60 lines
1.4 KiB
C
60 lines
1.4 KiB
C
// Emacs style mode select -*- C++ -*-
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//-----------------------------------------------------------------------------
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//
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// $Id:$
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//
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// Copyright (C) 1993-1996 by id Software, Inc.
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//
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// This source is available for distribution and/or modification
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// only under the terms of the DOOM Source Code License as
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// published by id Software. All rights reserved.
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//
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// The source is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// FITNESS FOR A PARTICULAR PURPOSE. See the DOOM Source Code License
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// for more details.
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//
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// $Log:$
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//
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// DESCRIPTION:
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// Fixed point implementation.
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//
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//-----------------------------------------------------------------------------
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#include "doom_config.h"
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#include "stdlib.h"
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#include "doomtype.h"
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#include "i_system.h"
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#include "m_fixed.h"
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fixed_t FixedMul(fixed_t a, fixed_t b)
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{
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return ((long long)a * (long long)b) >> FRACBITS;
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}
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//
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// FixedDiv, C version.
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//
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fixed_t FixedDiv(fixed_t a, fixed_t b)
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{
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if ((doom_abs(a) >> 14) >= doom_abs(b))
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return (a ^ b) < 0 ? DOOM_MININT : DOOM_MAXINT;
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return FixedDiv2(a, b);
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}
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fixed_t FixedDiv2(fixed_t a, fixed_t b)
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{
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double c;
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c = ((double)a) / ((double)b) * FRACUNIT;
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if (c >= 2147483648.0 || c < -2147483648.0)
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I_Error("Error: FixedDiv: divide by zero");
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return (fixed_t)c;
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}
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