| 1 | /* $Id: fixed.h,v 1.1 2000-02-29 00:48:30 sandervl Exp $ */
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| 2 |
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| 3 | /*
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| 4 | * Mesa 3-D graphics library
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| 5 | * Version: 3.1
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| 6 | *
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| 7 | * Copyright (C) 1999 Brian Paul All Rights Reserved.
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| 8 | *
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| 9 | * Permission is hereby granted, free of charge, to any person obtaining a
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| 10 | * copy of this software and associated documentation files (the "Software"),
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| 11 | * to deal in the Software without restriction, including without limitation
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| 12 | * the rights to use, copy, modify, merge, publish, distribute, sublicense,
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| 13 | * and/or sell copies of the Software, and to permit persons to whom the
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| 14 | * Software is furnished to do so, subject to the following conditions:
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| 15 | *
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| 16 | * The above copyright notice and this permission notice shall be included
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| 17 | * in all copies or substantial portions of the Software.
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| 18 | *
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| 19 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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| 20 | * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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| 21 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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| 22 | * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
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| 23 | * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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| 24 | * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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| 25 | */
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| 26 |
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| 27 |
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| 28 |
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| 29 |
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| 30 |
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| 31 | #ifndef FIXED_H
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| 32 | #define FIXED_H
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| 33 |
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| 34 |
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| 35 | typedef int GLfixed;
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| 36 |
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| 37 | #define FIXED_ONE 0x00000800
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| 38 | #define FIXED_HALF 0x00000400
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| 39 | #define FIXED_FRAC_MASK 0x000007FF
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| 40 | #define FIXED_INT_MASK (~FIXED_FRAC_MASK)
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| 41 | #define FIXED_EPSILON 1
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| 42 | #define FIXED_SCALE 2048.0f
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| 43 | #define FIXED_SHIFT 11
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| 44 | #define FloatToFixed(X) ((GLfixed) ((X) * FIXED_SCALE))
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| 45 | #define IntToFixed(I) ((I) << FIXED_SHIFT)
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| 46 | #define FixedToInt(X) ((X) >> FIXED_SHIFT)
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| 47 | #define FixedToUns(X) (((unsigned int)(X)) >> 11)
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| 48 | #define FixedCeil(X) (((X) + FIXED_ONE - FIXED_EPSILON) & FIXED_INT_MASK)
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| 49 | #define FixedFloor(X) ((X) & FIXED_INT_MASK)
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| 50 | /* 0.00048828125 = 1/FIXED_SCALE */
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| 51 | #define FixedToFloat(X) ((X) * 0.00048828125f)
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| 52 | #define PosFloatToFixed(X) FloatToFixed(X)
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| 53 | #define SignedFloatToFixed(X) FloatToFixed(X)
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| 54 |
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| 55 |
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| 56 | #if DEPTH_BITS==16
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| 57 | /* use fixed-point interpolation */
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| 58 | #define FixedToDepth(I) ((I) >> FIXED_SHIFT)
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| 59 | #else
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| 60 | /* don't really use fixed-point */
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| 61 | #define FixedToDepth(I) (I)
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| 62 | #endif
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| 63 |
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| 64 |
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| 65 | #endif
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