Function B2FindMaxSeparation

CollisionB2CollidePolygon.go:4–37

Find the max separation between poly1 and poly2 using edge normals from poly1.

(edgeIndex *int, poly1 *B2PolygonShape, xf1 B2Transform, poly2 *B2PolygonShape, xf2 B2Transform)

// Find the max separation between poly1 and poly2 using edge normals from poly1.
func B2FindMaxSeparation(edgeIndex *int, poly1 *B2PolygonShape, xf1 B2Transform, poly2 *B2PolygonShape, xf2 B2Transform) float64 {
	count1 := poly1.M_count
	count2 := poly2.M_count
	n1s := poly1.M_normals
	v1s := poly1.M_vertices
	v2s := poly2.M_vertices

	xf := B2TransformMulT(xf2, xf1)

	bestIndex := 0
	maxSeparation := -B2_maxFloat
	for i := 0; i < count1; i++ {
		// Get poly1 normal in frame2.
		n := B2RotVec2Mul(xf.Q, n1s[i])
		v1 := B2TransformVec2Mul(xf, v1s[i])

		// Find deepest point for normal i.
		si := B2_maxFloat
		for j := 0; j < count2; j++ {
			sij := B2Vec2Dot(n, B2Vec2Sub(v2s[j], v1))
			if sij < si {
				si = sij
			}
		}

		if si > maxSeparation {
			maxSeparation = si
			bestIndex = i
		}
	}

	*edgeIndex = bestIndex
	return maxSeparation
}

func B2FindIncidentEdge(c []B2ClipVertex, poly1 *B2PolygonShape, xf1 B2Transform, edge1 int, poly2 *B2PolygonShape, xf2 B2Transform) {