;;-*-Lisp-*-
(in-package goal)
(bundles "ENGINE.CGO" "GAME.CGO")
(require "engine/math/matrix.gc")
(require "engine/math/transform-h.gc")

;; note: transformq and trsq is mostly used instead of transform.

;; DECOMP BEGINS

(defmethod print ((this transform))
  (format #t "#<transform @ #x~X~%" this)
  (format #t "~T~Ttrans:~F ~F ~F ~F ~%" (-> this trans x) (-> this trans y) (-> this trans z) (-> this trans w))
  (format #t "~T~Trot:  ~F ~F ~F ~F ~%" (-> this rot x) (-> this rot y) (-> this rot z) (-> this rot w))
  (format #t "~T~Tscale:~F ~F ~F ~F>" (-> this scale x) (-> this scale y) (-> this scale z) (-> this scale w))
  this)

(defmethod new trs ((allocation symbol) (type-to-make type))
  "Create a new trs and set it equal to identity."
  (let ((this (object-new allocation type-to-make (the-as int (-> type-to-make size)))))
    (set! (-> this trans w) 1.0)
    (set! (-> this rot w) 1.0)
    (vector-identity! (-> this scale))
    this))

(defun transform-matrix-calc! ((tf transform) (dst-mat matrix))
  "Convert a transform to a matrix. This is not particularly efficient."
  (let ((s4-0 (new-stack-matrix0))
        (s3-0 (new-stack-matrix0)))
    ;; start with identity
    (matrix-identity! dst-mat)
    ;; set translation (which also sets identity...)
    (matrix-translate! dst-mat (-> tf trans))
    ;; rotate y axis (this is first, so yaw is "world aligned"
    (matrix-rotate-y! s4-0 (-> tf rot y))
    (matrix*! s3-0 s4-0 dst-mat)
    ;; rotate x axis
    (matrix-rotate-x! s4-0 (-> tf rot x))
    (matrix*! dst-mat s4-0 s3-0)
    ;; rotate z axis
    (matrix-rotate-z! s4-0 (-> tf rot z))
    (matrix*! s3-0 s4-0 dst-mat)
    ;; apply scale
    (matrix-scale! s4-0 (-> tf scale))
    (matrix*! dst-mat s4-0 s3-0)))

(defun transform-matrix-parent-calc! ((tf transform) (dst-mat matrix) (inv-scale vector))
  "Convert a transform to a matrix, applying an inverse scaling."
  (let ((s4-0 (new-stack-matrix0))
        (s3-0 (new-stack-matrix0)))
    (matrix-identity! s3-0)
    (matrix-translate! s3-0 (-> tf trans))
    (matrix-inv-scale! s4-0 inv-scale)
    (matrix*! dst-mat s4-0 s3-0)
    (matrix-rotate-y! s4-0 (-> tf rot y))
    (matrix*! s3-0 s4-0 dst-mat)
    (matrix-rotate-x! s4-0 (-> tf rot x))
    (matrix*! dst-mat s4-0 s3-0)
    (matrix-rotate-z! s4-0 (-> tf rot z))
    (matrix*! s3-0 s4-0 dst-mat)
    (matrix-scale! s4-0 (-> tf scale))
    (matrix*! dst-mat s4-0 s3-0)))

(defun trs-matrix-calc! ((tf trs) (dst-mat matrix))
  "Convert a trs to a matrix"
  ;; this relies on the fact that trs and transform both have the same memory layout.
  (transform-matrix-calc! (the-as transform (-> tf trans)) dst-mat))