func NewCape(width, height int) Cape {
	return Cape{w: width, h: height, Pix: make([]uint8, width*height*4)}
}
NewCape initialises a new Cape using the width and height passed. The pixels are pre-allocated so that the
Cape may be used immediately.
package skin
import (
	"image"
	"image/color"
)
type Cape struct {
	w, h int
	Pix []uint8
}