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) (CLAMP((c), 0.0f, 1.0f) * 65535.0)) 98 #define CHAN_TO_SHORT(c) ((GLshort) (CLAMP((c), 0.0f, 1.0f) * 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 */ 129
