Only the fly texture compression has been pretty slow in my experience, not something you'd want to, unless you can do it safely in a background thread, but this would in turn mean creating a seperate graphics context and sharing texture between them, or implementing your own compression routine.
Another factor to consider is mipmap generation - its expensive too, so the ability to create compressed & mipmapped texture on disk, and then just read them in the form you pass to OpenGL and in the form is passes to the GPU and in the form it stores it on local memory is nirvana for efficient texture upload.
What would be really cool is you could do more complex decompression down on the GPU, now that could be very efficient in bandwidth terms. However, I have no clue how much you could achieve in this direction.
Robert.
On 8/31/06, Chris Hanson <[EMAIL PROTECTED]> wrote:
Zach Deedler wrote:
> Chris,
> I've found dxt5 compresses the most without any noticeable artifacts. I
> assume it performs better compressed, but I'm not sure.
> myfile.ive = 117MB loadtime= 2.8
> myfile-dxt5.ive = 26MB loadtime=0.4
What I'm interested in is this -- my constraints do not allow me to precompress the
textures with DXT compression -- they'll be coming in from a wavelet compressed source.
So, I'm wondering if compressing on the fly to DXTn and then uploading to the card is
slower or faster than using uncompressed textures, and by how much.
Robert's test should allow me to document this.
> Zach
--
Chris 'Xenon' Hanson aka Eric Hammil | http://www.3DNature.com/ eric at logrus
"I set the wheels in motion, turn up all the machines, activate the programs,
and run behind the scenes. I set the clouds in motion, turn up light and sound,
activate the window, and watch the world go 'round." -Prime Mover, Rush.
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