Forums » Help » Strange canvas behaviour in Chrome

Hi all,

Without doubt Impact is the best $99 I have spent in a long time and I have level one of my game running flawlessly in IE9 and Firefox. But I've just tried it in Chrome and at first things run fine but then after a few seconds the graphics in the canvas fade and go dark for a few seconds and I start to see strange ghosting effects followed by things freezing up. My game is very simple with very little logic in it as I have just utilised the standard entities - although I do have a lot of entities on screen at the same time. Has anyone seen anything like this before?

Any suggestions as to what to look for/try would be most appreciated.

Dud

i’ve seen similar problems to that. Your first stop should be to use the web inspector within Chrome. You’ll have to google how to turn that on as I’ve not used Chrome in ages.

But that’ll have a console in it that’ll let you know what part of the script is buggy. If it’s a super vague error, stick it up here and we’ll all do our best to help. :)

ok thanks. I was kind of hoping it was a known issue but I'll do some deeper investigation with the developer console to see if I can see the problem.

ok in the Chrome console it seems to be throwing literally hundreds of errors at a time that are index_size_err dom exception 1 in the ig.Image.ig.Class.extend.drawTile function.

It seems to be the amount of these being thrown that are causing the canvas to misbehave.

Need to look into this some more...

This is likely caused by passing the wrong image / tile sizes to Impact. I have encountered this myself and it can be very tricky to track down. I suggest you check all of your Image, Animation, and AnimationSheet code.

yep wrong size . eg:

//in EntitySomething.js ...

size: {x: 45, y: 45},
animSheet: new ig.AnimationSheet('lib/media/sprite-sheet.png', 44, 45),

// notice that the animSheet's size is not equal to the size of the entity.. this causes the Index_Size_Err DOM thingy

Great guys thanks - I will double check everything - could take a while ;)

aha! Found it! It wasn't size related in the end but was related to animation. One of my animation sequences had 16 frames in it when my actual animation sheet image had only 15 frames.

phew glad I found that one!