;;-*-Lisp-*-
(in-package goal)

;; name: transformq.gc
;; name in dgo: transformq
;; dgos: GAME, ENGINE

(defmethod print transformq ((obj transformq))
  "Print a transformq"
  (format #t "#<transformq @ #x~X~%" obj)
  (format #t "~T~Ttrans:~F ~F ~F ~F ~%"
          (-> obj trans x)
          (-> obj trans y)
          (-> obj trans z)
          (-> obj trans w)
          )
  (format #t "~T~Tquat:  ~F ~F ~F ~F ~%"
          (-> obj rot x)
          (-> obj rot y)
          (-> obj rot z)
          (-> obj rot w)
          )
  (format #t "~T~Tscale:~F ~F ~F ~F>"
          (-> obj scale x)
          (-> obj scale y)
          (-> obj scale z)
          (-> obj scale w)
          )
  obj
  )

(defmethod get-quaternion trsqv ((obj trsqv))
  "Get the rotation as a quaternion."
  (-> obj quat)
  )

(defmethod set-quaternion! trsqv ((obj trsqv) (arg0 quaternion))
  "Set the rotation as a quaternion"
  (quaternion-copy! (get-quaternion obj) arg0)
  )

(defmethod rot->dir-targ! trsqv ((obj trsqv))
  "Set the dir-targ to our current orientation"
  (quaternion-copy! (-> obj dir-targ) (get-quaternion obj))
  )

(defmethod y-angle trsqv ((obj trsqv))
  "Get our current y-angle (y is up, so yaw)"
  (quaternion-y-angle (get-quaternion obj))
  )

(defmethod seek-toward-heading-vec! trsqv ((obj trsqv) (dir vector) (vel float) (frame-count time-frame))
  "Adjust the orientation to point along dir, only changing our yaw.
  The vel is a maximum velocity limit.
  The frame count is the time constant (first order).
  There's some logic to avoid rapidly changing directions"
  (let* ((yaw-error (deg-diff (quaternion-y-angle (-> obj quat)) (vector-y-angle dir)))
         ;; limit both on a max velocity, and a proportional to error term.
         (yaw-limit (fmin (* vel (-> *display* seconds-per-frame))
                          (/ (* 5.0 (fabs yaw-error)) (the float frame-count))
                          )
                    )
         ;; saturate the yaw error
         (saturated-yaw (fmax (fmin yaw-error yaw-limit) (- yaw-limit)))
         )
    (let ((old-diff (-> obj old-y-angle-diff)))
      (set! saturated-yaw
            (cond
              ;; I have no idea what this crazy thing is.
              ;; But it prevents changes in direction from happening too often.
              ((or (= old-diff 0.0)
                   (and (< 0.0 saturated-yaw) (< 0.0 old-diff))
                   (or (and (< saturated-yaw 0.0) (< old-diff 0.0))
                       (>=  (- (-> *display* base-frame-counter)
                               (-> obj angle-change-time)
                               )
                           60
                           )
                       )
                   )
               (set! (-> obj angle-change-time) (-> *display* base-frame-counter))
               saturated-yaw
               )
              (else
                ;; not sure why this isn't 0.
                (* 0.000000001 saturated-yaw)
                )
              )
            )
      )
    (set! (-> obj old-y-angle-diff) saturated-yaw)
    (let ((quat (get-quaternion obj)))
      (quaternion-rotate-y! quat quat saturated-yaw)
      )
    )
  )

(defmethod set-heading-vec! trsqv ((obj trsqv) (arg0 vector))
  "Makes us look in the arg0 direction immediately.  Pitch will be unchanged."
  (let ((s3-0 (get-quaternion obj)))
   (forward-up-nopitch->quaternion
    s3-0
    (vector-normalize-copy! (new 'stack-no-clear 'vector) arg0 1.0) ;; forward is the given dir.
    (vector-y-quaternion! (new 'stack-no-clear 'vector) s3-0)       ;; use the old up
    )
   )
  )

(defmethod seek-to-point-toward-point! trsqv ((obj trsqv) (arg0 vector) (arg1 float) (arg2 time-frame))
  "Seek toward pointing toward arg0 from our current location."
  (seek-toward-heading-vec!
   obj
   (vector-! (new 'stack-no-clear 'vector) arg0 (-> obj trans))
   arg1
   arg2
   )
  )

(defmethod point-toward-point! trsqv ((obj trsqv) (arg0 vector))
  "Immediately point toward arg0"
  (let ((s3-0 (get-quaternion obj)))
    (forward-up-nopitch->quaternion
     s3-0
     (vector-normalize! (vector-! (new 'stack-no-clear 'vector) arg0 (-> obj trans)) 1.0)
     (vector-y-quaternion! (new 'stack-no-clear 'vector) s3-0)
     )
    )
  )


(defmethod seek-toward-yaw-angle! trsqv ((obj trsqv) (yaw float) (vel float) (frame-count time-frame))
  "Seek toward the given yaw angle."
  (seek-toward-heading-vec!
   obj
   ;; make a vector that points toward +z (forward) rotated by the yaw.
   (set-vector! (new 'stack-no-clear 'vector) (sin yaw) 0.0 (cos yaw) 1.0)
   vel
   frame-count
   )
  )

(defmethod set-yaw-angle-clear-roll-pitch! trsqv ((obj trsqv) (yaw float))
  "Immediately clear our roll and pitch and set yaw to the given angle"
  (set-heading-vec-clear-roll-pitch!
   obj
   (set-vector! (new 'stack-no-clear 'vector) (sin yaw) 0.0 (cos yaw) 1.0)
   )
  )

(defmethod set-roll-to-grav! trsqv ((obj trsqv) (arg0 float))
  "Set our roll so that our local down aligns with standard gravity"
  (set-roll-to-grav-2! obj arg0)
  )

(defmethod set-roll-to-grav-2! trsqv ((obj trsqv) (arg0 float))
  "Set our roll so that our local down aligns with standard gravity"
  (let* ((quat (get-quaternion obj)) ;; our orientation
         (grav (-> *standard-dynamics* gravity-normal)) ;; dir of gravity
         (rot-mat (quaternion->matrix (new 'stack-no-clear 'matrix) quat)) ;; our orientation
         )
    (let ((dir-z (-> rot-mat vector 2))) ;; this is the direction of the z-axis.
      ;; this projects world gravity into our local z plane (killing its pitch component),
      ;; then updates the rotation matrix so that this is our y axis (up)
      (vector-normalize! (vector-flatten! (-> rot-mat vector 1) grav dir-z) 1.0)
      ;; fix up the rotation matrix x vector to make the matrix orthonormal again.
      (vector-cross!
       (-> rot-mat vector 0)
       (-> rot-mat vector 1)
       dir-z
       )
      )

    ;; add some additional roll offset
    (let ((a1-5 (matrix-rotate-z! (new 'stack-no-clear 'matrix) arg0)))
      (matrix*! rot-mat a1-5 rot-mat)
      )

    ;; write it back.
    (matrix->quaternion quat rot-mat)
    )
  )

(defmethod roll-relative-to-gravity trsqv ((obj trsqv))
  "Get our roll, relative to 'down' from gravity"
  (let* ((quat (get-quaternion obj))
         (dir-z (vector-z-quaternion! (new 'stack-no-clear 'vector) quat))
         (dir-y (vector-y-quaternion! (new 'stack-no-clear 'vector) quat))
         (dir-grav (-> *standard-dynamics* gravity-normal))
         ;; project gravity to our z plane (kills pitch)
         (grav-z-plane
          (vector-normalize!
           (vector-flatten! (new 'stack-no-clear 'vector) dir-grav dir-z)
           1.0
           )
           )
         (grav-dot (vector-dot grav-z-plane dir-y))
         )
    ;; normally we'd just do (acos (vector-dot grav-z-plane y))
    ;; but this won't give us the correct sign if we're rolled negatively.
    ;; this check below manually inverts the acos as needed.
    (if (< (vector-dot (vector-cross! (new 'stack-no-clear 'vector) grav-z-plane dir-y) dir-z)
           0.0
           )
        (- (acos grav-dot))
        (acos grav-dot)
        )
    )
  )


(defmethod rotate-toward-orientation! trsqv ((obj trsqv) (target quaternion) (y-rate float) (z-rate float))
  "Adjust our orientation toward target, subject to some rate limits.
   I don't think this is a very robust function and probably doesn't work right in cases
   where an axis flips by 180 degrees."

  ;; the basic idea is that we apply two rotations:
  ;; the first moves our y axis toward the desired's y axis, and the second moves
  ;; out z axis. These are both rate limited.
  
  (local-vars (sv-96 vector))
  (let ((quat (get-quaternion obj)))
    (let ((temp-quat (new 'stack-no-clear 'quaternion)))
      (when (< 0.0 z-rate)
        (let ((s1-0 quaternion-from-two-vectors-max-angle!)
              (s0-0 temp-quat)
              )
          (set! sv-96 (vector-y-quaternion! (new 'stack-no-clear 'vector) quat))
          (let ((a2-1 (vector-y-quaternion! (new 'stack-no-clear 'vector) target))
                (a3-1 (* z-rate (-> *display* seconds-per-frame)))
                )
            (s1-0 s0-0 sv-96 a2-1 a3-1)
            )
          )
        (quaternion-normalize! (quaternion*! quat temp-quat quat))
        )
      (when (< 0.0 y-rate)
        (quaternion-from-two-vectors-max-angle!
         temp-quat
         (vector-z-quaternion! (new 'stack-no-clear 'vector) quat)
         (vector-z-quaternion! (new 'stack-no-clear 'vector) target)
         (* y-rate (-> *display* seconds-per-frame))
         )
        (quaternion-normalize! (quaternion*! quat temp-quat quat))
        )
      )
    quat
    )
  )

(defmethod set-heading-vec-clear-roll-pitch! trsqv ((obj trsqv) (arg0 vector))
  "Set our rotation to point along the given heading, with no roll or pitch."
  (forward-up->quaternion
   (get-quaternion obj)
   (vector-normalize-copy! (new 'stack-no-clear 'vector) arg0 1.0)
   (new 'static 'vector :y 1.0 :w 1.0)
   )
  )

(defmethod point-toward-point-clear-roll-pitch! trsqv ((obj trsqv) (arg0 vector))
  "Set our orientation to point toward arg0, clearing roll and pitch"
  (forward-up->quaternion
   (get-quaternion obj)
   (vector-normalize!
    (vector-! (new 'stack-no-clear 'vector) arg0 (-> obj trans))
    1.0
    )
   (new 'static 'vector :y 1.0 :w 1.0)
   )
  )

(defun transformq-copy! ((arg0 transformq) (arg1 transformq))
  "Set arg0 = arg1"
  (set! (-> arg0 trans quad) (-> arg1 trans quad))
  (set! (-> arg0 rot quad) (-> arg1 rot quad))
  (set! (-> arg0 scale quad) (-> arg1 scale quad))
  arg0
  )

(defun matrix<-transformq! ((arg0 matrix) (arg1 transformq))
  "Convert to 4x4 affine transform."
  (local-vars (v1-1 float))
  (rlet ((vf0 :class vf)
         (vf1 :class vf)
         (vf2 :class vf)
         (vf3 :class vf)
         (vf4 :class vf)
         (vf5 :class vf)
         )
   (.lvf vf0 (new 'static 'vector :x 0.0 :y 0.0 :z 0.0 :w 1.0))
   (quaternion->matrix arg0 (the-as quaternion (-> arg1 rot)))
   (cond
    (#f
     (set! (-> arg0 vector 3 quad) (-> arg1 trans quad))
     )
    (else
     ;; apply scale and copy trans
     (.lvf vf1 (&-> arg1 scale quad))
     (.lvf vf2 (&-> arg1 trans quad))
     (.lvf vf3 (&-> arg0 vector 0 quad))
     (.lvf vf4 (&-> arg0 vector 1 quad))
     (.lvf vf5 (&-> arg0 vector 2 quad))
     (.mov.vf vf2 vf0 :mask #b1000) ;; don't forget the 1.
     (.mul.x.vf vf3 vf3 vf1)
     (.mul.y.vf vf4 vf4 vf1)
     (.mul.z.vf vf5 vf5 vf1)
     (.svf (&-> arg0 vector 3 quad) vf2)
     (.svf (&-> arg0 vector 0 quad) vf3)
     (.svf (&-> arg0 vector 1 quad) vf4)
     (.svf (&-> arg0 vector 2 quad) vf5)
     (.mov v1-1 vf5)
     )
    )
   arg0
   )
  )

(defun matrix<-no-trans-transformq! ((arg0 matrix) (arg1 transformq))
  "Create 4x4 affine transform with no translation."
  (rlet ((vf0 :class vf)
         (vf1 :class vf)
         (vf2 :class vf)
         (vf3 :class vf)
         (vf4 :class vf)
         (vf5 :class vf)
         )
   (.lvf vf0 (new 'static 'vector :x 0.0 :y 0.0 :z 0.0 :w 1.0))
   (quaternion->matrix arg0 (the-as quaternion (-> arg1 rot)))
   (.lvf vf1 (&-> arg1 scale quad))
   (.lvf vf3 (&-> arg0 vector 0 quad))
   (.lvf vf4 (&-> arg0 vector 1 quad))
   (.lvf vf5 (&-> arg0 vector 2 quad))
   (.mov.vf vf2 vf0) ;; trans = 0,0,0,1
   (.mul.x.vf vf3 vf3 vf1)
   (.mul.y.vf vf4 vf4 vf1)
   (.mul.z.vf vf5 vf5 vf1)
   (.svf (&-> arg0 vector 3 quad) vf2)
   (.svf (&-> arg0 vector 0 quad) vf3)
   (.svf (&-> arg0 vector 1 quad) vf4)
   (.svf (&-> arg0 vector 2 quad) vf5)
   arg0
   )
  )

(defun matrix<-transformq+trans! ((arg0 matrix) (arg1 transformq) (arg2 vector))
  "Convert to affine transform with an additional translation (in the local frame)."
  (rlet ((acc :class vf)
         (vf0 :class vf)
         (vf1 :class vf)
         (vf2 :class vf)
         (vf3 :class vf)
         (vf4 :class vf)
         (vf5 :class vf)
         (vf6 :class vf)
         )
   (.lvf vf0 (new 'static 'vector :x 0.0 :y 0.0 :z 0.0 :w 1.0))
   (quaternion->matrix arg0 (the-as quaternion (-> arg1 rot)))
   (.lvf vf1 (&-> arg1 scale quad))
   (.lvf vf2 (&-> arg1 trans quad))
   (.lvf vf6 (&-> arg2 quad))
   (.lvf vf3 (&-> arg0 vector 0 quad))
   (.lvf vf4 (&-> arg0 vector 1 quad))
   (.lvf vf5 (&-> arg0 vector 2 quad))
   (.mov.vf vf2 vf0 :mask #b1000)
   (.mul.x.vf vf3 vf3 vf1)
   (.mul.y.vf vf4 vf4 vf1)
   (.mul.z.vf vf5 vf5 vf1)
   (.mul.x.vf acc vf3 vf6)
   (.add.mul.y.vf acc vf4 vf6 acc)
   (.add.mul.z.vf acc vf5 vf6 acc)
   (.add.mul.w.vf vf2 vf2 vf0 acc :mask #b111)
   (.svf (&-> arg0 vector 3 quad) vf2)
   (.svf (&-> arg0 vector 0 quad) vf3)
   (.svf (&-> arg0 vector 1 quad) vf4)
   (.svf (&-> arg0 vector 2 quad) vf5)
   arg0
   )
  )

(defun matrix<-transformq+world-trans! ((arg0 matrix) (arg1 transformq) (arg2 vector))
  "Convert to affine transform with an additional translation in the world frame (not rotated)"
  (rlet ((vf0 :class vf)
         (vf1 :class vf)
         (vf2 :class vf)
         (vf3 :class vf)
         (vf4 :class vf)
         (vf5 :class vf)
         (vf6 :class vf)
         )
   (.lvf vf0 (new 'static 'vector :x 0.0 :y 0.0 :z 0.0 :w 1.0))
   (quaternion->matrix arg0 (the-as quaternion (-> arg1 rot)))
   (.lvf vf1 (&-> arg1 scale quad))
   (.lvf vf2 (&-> arg1 trans quad))
   (.lvf vf6 (&-> arg2 quad))
   (.lvf vf3 (&-> arg0 vector 0 quad))
   (.lvf vf4 (&-> arg0 vector 1 quad))
   (.lvf vf5 (&-> arg0 vector 2 quad))
   (.mov.vf vf2 vf0 :mask #b1000)
   (.mul.x.vf vf3 vf3 vf1)
   (.mul.y.vf vf4 vf4 vf1)
   (.mul.z.vf vf5 vf5 vf1)
   (.add.vf vf2 vf2 vf6 :mask #b111)
   (.svf (&-> arg0 vector 3 quad) vf2)
   (.svf (&-> arg0 vector 0 quad) vf3)
   (.svf (&-> arg0 vector 1 quad) vf4)
   (.svf (&-> arg0 vector 2 quad) vf5)
   arg0
   )
  )

(defun matrix<-parented-transformq! ((arg0 matrix) (arg1 transformq) (arg2 vector))
  "Unused. Seems like the parented thing means there's an inverse scale in arg2."
  (local-vars (v1-1 float))
  (rlet ((vf0 :class vf)
         (vf1 :class vf)
         (vf2 :class vf)
         (vf3 :class vf)
         (vf4 :class vf)
         (vf5 :class vf)
         (vf6 :class vf)
         )
    (init-vf0-vector)
    (quaternion->matrix arg0 (-> arg1 quat))
    (let ((v1-0 (new 'stack-no-clear 'vector)))
      (set! (-> v1-0 x) (/ 1.0 (-> arg2 x)))
      (set! (-> v1-0 y) (/ 1.0 (-> arg2 y)))
      (set! (-> v1-0 z) (/ 1.0 (-> arg2 z)))
      (.lvf vf1 (&-> arg1 scale quad))
      (.lvf vf2 (&-> arg1 trans quad))
      (.mov.vf vf2 vf0 :mask #b1000)
      (.lvf vf4 (&-> arg0 vector 0 quad))
      (.lvf vf5 (&-> arg0 vector 1 quad))
      (.lvf vf6 (&-> arg0 vector 2 quad))
      (.mul.x.vf vf4 vf4 vf1)
      (.mul.y.vf vf5 vf5 vf1)
      (.mul.z.vf vf6 vf6 vf1)
      (.lvf vf3 (&-> v1-0 quad))
      )
    (.mul.vf vf4 vf4 vf3)
    (.mul.vf vf5 vf5 vf3)
    (.mul.vf vf6 vf6 vf3)
    (.svf (&-> arg0 vector 3 quad) vf2)
    (.svf (&-> arg0 vector 0 quad) vf4)
    (.svf (&-> arg0 vector 1 quad) vf5)
    (.svf (&-> arg0 vector 2 quad) vf6)
    (.mov v1-1 vf6)
    arg0
    )
  )