Forums > Jitter

texture mipmap

May 27, 2006 | 4:59 pm

I can’t get mipmapping to work on my computer. I’m using power-of-two
textures (1024×1024), but setting mipmap or filter settings just gives me
errors.

@mipmap linear or nearest generates the following error: "jit.gl.texture:
setting texture filter mode.: GL Error: Invalid operation."

I guess bilinear and trilinear are not supported by my videocard because I
get: "jit.gl.texture: invalid filter mode bilinear".

I’m animating photos and the quality of the pictures is important. Scaling
from thumbs to fullscreen and back without interpolation looks really bad. I
hope someone knows a fix / workaround for this.

I’m using jitter 1.5.2 + nvidea go6800 (forceware 84.25)

-thijs


May 27, 2006 | 9:35 pm

Hi Thijs,

Unfortunately, the filter attribute of jit.gl.texture is broken in
1.5.2 and should be fixed in 1.5.3. I haven’t performed testing of
the mipmap case, but we can do this to verify. Standard bilinear
texture filtering is the default (same as linear), however it doesn’t
do a very good job at downsampling.

For image scaling, one could write a decent quality texture scaling
shader which uses something like a lancszos or mitchell filter for
texture sampling. Perhaps we’ll find time to make one for the jitter
1.5.3 release, but one quick workaround might be to use one of the
blurring shaders where blur width is increased as the scale is
decreased.

Hope this helps.

-Joshua


May 27, 2006 | 10:21 pm

That’s too bad. I’ll see if I have the time to get the shader thing working
for now. I just ran into a bigger problem… patch is on the way.

-thijs


Viewing 3 posts - 1 through 3 (of 3 total)