diff options
| -rw-r--r-- | sly/quaternion.scm | 40 |
1 files changed, 21 insertions, 19 deletions
diff --git a/sly/quaternion.scm b/sly/quaternion.scm index 9bf9427..663b0dd 100644 --- a/sly/quaternion.scm +++ b/sly/quaternion.scm @@ -34,8 +34,8 @@ identity-quaternion null-quaternion quaternion* quaternion-slerp quaternion-magnitude quaternion-normalize - vector->quaternion axis-angle->quaternion - quaternion->vector quaternion->transform)) + vector->quaternion axis-angle->quaternion quaternion->vector + rotate)) (define-record-type <quaternion> (make-quaternion w x y z) @@ -112,20 +112,22 @@ AXIS must be a 3D vector." ((? vector4? v) (make-quaternion (vx v) (vy v) (vz v) (vw v))))) -(define (quaternion->transform q) - "Convert the quaternion Q into a 4x4 transformation matrix." - (match q - (($ <quaternion> w x y z) - (make-transform - (- 1 (* 2 (square y)) (* 2 (square z))) - (- (* 2 x y) (* 2 w z)) - (+ (* 2 x z) (* 2 w y)) - 0 - (+ (* 2 x y) (* 2 w z)) - (- 1 (* 2 (square x)) (* 2 (square z))) - (- (* 2 y z) (* 2 w x)) - 0 - (- (* 2 x z) (* 2 w y)) - (+ (* 2 y z) (* 2 w x)) - (- 1 (* 2 (square x)) (* 2 (square y))) - 0 0 0 0 1)))) +(define rotate + (match-lambda* + ;; Automagically convert axis angles to quaternions. + (((? vector3? axis) (? number? theta)) + (rotate (axis-angle->quaternion axis theta))) + ((($ <quaternion> w x y z)) + (make-transform + (- 1 (* 2 (square y)) (* 2 (square z))) + (- (* 2 x y) (* 2 w z)) + (+ (* 2 x z) (* 2 w y)) + 0 + (+ (* 2 x y) (* 2 w z)) + (- 1 (* 2 (square x)) (* 2 (square z))) + (- (* 2 y z) (* 2 w x)) + 0 + (- (* 2 x z) (* 2 w y)) + (+ (* 2 y z) (* 2 w x)) + (- 1 (* 2 (square x)) (* 2 (square y))) + 0 0 0 0 1)))) |