src » librt

fixpt.h File Reference

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Data Structures

struct  fixpt

Defines

#define FIXPT_H   seen
#define FIXPT_SCALE   ((1<<28)-1)
#define FIXPT_FLOAT(fp, fl)
#define FLOAT_FIXPT(fp)   ( fp.i + ((double)fp.f)/FIXPT_SCALE )
#define FIXPT_NORMALIZE(fp)
#define FIXPT_ROUND(fp)
#define FIXPT_ADD2(o, a, b)
#define PR_FIX(str, fp)   bu_log("%s = %2d+x%8.8x\n", str, fp.i, fp.f )
#define PR_FIX2(str, fp)

Detailed Description

Data structures and macros for dealing with integer-based fixed point math.

These macros use integer instructions for a special "fixed point" format. The fractional part is stored in 28-bit integer form, to prevent roundoff errors.

Author - Michael John Muuss

Source - SECAD/VLD Computing Consortium, Bldg 394 The U. S. Army Ballistic Research Laboratory Aberdeen Proving Ground, Maryland 21005

Header
/cvsroot/brlcad/brlcad/src/librt/fixpt.h,v 14.9 2006/01/18 06:46:17 brlcad Exp

Definition in file fixpt.h.

Define Documentation

#define FIXPT_H   seen
 

Definition at line 47 of file fixpt.h.

#define FIXPT_SCALE   ((1<<28)-1)
 

Definition at line 49 of file fixpt.h.

#define FIXPT_FLOAT (  fp,
fl   ) 
 

Value:

{ \
        register double d = fl; \
        fp.f = (d - (fp.i = (int)d)) * FIXPT_SCALE; \
        FIXPT_NORMALIZE(fp); }

Definition at line 55 of file fixpt.h.

#define FLOAT_FIXPT (  fp   )     ( fp.i + ((double)fp.f)/FIXPT_SCALE )
 

Definition at line 60 of file fixpt.h.

#define FIXPT_NORMALIZE (  fp   ) 
 

Value:

{ \
        if( fp.f < 0 )  { \
                do {  \
                        fp.i--; \
                        fp.f += FIXPT_SCALE; \
                } while( fp.f < 0 ); \
        } else if( fp.f >= FIXPT_SCALE )  { \
                do { \
                        fp.i++; \
                        fp.f -= FIXPT_SCALE; \
                } while( fp.f >= FIXPT_SCALE ); \
        } }

Definition at line 62 of file fixpt.h.

#define FIXPT_ROUND (  fp   ) 
 

Value:

{ \
        if( fp.f > FIXPT_SCALE/2 )  { \
                if( fp.i >= 0 ) fp.i++; \
                else fp.i--; \
        }  fp.f = 0; }

Definition at line 75 of file fixpt.h.

#define FIXPT_ADD2 (  o,
a,
b   ) 
 

Value:

{\
        o.i = a.i + b.i; \
        o.f = a.f + b.f; \
        FIXPT_NORMALIZE(o); }

Definition at line 81 of file fixpt.h.

#define PR_FIX (  str,
fp   )     bu_log("%s = %2d+x%8.8x\n", str, fp.i, fp.f )
 

Definition at line 86 of file fixpt.h.

#define PR_FIX2 (  str,
fp   ) 
 

Value:

bu_log("%s = (%2d+x%8.8x,%2d+x%8.8x)\n", \
                                str, fp[0].i, fp[0].f, fp[1].i, fp[1].f )

Definition at line 88 of file fixpt.h.

Generated on Mon Sep 18 01:25:05 2006 for BRL-CAD by  doxygen 1.4.6