/********************************************************************\
**                             _________________________________    **
**   A n t h o n y            |________    __    __    _________|   **
**                                     |  |o_|  |o_|  |             **
**           T h y s s e n           __|   __    __   |__           **
**                                __|   __|  |  |  |__   |__        **
**  `` Dragon Computing! ''    __|   __|     |  |     |__   |__     **
**                            |_____|        |__|        |_____|    **
**                                                                  **
\********************************************************************/

/*  Fixed point math routines - with separate routines for trig functions */

/*  definitions for normal fixpoint math   */

#define fixpoint   LONG

#define  PLACE                  8    /* binary point digits to provide */
#define  fix1                 256    /*  1 << PLACE - a value of one */
#define  HPLACE                 4    /* place divided by two */

/* interger conversions */
#define  inttofix(i)     ((i) << PLACE)
#define  fixtoint(f)     ((f) >> PLACE)

/* floating to fix point - floats can't handle bit operations */
#define  flttofix(F)     ( (fixpoint) ((F) * fix1) )
#define  fixtoflt(F)     ( ((float)(F)) / fix1 )

/* fixpoint multiplys and divides */
#define  fixmul(f1,f2)   ( ((f1) * (f2)) >> PLACE )
#define  fixdiv(f1,f2)   ( ((f1) << PLACE) / (f2) )
/* this multiply has a larger maximum result without overflow
  but with loss of precision of values multiplied              */
#define  fixmul2(f1,f2)  ( ((f1) >> HPLACE) * ((f2) >> HPLACE) )


/*              definitions for unit values
**    These definitions provide greater precision for fixpoint numbers
**  of the range 0 to 1, as is the case for the result of SIN() and COS()
**  say from table lookup, or for unit vectors and matrix rotations
**  as in vector graphics / calculations. The multiply provided below
**  can be used for any fixpoint number to return a number in the same
**  scale. IE   (if u = unitpoint and f = any fixpoint type )
**      f = unitmul( f , u )     =>      i = unitmul( i , u )
**                               =>      u = unitmul( u , u )
**    Largest result possible for unitpoint * fixpoint =
**              2^( 31 - UNIT_PLACE - PLACE )
**     =>   2^( 31 - 15 - 8 )   =>   2 ^ 8   =>   256.0 fixpoint
*/

#define  UNIT_PLACE       15
#define  unit1         32768

#define flttounit(F)      ( (fixpoint) ((F) * unit1) )
#define unitmul(f1,f2)    ( ((f1) * (f2)) >> UNIT_PLACE )