diff options
| -rw-r--r-- | starling/node-2d.scm | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/starling/node-2d.scm b/starling/node-2d.scm index 095c5ca..9a18284 100644 --- a/starling/node-2d.scm +++ b/starling/node-2d.scm @@ -284,9 +284,24 @@ (move-by node dx dy duration smoothstep)) (define-method (teleport (node <node-2d>) x y) - (move-to node x y) + ;; When teleporting, we want to avoid position interpolation and odd + ;; looking camera jumps. Interpolation is avoided by setting all 3 + ;; position vectors to the same values. This prevents a visual + ;; artifact where the player sees 1 frame where the node is + ;; somewhere in between its former position and the new position. + ;; The camera jump problem occurs when a camera has a node as its + ;; tracking target and that node teleports. Normally, the camera's + ;; view matrix is updated before any nodes are rendered, and thus + ;; *before* the node can recompute its world matrix based on the new + ;; position. This creates 1 frame where the camera is improperly + ;; positioned at the target's old location. This 1 frame lag is not + ;; an issue during normal movement, but when teleporting it causes a + ;; noticably unsmooth blip. Forcing the matrices to be recomputed + ;; immediately solves this issue. + (set-vec2! (position node) x y) (set-vec2! (last-position node) x y) - (set-vec2! (render-position node) x y)) + (set-vec2! (render-position node) x y) + (compute-matrices! node)) (define-method (rotate-to (node <node-2d>) theta) (set! (rotation node) theta) |