View Full Version : Horrible texture blur\pixelization
05-03-2011, 12:04 PM
hey. today i discovered weird bug on radeon x700. actually, it's not my system, but one of my testers. so, according to subject, textures are horribly blurry(if i disable filtering - horribly pixelated), when on other systems they're ok.
OS: Win 7 x64
I tried every filtering mode(i mean GL_TEXTURE_MAG\MIN_FILTER) that did not help, because most of textures are not scaled. They could be scaled, but that doesn't affect anything. I also tried
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 0);
, that didn't help either. At current time i cannot directly access that system(maybe later), so i'm asking you, maybe someone already encountered simillar issues? And there, you think, i should dig? Is it my fault or notorious ATI drivers?
05-03-2011, 12:09 PM
Part of screenshot he sent me. For you to know how it looks like.
05-03-2011, 09:59 PM
Aw, silly me, it looks like blur caused by NPOT textures and enabled mipmapping(i still can use NPOT withous scaling, just by disabling GL_GENERATE_MIPMAP, right?).
05-04-2011, 05:51 AM
why do you need mipmaps for 2d stuff ?
05-04-2011, 09:14 AM
To make images scalable. Application GUI is fully customizable. At least, fonts are needed to be scalable. It looks like on FX series and all older cards i cannot use NPoT textures even with disabled mipmaps, right?
05-04-2011, 09:57 AM
Standard NPoT is either unavailable or - even worse - software emulated on this kind of hardware, yes. GL_ARB_texture_rectangle should however work on at least the more recent models.
05-04-2011, 08:07 PM
Oh thank you, that looks like the best fix possible. I didn't knew about that extension(to be more certain, i didn't knew what it is for) and thought about alternative render using glDrawPixels(and almost done it). According to GL Extension Viewer, GL_ARB_texture_rectangle is supported by almost every adapter.
05-05-2011, 01:04 AM
Just be aware the GL_ARB_texture_rectangle explicitly does not support mipmap filtering. This will limit the range of scaling you can do and maintain quality.
05-05-2011, 02:53 AM
I've noticed weird behavior. OpenGL reports that GL_ARB_texture_non_power_of_two is supported by Radeon x700, but really it's not, it doesn't work. But on Integrated GF 6150SE it reports that GL_ARB_texture_non_power_of_two and GL_ARB_texture_rectangle are NOT supported, but they should be(it works just fine with NPOT textures and mipmapping and rectangle textures work too and they're listed in GLEXViewer database for that adapter).
I just don't get it. And how should i make it automatically determine support of those extensions. Any suggestions?
Also GF 6150 SE running under XP with 258.xx driver.
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