geom.go
func (g *GeoM) Element(i, j int) float64 {
	switch {
	case i == 0 && j == 0:
		return float64(g.a_1) + 1
	case i == 0 && j == 1:
		return float64(g.b)
	case i == 0 && j == 2:
		return float64(g.tx)
	case i == 1 && j == 0:
		return float64(g.c)
	case i == 1 && j == 1:
		return float64(g.d_1) + 1
	case i == 1 && j == 2:
		return float64(g.ty)
	default:
		panic("ebiten: i or j is out of index")
	}
}
func (g *GeoM) Element(i, j int) float64 {
	switch {
	case i == 0 && j == 0:
		return float64(g.a_1) + 1
	case i == 0 && j == 1:
		return float64(g.b)
	case i == 0 && j == 2:
		return float64(g.tx)
	case i == 1 && j == 0:
		return float64(g.c)
	case i == 1 && j == 1:
		return float64(g.d_1) + 1
	case i == 1 && j == 2:
		return float64(g.ty)
	default:
		panic("ebiten: i or j is out of index")
	}
}
// Element returns a value of a matrix at (i, j).