/**
* Find the separation between poly1 and poly2 for a given edge normal on poly1.
*
* @param poly1
* @param xf1
* @param edge1
* @param poly2
* @param xf2
*/
public final float edgeSeparation(
final PolygonShape poly1,
final Transform xf1,
final int edge1,
final PolygonShape poly2,
final Transform xf2) {
int count1 = poly1.m_vertexCount;
final Vec2[] vertices1 = poly1.m_vertices;
final Vec2[] normals1 = poly1.m_normals;
int count2 = poly2.m_vertexCount;
final Vec2[] vertices2 = poly2.m_vertices;
assert (0 <= edge1 && edge1 < count1);
// Convert normal from poly1's frame into poly2's frame.
// Vec2 normal1World = Mul(xf1.R, normals1[edge1]);
Mat22.mulToOut(xf1.R, normals1[edge1], normal1World);
// Vec2 normal1 = MulT(xf2.R, normal1World);
Mat22.mulTransToOut(xf2.R, normal1World, normal1);
// Find support vertex on poly2 for -normal.
int index = 0;
float minDot = Float.MAX_VALUE;
for (int i = 0; i < count2; ++i) {
float dot = Vec2.dot(vertices2[i], normal1);
if (dot < minDot) {
minDot = dot;
index = i;
}
}
// Vec2 v1 = Mul(xf1, vertices1[edge1]);
// Vec2 v2 = Mul(xf2, vertices2[index]);
Transform.mulToOut(xf1, vertices1[edge1], v1);
Transform.mulToOut(xf2, vertices2[index], v2);
float separation = Vec2.dot(v2.subLocal(v1), normal1World);
return separation;
}
/** @see Shape#testSegment(XForm, RaycastResult, Segment, float) */
@Override
public SegmentCollide testSegment(
final XForm xf, final RaycastResult out, final Segment segment, final float maxLambda) {
final Vec2 r = tlR.get();
final Vec2 v1 = tlV1.get();
final Vec2 d = tlD.get();
final Vec2 n = tlN.get();
final Vec2 b = tlB.get();
r.set(segment.p2).subLocal(segment.p1);
XForm.mulToOut(xf, m_v1, v1);
XForm.mulToOut(xf, m_v2, d);
d.subLocal(v1);
Vec2.crossToOut(d, 1.0f, n);
final float k_slop = 100.0f * Settings.EPSILON;
final float denom = -Vec2.dot(r, n);
// Cull back facing collision and ignore parallel segments.
if (denom > k_slop) {
// Does the segment intersect the infinite line associated with this segment?
b.set(segment.p1).subLocal(v1);
float a = Vec2.dot(b, n);
if (0.0f <= a && a <= maxLambda * denom) {
final float mu2 = -r.x * b.y + r.y * b.x;
// Does the segment intersect this segment?
if (-k_slop * denom <= mu2 && mu2 <= denom * (1.0f + k_slop)) {
a /= denom;
n.normalize();
out.lambda = a;
out.normal.set(n);
return SegmentCollide.HIT_COLLIDE;
}
}
}
return SegmentCollide.MISS_COLLIDE;
}
/**
* Find the max separation between poly1 and poly2 using edge normals from poly1.
*
* @param edgeIndex
* @param poly1
* @param xf1
* @param poly2
* @param xf2
* @return
*/
public final void findMaxSeparation(
EdgeResults results,
final PolygonShape poly1,
final Transform xf1,
final PolygonShape poly2,
final Transform xf2) {
int count1 = poly1.m_vertexCount;
final Vec2[] normals1 = poly1.m_normals;
// Vector pointing from the centroid of poly1 to the centroid of poly2.
Transform.mulToOut(xf2, poly2.m_centroid, d);
Transform.mulToOut(xf1, poly1.m_centroid, temp);
d.subLocal(temp);
Mat22.mulTransToOut(xf1.R, d, dLocal1);
// Find edge normal on poly1 that has the largest projection onto d.
int edge = 0;
float dot;
float maxDot = Float.MIN_VALUE;
for (int i = 0; i < count1; i++) {
dot = Vec2.dot(normals1[i], dLocal1);
if (dot > maxDot) {
maxDot = dot;
edge = i;
}
}
// Get the separation for the edge normal.
float s = edgeSeparation(poly1, xf1, edge, poly2, xf2);
// Check the separation for the previous edge normal.
int prevEdge = edge - 1 >= 0 ? edge - 1 : count1 - 1;
float sPrev = edgeSeparation(poly1, xf1, prevEdge, poly2, xf2);
// Check the separation for the next edge normal.
int nextEdge = edge + 1 < count1 ? edge + 1 : 0;
float sNext = edgeSeparation(poly1, xf1, nextEdge, poly2, xf2);
// Find the best edge and the search direction.
int bestEdge;
float bestSeparation;
int increment;
if (sPrev > s && sPrev > sNext) {
increment = -1;
bestEdge = prevEdge;
bestSeparation = sPrev;
} else if (sNext > s) {
increment = 1;
bestEdge = nextEdge;
bestSeparation = sNext;
} else {
results.edgeIndex = edge;
results.separation = s;
return;
}
// Perform a local search for the best edge normal.
for (; ; ) {
if (increment == -1) {
edge = bestEdge - 1 >= 0 ? bestEdge - 1 : count1 - 1;
} else {
edge = bestEdge + 1 < count1 ? bestEdge + 1 : 0;
}
s = edgeSeparation(poly1, xf1, edge, poly2, xf2);
if (s > bestSeparation) {
bestEdge = edge;
bestSeparation = s;
} else {
break;
}
}
results.edgeIndex = bestEdge;
results.separation = bestSeparation;
}
private void drawShape(Fixture fixture, Transform xf, Color3f color) {
switch (fixture.getType()) {
case CIRCLE:
{
CircleShape circle = (CircleShape) fixture.getShape();
// Vec2 center = Mul(xf, circle.m_p);
Transform.mulToOutUnsafe(xf, circle.m_p, center);
float radius = circle.m_radius;
xf.q.getXAxis(axis);
if (fixture.getUserData() != null && fixture.getUserData().equals(LIQUID_INT)) {
Body b = fixture.getBody();
liquidOffset.set(b.m_linearVelocity);
float linVelLength = b.m_linearVelocity.length();
if (averageLinearVel == -1) {
averageLinearVel = linVelLength;
} else {
averageLinearVel = .98f * averageLinearVel + .02f * linVelLength;
}
liquidOffset.mulLocal(liquidLength / averageLinearVel / 2);
circCenterMoved.set(center).addLocal(liquidOffset);
center.subLocal(liquidOffset);
m_debugDraw.drawSegment(center, circCenterMoved, liquidColor);
return;
}
m_debugDraw.drawSolidCircle(center, radius, axis, color);
}
break;
case POLYGON:
{
PolygonShape poly = (PolygonShape) fixture.getShape();
int vertexCount = poly.m_count;
assert (vertexCount <= Settings.maxPolygonVertices);
Vec2[] vertices = tlvertices.get(Settings.maxPolygonVertices);
for (int i = 0; i < vertexCount; ++i) {
// vertices[i] = Mul(xf, poly.m_vertices[i]);
Transform.mulToOutUnsafe(xf, poly.m_vertices[i], vertices[i]);
}
m_debugDraw.drawSolidPolygon(vertices, vertexCount, color);
}
break;
case EDGE:
{
EdgeShape edge = (EdgeShape) fixture.getShape();
Transform.mulToOutUnsafe(xf, edge.m_vertex1, v1);
Transform.mulToOutUnsafe(xf, edge.m_vertex2, v2);
m_debugDraw.drawSegment(v1, v2, color);
}
break;
case CHAIN:
{
ChainShape chain = (ChainShape) fixture.getShape();
int count = chain.m_count;
Vec2[] vertices = chain.m_vertices;
Transform.mulToOutUnsafe(xf, vertices[0], v1);
for (int i = 1; i < count; ++i) {
Transform.mulToOutUnsafe(xf, vertices[i], v2);
m_debugDraw.drawSegment(v1, v2, color);
m_debugDraw.drawCircle(v1, 0.05f, color);
v1.set(v2);
}
}
break;
default:
break;
}
}
/**
* Rozbije objekt. Upravi objekt world tak, ze vymaze triesteny objekt a nahradi ho fragmentami na
* zaklade nastaveneho materialu a clenskych premennych.
*
* @param dt casova dlzka framu
*/
public void smash(float dt) {
if (contact == null) { // riesi sa staticky prvok, ktory ma priliz maly obsah
b1.setType(BodyType.DYNAMIC);
return;
}
World w = b1.m_world;
Shape s = f1.m_shape;
Polygon p = f1.m_polygon;
if (p == null) {
switch (s.m_type) {
case POLYGON:
PolygonShape ps = (PolygonShape) s;
Vec2[] vertices = ps.m_vertices;
p = new Polygon();
for (int i = 0; i < ps.m_count; ++i) {
p.add(vertices[ps.m_count - i - 1]);
}
break;
case CIRCLE:
CircleShape cs = (CircleShape) s;
p = new Polygon();
float radius = cs.m_radius;
double u = Math.PI * 2 / CIRCLEVERTICES;
radius =
(float) Math.sqrt(u / Math.sin(u))
* radius; // upravim radius tak, aby bola zachovana velkost obsahu
Vec2 center = cs.m_p;
for (int i = 0; i < CIRCLEVERTICES; ++i) {
double j = u * i; // uhol
float sin = (float) Math.sin(j);
float cos = (float) Math.cos(j);
Vec2 v = new Vec2(sin, cos).mulLocal(radius).addLocal(center);
p.add(v);
}
break;
default:
throw new RuntimeException("Dany typ tvaru nepodporuje stiepenie");
}
}
float mConst = f1.m_material.m_rigidity / normalImpulse; // sila v zavislosti na pevnosti telesa
boolean fixA = f1 == contact.m_fixtureA; // true, ak f2 je v objekte contact ako m_fixtureA
float oldAngularVelocity =
fixA ? contact.m_angularVelocity_bodyA : contact.m_angularVelocity_bodyB;
Vec2 oldLinearVelocity = fixA ? contact.m_linearVelocity_bodyA : contact.m_linearVelocity_bodyB;
b1.setAngularVelocity(
(b1.m_angularVelocity - oldAngularVelocity) * mConst + oldAngularVelocity);
b1.setLinearVelocity(
b1.m_linearVelocity.sub(oldLinearVelocity).mulLocal(mConst).addLocal(oldLinearVelocity));
if (!w.isFractured(f2)
&& b2.m_type == BodyType.DYNAMIC
&& !b2.m_fractureTransformUpdate) { // ak sa druhy objekt nerozbija, tak sa jej nahodia
// povodne hodnoty (TREBA MODIFIKOVAT POHYB OBJEKTU,
// KTORY SPOSOBUJE ROZPAD)
oldAngularVelocity =
!fixA ? contact.m_angularVelocity_bodyA : contact.m_angularVelocity_bodyB;
oldLinearVelocity = !fixA ? contact.m_linearVelocity_bodyA : contact.m_linearVelocity_bodyB;
b2.setAngularVelocity(
(b2.m_angularVelocity - oldAngularVelocity) * mConst + oldAngularVelocity);
b2.setLinearVelocity(
b2.m_linearVelocity.sub(oldLinearVelocity).mulLocal(mConst).addLocal(oldLinearVelocity));
b2.setTransform(
b2.m_xf0.p.add(b2.m_linearVelocity.mul(dt)),
b2.m_xf0.q.getAngle()); // osetruje jbox2d od posuvania telesa pri rieseni kolizie
b2.m_fractureTransformUpdate = true;
}
Vec2 localPoint = Transform.mulTrans(b1.m_xf, point);
Vec2 b1Vec = b1.getLinearVelocityFromWorldPoint(point);
Vec2 b2Vec = b2.getLinearVelocityFromWorldPoint(point);
Vec2 localVector = b2Vec.subLocal(b1Vec);
localVector.mulLocal(dt);
Polygon[] fragment;
try {
fragment = m.split(p, localPoint, localVector, normalImpulse); // rodeli to
} catch (RuntimeException ex) {
return;
}
if (fragment.length == 1) { // nerozbilo to na ziadne fragmenty
return;
}
// definuje tela fragmentov - tie maju vsetky rovnaku definiciu (preberaju parametre z povodneho
// objektu)
BodyDef bodyDef = new BodyDef();
bodyDef.position.set(b1.m_xf.p); // pozicia
bodyDef.angle = b1.m_xf.q.getAngle(); // otocenie
bodyDef.fixedRotation = b1.isFixedRotation();
bodyDef.angularDamping = b1.m_angularDamping;
bodyDef.allowSleep = b1.isSleepingAllowed();
FixtureDef fd = new FixtureDef();
fd.friction = f1.m_friction; // trenie
fd.restitution = f1.m_restitution; // odrazivost
fd.isSensor = f1.m_isSensor;
fd.density = f1.m_density;
// odstrani fragmentacne predmety/cele teleso
ArrayList<Fixture> fixtures = new ArrayList<>();
if (f1.m_polygon != null) {
for (Fixture f = b1.m_fixtureList; f != null; f = f.m_next) {
if (f.m_polygon == f1.m_polygon) {
fixtures.add(f);
}
}
} else {
fixtures.add(f1);
}
for (Fixture f : fixtures) {
b1.destroyFixture(f);
}
if (b1.m_fixtureCount == 0) {
w.destroyBody(b1);
}
// prida fragmenty do simulacie
MyList<Body> newbodies = new MyList<>();
for (Polygon pg : fragment) { // vytvori tela, prida fixtury, poriesi konvexnu dekompoziciu
if (pg.isCorrect()) {
if (pg instanceof Fragment) {
Polygon[] convex = pg.convexDecomposition();
bodyDef.type = BodyType.DYNAMIC;
for (Polygon pgx : convex) {
Body f_body = w.createBody(bodyDef);
pgx.flip();
PolygonShape ps = new PolygonShape();
ps.set(pgx.getArray(), pgx.size());
fd.shape = ps;
fd.polygon = null;
fd.material = f1.m_material.m_fragments; // rekurzivne stiepenie
f_body.createFixture(fd);
f_body.setAngularVelocity(b1.m_angularVelocity);
f_body.setLinearVelocity(b1.getLinearVelocityFromLocalPoint(f_body.getLocalCenter()));
newbodies.add(f_body);
}
} else {
fd.material = f1.m_material.m_fragments; // rekurzivne stiepenie
bodyDef.type = b1.getType();
Body f_body = w.createBody(bodyDef);
PolygonFixture pf = new PolygonFixture(pg);
f_body.createFixture(pf, fd);
f_body.setLinearVelocity(b1.getLinearVelocityFromLocalPoint(f_body.getLocalCenter()));
f_body.setAngularVelocity(b1.m_angularVelocity);
newbodies.add(f_body);
}
}
}
// zavola sa funkcia z fraction listeneru (pokial je nadefinovany)
FractureListener fl = w.getContactManager().m_fractureListener;
if (fl != null) {
fl.action(m, normalImpulse, newbodies);
}
}