It looks like there is S3TC implementation for Mesa, as external library. There is also S2TC which Mesa might try to use if there is no S3TC. Closed source drivers (currently only nVidia, AMD deleted it's fglrx drivers) might have it's own, legal implementation.

Linux users will likely have problems. Mesa does not implement S3TC due to patent. We could use ASTC, but it's only present in very modern hardware. There's also generic compressed format but who knows how that would work.

Most Colobot textures will work just fine. But I think we could use some external way of determining which textures should use compression and which ones should not.

Programs that use S3TC but don't implement its algorithm are not covered by patent. It's not illegal to use it externally. Besides, I can implement it in a way that Colobot itself doesn't know compression method beforehand. You'd have to set it in configuration file.

"Hand-drawn cartoon-like images do not compress well, nor do normal map data, both of which usually generate artifacts." - After thinking about some of Colobot's textures I have a really bad feelings about this...

"The patent on S3 Texture Compression expires on October 2, 2017" - So GOLD will be faster after this date, huh?

Compression ratio must be known while compiling, or it may be configured on-line? I mean if it's possible to detect how much compressed must be a texture if it's too big for GPU.

If it can store it in memory and GPU allows this size, yes.

Does it even allow to use more detailed textures than GPU can handle?

So 8192 textures will take as much memory as 4096 textures and so on?

With 4:1 compression ratio, compressed 256x256 texture uses the same amount of space as uncompressed 128x128 texture. Difference gets important with larger resolutions. For 1024x1024 RGBA textures, VRAM usage goes down from 1 MB to 256 KB.

That's one of the reasons, actually. Back when Unreal Tournament was popular and updated, they introduced S3TC in order to allow better textures.

Might be helpfull in future, when GPU memory usage will be increased due to hi-res textures and new models.

S3TC. It's something OpenGL can use when an extension is available. Compression ratio is 8:1 or 4:1, depending on format used. Needless to say, it's a lossy compression algorithm.

I guess it's compressing image data in hardware memory

@tomaszkax86 : What kind of compression? PNG, other image format or something engine related?

I haven't been able to do enough testing, but I read that texture compression can improve performance. And it obviously decreases VRAM usage. I'll try to add it to our game.

@krzys_h that's nice, thank you.

@Simbax I really like the style of help files in new exercises!

I think I'll just surrender with this pausing. I created silenced ogg file, pasted to music folder, code still can't load it, displays "Not found". Screw it all.