nuclear@29: #include <stdlib.h>
nuclear@29: 
nuclear@29: /** Generates a random number in [0, range) */
nuclear@29: static inline scalar_t frand(scalar_t range)
nuclear@29: {
nuclear@29: 	return range * (scalar_t)rand() / (scalar_t)RAND_MAX;
nuclear@29: }
nuclear@29: 
nuclear@29: /** Generates a random vector on the surface of a sphere */
nuclear@29: static inline vec3_t sphrand(scalar_t rad)
nuclear@29: {
nuclear@29: 	scalar_t u = (scalar_t)rand() / RAND_MAX;
nuclear@29: 	scalar_t v = (scalar_t)rand() / RAND_MAX;
nuclear@29: 
nuclear@29: 	scalar_t theta = 2.0 * M_PI * u;
nuclear@29: 	scalar_t phi = acos(2.0 * v - 1.0);
nuclear@29: 
nuclear@29: 	vec3_t res;
nuclear@29: 	res.x = rad * cos(theta) * sin(phi);
nuclear@29: 	res.y = rad * sin(theta) * sin(phi);
nuclear@29: 	res.z = rad * cos(phi);
nuclear@29: 	return res;
nuclear@29: }
nuclear@29: 
nuclear@29: /** linear interpolation */
nuclear@29: static inline scalar_t lerp(scalar_t a, scalar_t b, scalar_t t)
nuclear@29: {
nuclear@29: 	return a + (b - a) * t;
nuclear@29: }