCLAMPED_FLOAT_TO_CHAN((dst)[1], (f)[1]);   \
 121    UNCLAMPED_FLOAT_TO_CHAN((dst)[2], (f)[2]);   \
 122    UNCLAMPED_FLOAT_TO_CHAN((dst)[3], (f)[3]);   \
 123 } while (0)
 124
 125
 126
 127 #endif /* U_CHAN_H */