private void scaleShape(b2Shape shape, bool isOnlyCenter = false)
{
if (shape is b2PolygonShape)
{
b2PolygonShape poly = shape as b2PolygonShape;
List <b2Vec2> vertices = poly.GetVertices();
for (int i = 0; i < vertices.Count; i++)
{
vertices[i].x *= transform.lossyScale.x;
vertices[i].y *= transform.lossyScale.y;
}
}
else if (shape is b2CircleShape)
{
b2CircleShape circle = shape as b2CircleShape;
if (!isOnlyCenter)
{
float scale = Mathf.Max(transform.lossyScale.x, transform.lossyScale.y);
circle.SetRadius(circle.GetRadius() * scale);
}
var offset = circle.GetLocalPosition();
offset.x *= transform.lossyScale.x;
offset.y *= transform.lossyScale.y;
circle.SetLocalPosition(offset);
}
}
public CircleProp(
b2World b2world,
double[] size,
double[] position
)
{
/*
* static rectangle shaped prop
*
* pars:
* size - array [width, height]
* position - array [x, y], in world meters, of center
*/
this.size = size;
//initialize body
var bdef = new b2BodyDef();
bdef.position = new b2Vec2(position[0], position[1]);
bdef.angle = 0;
bdef.fixedRotation = true;
this.body = b2world.CreateBody(bdef);
//initialize shape
var fixdef = new b2FixtureDef();
var shape = new b2CircleShape();
fixdef.shape = shape;
shape.SetRadius(this.size[0] / 2);
fixdef.restitution = 0.4; //positively bouncy!
this.body.CreateFixture(fixdef);
}
/**在编辑器更改碰撞器的形状Shape时*/
private void onEditShape(object[] args)
{
Collider2D collider = (Collider2D)args [0];
b2Fixture[] fixtures = _fixtureDict [collider];
if (collider is BoxCollider2D)
{
b2Fixture fixture = fixtures[0];
b2Shape s = fixture.GetShape();
float sizeX = (float)args [1];
float sizeY = (float)args [2];
BoxCollider2D boxColl = collider as BoxCollider2D;
b2PolygonShape polygon = s as b2PolygonShape;
polygon.SetAsOrientedBox(sizeX * 0.5f, sizeY * 0.5f, new b2Vec2(boxColl.offset.x, boxColl.offset.y), 0);
scaleShape(polygon);
_body.SetAwake(true);
}
else if (collider is PolygonCollider2D)
{
Vector2[] points = (Vector2[])args[1];
int len = points.Length;
b2Vec2[] vertices = new b2Vec2[len];
for (int i = 0; i < len; i++)
{
vertices[i] = new b2Vec2(points[i].x, points[i].y);
}
b2FixtureDef fixtureDef = new b2FixtureDef();
fixtureDef.density = fixtures[0].GetDensity();
fixtureDef.friction = fixtures[0].GetFriction();
fixtureDef.isSensor = fixtures[0].IsSensor();
fixtureDef.restitution = fixtures[0].GetRestitution();
int j = fixtures.Length;
while (--j >= 0)
{
_body.DestroyFixture(fixtures[j]);
}
b2Separator sep = new b2Separator();
_fixtureDict [collider] = sep.Separate(_body, fixtureDef, vertices, 1);
fixtures = _fixtureDict [collider];
for (j = 0; j < fixtures.Length; j++)
{
scaleShape(fixtures[j].GetShape());
}
_body.SetAwake(true);
}
else if (collider is CircleCollider2D)
{
b2Fixture fixture = fixtures[0];
float radius = (float)args[1];
float cx = (float)args[2];
float cy = (float)args[3];
b2Shape s = fixture.GetShape();
b2CircleShape circle = s as b2CircleShape;
circle.SetRadius(radius);
circle.SetLocalPosition(new b2Vec2(cx, cy));
scaleShape(circle);
_body.SetAwake(true);
}
}