A fast, easy to use, free, and community supported 2D game engine
FBryant
Member
After running Instruments on my game I see these allocs take up 4MB:
gfxAllocateTextureLevel
glLoadTextureLevelBuffer
are these just standard libraries cocos2d uses?
I'm not really sure of the memory limit but isn't that taking up a pretty large chunk of my apps allowance?
Questor
Member
FBryant,
4MB is the memory needed to load a 1024x1024 texture (image) in 32bit mode. My guess is that is what it is causing it.
Regards,
Q
UPDATED:
Take a look here as this may help clarify:
http://www.cocos2d-iphone.org/forum/topic/3805
and, of course the standard reading material:
http://www.cocos2d-iphone.org/wiki/doku.php/prog_guide:best_practices
FBryant
Member
Questor,
I read your forum post about the images, I'll admit I didn't get a lot of it as I don't know much about this buffer stuff. Could you briefly sum up what you learnt from that thread? What bit PNGs did you use in the end? Did you convert 32bit images to something?
I'm insanely confused as to why a 50kb image is costing me 4MB to print it on the screen, how on earth do 3D games cope?
Thanks for your help.
Images on disk are compressed, when they are put in memory they are uncompressed. Like working with a zip file, while actually working with the file you need to uncompress it first, when youre done with working with it you can zip it up again. Search the forums, theres loads of posts on this.
An exception to this rule are pvrtc images, which remain compressed in memory, however this is not a lossless compression, your images (especially line art) will not look good. Again search the forum, there are loads of posts on this.
Questor
Member
FBryant,
Most platfromers use tilemaps to create large worlds from small building blocks. Checkout Tilemap example in cocos2d testbed.
As Hactar pointed out, there are alot of posts about graphics and memory usage...do some searches. Also, remember to also use google to search for older cocos2d posts (as sometimes the links on old posts are a bit messed up). Just add cocos2d iphone to your google search.
Important things to understand:
1) Pick the pixel format that makes sense for your image.
2) Understand that images memory is allocated in powers of two...a 512x513 pixel image will take up as much memory as a 1024x1024 image (but a 512x512 image will be allocated as exactly that (512x512) as it is already a power of 2)
3) Images are all loaded as 32bit then converted to the pixel format you specify...then the temporary 32but buffer will get released at the end of the next code block (or there abouts)...so if you have a 1024x1024 image with the pixel format set to 4444 then your
program will alloc 4MB to initially read the image in 32bits, then it will convert it to 4444 (16bit) taking up an additional 2MB...but at the end of that code block the 4MB buffer will get released.
4) As you can see you would want to stagger the loading of several large images so that the temporary 4mb buffers can get released.
Again, there are many threads regarding this, just do a search for the relevant keywords (the articles I posted above should help you with the terms to search for.) It sounds complicated (it did to me at first as well), but if you spend some time searching and reading posts you will find many of your questions (and even unasked questions) have been asked and answered several times before.
I hope this helped a little.
Regards,
Q
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