src/mesa/main/format_utils.h

   1 /**
   2  * \file format_utils.h
   3  * A collection of format conversion utility functions.
   4  */
   5
   6 /*
   7  * Mesa 3-D graphics library
   8  *
   9  * Copyright (C) 1999-2006  Brian Paul  All Rights Reserved.
  10  * Copyright (C) 2014  Intel Corporation  All Rights Reserved.
  11  *
  12  * Permission is hereby granted, free of charge, to any person obtaining a
  13  * copy of this software and associated documentation files (the "Software"),
  14  * to deal in the Software without restriction, including without limitation
  15  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  16  * and/or sell copies of the Software, and to permit persons to whom the
  17  * Software is furnished to do so, subject to the following conditions:
  18  *
  19  * The above copyright notice and this permission notice shall be included
  20  * in all copies or substantial portions of the Software.
  21  *
  22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  23  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  25  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  26  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  27  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  28  * OTHER DEALINGS IN THE SOFTWARE.
  29  */
  30
  31 #ifndef FORMAT_UTILS_H
  32 #define FORMAT_UTILS_H
  33
  34 #include "imports.h"
  35
  36 /* Only guaranteed to work for BITS <= 32 */
  37 #define MAX_UINT(BITS) ((BITS) == 32 ? UINT32_MAX : ((1u << (BITS)) - 1))
  38 #define MAX_INT(BITS) ((int)MAX_UINT((BITS) - 1))
  39
  40 /* Extends an integer of size SRC_BITS to one of size DST_BITS linearly */
  41 #define EXTEND_NORMALIZED_INT(X, SRC_BITS, DST_BITS) \
  42       (((X) * (int)(MAX_UINT(DST_BITS) / MAX_UINT(SRC_BITS))) + \
  43        ((DST_BITS % SRC_BITS) ? ((X) >> (SRC_BITS - DST_BITS % SRC_BITS)) : 0))
  44
  45 static inline float
  46 _mesa_unorm_to_float(unsigned x, unsigned src_bits)
  47 {
  48    return x * (1.0f / (float)MAX_UINT(src_bits));
  49 }
  50
  51 static inline float
  52 _mesa_snorm_to_float(int x, unsigned src_bits)
  53 {
  54    if (x <= -MAX_INT(src_bits))
  55       return -1.0f;
  56    else
  57       return x * (1.0f / (float)MAX_INT(src_bits));
  58 }
  59
  60 static inline uint16_t
  61 _mesa_unorm_to_half(unsigned x, unsigned src_bits)
  62 {
  63    return _mesa_float_to_half(_mesa_unorm_to_float(x, src_bits));
  64 }
  65
  66 static inline uint16_t
  67 _mesa_snorm_to_half(int x, unsigned src_bits)
  68 {
  69    return _mesa_float_to_half(_mesa_snorm_to_float(x, src_bits));
  70 }
  71
  72 static inline unsigned
  73 _mesa_float_to_unorm(float x, unsigned dst_bits)
  74 {
  75    if (x < 0.0f)
  76       return 0;
  77    else if (x > 1.0f)
  78       return MAX_UINT(dst_bits);
  79    else
  80       return F_TO_I(x * MAX_UINT(dst_bits));
  81 }
  82
  83 static inline unsigned
  84 _mesa_half_to_unorm(uint16_t x, unsigned dst_bits)
  85 {
  86    return _mesa_float_to_unorm(_mesa_half_to_float(x), dst_bits);
  87 }
  88
  89 static inline unsigned
  90 _mesa_unorm_to_unorm(unsigned x, unsigned src_bits, unsigned dst_bits)
  91 {
  92    if (src_bits < dst_bits)
  93       return EXTEND_NORMALIZED_INT(x, src_bits, dst_bits);
  94    else
  95       return x >> (src_bits - dst_bits);
  96 }
  97
  98 static inline unsigned
  99 _mesa_snorm_to_unorm(int x, unsigned src_bits, unsigned dst_bits)
 100 {
 101    if (x < 0)
 102       return 0;
 103    else
 104       return _mesa_unorm_to_unorm(x, src_bits - 1, dst_bits);
 105 }
 106
 107 static inline int
 108 _mesa_float_to_snorm(float x, unsigned dst_bits)
 109 {
 110    if (x < -1.0f)
 111       return -MAX_INT(dst_bits);
 112    else if (x > 1.0f)
 113       return MAX_INT(dst_bits);
 114    else
 115       return F_TO_I(x * MAX_INT(dst_bits));
 116 }
 117
 118 static inline int
 119 _mesa_half_to_snorm(uint16_t x, unsigned dst_bits)
 120 {
 121    return _mesa_float_to_snorm(_mesa_half_to_float(x), dst_bits);
 122 }
 123
 124 static inline int
 125 _mesa_unorm_to_snorm(unsigned x, unsigned src_bits, unsigned dst_bits)
 126 {
 127    return _mesa_unorm_to_unorm(x, src_bits, dst_bits - 1);
 128 }
 129
 130 static inline int
 131 _mesa_snorm_to_snorm(int x, unsigned src_bits, unsigned dst_bits)
 132 {
 133    if (x < -MAX_INT(src_bits))
 134       return -MAX_INT(dst_bits);
 135    else if (src_bits < dst_bits)
 136       return EXTEND_NORMALIZED_INT(x, src_bits - 1, dst_bits - 1);
 137    else
 138       return x >> (src_bits - dst_bits);
 139 }
 140
 141 bool
 142 _mesa_format_to_array(mesa_format, GLenum *type, int *num_components,
 143                       uint8_t swizzle[4], bool *normalized);
 144
 145 void
 146 _mesa_swizzle_and_convert(void *dst, GLenum dst_type, int num_dst_channels,
 147                           const void *src, GLenum src_type, int num_src_channels,
 148                           const uint8_t swizzle[4], bool normalized, int count);
 149
 150 #endif