nuclear@25: #ifndef FIXED_POINT_H_
nuclear@25: #define FIXED_POINT_H_
nuclear@25: 
nuclear@25: #include "inttypes.h"
nuclear@25: 
nuclear@25: #ifdef DBG_USE_FLOAT
nuclear@25: typedef float fixed;
nuclear@25: #else
nuclear@25: typedef int32_t fixed;
nuclear@25: #endif
nuclear@25: 
nuclear@25: /* valid choices for DECIMAL_BITS
nuclear@25:  *      8: for fixed point 24:8
nuclear@25:  *     16: for fixed point 16:16
nuclear@25:  */
nuclear@25: #define DECIMAL_BITS	16
nuclear@25: 
nuclear@25: #if DECIMAL_BITS == 8
nuclear@25: #define FIXED_SHIFT		8
nuclear@25: #define FLT_SCALE		256.0f
nuclear@25: #define FRAC_MASK		0xff
nuclear@25: #else	/* DECIMAL_BITS == 16 */
nuclear@25: #define FIXED_SHIFT		16
nuclear@25: #define FLT_SCALE		65536.0f
nuclear@25: #define FRAC_MASK		0xffff
nuclear@25: #endif	/* DECIMAL_BITS */
nuclear@25: 
nuclear@25: /*extern const fixed fixed_zero;
nuclear@25: extern const fixed fixed_one;
nuclear@25: extern const fixed fixed_half;
nuclear@25: extern const fixed fixed_tenth;
nuclear@25: extern const fixed fixed_255;*/
nuclear@25: 
nuclear@25: #ifdef DBG_USE_FLOAT
nuclear@25: /* ------- debug mode, use floating point -------- */
nuclear@25: #define FIXED_INT_PART(n)	((int)(n))
nuclear@25: #define FIXED_FRAC_PART(n)	((n) > 0.0f ? (FIXED_INT_PART(n) - (n)) : (FIXED_INT_PART(n) + (n)))
nuclear@25: #define FIXED_ROUND(n)		FIXED_INT_PART((n) >= 0.0 ? (n) + 0.5f : (n) - 0.5f)
nuclear@25: 
nuclear@25: #define FIXED_TO_FLOAT(n)	(n)
nuclear@25: #define FLOAT_TO_FIXED(n)	(n)
nuclear@25: #define INT_TO_FIXED(n)		((float)(n))
nuclear@25: 
nuclear@25: #define FIXED_EPSILON		(1e-6)
nuclear@25: 
nuclear@25: #else	/* ---- really fixed point ---- */
nuclear@25: 
nuclear@25: #define FIXED_INT_PART(n)	((n) >> FIXED_SHIFT)
nuclear@25: #define FIXED_FRAC_PART(n)	((n) & FRAC_MASK)
nuclear@25: #define FIXED_ROUND(n)		FIXED_INT_PART((n) >= 0 ? (n) + fixedf(0.5) : (n) - fixedf(0.5))
nuclear@25: /*#define FIXED_ROUND(n)		FIXED_INT_PART(n)*/
nuclear@25: 
nuclear@25: #define FIXED_TO_FLOAT(n)	(float)((n) / FLT_SCALE)
nuclear@25: #define FLOAT_TO_FIXED(n)	(fixed)((n) * FLT_SCALE)
nuclear@25: #define INT_TO_FIXED(n)		(fixed)((n) << FIXED_SHIFT)
nuclear@25: 
nuclear@25: #define FIXED_EPSILON		(1)
nuclear@25: 
nuclear@25: #endif
nuclear@25: 
nuclear@25: 
nuclear@25: #define fixed_int(n)		FIXED_INT_PART(n)
nuclear@25: #define fixed_frac(n)		FIXED_FRAC_PART(n)
nuclear@25: #define fixed_float(n)		FIXED_TO_FLOAT(n)
nuclear@25: #define fixed_round(n)		FIXED_ROUND(n)
nuclear@25: 
nuclear@25: #define fixedf(n)			FLOAT_TO_FIXED(n)
nuclear@25: #define fixedi(n)			INT_TO_FIXED(n)
nuclear@25: 
nuclear@25: #define fixed_add(n1, n2)	((n1) + (n2))
nuclear@25: #define fixed_sub(n1, n2)	((n1) - (n2))
nuclear@25: 
nuclear@25: 
nuclear@25: 
nuclear@25: #ifdef DBG_USE_FLOAT
nuclear@25: 
nuclear@25: #define fixed_mul(n1, n2)	((n1) * (n2))
nuclear@25: #define fixed_div(n1, n2)	((n1) / (n2))
nuclear@25: 
nuclear@25: #define fixed_sin(x)	(fixed)sin(x)
nuclear@25: #define fixed_cos(x)	(fixed)cos(x)
nuclear@25: 
nuclear@25: #else
nuclear@25: 
nuclear@25: #if DECIMAL_BITS == 8
nuclear@25: #define fixed_mul(n1, n2)	(fixed)((n1) * (n2) >> FIXED_SHIFT)
nuclear@25: #define fixed_div(n1, n2)	(((n1) << FIXED_SHIFT) / (n2))
nuclear@25: #else
nuclear@27: #define fixed_div(n1, n2)	(((n2) >> 8) ? (((n1) << 8) / ((n2) >> 8)) : (n1))
nuclear@25: #define fixed_mul(n1, n2)	(((n1) >> 8) * ((n2) >> 8))
nuclear@25: #endif	/* DECIMAL_BITS */
nuclear@25: 
nuclear@25: #ifdef __cplusplus
nuclear@25: extern "C" {
nuclear@25: #endif
nuclear@25: 
nuclear@25: fixed fixed_sin(fixed angle);
nuclear@25: fixed fixed_cos(fixed angle);
nuclear@25: 
nuclear@25: #ifdef __cplusplus
nuclear@25: }
nuclear@25: #endif
nuclear@25: 
nuclear@25: #endif
nuclear@25: 
nuclear@25: #endif	/* FIXED_POINT_H_ */