Example #1
0
// Calculates the transformed vertices and axes and the bounding box.
func (poly *PolygonShape) update(xf transform.Transform) AABB {
	//transform axes
	{
		src := poly.Axes
		dst := poly.TAxes

		for i := 0; i < poly.NumVerts; i++ {
			n := xf.RotateVect(src[i].N)
			dst[i].N = n
			dst[i].D = vect.Dot(xf.Position, n) + src[i].D
		}
		/*
			fmt.Println("")
			fmt.Println("Started Axes")
			fmt.Println(xf.Rotation, xf.Position)
			for i:=0;i<poly.NumVerts;i++ {
				fmt.Println(src[i], dst[i])
			}
		*/
	}
	//transform verts
	{
		inf := vect.Float(math.Inf(1))
		aabb := AABB{
			Lower: vect.Vect{inf, inf},
			Upper: vect.Vect{-inf, -inf},
		}

		src := poly.Verts
		dst := poly.TVerts

		for i := 0; i < poly.NumVerts; i++ {
			v := xf.TransformVect(src[i])

			dst[i] = v
			aabb.Lower.X = vect.FMin(aabb.Lower.X, v.X)
			aabb.Upper.X = vect.FMax(aabb.Upper.X, v.X)
			aabb.Lower.Y = vect.FMin(aabb.Lower.Y, v.Y)
			aabb.Upper.Y = vect.FMax(aabb.Upper.Y, v.Y)
		}

		/*
			fmt.Println("Verts")
			for i:=0;i<poly.NumVerts;i++ {
				fmt.Println(src[i], dst[i])
			}
		*/
		return aabb
	}
}
Example #2
0
func (arb *Arbiter) applyImpulse3() {
	a := arb.ShapeA.Body
	b := arb.ShapeB.Body

	for i := 0; i < arb.NumContacts; i++ {
		con := arb.Contacts[i]
		n := con.n
		r1 := con.r1
		r2 := con.r2

		// Calculate the relative bias velocities.
		vb1 := vect.Add(a.v_bias, vect.Mult(vect.Perp(r1), a.w_bias))
		vb2 := vect.Add(b.v_bias, vect.Mult(vect.Perp(r2), b.w_bias))
		vbn := vect.Dot(vect.Sub(vb2, vb1), n)

		// Calculate the relative velocity.
		vr := relative_velocity(a, b, r1, r2)
		vrn := vect.Dot(vr, n)
		// Calculate the relative tangent velocity.
		vrt := vect.Dot(vect.Add(vr, arb.Surface_vr), vect.Perp(n))

		// Calculate and clamp the bias impulse.
		jbn := (con.bias - vbn) * con.nMass
		jbnOld := con.jBias
		con.jBias = vect.FMax(jbnOld+jbn, 0.0)

		// Calculate and clamp the normal impulse.
		jn := -(con.bounce + vrn) * con.nMass
		jnOld := con.jnAcc
		con.jnAcc = vect.FMax(jnOld+jn, 0.0)

		// Calculate and clamp the friction impulse.
		jtMax := arb.u * con.jnAcc
		jt := -vrt * con.tMass
		jtOld := con.jtAcc
		con.jtAcc = vect.FClamp(jtOld+jt, -jtMax, jtMax)

		// Apply the bias impulse.
		apply_bias_impulses(a, b, r1, r2, vect.Mult(n, con.jBias-jbnOld))

		// Apply the final impulse.
		apply_impulses(a, b, r1, r2, transform.RotateVect(n, transform.Rotation{con.jnAcc - jnOld, con.jtAcc - jtOld}))

	}
}
Example #3
0
func (tree *BBTree) GetBB(obj Indexable) AABB {
	v, ok := obj.Velocity()
	if ok {
		bb := obj.AABB()
		coef := vect.Float(0.1)

		l := bb.Lower.X
		b := bb.Lower.Y
		r := bb.Upper.X
		t := bb.Upper.Y

		x := (r - l) * coef
		y := (t - b) * coef

		v = vect.Mult(v, 0.1)

		return NewAABB(l+vect.FMin(-x, v.X), b+vect.FMin(-y, v.Y), r+vect.FMax(x, v.X), t+vect.FMax(y, v.Y))
	}

	return obj.AABB()
}
Example #4
0
func MergedAreaPtr(a, b *AABB) vect.Float {
	return (vect.FMax(a.Upper.X, b.Upper.X) - vect.FMin(a.Lower.X, b.Lower.X)) * (vect.FMax(a.Upper.Y, b.Upper.Y) - vect.FMin(a.Lower.Y, b.Lower.Y))
}