/// Initialize the proxy using the given shape. The shape
/// must remain in scope while the proxy is in use.
public void Set(Shape shape, int index)
{
switch (shape.ShapeType)
{
case ShapeType.Circle:
{
CircleShape circle = (CircleShape)shape;
_vertices[0] = circle._p;
_count = 1;
_radius = circle._radius;
}
break;
case ShapeType.Polygon:
{
PolygonShape polygon = (PolygonShape)shape;
_vertices = polygon._vertices;
_count = polygon._vertexCount;
_radius = polygon._radius;
}
break;
case ShapeType.Loop:
{
LoopShape loop = (LoopShape)shape;
Debug.Assert(0 <= index && index < loop._count);
_buffer[0] = loop._vertices[index];
if (index + 1 < loop._count)
{
_buffer[1] = loop._vertices[index + 1];
}
else
{
_buffer[1] = loop._vertices[0];
}
_vertices[0] = _buffer[0];
_vertices[1] = _buffer[1];
_count = 2;
_radius = loop._radius;
}
break;
case ShapeType.Edge:
{
EdgeShape edge = (EdgeShape)shape;
_vertices[0] = edge._vertex1;
_vertices[1] = edge._vertex2;
_count = 2;
_radius = edge._radius;
}
break;
default:
Debug.Assert(false);
break;
}
}
/// Implement Shape.
public override Shape Clone()
{
var loop = new LoopShape();
loop._count = _count;
loop._radius = _radius;
loop._vertices = (Vector2[])_vertices.Clone();
return loop;
}
void DrawShape(Fixture fixture, Transform xf, Color color)
{
switch (fixture.ShapeType)
{
case ShapeType.Circle:
{
CircleShape circle = (CircleShape)fixture.GetShape();
Vector2 center = MathUtils.Multiply(ref xf, circle._p);
float radius = circle._radius;
Vector2 axis = xf.R.col1;
DebugDraw.DrawSolidCircle(center, radius, axis, color);
}
break;
case ShapeType.Polygon:
{
PolygonShape poly = (PolygonShape)fixture.GetShape();
int vertexCount = poly._vertexCount;
Debug.Assert(vertexCount <= Settings.b2_maxPolygonVertices);
FixedArray8 <Vector2> vertices = new FixedArray8 <Vector2>();
for (int i = 0; i < vertexCount; ++i)
{
vertices[i] = MathUtils.Multiply(ref xf, poly._vertices[i]);
}
DebugDraw.DrawSolidPolygon(ref vertices, vertexCount, color);
}
break;
case ShapeType.Edge:
{
EdgeShape edge = (EdgeShape)fixture.GetShape();
Vector2 v1 = MathUtils.Multiply(ref xf, edge._vertex1);
Vector2 v2 = MathUtils.Multiply(ref xf, edge._vertex2);
DebugDraw.DrawSegment(v1, v2, color);
}
break;
case ShapeType.Loop:
{
LoopShape loop = (LoopShape)fixture.GetShape();
int count = loop._count;
Vector2 v1 = MathUtils.Multiply(ref xf, loop._vertices[count - 1]);
for (int i = 0; i < count; ++i)
{
Vector2 v2 = MathUtils.Multiply(ref xf, loop._vertices[i]);
DebugDraw.DrawSegment(v1, v2, color);
v1 = v2;
}
}
break;
}
}
/// <summary> Implement Shape.
/// </summary>
public override Shape Clone()
{
var loop = new LoopShape();
loop._count = _count;
loop._radius = _radius;
loop._vertices = (Vector2[])_vertices.Clone();
return(loop);
}
public CharacterCollision()
{
// Ground body
{
BodyDef bd = new BodyDef();
Body ground = _world.CreateBody(bd);
PolygonShape shape = new PolygonShape();
shape.SetAsEdge(new Vector2(-20.0f, 0.0f), new Vector2(20.0f, 0.0f));
ground.CreateFixture(shape, 0.0f);
}
// Collinear edges
{
BodyDef bd = new BodyDef();
Body ground = _world.CreateBody(bd);
PolygonShape shape = new PolygonShape();
shape.SetAsEdge(new Vector2(-8.0f, 1.0f), new Vector2(-6.0f, 1.0f));
ground.CreateFixture(shape, 0.0f);
shape.SetAsEdge(new Vector2(-6.0f, 1.0f), new Vector2(-4.0f, 1.0f));
ground.CreateFixture(shape, 0.0f);
shape.SetAsEdge(new Vector2(-4.0f, 1.0f), new Vector2(-2.0f, 1.0f));
ground.CreateFixture(shape, 0.0f);
}
// Square tiles
{
BodyDef bd = new BodyDef();
Body ground = _world.CreateBody(bd);
PolygonShape shape = new PolygonShape();
shape.SetAsBox(1.0f, 1.0f, new Vector2(4.0f, 3.0f), 0.0f);
ground.CreateFixture(shape, 0.0f);
shape.SetAsBox(1.0f, 1.0f, new Vector2(6.0f, 3.0f), 0.0f);
ground.CreateFixture(shape, 0.0f);
shape.SetAsBox(1.0f, 1.0f, new Vector2(8.0f, 3.0f), 0.0f);
ground.CreateFixture(shape, 0.0f);
}
// Square made from edges notice how the edges are shrunk to account
// for the polygon radius. This makes it so the square character does
// not get snagged. However, ray casts can now go through the cracks.
for (int i = 0; i < 4; i++)
{
BodyDef bd = new BodyDef();
Body ground = _world.CreateBody(bd);
ground.SetTransform(new Vector2(-2f * i, 0), 0);
Vector2[] vs = new Vector2[4];
vs[0] = new Vector2(-1.0f, 3.0f);
vs[1] = new Vector2(1.0f, 3.0f);
vs[2] = new Vector2(1.0f, 5.0f);
vs[3] = new Vector2(-1.0f, 5.0f);
LoopShape shape = new LoopShape();
shape._count = 4;
shape._vertices = vs;
ground.CreateFixture(shape, 0.0f);
//PolygonShape shape = new PolygonShape();
//float d = 2.0f * Settings.b2_polygonRadius;
//shape.SetAsEdge(new Vector2(-1.0f + d, 3.0f), new Vector2(1.0f - d, 3.0f));
//ground.CreateFixture(shape, 0.0f);
//shape.SetAsEdge(new Vector2(1.0f, 3.0f + d), new Vector2(1.0f, 5.0f - d));
//ground.CreateFixture(shape, 0.0f);
//shape.SetAsEdge(new Vector2(1.0f - d, 5.0f), new Vector2(-1.0f + d, 5.0f));
//ground.CreateFixture(shape, 0.0f);
//shape.SetAsEdge(new Vector2(-1.0f, 5.0f - d), new Vector2(-1.0f, 3.0f + d));
//ground.CreateFixture(shape, 0.0f);
}
// Square character
{
BodyDef bd = new BodyDef();
bd.position = new Vector2(-3.0f, 5.0f);
bd.type = BodyType.Dynamic;
bd.fixedRotation = true;
bd.allowSleep = false;
Body body = _world.CreateBody(bd);
PolygonShape shape = new PolygonShape();
shape.SetAsBox(0.5f, 0.5f);
FixtureDef fd = new FixtureDef();
fd.shape = shape;
fd.density = 20.0f;
body.CreateFixture(fd);
}
#if false
// Hexagon character
{
BodyDef bd = new BodyDef();
bd.position = new Vector2(-5.0f, 5.0f);
bd.type = BodyType.Dynamic;
bd.fixedRotation = true;
bd.allowSleep = false;
Body body = _world.CreateBody(bd);
float angle = 0.0f;
float delta = (float)Math.PI / 3.0f;
Vector2[] vertices = new Vector2[6];
for (int i = 0; i < 6; ++i)
{
vertices[i] = new Vector2(0.5f * (float)Math.Cos(angle), 0.5f * (float)Math.Sin(angle));
angle += delta;
}
PolygonShape shape = new PolygonShape();
shape.Set(vertices, 6);
FixtureDef fd = new FixtureDef();
fd.shape = shape;
fd.density = 20.0f;
body.CreateFixture(fd);
}
// Circle character
{
BodyDef bd = new BodyDef();
bd.position = new Vector2(3.0f, 5.0f);
bd.type = BodyType.Dynamic;
bd.fixedRotation = true;
bd.allowSleep = false;
Body body = _world.CreateBody(bd);
CircleShape shape = new CircleShape();
shape._radius = 0.5f;
FixtureDef fd = new FixtureDef();
fd.shape = shape;
fd.density = 20.0f;
body.CreateFixture(fd);
}
#endif
}
