1 files changed, 94 insertions, 0 deletions

diff --git a/apps/plugins/doom/m_fixed.h b/apps/plugins/doom/m_fixed.h
new file mode 100644
index 0000000000..3c922e8f50
--- /dev/null
+++ b/apps/plugins/doom/m_fixed.h
@@ -0,0 +1,94 @@
+// Emacs style mode select   -*- C++ -*-
+//-----------------------------------------------------------------------------
+//
+// $Id$
+//
+// Copyright (C) 1993-1996 by id Software, Inc.
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License
+// as published by the Free Software Foundation; either version 2
+// of the License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// DESCRIPTION:
+// Fixed point arithemtics, implementation.
+//
+//-----------------------------------------------------------------------------
+
+
+#ifndef __M_FIXED__
+#define __M_FIXED__
+
+
+#ifdef __GNUG__
+#pragma interface
+#endif
+
+#include "doomtype.h"
+#include "rockmacros.h"
+
+//
+// Fixed point, 32bit as 16.16.
+//
+#define FRACBITS  16
+#define FRACUNIT  (1<<FRACBITS)
+
+#define D_abs(x) ({fixed_t _t = (x), _s = _t >> (8*sizeof _t-1); (_t^_s)-_s;})
+
+typedef int fixed_t;
+
+inline static int FixedMul( int a, int b )
+{
+#if defined(CPU_COLDFIRE) && !defined(SIMULATOR)
+   // Code contributed by Thom Johansen
+   register int result;
+   asm volatile (
+      "mac.l   %[x],%[y],%%acc0  \n"   /* multiply */
+      "move.l  %[y],%%d2         \n"
+      "mulu.l  %[x],%%d2         \n"   /* get lower half, avoid emac stall */
+      "movclr.l %%acc0,%[result] \n"   /* get higher half */
+      "moveq.l #15,%%d1          \n"
+      "asl.l   %%d1,%[result]    \n"   /* hi <<= 15, plus one free */
+      "moveq.l #16,%%d1          \n"
+      "lsr.l   %%d1,%%d2         \n"   /* (unsigned)lo >>= 16 */
+      "or.l    %%d2 ,%[result]   \n"   /* combine result */
+   : /* outputs */
+      [result]"=&d"(result)
+   : /* inputs */
+      [x] "d" (a),
+      [y] "d" (b)
+   : /* clobbers */
+      "d1", "d2"
+   );
+   return result;
+#else
+   return (fixed_t)((long long) a*b >> FRACBITS);
+#endif
+}
+
+inline static fixed_t FixedDiv( fixed_t  a, fixed_t  b )
+{
+   return (D_abs(a)>>14) >= D_abs(b) ? ((a^b)>>31) ^ MAXINT :
+          (fixed_t)(((long long) a << FRACBITS) / b);
+}
+
+/* CPhipps -
+ * FixedMod - returns a % b, guaranteeing 0<=a<b
+ * (notice that the C standard for % does not guarantee this)
+ */
+
+inline static fixed_t FixedMod(fixed_t a, fixed_t b)
+{
+   if (b & (b-1)) {
+      fixed_t r = a % b;
+      return ((r<0) ? r+b : r);
+   } else
+      return (a & (b-1));
+}
+
+#endif