static cpBool
cpSegmentShapePointQuery(cpSegmentShape *seg, cpVect p){
if(!cpBBContainsVect(seg->shape.bb, p)) return cpFalse;
// Calculate normal distance from segment.
cpFloat dn = cpvdot(seg->tn, p) - cpvdot(seg->ta, seg->tn);
cpFloat dist = cpfabs(dn) - seg->r;
if(dist > 0.0f) return cpFalse;
// Calculate tangential distance along segment.
cpFloat dt = -cpvcross(seg->tn, p);
cpFloat dtMin = -cpvcross(seg->tn, seg->ta);
cpFloat dtMax = -cpvcross(seg->tn, seg->tb);
// Decision tree to decide which feature of the segment to collide with.
if(dt <= dtMin){
if(dt < (dtMin - seg->r)){
return cpFalse;
} else {
return cpvlengthsq(cpvsub(seg->ta, p)) < (seg->r*seg->r);
}
} else {
if(dt < dtMax){
return cpTrue;
} else {
if(dt < (dtMax + seg->r)) {
return cpvlengthsq(cpvsub(seg->tb, p)) < (seg->r*seg->r);
} else {
return cpFalse;
}
}
}
return cpTrue;
}
static void
cpSegmentShapePointQuery(cpSegmentShape *seg, cpVect p, cpPointQueryExtendedInfo *info){
if(!cpBBContainsVect(seg->shape.bb, p)) return;
cpVect a = seg->ta;
cpVect b = seg->tb;
cpVect seg_delta = cpvsub(b, a);
cpFloat closest_t = cpfclamp01(cpvdot(seg_delta, cpvsub(p, a))/cpvlengthsq(seg_delta));
cpVect closest = cpvadd(a, cpvmult(seg_delta, closest_t));
cpVect delta = cpvsub(p, closest);
cpFloat distsq = cpvlengthsq(delta);
cpFloat r = seg->r;
if(distsq < r*r){
info->shape = (cpShape *)seg;
cpFloat dist = cpfsqrt(distsq);
info->d = r - dist;
info->n = cpvmult(delta, 1.0/dist);
}
}
static VALUE
rb_cpBBContainsVect(VALUE self, VALUE other) {
int value = cpBBContainsVect(*BBGET(self), *VGET(other));
return CP_INT_BOOL(value);
}
