;; SCALE-4-BY-4
;; By Peter Reidy
;; Filed as {ERIS}<LISPCORE>TEST>DISPLAY>MATMULT>SCALE-4-BY-4.TEST
;; Syntax: (SCALE-4-BY-4 SX SY SZ &optional RESULT)
;; Function description: returns a 4-by-4 homogeneous scaling transformation that scales by factors of SX, SY and SZ along the 3 axes.  If RESULT is supplied and is a 4-by-4 single-float matrix, it is set to the function's result.
;; Arguments:
;;	SX SY SZ: real numbers
;;	RESULT: a 4-by-4 single-float matrix.
;;
(do-test-group scale-4-by-4-group
	:before
	(progn
		(il:load? '{eris}<lispcore>test>display>matmult>matmult-test.source)
		(test-setq sample (make-array '(4 4) :initial-contents '((1.0 2.0 3.0 4.0) (5.0 6.0 7.0 8.0) (9.0 10.0 11.0 12.0) (13.0 14.0 15.0 16.0)) :element-type 'single-float))
	)
	(do-test scale-4-by-4-simple-case
		(matrix-p (il:scale-4-by-4 (randmost) (- (random most-positive-fixnum)) 13/30) 4)
	)
;;
	(do-test scale-4-by-4-with-result
		(let ((fact1 (randmost)) (fact2 (random most-positive-fixnum)))
			(and
				(not
					(equal
						(2dlist sample)
						(2dlist
							(il:scale-4-by-4 fact1 fact2 most-negative-fixnum)
						)
					)
				)  ; before
				(il:scale-4-by-4 fact1 fact2 most-negative-fixnum sample)
				(equal (2dlist sample) (2dlist (il:scale-4-by-4 fact1 fact2 most-negative-fixnum)))  ; after
			)
		)
	)
)
END