scaled hires-tex problem (wall vs. floor)

simc · Post by **simc** » Sat Nov 24, 2007 15:35

If a hi-res texture has an "un-orthodox" scaling, it might not be scaled equally both on the floors and on the walls.

A small 64x64 PNG defined as a 21x21 texture is scaled correctly on the wall but it appears as a bit too small if it is used as a floor flat instead.

http://www.geocities.com/gearlost/misc3/doom0011.png

http://www.geocities.com/gearlost/misc3/texscale.zip

However if the same png is scaled as a 21x32 texture only the flat's 21-side is scaled wrong. And if it is scaled as a 16x16 or 32x32 texture it'll be all fine.

Wonder if this is a problem with my graphics card? This happens only with the opengl renderer, but the textures are rendered correctly if the GL system is disabled. Please, check.

Post by **Graf Zahl** » Sat Nov 24, 2007 16:08

It's not your graphics card. There seems to be a precision problem somewhere in the calculations.

InsanityBringer · Post by **InsanityBringer** » Sat Nov 24, 2007 16:08

Flat sizes have to be a power of two
ex 2,4,8,16,32,64,128,

edit:or graf explained it as something different

Post by **Graf Zahl** » Sat Nov 24, 2007 17:01

No. Scales can be any factor. But apparently there's a bug either in OpenGL or NVidia's graphics driver because the scaling factors are not correct. The annoying thing is that I can't fix this without introducing a lot of overhead into the flat rendering code.

InsanityBringer · Post by **InsanityBringer** » Sat Nov 24, 2007 17:21

ahh. I was getting confused about something else

simc · Post by **simc** » Mon Nov 26, 2007 18:55

Btw, it looks like those odd-scaled textures (like 21x21) are scaled all correctly with older GZDoom 1.0.18. (But it used devil.dll?)

Post by **Graf Zahl** » Mon Nov 26, 2007 22:56

It has nothing to do with DevIL. Actually, in that version both walls and flats are wrong due to imprecise scaling values which I fixed about a year ago. How this still persists for flats is a bit strange though.

Post by **Graf Zahl** » Sat Jun 14, 2008 16:55

I just retested this WAD and the problem was gone. The only relevant change I made since then was updating the graphics driver so that seems to habe been the cause of the problem.