public virtual int Collide(PShape s1, PShape s2, PContact[] cs) {
if (s1._type != PShapeType.CONVEX_SHAPE
&& s1._type != PShapeType.BOX_SHAPE
|| s2._type != PShapeType.CONVEX_SHAPE
&& s2._type != PShapeType.BOX_SHAPE) {
return 0;
}
PConvexPolygonShape p1 = (PConvexPolygonShape) s1;
PConvexPolygonShape p2 = (PConvexPolygonShape) s2;
PPolygonPolygonCollider.PWDistanceData dis1 = GetDistance(p1, p2);
if (dis1.dist > 0.0F)
return 0;
PPolygonPolygonCollider.PWDistanceData dis2 = GetDistance(p2, p1);
if (dis2.dist > 0.0F)
return 0;
float error = 0.008F;
int edgeA;
PConvexPolygonShape pa;
PConvexPolygonShape pb;
bool flip;
if (dis1.dist > dis2.dist + error) {
pa = p1;
pb = p2;
edgeA = dis1.edge;
flip = false;
} else {
pa = p2;
pb = p1;
edgeA = dis2.edge;
flip = true;
}
Vector2f normal = pa.nors[edgeA];
Vector2f tangent = new Vector2f(-normal.y, normal.x);
Vector2f[] paVers = pa.vers;
PPolygonPolygonCollider.PWContactedVertex [] cv = GetEdgeOfPotentialCollision(pa, pb, edgeA,
flip);
cv = ClipEdge(cv, tangent.Negate(), -tangent.Dot(paVers[edgeA]));
if (cv == null)
return 0;
cv = ClipEdge(cv, tangent,
tangent.Dot(paVers[(edgeA + 1) % pa.numVertices]));
if (cv == null)
return 0;
Vector2f contactNormal = (flip) ? normal : normal.Negate();
int numContacts = 0;
for (int i = 0; i < 2; i++) {
float dist = normal.Dot(cv[i].v) - normal.Dot(paVers[edgeA]);
if (dist < 0.0F) {
PContact c = new PContact();
c.normal.Set(contactNormal.x, contactNormal.y);
c.pos.Set(cv[i].v.x, cv[i].v.y);
c.overlap = dist;
c.data = cv[i].data;
c.data.flip = flip;
cs[numContacts] = c;
numContacts++;
}
}
return numContacts;
}
