/// Implement b2Shape. Vertices are cloned using b2Alloc.
public override b2Shape Clone()
{
b2ChainShape clone = new b2ChainShape();
clone.CreateChain(m_vertices, m_count);
clone.m_prevVertex = m_prevVertex;
clone.m_nextVertex = m_nextVertex;
clone.m_hasPrevVertex = m_hasPrevVertex;
clone.m_hasNextVertex = m_hasNextVertex;
return(clone);
}
public CharacterCollision()
{
// Ground body
{
b2BodyDef bd = new b2BodyDef();
b2Body ground = m_world.CreateBody(bd);
b2EdgeShape shape = new b2EdgeShape();
shape.Set(new b2Vec2(-20.0f, 0.0f), new b2Vec2(20.0f, 0.0f));
ground.CreateFixture(shape, 0.0f);
}
// Collinear edges with no adjacency information.
// This shows the problematic case where a box shape can hit
// an internal vertex.
{
b2BodyDef bd = new b2BodyDef();
b2Body ground = m_world.CreateBody(bd);
b2EdgeShape shape = new b2EdgeShape();
shape.Set(new b2Vec2(-8.0f, 1.0f), new b2Vec2(-6.0f, 1.0f));
ground.CreateFixture(shape, 0.0f);
shape.Set(new b2Vec2(-6.0f, 1.0f), new b2Vec2(-4.0f, 1.0f));
ground.CreateFixture(shape, 0.0f);
shape.Set(new b2Vec2(-4.0f, 1.0f), new b2Vec2(-2.0f, 1.0f));
ground.CreateFixture(shape, 0.0f);
}
// Chain shape
{
b2BodyDef bd = new b2BodyDef();
bd.angle = 0.25f * b2Settings.b2_pi;
b2Body ground = m_world.CreateBody(bd);
b2Vec2[] vs = new b2Vec2[4];
vs[0].Set(5.0f, 7.0f);
vs[1].Set(6.0f, 8.0f);
vs[2].Set(7.0f, 8.0f);
vs[3].Set(8.0f, 7.0f);
b2ChainShape shape = new b2ChainShape();
shape.CreateChain(vs, 4);
ground.CreateFixture(shape, 0.0f);
}
// Square tiles. This shows that adjacency shapes may
// have non-smooth collision. There is no solution
// to this problem.
{
b2BodyDef bd = new b2BodyDef();
b2Body ground = m_world.CreateBody(bd);
b2PolygonShape shape = new b2PolygonShape();
shape.SetAsBox(1.0f, 1.0f, new b2Vec2(4.0f, 3.0f), 0.0f);
ground.CreateFixture(shape, 0.0f);
shape.SetAsBox(1.0f, 1.0f, new b2Vec2(6.0f, 3.0f), 0.0f);
ground.CreateFixture(shape, 0.0f);
shape.SetAsBox(1.0f, 1.0f, new b2Vec2(8.0f, 3.0f), 0.0f);
ground.CreateFixture(shape, 0.0f);
}
// Square made from an edge loop. Collision should be smooth.
{
b2BodyDef bd = new b2BodyDef();
b2Body ground = m_world.CreateBody(bd);
b2Vec2[] vs = new b2Vec2[4];
vs[0].Set(-1.0f, 3.0f);
vs[1].Set(1.0f, 3.0f);
vs[2].Set(1.0f, 5.0f);
vs[3].Set(-1.0f, 5.0f);
b2ChainShape shape = new b2ChainShape();
shape.CreateLoop(vs, 4);
ground.CreateFixture(shape, 0.0f);
}
// Edge loop. Collision should be smooth.
{
b2BodyDef bd = new b2BodyDef();
bd.position.Set(-10.0f, 4.0f);
b2Body ground = m_world.CreateBody(bd);
b2Vec2[] vs = new b2Vec2[10];
vs[0].Set(0.0f, 0.0f);
vs[1].Set(6.0f, 0.0f);
vs[2].Set(6.0f, 2.0f);
vs[3].Set(4.0f, 1.0f);
vs[4].Set(2.0f, 2.0f);
vs[5].Set(0.0f, 2.0f);
vs[6].Set(-2.0f, 2.0f);
vs[7].Set(-4.0f, 3.0f);
vs[8].Set(-6.0f, 2.0f);
vs[9].Set(-6.0f, 0.0f);
b2ChainShape shape = new b2ChainShape();
shape.CreateLoop(vs, 10);
ground.CreateFixture(shape, 0.0f);
}
// Square character 1
{
b2BodyDef bd = new b2BodyDef();
bd.position.Set(-3.0f, 8.0f);
bd.type = b2BodyType.b2_dynamicBody;
bd.fixedRotation = true;
bd.allowSleep = false;
b2Body body = m_world.CreateBody(bd);
b2PolygonShape shape = new b2PolygonShape();
shape.SetAsBox(0.5f, 0.5f);
b2FixtureDef fd = new b2FixtureDef();
fd.Defaults();
fd.shape = shape;
fd.density = 20.0f;
body.CreateFixture(fd);
}
// Square character 2
{
b2BodyDef bd = new b2BodyDef();
bd.position.Set(-5.0f, 5.0f);
bd.type = b2BodyType.b2_dynamicBody;
bd.fixedRotation = true;
bd.allowSleep = false;
b2Body body = m_world.CreateBody(bd);
b2PolygonShape shape = new b2PolygonShape();
shape.SetAsBox(0.25f, 0.25f);
b2FixtureDef fd = new b2FixtureDef();
fd.Defaults();
fd.shape = shape;
fd.density = 20.0f;
body.CreateFixture(fd);
}
// Hexagon character
{
b2BodyDef bd = new b2BodyDef();
bd.position.Set(-5.0f, 8.0f);
bd.type = b2BodyType.b2_dynamicBody;
bd.fixedRotation = true;
bd.allowSleep = false;
b2Body body = m_world.CreateBody(bd);
float angle = 0.0f;
float delta = b2Settings.b2_pi / 3.0f;
b2Vec2[] vertices = new b2Vec2[6];
for (int i = 0; i < 6; ++i)
{
vertices[i].Set(0.5f * (float)Math.Cos(angle), 0.5f * (float)Math.Sin(angle));
angle += delta;
}
b2PolygonShape shape = new b2PolygonShape();
shape.Set(vertices, 6);
b2FixtureDef fd = new b2FixtureDef();
fd.Defaults();
fd.shape = shape;
fd.density = 20.0f;
body.CreateFixture(fd);
}
// Circle character
{
b2BodyDef bd = new b2BodyDef();
bd.position.Set(3.0f, 5.0f);
bd.type = b2BodyType.b2_dynamicBody;
bd.fixedRotation = true;
bd.allowSleep = false;
b2Body body = m_world.CreateBody(bd);
b2CircleShape shape = new b2CircleShape();
shape.Radius = 0.5f;
b2FixtureDef fd = new b2FixtureDef();
fd.shape = shape;
fd.density = 20.0f;
body.CreateFixture(fd);
}
// Circle character
{
b2BodyDef bd = new b2BodyDef();
bd.position.Set(-7.0f, 6.0f);
bd.type = b2BodyType.b2_dynamicBody;
bd.allowSleep = false;
m_character = m_world.CreateBody(bd);
b2CircleShape shape = new b2CircleShape();
shape.Radius = 0.25f;
b2FixtureDef fd = new b2FixtureDef();
fd.Defaults();
fd.shape = shape;
fd.density = 20.0f;
fd.friction = 1.0f;
m_character.CreateFixture(fd);
}
}
