blitz3d/blitz3d/collision.cpp

362 lines
8.1 KiB
C++

#include "std.h"
#include "collision.h"
const float COLLISION_EPSILON=.001f;
/*
//
// OLD VERSION
//
bool Collision::sphereCollide( const Line &line,float radius,const Vector &dest,float dest_radius ){
radius+=dest_radius;
Line l( line.o-dest,line.d );
float a=l.d.dot(l.d);
if( !a ) return false;
float b=l.o.dot(l.d)*2;
float c=l.o.dot(l.o)-radius*radius;
float d=b*b-4*a*c;
if( d<0 ) return false;
float t1=(-b+sqrt(d))/(2*a);
float t2=(-b-sqrt(d))/(2*a);
float t=t1<t2 ? t1 : t2;
if( t<0 || t>=time ) return false;
time=t;
normal=(l*t).normalized();
return true;
}
bool Collision::sphereCollide( const Line &line,float radius,const Vector &dest,const Vector &radii ){
radius+=radii.x;
Line l( line.o-dest,line.d );
// float y_scale=1;
// if( radii.x!=radii.y ){
// y_scale=radii.x/radii.y;
// l.o.y*=y_scale;
// l.d.y*=y_scale;
// }
float a=l.d.dot(l.d);
if( !a ) return false;
float b=l.o.dot(l.d)*2;
float c=l.o.dot(l.o)-radius*radius;
float d=b*b-4*a*c;
if( d<0 ) return false;
float t1=(-b+sqrt(d))/(2*a);
float t2=(-b-sqrt(d))/(2*a);
float t=t1<t2 ? t1 : t2;
if( t<0 || t>=time ) return false;
time=t;
normal=(l*t).normalized();
return true;
}
//v0,v1 = edge verts
//pn = poly normal
//en = edge normal
static bool edgeTest( const Vector &v0,const Vector &v1,const Vector &pn,const Vector &en,const Line &line,float radius,Collision *curr_coll ){
Matrix tm=~Matrix( en,(v1-v0).normalized(),pn );
Vector sv=tm*(line.o-v0),dv=tm*(line.o+line.d-v0);
Line l( sv,dv-sv );
//do cylinder test...
float a,b,c,d,t1,t2,t;
a=(l.d.x*l.d.x+l.d.z*l.d.z);
if( !a ) return false; //ray parallel to cylinder
b=(l.o.x*l.d.x+l.o.z*l.d.z)*2;
c=(l.o.x*l.o.x+l.o.z*l.o.z)-radius*radius;
d=b*b-4*a*c;
if( d<0 ) return false; //ray misses cylinder
t1=(-b+sqrt(d))/(2*a);
t2=(-b-sqrt(d))/(2*a);
t=t1<t2 ? t1 : t2;
if( t>curr_coll->time ) return false; //intersects too far away
Vector i=l*t,p;
if( i.y>v0.distance(v1) ) return false; //intersection above cylinder
if( i.y>=0 ){
if( t<0 ) return false;
p.y=i.y;
}else{
//below bottom of cylinder...do sphere test...
a=l.d.dot(l.d);
if( !a ) return false; //ray parallel to sphere
b=l.o.dot(l.d)*2;
c=l.o.dot(l.o)-radius*radius;
d=b*b-4*a*c;
if( d<0 ) return false; //ray misses sphere
t1=(-b+sqrt(d))/(2*a);
t2=(-b-sqrt(d))/(2*a);
t=t1<t2 ? t1 : t2;
if( t<0 || t>curr_coll->time ) return false; //intersects behind or too far away
i=l*t;
}
curr_coll->time=t;
curr_coll->normal=~tm*(i-p);
curr_coll->normal.normalize();
return true;
}
bool Collision::triangleCollide( const Line &line,float radius,const Vector &v0,const Vector &v1,const Vector &v2 ){
//triangle plane
Plane p( v0,v1,v2 );
if( p.n.dot( line.d )>=0 ) return false;
//intersection time
Plane tp=p;tp.d-=radius;
float t=tp.t_intersect( line );
if( t>time ) return false;
//intersection point
Plane p0( v0+p.n,v1,v0 ),p1( v1+p.n,v2,v1 ),p2( v2+p.n,v0,v2 );
if( t>=0 ){
Vector i=line*t;
if( p0.distance(i)>=0 && p1.distance(i)>=0 && p2.distance(i)>=0 ){
time=t;
normal=p.n;
return true;
}
}
if( radius<=0 ) return false;
return
edgeTest( v0,v1,p.n,p0.n,line,radius,this )|
edgeTest( v1,v2,p.n,p1.n,line,radius,this )|
edgeTest( v2,v0,p.n,p2.n,line,radius,this );
}
bool Collision::boxCollide( const Line &line,float radius,const Box &box ){
static int quads[]={
2,3,1,0,
3,7,5,1,
7,6,4,5,
6,2,0,4,
6,7,3,2,
0,1,5,4
};
bool hit=false;
for( int n=0;n<24;n+=4 ){
Vector
v0( box.corner( quads[n] ) ),
v1( box.corner( quads[n+1] ) ),
v2( box.corner( quads[n+2] ) ),
v3( box.corner( quads[n+3] ) );
//quad plane
Plane p( v0,v1,v2 );
if( p.n.dot( line.d )>=0 ) continue;
p.d-=radius;
float t=p.t_intersect( line );
if( t>time ) continue;
//intersection point
Plane
p0( v0+p.n,v1,v0 ),
p1( v1+p.n,v2,v1 ),
p2( v2+p.n,v3,v2 ),
p3( v3+p.n,v0,v3 );
if( t>=0 ){
Vector i=line*t;
if( p0.distance(i)>=0 && p1.distance(i)>=0 && p2.distance(i)>=0 && p3.distance(i)>=0 ){
time=t;
normal=p.n;
hit=true;
continue;
}
}
if( radius<=0 ) continue;
hit|=
edgeTest( v0,v1,p.n,p0.n,line,radius,this )|
edgeTest( v1,v2,p.n,p1.n,line,radius,this )|
edgeTest( v2,v3,p.n,p2.n,line,radius,this )|
edgeTest( v3,v0,p.n,p3.n,line,radius,this );
}
return hit;
}
*/
bool Collision::update( const Line &line,float t,const Vector &n ){
// if( t<0 || t>time ) return false;
if( t>time ) return false;
Plane p(line*t,n);
if( p.n.dot( line.d )>=0 ) return false;
if( p.distance(line.o)<-COLLISION_EPSILON ) return false;
time=t;
normal=n;
return true;
}
//
// NEW VERSION
//
extern gxRuntime *gx_runtime;
bool Collision::sphereCollide( const Line &line,float radius,const Vector &dest,float dest_radius ){
radius+=dest_radius;
Line l( line.o-dest,line.d );
float a=l.d.dot(l.d);
if( !a ) return false;
float b=l.o.dot(l.d)*2;
float c=l.o.dot(l.o)-radius*radius;
float d=b*b-4*a*c;
if( d<0 ) return false;
float t1=(-b+sqrt(d))/(2*a);
float t2=(-b-sqrt(d))/(2*a);
float t=t1<t2 ? t1 : t2;
if( t>time ) return false;
return update( line,t,(l*t).normalized() );
}
//v0,v1 = edge verts
//pn = poly normal
//en = edge normal
static bool edgeTest( const Vector &v0,const Vector &v1,const Vector &pn,const Vector &en,const Line &line,float radius,Collision *curr_coll ){
Matrix tm=~Matrix( en,(v1-v0).normalized(),pn );
Vector sv=tm*(line.o-v0),dv=tm*(line.o+line.d-v0);
Line l( sv,dv-sv );
//do cylinder test...
float a,b,c,d,t1,t2,t;
a=(l.d.x*l.d.x+l.d.z*l.d.z);
if( !a ) return false; //ray parallel to cylinder
b=(l.o.x*l.d.x+l.o.z*l.d.z)*2;
c=(l.o.x*l.o.x+l.o.z*l.o.z)-radius*radius;
d=b*b-4*a*c;
if( d<0 ) return false; //ray misses cylinder
t1=(-b+sqrt(d))/(2*a);
t2=(-b-sqrt(d))/(2*a);
t=t1<t2 ? t1 : t2;
if( t>curr_coll->time ) return false; //intersects too far away
Vector i=l*t,p;
if( i.y>v0.distance(v1) ) return false; //intersection above cylinder
if( i.y>=0 ){
p.y=i.y;
}else{
//below bottom of cylinder...do sphere test...
a=l.d.dot(l.d);
if( !a ) return false; //ray parallel to sphere
b=l.o.dot(l.d)*2;
c=l.o.dot(l.o)-radius*radius;
d=b*b-4*a*c;
if( d<0 ) return false; //ray misses sphere
t1=(-b+sqrt(d))/(2*a);
t2=(-b-sqrt(d))/(2*a);
t=t1<t2 ? t1 : t2;
if( t>curr_coll->time ) return false;
i=l*t;
}
return curr_coll->update( line,t,(~tm*(i-p)).normalized() );
}
bool Collision::triangleCollide( const Line &line,float radius,const Vector &v0,const Vector &v1,const Vector &v2 ){
//triangle plane
Plane p( v0,v1,v2 );
if( p.n.dot( line.d )>=0 ) return false;
//move plane out
p.d-=radius;
float t=p.t_intersect( line );
if( t>time ) return false;
//edge planes
Plane p0( v0+p.n,v1,v0 ),p1( v1+p.n,v2,v1 ),p2( v2+p.n,v0,v2 );
//intersects triangle?
Vector i=line*t;
if( p0.distance(i)>=0 && p1.distance(i)>=0 && p2.distance(i)>=0 ){
return update( line,t,p.n );
}
if( radius<=0 ) return false;
return
edgeTest( v0,v1,p.n,p0.n,line,radius,this )|
edgeTest( v1,v2,p.n,p1.n,line,radius,this )|
edgeTest( v2,v0,p.n,p2.n,line,radius,this );
}
bool Collision::boxCollide( const Line &line,float radius,const Box &box ){
static int quads[]={
2,3,1,0,
3,7,5,1,
7,6,4,5,
6,2,0,4,
6,7,3,2,
0,1,5,4
};
bool hit=false;
for( int n=0;n<24;n+=4 ){
Vector
v0( box.corner( quads[n] ) ),
v1( box.corner( quads[n+1] ) ),
v2( box.corner( quads[n+2] ) ),
v3( box.corner( quads[n+3] ) );
//quad plane
Plane p( v0,v1,v2 );
if( p.n.dot( line.d )>=0 ) continue;
//move plane out
p.d-=radius;
float t=p.t_intersect( line );
if( t>time ) return false;
//edge planes
Plane
p0( v0+p.n,v1,v0 ),
p1( v1+p.n,v2,v1 ),
p2( v2+p.n,v3,v2 ),
p3( v3+p.n,v0,v3 );
//intersects triangle?
Vector i=line*t;
if( p0.distance(i)>=0 && p1.distance(i)>=0 && p2.distance(i)>=0 && p3.distance(i)>=0 ){
hit|=update( line,t,p.n );
continue;
}
if( radius<=0 ) continue;
hit|=
edgeTest( v0,v1,p.n,p0.n,line,radius,this )|
edgeTest( v1,v2,p.n,p1.n,line,radius,this )|
edgeTest( v2,v3,p.n,p2.n,line,radius,this )|
edgeTest( v3,v0,p.n,p3.n,line,radius,this );
}
return hit;
}