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 */ 128