What steps produce the bug: Just create an animated Sprite (the more frames, the more likely the bug will appear)
What should happen: In my codepen, the animation is 30 frames length, so by setting the Speed value to 30, I expect each loop to take approx. 1 second.
What happens instead: As seen in the codepen: a 30 frames animation set to a speed of 30 FPS takes around 1500ms to loop. Which means 50% more time than expected.
This behaviour may be the expected behaviour of Phaser, in this case, I would just like to know why.
The source of this problem comes from this line of code :
Indeed it appears that any frameDiff (i.e. time lag) between two frame updates is just wiped out if this difference is not significant enough to requires a "jump" of frame.
Meaning that if there is a small lag, the delay to wait for the next frame update will not take this lag into account (because set back to 0 in the code), and the overall timing of the animation will be therefore increased.
I'm not sure if I am clear enough, so here is a little diagram to explain:
This is the ideal case where no lag occurs :
This is the current Phaser's behaviour when encountering lags:
This is what I believe Phaser should do when encountering lags:
In the following CodePen, I've overridden the Animation.update function and removed the this._frameDiff = 0;. To try my proposed solution.
This behaviour may be the expected behaviour of Phaser, in this case, I would just like to know why.
The source of this problem comes from this line of code :
https://github.com/photonstorm/phaser-ce/blob/18e68a4f39ffcf1af238460674857124f19d0b97/src/animation/Animation.js#L436
Indeed it appears that any
frameDiff(i.e. time lag) between two frame updates is just wiped out if this difference is not significant enough to requires a "jump" of frame. Meaning that if there is a small lag, thedelayto wait for the next frame update will not take this lag into account (because set back to0in the code), and the overall timing of the animation will be therefore increased.I'm not sure if I am clear enough, so here is a little diagram to explain:
This is the ideal case where no lag occurs :
This is the current Phaser's behaviour when encountering lags:
This is what I believe Phaser should do when encountering lags:
In the following CodePen, I've overridden the Animation.update function and removed the
this._frameDiff = 0;. To try my proposed solution.https://codepen.io/anon/pen/eQNwXe
It seems to work as the animation duration is clearly closer to the animation duration than before.
Thanks for your help.