geom/polygonf32.go

package geom

// PointsF32 is a set of points.
type PointsF32 []PointF32

// PolF32 creates a polygon of points q.
func PolF32(q ...PointF32) PolygonF32 { return PolygonF32{Points: q} }

// PolygonF32 is defined by a set of points (floating point).
type PolygonF32 struct {
	Points PointsF32
}

// Add adds q as a vector to all points in p.
func (p PolygonF32) Add(q PointF32) PolygonF32 {
	var r = p.copy()
	for i, pt := range r.Points {
		r.Points[i] = pt.Add(q)
	}
	return r
}

func (p PolygonF32) copy() PolygonF32 {
	var q = PolygonF32{make(PointsF32, len(p.Points))}
	copy(q.Points, p.Points)
	return q
}

// Extend creates a new polygon based on p with one or more extra points q.
func (p PolygonF32) Extend(q ...PointF32) PolygonF32 {
	var t = PolygonF32{make(PointsF32, len(p.Points)+len(q))}
	copy(t.Points, p.Points)
	copy(t.Points[len(p.Points):], q)
	return t
}

// Mul multiplies the points of polygon p with t and returns the result.
func (p PolygonF32) Mul(t float32) PolygonF32 {
	var q = p.copy()
	for i, pt := range q.Points {
		q.Points[i] = pt.Mul(t)
	}
	return q
}