gtkradiant/libs/mathlib/bbox.c

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/*
Copyright (C) 1999-2007 id Software, Inc. and contributors.
For a list of contributors, see the accompanying CONTRIBUTORS file.
This file is part of GtkRadiant.
GtkRadiant 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.
GtkRadiant 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 GtkRadiant; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <float.h>
#include "mathlib.h"
void aabb_construct_for_vec3( aabb_t *aabb, const vec3_t min, const vec3_t max ){
VectorMid( min, max, aabb->origin );
VectorSubtract( max, aabb->origin, aabb->extents );
}
void aabb_update_radius( aabb_t *aabb ){
aabb->radius = VectorLength( aabb->extents );
}
void aabb_clear( aabb_t *aabb ){
aabb->origin[0] = aabb->origin[1] = aabb->origin[2] = 0;
aabb->extents[0] = aabb->extents[1] = aabb->extents[2] = -FLT_MAX;
}
void aabb_extend_by_point( aabb_t *aabb, const vec3_t point ){
int i;
vec_t min, max, displacement;
for ( i = 0; i < 3; i++ )
{
displacement = point[i] - aabb->origin[i];
if ( fabs( displacement ) > aabb->extents[i] ) {
if ( aabb->extents[i] < 0 ) { // degenerate
min = max = point[i];
}
else if ( displacement > 0 ) {
min = aabb->origin[i] - aabb->extents[i];
max = aabb->origin[i] + displacement;
}
else
{
max = aabb->origin[i] + aabb->extents[i];
min = aabb->origin[i] + displacement;
}
aabb->origin[i] = ( min + max ) * 0.5f;
aabb->extents[i] = max - aabb->origin[i];
}
}
}
void aabb_extend_by_aabb( aabb_t *aabb, const aabb_t *aabb_src ){
int i;
vec_t min, max, displacement, difference;
for ( i = 0; i < 3; i++ )
{
displacement = aabb_src->origin[i] - aabb->origin[i];
difference = aabb_src->extents[i] - aabb->extents[i];
if ( aabb->extents[i] < 0
|| difference >= fabs( displacement ) ) {
// 2nd contains 1st
aabb->extents[i] = aabb_src->extents[i];
aabb->origin[i] = aabb_src->origin[i];
}
else if ( aabb_src->extents[i] < 0
|| -difference >= fabs( displacement ) ) {
// 1st contains 2nd
continue;
}
else
{
// not contained
if ( displacement > 0 ) {
min = aabb->origin[i] - aabb->extents[i];
max = aabb_src->origin[i] + aabb_src->extents[i];
}
else
{
min = aabb_src->origin[i] - aabb_src->extents[i];
max = aabb->origin[i] + aabb->extents[i];
}
aabb->origin[i] = ( min + max ) * 0.5f;
aabb->extents[i] = max - aabb->origin[i];
}
}
}
void aabb_extend_by_vec3( aabb_t *aabb, vec3_t extension ){
VectorAdd( aabb->extents, extension, aabb->extents );
}
int aabb_intersect_point( const aabb_t *aabb, const vec3_t point ){
int i;
for ( i = 0; i < 3; i++ )
if ( fabs( point[i] - aabb->origin[i] ) >= aabb->extents[i] ) {
return 0;
}
return 1;
}
int aabb_intersect_aabb( const aabb_t *aabb, const aabb_t *aabb_src ){
int i;
for ( i = 0; i < 3; i++ )
if ( fabs( aabb_src->origin[i] - aabb->origin[i] ) > ( fabs( aabb->extents[i] ) + fabs( aabb_src->extents[i] ) ) ) {
return 0;
}
return 1;
}
int aabb_intersect_plane( const aabb_t *aabb, const float *plane ){
float fDist, fIntersect;
// calc distance of origin from plane
fDist = DotProduct( plane, aabb->origin ) + plane[3];
// trivial accept/reject using bounding sphere
if ( fabs( fDist ) > aabb->radius ) {
if ( fDist < 0 ) {
return 2; // totally inside
}
else{
return 0; // totally outside
}
}
// calc extents distance relative to plane normal
fIntersect = (vec_t)( fabs( plane[0] * aabb->extents[0] ) + fabs( plane[1] * aabb->extents[1] ) + fabs( plane[2] * aabb->extents[2] ) );
// accept if origin is less than or equal to this distance
if ( fabs( fDist ) < fIntersect ) {
return 1; // partially inside
}
else if ( fDist < 0 ) {
return 2; // totally inside
}
return 0; // totally outside
}
/*
Fast Ray-Box Intersection
by Andrew Woo
from "Graphics Gems", Academic Press, 1990
*/
#define NUMDIM 3
#define RIGHT 0
#define LEFT 1
#define MIDDLE 2
int aabb_intersect_ray( const aabb_t *aabb, const ray_t *ray, vec_t *dist ){
int inside = 1;
char quadrant[NUMDIM];
register int i;
int whichPlane;
double maxT[NUMDIM];
double candidatePlane[NUMDIM];
vec3_t coord, segment;
const float *origin = ray->origin;
const float *direction = ray->direction;
/* Find candidate planes; this loop can be avoided if
rays cast all from the eye(assume perpsective view) */
for ( i = 0; i < NUMDIM; i++ )
{
if ( origin[i] < ( aabb->origin[i] - aabb->extents[i] ) ) {
quadrant[i] = LEFT;
candidatePlane[i] = ( aabb->origin[i] - aabb->extents[i] );
inside = 0;
}
else if ( origin[i] > ( aabb->origin[i] + aabb->extents[i] ) ) {
quadrant[i] = RIGHT;
candidatePlane[i] = ( aabb->origin[i] + aabb->extents[i] );
inside = 0;
}
else
{
quadrant[i] = MIDDLE;
}
}
/* Ray origin inside bounding box */
if ( inside == 1 ) {
*dist = 0.0f;
return 1;
}
/* Calculate T distances to candidate planes */
for ( i = 0; i < NUMDIM; i++ )
{
if ( quadrant[i] != MIDDLE && direction[i] != 0. ) {
maxT[i] = ( candidatePlane[i] - origin[i] ) / direction[i];
}
else{
maxT[i] = -1.;
}
}
/* Get largest of the maxT's for final choice of intersection */
whichPlane = 0;
for ( i = 1; i < NUMDIM; i++ )
if ( maxT[whichPlane] < maxT[i] ) {
whichPlane = i;
}
/* Check final candidate actually inside box */
if ( maxT[whichPlane] < 0. ) {
return 0;
}
for ( i = 0; i < NUMDIM; i++ )
{
if ( whichPlane != i ) {
coord[i] = (vec_t)( origin[i] + maxT[whichPlane] * direction[i] );
if ( fabs( coord[i] - aabb->origin[i] ) > aabb->extents[i] ) {
return 0;
}
}
else
{
coord[i] = (vec_t)candidatePlane[i];
}
}
VectorSubtract( coord, origin, segment );
*dist = DotProduct( segment, direction );
return 1; /* ray hits box */
}
int aabb_test_ray( const aabb_t* aabb, const ray_t* ray ){
vec3_t displacement, ray_absolute;
vec_t f;
displacement[0] = ray->origin[0] - aabb->origin[0];
if ( fabs( displacement[0] ) > aabb->extents[0] && displacement[0] * ray->direction[0] >= 0.0f ) {
return 0;
}
displacement[1] = ray->origin[1] - aabb->origin[1];
if ( fabs( displacement[1] ) > aabb->extents[1] && displacement[1] * ray->direction[1] >= 0.0f ) {
return 0;
}
displacement[2] = ray->origin[2] - aabb->origin[2];
if ( fabs( displacement[2] ) > aabb->extents[2] && displacement[2] * ray->direction[2] >= 0.0f ) {
return 0;
}
ray_absolute[0] = (float)fabs( ray->direction[0] );
ray_absolute[1] = (float)fabs( ray->direction[1] );
ray_absolute[2] = (float)fabs( ray->direction[2] );
f = ray->direction[1] * displacement[2] - ray->direction[2] * displacement[1];
if ( (float)fabs( f ) > aabb->extents[1] * ray_absolute[2] + aabb->extents[2] * ray_absolute[1] ) {
return 0;
}
f = ray->direction[2] * displacement[0] - ray->direction[0] * displacement[2];
if ( (float)fabs( f ) > aabb->extents[0] * ray_absolute[2] + aabb->extents[2] * ray_absolute[0] ) {
return 0;
}
f = ray->direction[0] * displacement[1] - ray->direction[1] * displacement[0];
if ( (float)fabs( f ) > aabb->extents[0] * ray_absolute[1] + aabb->extents[1] * ray_absolute[0] ) {
return 0;
}
return 1;
}
void aabb_for_bbox( aabb_t *aabb, const bbox_t *bbox ){
int i;
vec3_t temp[3];
VectorCopy( bbox->aabb.origin, aabb->origin );
// calculate the AABB extents in local coord space from the OBB extents and axes
VectorScale( bbox->axes[0], bbox->aabb.extents[0], temp[0] );
VectorScale( bbox->axes[1], bbox->aabb.extents[1], temp[1] );
VectorScale( bbox->axes[2], bbox->aabb.extents[2], temp[2] );
for ( i = 0; i < 3; i++ ) aabb->extents[i] = (vec_t)( fabs( temp[0][i] ) + fabs( temp[1][i] ) + fabs( temp[2][i] ) );
}
void aabb_for_area( aabb_t *aabb, vec3_t area_tl, vec3_t area_br, int axis ){
aabb_clear( aabb );
aabb->extents[axis] = FLT_MAX;
aabb_extend_by_point( aabb, area_tl );
aabb_extend_by_point( aabb, area_br );
}
void aabb_for_transformed_aabb( aabb_t* dst, const aabb_t* src, const m4x4_t transform ){
VectorCopy( src->origin, dst->origin );
m4x4_transform_point( transform, dst->origin );
dst->extents[0] = (vec_t)( fabs( transform[0] * src->extents[0] )
+ fabs( transform[4] * src->extents[1] )
+ fabs( transform[8] * src->extents[2] ) );
dst->extents[1] = (vec_t)( fabs( transform[1] * src->extents[0] )
+ fabs( transform[5] * src->extents[1] )
+ fabs( transform[9] * src->extents[2] ) );
dst->extents[2] = (vec_t)( fabs( transform[2] * src->extents[0] )
+ fabs( transform[6] * src->extents[1] )
+ fabs( transform[10] * src->extents[2] ) );
}
void bbox_for_oriented_aabb( bbox_t *bbox, const aabb_t *aabb, const m4x4_t matrix, const vec3_t euler, const vec3_t scale ){
double rad[3];
double pi_180 = Q_PI / 180;
double A, B, C, D, E, F, AD, BD;
VectorCopy( aabb->origin, bbox->aabb.origin );
m4x4_transform_point( matrix, bbox->aabb.origin );
bbox->aabb.extents[0] = aabb->extents[0] * scale[0];
bbox->aabb.extents[1] = aabb->extents[1] * scale[1];
bbox->aabb.extents[2] = aabb->extents[2] * scale[2];
rad[0] = euler[0] * pi_180;
rad[1] = euler[1] * pi_180;
rad[2] = euler[2] * pi_180;
A = cos( rad[0] );
B = sin( rad[0] );
C = cos( rad[1] );
D = sin( rad[1] );
E = cos( rad[2] );
F = sin( rad[2] );
AD = A * -D;
BD = B * -D;
bbox->axes[0][0] = (vec_t)( C * E );
bbox->axes[0][1] = (vec_t)( -BD * E + A * F );
bbox->axes[0][2] = (vec_t)( AD * E + B * F );
bbox->axes[1][0] = (vec_t)( -C * F );
bbox->axes[1][1] = (vec_t)( BD * F + A * E );
bbox->axes[1][2] = (vec_t)( -AD * F + B * E );
bbox->axes[2][0] = (vec_t)D;
bbox->axes[2][1] = (vec_t)( -B * C );
bbox->axes[2][2] = (vec_t)( A * C );
aabb_update_radius( &bbox->aabb );
}
int bbox_intersect_plane( const bbox_t *bbox, const vec_t* plane ){
vec_t fDist, fIntersect;
// calc distance of origin from plane
fDist = DotProduct( plane, bbox->aabb.origin ) + plane[3];
// trivial accept/reject using bounding sphere
if ( fabs( fDist ) > bbox->aabb.radius ) {
if ( fDist < 0 ) {
return 2; // totally inside
}
else{
return 0; // totally outside
}
}
// calc extents distance relative to plane normal
fIntersect = (vec_t)( fabs( bbox->aabb.extents[0] * DotProduct( plane, bbox->axes[0] ) )
+ fabs( bbox->aabb.extents[1] * DotProduct( plane, bbox->axes[1] ) )
+ fabs( bbox->aabb.extents[2] * DotProduct( plane, bbox->axes[2] ) ) );
// accept if origin is less than this distance
if ( fabs( fDist ) < fIntersect ) {
return 1; // partially inside
}
else if ( fDist < 0 ) {
return 2; // totally inside
}
return 0; // totally outside
}