obs-studio/libobs/graphics/plane.c

163 lines
4.0 KiB
C

/******************************************************************************
Copyright (C) 2013 by Hugh Bailey <obs.jim@gmail.com>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
******************************************************************************/
#include "../util/c99defs.h"
#include "matrix3.h"
#include "plane.h"
void plane_from_tri(struct plane *dst,
const struct vec3 *v1,
const struct vec3 *v2,
const struct vec3 *v3)
{
struct vec3 temp;
vec3_sub(&temp, v2, v1);
vec3_sub(&dst->dir, v3, v1);
vec3_cross(&dst->dir, &temp, &dst->dir);
vec3_norm(&dst->dir, &dst->dir);
dst->dist = vec3_dot(v1, &dst->dir);
}
void plane_transform(struct plane *dst, const struct plane *p,
const struct matrix4 *m)
{
struct vec3 temp;
vec3_zero(&temp);
vec3_transform(&dst->dir, &p->dir, m);
vec3_norm(&dst->dir, &dst->dir);
vec3_transform(&temp, &temp, m);
dst->dist = p->dist - vec3_dot(&dst->dir, &temp);
}
void plane_transform3x4(struct plane *dst, const struct plane *p,
const struct matrix3 *m)
{
struct vec3 temp;
vec3_transform3x4(&dst->dir, &p->dir, m);
vec3_norm(&dst->dir, &dst->dir);
vec3_transform3x4(&temp, &m->t, m);
dst->dist = p->dist - vec3_dot(&dst->dir, &temp);
}
bool plane_intersection_ray(const struct plane *p, const struct vec3 *orig,
const struct vec3 *dir, float *t)
{
float c = vec3_dot(&p->dir, dir);
if (fabsf(c) < EPSILON) {
*t = 0.0f;
return false;
} else {
*t = (p->dist - vec3_dot(&p->dir, orig)) / c;
return true;
}
}
bool plane_intersection_line(const struct plane *p, const struct vec3 *v1,
const struct vec3 *v2, float *t)
{
float p1_dist, p2_dist, p1_abs_dist, dist2;
bool p1_over, p2_over;
p1_dist = vec3_plane_dist(v1, p);
p2_dist = vec3_plane_dist(v2, p);
if (close_float(p1_dist, 0.0f, EPSILON)) {
if (close_float(p2_dist, 0.0f, EPSILON))
return false;
*t = 0.0f;
return true;
} else if (close_float(p2_dist, 0.0f, EPSILON)) {
*t = 1.0f;
return true;
}
p1_over = (p1_dist > 0.0f);
p2_over = (p2_dist > 0.0f);
if (p1_over == p2_over)
return false;
p1_abs_dist = fabsf(p1_dist);
dist2 = p1_abs_dist + fabsf(p2_dist);
if (dist2 < EPSILON)
return false;
*t = p1_abs_dist / dist2;
return true;
}
bool plane_tri_inside(const struct plane *p,
const struct vec3 *v1,
const struct vec3 *v2,
const struct vec3 *v3,
float precision)
{
/* bit 1: part or all is behind the plane */
/* bit 2: part or all is in front of the plane */
int sides = 0;
float d1 = vec3_plane_dist(v1, p);
float d2 = vec3_plane_dist(v2, p);
float d3 = vec3_plane_dist(v3, p);
if (d1 >= precision)
sides = 2;
else if (d1 <= -precision)
sides = 1;
if (d2 >= precision)
sides |= 2;
else if (d2 <= -precision)
sides |= 1;
if (d3 >= precision)
sides |= 2;
else if (d3 <= -precision)
sides |= 1;
return sides;
}
bool plane_line_inside(const struct plane *p, const struct vec3 *v1,
const struct vec3 *v2, float precision)
{
/* bit 1: part or all is behind the plane */
/* bit 2: part or all is in front of the plane */
int sides = 0;
float d1 = vec3_plane_dist(v1, p);
float d2 = vec3_plane_dist(v2, p);
if (d1 >= precision)
sides = 2;
else if (d1 <= -precision)
sides = 1;
if (d2 >= precision)
sides |= 2;
else if (d2 <= -precision)
sides |= 1;
return sides;
}