cocos2d for iPhone

A fast, easy to use, free, and community supported 2D game engine

1. 

   claudefan
   Member

   In my program, I use the default alpha pixel format which is RGBA8888.

   Yesterday, I imported a new PNG (1024 * 1024)which is RGB Color and 8bits per channel created by Photoshop CS3 into my program, and I found the FPS < 1!!!

   I tried and found there were two ways to restore FPS to 50+:
   1) add the line before loading the PNG
   [Texture2D setDefaultAlphaPixelFormat: kTexture2DPixelFormat_RGBA4444];
   after loading, just restore the RGBA8888

   2) convert the PNG to PVR (4bits per channel)

   But other PNGs which had the same specifications worked well for a long time!
   Could you help me to find the reason? Thx!

   Posted 2 years ago #
2. 

   Kahless
   Member

   You will find a PNG saved in photoshop is much larger than a PNG need be i'm hazarding a guess that is what is causing your slowdown, you could use an optimizing tool to reduce it's size.

   http://en.wikipedia.org/wiki/Portable_Network_Graphics#Optimizing_tools

   Even using the save for web and devices option in CS3 and saving as 24bit PNG will reduce the size drastically.

   Posted 2 years ago #
3. 

   claudefan
   Member

   I tried the save for web and devices option in CS3 and saving as 24bit PNG, the PNG file reduced about 2K.

   When I use the newer PNG file, the problem still exist: FPS < 1!!!

   Posted 2 years ago #
4. 

   Clain
   Member

   Do you display this 1024x1024 png file as a sprite ? How many big images do you try to display at the same time ?

   Posted 2 years ago #
5. 

   Steve Oldmeadow
   Administrator

   Check your texture memory usage using Instruments. I'm guessing you are close to the 24Mb limit and the new texture pushes you over but when you use 4444 or PVR you sneak in under 24Mb.

   Posted 2 years ago #
6. 

   Codemattic
   Moderator

   "You will find a PNG saved in photoshop is much larger than a PNG need be" true, and that will make the app's filesize bigger, but shouldnt change how much RAM is used, which is probably the problem here.

   Posted 2 years ago #
7. 

   claudefan
   Member

   hi Steve, you are right! :)

   I used Instruments to profiling the OpenGL ES, and found that the texture memory is over 24Mb.

   When I changed the line:
   [Texture2D setDefaultAlphaPixelFormat: kTexture2DPixelFormat_RGBA4444];
   to the begin of my program for all my PNGs, the texture memory is under 16M. :)

   Posted 2 years ago #

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