OK, so we have loved them, made them, used them, now I recommend compressing them.
There are four of options for compressions technologies in the apple PVRTC tool, texturetool:
–channel-weighting-linear
–channel-weighting-perceptual
–bits-per-pixel-2
–bits-per-pixel-4
For realistic looking images, they recommend perceptual, but there’s still a lot of artifacting with that technology.
You might try compressing them with [...]
OK, so we have seen how cool they are, we’ve discussed how to make them, now we are going to look at how to read them into your OpenGL application.
First you need to understand how textures map in Open GL. Jeff Lemarche does an amazing job explaining that in his blog, http://iphonedevelopment.blogspot.com/2009/05/opengl-es-from-ground-up-part-6_25.html.
I love [...]
I haven’t checked the iPhone 4.0 sdk yet, but last time I looked you could not do non-rectangular buttons or UIViews with the UIKit.
This becomes a problem when you do UI’s that overlap clickable areas of non-rectangular shape. You see this a lot in games.
In order to get this working I had to add the [...]
Making texture atlas is either the responsibility of the artist or the developers. In my last project it was the developers
So I created a tool that produced square pngs files with widths and heights a power of two (128×128, 256×256, 512×512, 1024×1024). These texture atlases contained as many smaller images as possible.
I then stored information [...]
Texture atlases are a great way to minimize your memory footprint when you have an Open GL application with lots of images. I ran into this when porting a game from Mac/Windows to the iPhone.
Texture atlases allow you to pack multiple images in one image allowing for multiple images to be loaded at once. This [...]