88 lines
1.6 KiB
C
88 lines
1.6 KiB
C
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// 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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static const char
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rcsid[] = "$Id: m_bbox.c,v 1.1 1997/02/03 22:45:10 b1 Exp $";
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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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#ifdef __GNUG__
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#pragma implementation "m_fixed.h"
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#endif
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#include "m_fixed.h"
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// Fixme. __USE_C_FIXED__ or something.
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fixed_t
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FixedMul
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( fixed_t a,
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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
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FixedDiv
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( fixed_t a,
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fixed_t b )
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{
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if ( (abs(a)>>14) >= abs(b))
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return (a^b)<0 ? MININT : MAXINT;
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return FixedDiv2 (a,b);
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}
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fixed_t
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FixedDiv2
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( fixed_t a,
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fixed_t b )
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{
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#if 0
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long long c;
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c = ((long long)a<<16) / ((long long)b);
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return (fixed_t) c;
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#endif
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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("FixedDiv: divide by zero");
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return (fixed_t) c;
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}
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