BitmapFontAtlas on same texture as other game images

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BitmapFontAtlas on same texture as other game images

(10 posts) (4 voices)

Started 2 years ago by meboz
Latest reply from meboz

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BitmapFontAtlas

meboz
Member

Hi,

Im trying to resolve a performance issue in my game.

I have all of my game images on the one spritesheet. I now have a score label for which i have generated a font file with the Hiero tool.

Ideally I'd like to update my score label with the current score on every update. However there seems to be a significant performance hit when doing so, which i believe is the result of the game images texture and the font texture swapping each update.

Can anyone suggest a way to avoid this? Possibly by combining the font images with the game images in the one image file to avoid the texture swapping?

Cheers

Posted 2 years ago #
sowbug
Member

I had a similar problem using 0.90 and solved it by drawing the text with good old CCLabel instead of CCBitmapFontAtlas. Although I was using 0.90, I had applied various speed improvements from the tip of the tree, none of which seemed to help.

Posted 2 years ago #
meboz
Member

yeah ive been using CCLabel and that has resulted in the texture swapping.

Im guessing that given the BitMapFontAtlas will still need to bind its texture when drawing a string, i will still have the texture swapping issue.

There doesnt appear to be an initilizer available on the BitMapFontAtlas to give it a texture thats already in memory, thats what im aiming for.

Posted 2 years ago #
MikeSz
Member

I know it's not a direct answer to your question, but do you absolutely need to do it on every frame ? you can just use some boolean across your app (say scoreDirty) that changes to true whenever there's a score change, and only update the label when it's really needed

Posted 2 years ago #
meboz
Member

hey,

yeah i settled on that approach as an interim solution, i was basically updating the score label each second.

After playing for a bit, it didn't feel right, i really liked seeing the score update quickly, in the context of the game it makes sense.

Having said that, ive used that approach elsewhere in the game. My collision detection routine is a little intensive, so i only run that every second frame, pinpoint accuracy isnt essential for this game.

The ultimate solution i settled on was actually the use a UILabel for the score and add as a subview to my openglview. Im still only updating 10 times a second.

I think maybe ill go back to the BitMapFontAtlas and limit the number times it updates.

I think though that there should be scope to place the fonts in the same image as the rest of the game images. Once i learn more about bitmapfonts, ill try and work towards this.

Posted 2 years ago #
riq
Key Master

BitmapFontAtlas should be very fast in when updating the labels. There should not be any penalty in updating the label every frame.
If not, it is a bug, and I would appreciate if you open a bug with the test case. Thanks.

Posted 2 years ago #
meboz
Member

Hi riq,

Thanks for the reply, Im pretty new to cocos2d and iphone game dev in general. This is my first game.

I just noticed in the console that when the label is updated every frame, theres a dealloc call to the texture that holds the game images, and then when the game entities are drawn, it seems the texture that holds the font images is deallocd.

I have limited understanding of opengl but is it the case that opengl has to bind the textures before drawing, which is reasonably expensive?

Is that the norm or is there something im doing wrong? Im happy to try and raise a bug if thats the case, but like i said, im a noob.

By the way, good work with the framework. I will be using it alot and will be happy to provide feedback or patches where i can.

Posted 2 years ago #
riq
Key Master

@meboz: CCLabel is slow... it works as you said, but CCBitmapFontAtlas should not alloc/dealloc anything... if so, it is a bug.

What cocos2d version are you using ?

Posted 2 years ago #
meboz
Member

im on 0.99, ill give the bitmapfontatlas another go and get back to you with some results.

Posted 2 years ago #
meboz
Member

k, i used the bitmapfontatlas and as riq pointed out there is no penalty for updating the labels every frame.

Its very performant. I made the wrongs assumption in comparing it to CCLabel.

Thanks for the replies everyone!

Posted 2 years ago #

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