// RandomInSemiSphere is a function to find a ray for diffuse reflection in semisphere.
//
// Parameters:
//  normal - the normal.
//
// Returns:
// 	the vector.
//
func RandomInSemiSphere(normal utils.Vector) utils.Vector {
	random1 := rand.Float64()
	random2 := rand.Float64()
	v1 := utils.Vector{Coordinates: []float64{random1 + normal.Coordinates[0], -1 * normal.Coordinates[1], -1 * normal.Coordinates[2]}}
	v1 = utils.NormalizeVector(&v1)
	if utils.DotProduct(&normal, &v1) < 0 { // cos
		random1 = -1 * random1
	}
	v2 := utils.Vector{Coordinates: []float64{-1 * normal.Coordinates[0], random2 + normal.Coordinates[1], -1 * normal.Coordinates[2]}}
	v2 = utils.NormalizeVector(&v2)
	if utils.DotProduct(&normal, &v2) < 0 {
		random2 = -1 * random2
	}
	resultingVector := utils.Vector{Coordinates: []float64{normal.Coordinates[0] + random1, normal.Coordinates[1] + random2, normal.Coordinates[2]}}

	return resultingVector
}