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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 298 | serge | 1 | // Emacs style mode select -*- C++ -*- |
| 2 | //----------------------------------------------------------------------------- |
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| 3 | // |
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| 4 | // $Id:$ |
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| 5 | // |
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| 6 | // Copyright (C) 1993-1996 by id Software, Inc. |
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| 7 | // |
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| 8 | // This source is available for distribution and/or modification |
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| 9 | // only under the terms of the DOOM Source Code License as |
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| 10 | // published by id Software. All rights reserved. |
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| 11 | // |
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| 12 | // The source is distributed in the hope that it will be useful, |
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| 13 | // but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 14 | // FITNESS FOR A PARTICULAR PURPOSE. See the DOOM Source Code License |
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| 15 | // for more details. |
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| 16 | // |
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| 17 | // $Log:$ |
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| 18 | // |
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| 19 | // DESCRIPTION: |
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| 20 | // Fixed point implementation. |
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| 21 | // |
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| 22 | //----------------------------------------------------------------------------- |
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| 23 | |||
| 24 | |||
| 25 | static const char |
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| 26 | rcsid[] = "$Id: m_bbox.c,v 1.1 1997/02/03 22:45:10 b1 Exp $"; |
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| 27 | |||
| 28 | #include "stdlib.h" |
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| 29 | |||
| 30 | #include "doomtype.h" |
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| 31 | #include "i_system.h" |
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| 32 | |||
| 33 | #ifdef __GNUG__ |
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| 34 | #pragma implementation "m_fixed.h" |
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| 35 | #endif |
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| 36 | #include "m_fixed.h" |
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| 37 | |||
| 38 | |||
| 39 | |||
| 40 | |||
| 41 | // Fixme. __USE_C_FIXED__ or something. |
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| 42 | |||
| 43 | fixed_t |
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| 44 | FixedMul |
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| 45 | ( fixed_t a, |
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| 46 | fixed_t b ) |
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| 47 | { |
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| 48 | return ((long long) a * (long long) b) >> FRACBITS; |
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| 49 | } |
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| 50 | |||
| 51 | |||
| 52 | |||
| 53 | // |
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| 54 | // FixedDiv, C version. |
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| 55 | // |
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| 56 | |||
| 57 | fixed_t |
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| 58 | FixedDiv |
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| 59 | ( fixed_t a, |
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| 60 | fixed_t b ) |
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| 61 | { |
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| 62 | if ( (abs(a)>>14) >= abs(b)) |
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| 63 | return (a^b)<0 ? MININT : MAXINT; |
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| 64 | return FixedDiv2 (a,b); |
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| 65 | } |
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| 66 | |||
| 67 | |||
| 68 | |||
| 69 | fixed_t |
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| 70 | FixedDiv2 |
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| 71 | ( fixed_t a, |
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| 72 | fixed_t b ) |
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| 73 | { |
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| 74 | #if 0 |
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| 75 | long long c; |
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| 76 | c = ((long long)a<<16) / ((long long)b); |
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| 77 | return (fixed_t) c; |
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| 78 | #endif |
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| 79 | |||
| 80 | double c; |
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| 81 | |||
| 82 | c = ((double)a) / ((double)b) * FRACUNIT; |
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| 83 | |||
| 84 | if (c >= 2147483648.0 || c < -2147483648.0) |
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| 85 | I_Error("FixedDiv: divide by zero"); |
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| 86 | return (fixed_t) c; |
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| 87 | } |