1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/prototype/vmath/geom.c	Thu Jun 28 06:05:50 2012 +0300
     1.3 @@ -0,0 +1,150 @@
     1.4 +/*
     1.5 +libvmath - a vector math library
     1.6 +Copyright (C) 2004-2011 John Tsiombikas <nuclear@member.fsf.org>
     1.7 +
     1.8 +This program is free software: you can redistribute it and/or modify
     1.9 +it under the terms of the GNU Lesser General Public License as published
    1.10 +by the Free Software Foundation, either version 3 of the License, or
    1.11 +(at your option) any later version.
    1.12 +
    1.13 +This program is distributed in the hope that it will be useful,
    1.14 +but WITHOUT ANY WARRANTY; without even the implied warranty of
    1.15 +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    1.16 +GNU Lesser General Public License for more details.
    1.17 +
    1.18 +You should have received a copy of the GNU Lesser General Public License
    1.19 +along with this program.  If not, see <http://www.gnu.org/licenses/>.
    1.20 +*/
    1.21 +
    1.22 +
    1.23 +#include <math.h>
    1.24 +#include "geom.h"
    1.25 +#include "vector.h"
    1.26 +
    1.27 +plane_t plane_cons(scalar_t nx, scalar_t ny, scalar_t nz, scalar_t d)
    1.28 +{
    1.29 +	plane_t p;
    1.30 +	p.norm.x = nx;
    1.31 +	p.norm.y = ny;
    1.32 +	p.norm.z = nz;
    1.33 +	p.d = d;
    1.34 +	return p;
    1.35 +}
    1.36 +
    1.37 +plane_t plane_poly(vec3_t v0, vec3_t v1, vec3_t v2)
    1.38 +{
    1.39 +	vec3_t a, b, norm;
    1.40 +
    1.41 +	a = v3_sub(v1, v0);
    1.42 +	b = v3_sub(v2, v0);
    1.43 +	norm = v3_cross(a, b);
    1.44 +	norm = v3_normalize(norm);
    1.45 +
    1.46 +	return plane_ptnorm(v0, norm);
    1.47 +}
    1.48 +
    1.49 +plane_t plane_ptnorm(vec3_t pt, vec3_t normal)
    1.50 +{
    1.51 +	plane_t plane;
    1.52 +
    1.53 +	plane.norm = normal;
    1.54 +	plane.d = v3_dot(pt, normal);
    1.55 +
    1.56 +	return plane;
    1.57 +}
    1.58 +
    1.59 +plane_t plane_invert(plane_t p)
    1.60 +{
    1.61 +	p.norm = v3_neg(p.norm);
    1.62 +	p.d = -p.d;
    1.63 +	return p;
    1.64 +}
    1.65 +
    1.66 +scalar_t plane_signed_dist(plane_t plane, vec3_t pt)
    1.67 +{
    1.68 +	vec3_t pp = plane_point(plane);
    1.69 +	vec3_t pptopt = v3_sub(pt, pp);
    1.70 +	return v3_dot(pptopt, plane.norm);
    1.71 +}
    1.72 +
    1.73 +scalar_t plane_dist(plane_t plane, vec3_t pt)
    1.74 +{
    1.75 +	return fabs(plane_signed_dist(plane, pt));
    1.76 +}
    1.77 +
    1.78 +vec3_t plane_point(plane_t plane)
    1.79 +{
    1.80 +	return v3_scale(plane.norm, plane.d);
    1.81 +}
    1.82 +
    1.83 +int plane_ray_intersect(ray_t ray, plane_t plane, scalar_t *pos)
    1.84 +{
    1.85 +	vec3_t pt, orig_to_pt;
    1.86 +	scalar_t ndotdir;
    1.87 +
    1.88 +	pt = plane_point(plane);
    1.89 +	ndotdir = v3_dot(plane.norm, ray.dir);
    1.90 +
    1.91 +	if(fabs(ndotdir) < 1e-7) {
    1.92 +		return 0;
    1.93 +	}
    1.94 +
    1.95 +	if(pos) {
    1.96 +		orig_to_pt = v3_sub(pt, ray.origin);
    1.97 +		*pos = v3_dot(plane.norm, orig_to_pt) / ndotdir;
    1.98 +	}
    1.99 +	return 1;
   1.100 +}
   1.101 +
   1.102 +sphere_t sphere_cons(scalar_t x, scalar_t y, scalar_t z, scalar_t rad)
   1.103 +{
   1.104 +	sphere_t sph;
   1.105 +	sph.pos.x = x;
   1.106 +	sph.pos.y = y;
   1.107 +	sph.pos.z = z;
   1.108 +	sph.rad = rad;
   1.109 +	return sph;
   1.110 +}
   1.111 +
   1.112 +int sphere_ray_intersect(ray_t ray, sphere_t sph, scalar_t *pos)
   1.113 +{
   1.114 +	scalar_t a, b, c, d, sqrt_d, t1, t2, t;
   1.115 +
   1.116 +	a = v3_dot(ray.dir, ray.dir);
   1.117 +	b = 2.0 * ray.dir.x * (ray.origin.x - sph.pos.x) +
   1.118 +		2.0 * ray.dir.y * (ray.origin.y - sph.pos.y) +
   1.119 +		2.0 * ray.dir.z * (ray.origin.z - sph.pos.z);
   1.120 +	c = v3_dot(sph.pos, sph.pos) + v3_dot(ray.origin, ray.origin) +
   1.121 +		2.0 * v3_dot(v3_neg(sph.pos), ray.origin) - sph.rad * sph.rad;
   1.122 +
   1.123 +	d = b * b - 4.0 * a * c;
   1.124 +	if(d < 0.0) {
   1.125 +		return 0;
   1.126 +	}
   1.127 +
   1.128 +	sqrt_d = sqrt(d);
   1.129 +	t1 = (-b + sqrt_d) / (2.0 * a);
   1.130 +	t2 = (-b - sqrt_d) / (2.0 * a);
   1.131 +
   1.132 +	if(t1 < 1e-7 || t1 > 1.0) {
   1.133 +		t1 = t2;
   1.134 +	}
   1.135 +	if(t2 < 1e-7 || t2 > 1.0) {
   1.136 +		t2 = t1;
   1.137 +	}
   1.138 +	t = t1 < t2 ? t1 : t2;
   1.139 +
   1.140 +	if(t < 1e-7 || t > 1.0) {
   1.141 +		return 0;
   1.142 +	}
   1.143 +
   1.144 +	if(pos) {
   1.145 +		*pos = t;
   1.146 +	}
   1.147 +	return 1;
   1.148 +}
   1.149 +
   1.150 +int sphere_sphere_intersect(sphere_t sph1, sphere_t sph2, scalar_t *pos, scalar_t *rad)
   1.151 +{
   1.152 +	return -1;
   1.153 +}