mdw@git.distorted.org.uk Git - ssr/blob - StraySrc/Libraries/Sapphire/csapph/h/fixedPt

   1 /*
   2  * fixedPt.h
   3  *
   4  * [Generated from fixedPt, 25 September 1996]
   5  */
   6
   7 #if !defined(__CC_NORCROFT) || !defined(__arm)
   8   #error You must use the Norcroft ARM Compiler for Sapphire programs
   9 #endif
  10
  11 #pragma include_only_once
  12 #pragma force_top_level
  13
  14 #ifndef __fixedPt_h
  15 #define __fixedPt_h
  16
  17 #ifndef __sapphire_h
  18   #include "sapphire.h"
  19 #endif
  20
  21 /*----- Overview ----------------------------------------------------------*
  22  *
  23  * Functions provided:
  24  *
  25  *  fxp_atan
  26  *  fxp_pol
  27  *  fxp_sin
  28  *  fxp_cos
  29  */
  30
  31 /* --- fxp_atan --- *
  32  *
  33  * On entry:    R0 == x, in 16.16 fixed point form
  34  *
  35  * On exit:     R0 == arctan x, in degrees, in 16.16 fixed point
  36  *
  37  * Use:         Calculates arctan x, hopefully fairly swiftly. The
  38  *              accuracy of the result is open to doubt, although
  39  *              it's usually good to about 3 significant figures.
  40  *              It uses a small lookup table and linear interpolation
  41  *              to calculate the result.
  42  */
  43
  44 extern routine fxp_atan;
  45
  46 /* --- fxp_pol --- *
  47  *
  48  * On entry:    R0 == x coordinate
  49  *              R1 == y coordinate
  50  *
  51  * On exit:     R0 == angle in degrees, in 16.16 form
  52  *
  53  * Use:         Calculates the angle a vector makes with the +ve x axis.
  54  *              The angle is given in degrees, rather than radians,
  55  *              although this isn't really overly significant; it just
  56  *              makes it slightly easier to work with, because it's
  57  *              bigger.
  58  *
  59  *              This routine uses the arctan table and linear
  60  *              interpolation, so it's fairly quick, but the accuracy
  61  *              of its results is restricted to about 3 significant figures.
  62  */
  63
  64 extern routine fxp_pol;
  65
  66 /* --- fxp_sin --- *
  67  *
  68  * On entry:    R0 == angle in degrees, in 16.16 form
  69  *
  70  * On exit:     R0 == sin of angle, in 16.16 form
  71  *
  72  * Use:         Calculates a sin of an angle with a degree of swiftness and
  73  *              a lot less accuracy.
  74  */
  75
  76 extern routine fxp_sin;
  77
  78 /* --- fxp_cos --- *
  79  *
  80  * On entry:    R0 == angle in degrees, in 16.16 form
  81  *
  82  * On exit:     R0 == cos of angle, in 16.16 form
  83  *
  84  * Use:         Calculates a cos of an angle with a degree of swiftness and
  85  *              a lot less accuracy.
  86  */
  87
  88 extern routine fxp_cos;
  89
  90 /*----- That's all, folks -------------------------------------------------*/
  91
  92 #endif