1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/fixed_point.h	Sun Sep 22 02:21:30 2013 +0300
     1.3 @@ -0,0 +1,106 @@
     1.4 +#ifndef FIXED_POINT_H_
     1.5 +#define FIXED_POINT_H_
     1.6 +
     1.7 +#include "inttypes.h"
     1.8 +
     1.9 +#ifdef DBG_USE_FLOAT
    1.10 +typedef float fixed;
    1.11 +#else
    1.12 +typedef int32_t fixed;
    1.13 +#endif
    1.14 +
    1.15 +/* valid choices for DECIMAL_BITS
    1.16 + *      8: for fixed point 24:8
    1.17 + *     16: for fixed point 16:16
    1.18 + */
    1.19 +#define DECIMAL_BITS	16
    1.20 +
    1.21 +#if DECIMAL_BITS == 8
    1.22 +#define FIXED_SHIFT		8
    1.23 +#define FLT_SCALE		256.0f
    1.24 +#define FRAC_MASK		0xff
    1.25 +#else	/* DECIMAL_BITS == 16 */
    1.26 +#define FIXED_SHIFT		16
    1.27 +#define FLT_SCALE		65536.0f
    1.28 +#define FRAC_MASK		0xffff
    1.29 +#endif	/* DECIMAL_BITS */
    1.30 +
    1.31 +/*extern const fixed fixed_zero;
    1.32 +extern const fixed fixed_one;
    1.33 +extern const fixed fixed_half;
    1.34 +extern const fixed fixed_tenth;
    1.35 +extern const fixed fixed_255;*/
    1.36 +
    1.37 +#ifdef DBG_USE_FLOAT
    1.38 +/* ------- debug mode, use floating point -------- */
    1.39 +#define FIXED_INT_PART(n)	((int)(n))
    1.40 +#define FIXED_FRAC_PART(n)	((n) > 0.0f ? (FIXED_INT_PART(n) - (n)) : (FIXED_INT_PART(n) + (n)))
    1.41 +#define FIXED_ROUND(n)		FIXED_INT_PART((n) >= 0.0 ? (n) + 0.5f : (n) - 0.5f)
    1.42 +
    1.43 +#define FIXED_TO_FLOAT(n)	(n)
    1.44 +#define FLOAT_TO_FIXED(n)	(n)
    1.45 +#define INT_TO_FIXED(n)		((float)(n))
    1.46 +
    1.47 +#define FIXED_EPSILON		(1e-6)
    1.48 +
    1.49 +#else	/* ---- really fixed point ---- */
    1.50 +
    1.51 +#define FIXED_INT_PART(n)	((n) >> FIXED_SHIFT)
    1.52 +#define FIXED_FRAC_PART(n)	((n) & FRAC_MASK)
    1.53 +#define FIXED_ROUND(n)		FIXED_INT_PART((n) >= 0 ? (n) + fixedf(0.5) : (n) - fixedf(0.5))
    1.54 +/*#define FIXED_ROUND(n)		FIXED_INT_PART(n)*/
    1.55 +
    1.56 +#define FIXED_TO_FLOAT(n)	(float)((n) / FLT_SCALE)
    1.57 +#define FLOAT_TO_FIXED(n)	(fixed)((n) * FLT_SCALE)
    1.58 +#define INT_TO_FIXED(n)		(fixed)((n) << FIXED_SHIFT)
    1.59 +
    1.60 +#define FIXED_EPSILON		(1)
    1.61 +
    1.62 +#endif
    1.63 +
    1.64 +
    1.65 +#define fixed_int(n)		FIXED_INT_PART(n)
    1.66 +#define fixed_frac(n)		FIXED_FRAC_PART(n)
    1.67 +#define fixed_float(n)		FIXED_TO_FLOAT(n)
    1.68 +#define fixed_round(n)		FIXED_ROUND(n)
    1.69 +
    1.70 +#define fixedf(n)			FLOAT_TO_FIXED(n)
    1.71 +#define fixedi(n)			INT_TO_FIXED(n)
    1.72 +
    1.73 +#define fixed_add(n1, n2)	((n1) + (n2))
    1.74 +#define fixed_sub(n1, n2)	((n1) - (n2))
    1.75 +
    1.76 +
    1.77 +
    1.78 +#ifdef DBG_USE_FLOAT
    1.79 +
    1.80 +#define fixed_mul(n1, n2)	((n1) * (n2))
    1.81 +#define fixed_div(n1, n2)	((n1) / (n2))
    1.82 +
    1.83 +#define fixed_sin(x)	(fixed)sin(x)
    1.84 +#define fixed_cos(x)	(fixed)cos(x)
    1.85 +
    1.86 +#else
    1.87 +
    1.88 +#if DECIMAL_BITS == 8
    1.89 +#define fixed_mul(n1, n2)	(fixed)((n1) * (n2) >> FIXED_SHIFT)
    1.90 +#define fixed_div(n1, n2)	(((n1) << FIXED_SHIFT) / (n2))
    1.91 +#else
    1.92 +#define fixed_div(n1, n2)	(((int64_t)(n1) << FIXED_SHIFT) / (int64_t)(n2))
    1.93 +#define fixed_mul(n1, n2)	(((n1) >> 8) * ((n2) >> 8))
    1.94 +#endif	/* DECIMAL_BITS */
    1.95 +
    1.96 +#ifdef __cplusplus
    1.97 +extern "C" {
    1.98 +#endif
    1.99 +
   1.100 +fixed fixed_sin(fixed angle);
   1.101 +fixed fixed_cos(fixed angle);
   1.102 +
   1.103 +#ifdef __cplusplus
   1.104 +}
   1.105 +#endif
   1.106 +
   1.107 +#endif
   1.108 +
   1.109 +#endif	/* FIXED_POINT_H_ */