support mapping for basic primitives

support_map.cpp

void supportPoint(const Body &body, const vec3 &dir, vec3 &v) {
	v = vec3::ZERO;
}

void supportSegment(const Body &body, const vec3 &dir, vec3 &v) {
	v.x = v.z = 0.0f;
	v.y = sign(dir.y) * body.height;
}

void supportRect(const Body &body, const vec3 &dir, vec3 &v) {
	v.x = sign(dir.x) * body.size.x;
	v.y = sign(dir.y) * body.size.y;
	v.z = 0.0f;
}

void supportDisc(const Body &body, const vec3 &dir, vec3 &v) {
	v = vec3(dir.x, 0, dir.z).normal() * body.radius;
}

void supportSphere(const Body &body, const vec3 &dir, vec3 &v) {
	v = dir * (body.radius / dir.length());
}

void supportBox(const Body &body, const vec3 &dir, vec3 &v) {
	v = vec3(sign(dir.x), sign(dir.y), sign(dir.z)) * body.size;
}

void supportRound(const Body &body, const vec3 &dir, vec3 &v) {
	vec3 s;
	supportBox(body, dir, v);
	supportSphere(body, dir, s);
	v += s;
}

void supportCapsule(const Body &body, const vec3 &dir, vec3 &v) {
	vec3 s;
	supportSegment(body, dir, v);
	supportSphere(body, dir, s);
	v += s;
}

void supportCylinder(const Body &body, const vec3 &dir, vec3 &v) {
	vec3 s;
	supportSegment(body, dir, v);
	supportDisc(body, dir, s);
	v += s;
}

void supportCone(const Body &body, const vec3 &dir, vec3 &v) {
	vec3 s = vec3(0.0f, body.height, 0.0f);
	supportDisc(body, dir, v);
	v = dir.dot(v) > dir.dot(s) ? v : s;
}

void supportWheel(const Body &body, const vec3 &dir, vec3 &v) {
	vec3 s;
	supportDisc(body, dir, v);
	supportSphere(body, dir, s);
	v += s;
}