On Sunday, 17 September 2006 at 0:03, Dennis Schridde wrote: > > I was almost convinced about DDS, until I tried (wanted to try) your > > example. It compiled and ran and showed a white cube. Then I installed > > the GIMP plugin and wanted to convert the tertiles image. But the plugin > > complains about "GL_S3_s3tc or GL_EXT_texture_compression_s3tc is not > > supported by your OpenGL implementation" (the mesa3d r300 driver). Your > > test program doesn't seem to use those extensions, can you send me the > > dds file to test it? > Erm, well, the example _does_ use it. > glCompressedTexImage2D is part of the GL_EXT_texture_compression and
You mean GL_EXT_texture_compression_s3tc? I have GL_EXT_texture_compression. I wasn't sure about that glCompressedImage2D. > li->internalFormat contains eg. GL_COMPRESSED_RGBA_S3TC_DXT1_EXT (for a DXT1 > compressed image). > > So it seems like the Mesa drivers do not support S3TC. :( Pretty odd since > the > extension itself is supported even by TNT2 or Radeon (1st generation) cards. See http://homepage.hispeed.ch/rscheidegger/dri_experimental/s3tc_index.html . Ironically the older radeon and r200 driver are listed as working on that page, but not (yet) the r300. Anyway, the stupid patent stuff rules DDS out for me. > > > I think some time ago someone said that he/she thinks that pngs > > > are quite big. > > > > Compared to what? > I don't know. I just heard someone saying that. Well, PNG is about the best compromise between speed and size, as long as you stay with lossless compression. > > Not good. > Why not? Are you able to see the difference? I saw comparisons of different > images from an original 32bit image to 16bit, S3TC and FLX1. S3TC had nearly > no difference to the original expect in hard cases. (Very dark images with > some pattern in it.) The problem with lossy compression is the loss of data. Every time you save a file in a lossy format you lose information that cannot be restored. So if you modify a texture and save it again, you lose quality. Perhaps not noticeable at the beginning, but after some cycles of that? (And even if the S3TC compressor can save unmodified images several times without losing information, as soon as you change something some data will be lost again.) The difference might not be visible (at least to the eye, see http://www.sjbaker.org/steve/omniv/jpegs_are_evil_too.html on why using JPGs for textures is a bad idea - I'd imagine S3TC will take that into account, but I don't know). The thing is, lossy compression should be the last thing that is ever done to data (except viewing/listening...) > > (As is OGG, by the way. Strictly speaking, the conversion of the WAV files > > to OGG is a GPL violation. > Are you going to sue us? No, that would be Eidos (or whoever owns the copyright to the Warzone stuff now). > > ("The source code for a work means the preferred > > form of the work for making modifications to it", and that's WAV, not OGG.) > Doesn't that depend on the POV? If I like to work with OGG files because they > are smaller, then that's my preffered form of work. Does the GPL also define > what prefered means to me? "Preferred for modification", not just "preferrer format", and that seems (in that case) quite clear to me. As I said above, a lossy format is not suitable for something that someone might want to edit again. And I don't have a problem with oggifying the sound files for a release, but what's in SVN should be lossless. "Remember, licenses are written in legalese, which is formed from English words but where the meaning of certain terms is determined by heaps of case law and precedent, not necessarily by the dictionary." -- I am having FUN... I wonder if it's NET FUN or GROSS FUN? _______________________________________________ Warzone-dev mailing list [email protected] https://mail.gna.org/listinfo/warzone-dev
