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Update painting.c with new storage method for floating point operations.

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svn path=/trunk/; revision=26772
This commit is contained in:
James Tabor 2007-05-14 03:18:42 +00:00
parent ac6836eee1
commit 5bca352f7d
1 changed files with 66 additions and 14 deletions
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80
reactos/dll/win32/gdi32/objects/painting.c
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@ -1,15 +1,66 @@
#include "precomp.h"
/* the following deal with IEEE single-precision numbers */
#define EXCESS 126L
#define SIGNBIT 0x80000000L
#define SIGN(fp) ((fp) & SIGNBIT)
#define EXP(fp) (((fp) >> 23L) & 0xFF)
#define MANT(fp) ((fp) & 0x7FFFFFL)
#define PACK(s,e,m) ((s) | ((e) << 23L) | (m))
typedef union
// Sames as lrintf.
#ifdef __GNUC__
#define FLOAT_TO_INT(in,out) \
__asm__ __volatile__ ("fistpl %0" : "=m" (out) : "t" (in) : "st");
#else
#define FLOAT_TO_INT(in,out) \
__asm fld in \
__asm fistp out
#endif
LONG
FASTCALL
EFtoF( EFLOAT_S * efp)
{
FLOAT f;
ULONG l;
} gxf_long;
long Mant, Exp, Sign = 0;
#define XFPMANT(fp) ((fp.l) & 0x7fffff)
#define XFPEXP(fp) ((fp.l) >> 23) & 0xff)
#define XFPBUILD(e, m) (((e << 23) & 0x7f800000) | (m & 0x7fffff))
if (!efp->lMant) return 0;
Mant = efp->lMant;
Exp = efp->lExp;
Sign = SIGN(Mant);
//// M$ storage emulation
Mant = ((Mant & 0x3fffffff) >> 7);
Exp += (1 - EXCESS);
////
Mant = MANT(Mant);
return PACK(Sign, Exp, Mant);
}
VOID
FASTCALL
FtoEF( EFLOAT_S * efp, FLOATL f)
{
long Mant, Exp;
gxf_long worker;
#ifdef _X86_
worker.l = f; // It's a float stored in a long.
#else
worker.f = f;
#endif
Exp = EXP(worker.l);
Mant = MANT(worker.l);
//// M$ storage emulation
Mant = ((Mant << 7) | 0x40000000 | SIGN(worker.l));
Exp -= (1 - EXCESS);
////
efp->lMant = Mant;
efp->lExp = Exp;
}
VOID FASTCALL
@ -21,15 +72,16 @@ CoordCnvP(MATRIX_S * mx, LPPOINT Point)
x = (FLOAT)Point->x;
y = (FLOAT)Point->y;
a.l = XFPBUILD( mx->efM11.lExp, mx->efM11.lMant);
b.l = XFPBUILD( mx->efM21.lExp, mx->efM21.lMant);
a.l = EFtoF( &mx->efM11 );
b.l = EFtoF( &mx->efM21 );
x = x * a.f + y * b.f + mx->fxDx;
Point->x = x * a.f + y * b.f + mx->fxDx;
a.l = EFtoF( &mx->efM12 );
b.l = EFtoF( &mx->efM22 );
y = x * a.f + y * b.f + mx->fxDy;
a.l = XFPBUILD( mx->efM12.lExp, mx->efM12.lMant);
b.l = XFPBUILD( mx->efM22.lExp, mx->efM22.lMant);
Point->y = x * a.f + y * b.f + mx->fxDy;
FLOAT_TO_INT(x, Point->x );
FLOAT_TO_INT(y, Point->y );
}