Can someone sum up the ATI filtering thread please?

[Evildeus]

 

[Evildeus]

Does anyone have some reasons on why the algorithm seems to work better under DX than OGL

 

[davepermen]

most that use the automipmap from dx, possibly use gluBuildMipmaps in opengl (the old way to "autogen mipmaps"), wich is just a function that does manually the stuff.. the new way, GL_SGIS_generate_mipmaps is not yet widely supported (not in any q3 based game, for example, nor in any other i knew of..).

doom3 will be one of the first really supporting that ext, i'd guess, and gain some performance due it...

this is all speculation, of course!

 

[Evildeus]

Ok, thanks.

 

[Xmas]

most that use the automipmap from dx, possibly use gluBuildMipmaps in opengl (the old way to "autogen mipmaps"), wich is just a function that does manually the stuff.. the new way, GL_SGIS_generate_mipmaps is not yet widely supported (not in any q3 based game, for example, nor in any other i knew of..).

Just a note, automatic mipmap generation has been promoted to a core feature in OpenGL 1.4.

 

[davepermen]

most that use the automipmap from dx, possibly use gluBuildMipmaps in opengl (the old way to "autogen mipmaps"), wich is just a function that does manually the stuff.. the new way, GL_SGIS_generate_mipmaps is not yet widely supported (not in any q3 based game, for example, nor in any other i knew of..).

Just a note, automatic mipmap generation has been promoted to a core feature in OpenGL 1.4.

i know. but how much apps use 1.4 yet really? and on windows, you have to handle it as an ext, wich most don't want to touch (yes, i know, using that ext/core feature is very simple.. still.. so is gluBuildMipmaps..).

there aren't much opengl apps wich use 1.4, or the ext. i don't know any at least.

 

[Hyp-X]

most that use the automipmap from dx, possibly use gluBuildMipmaps in opengl (the old way to "autogen mipmaps"), wich is just a function that does manually the stuff.. the new way,

I beleive most people use D3DXCreateTextureFromFile to build the mipmaps or use .dds files which already contain mipmaps pre-generated.
D3DXCreateTextureFromFile does things manually like gluBuildMipmaps.

I still doubt that many existing applications use automipmap.

 

[davepermen]

more than in gl at least (as there are quite some new dx apps, but about no new gl app).

and possibly, they can even detect you load it from file, and check then, too.. in dx, this loading is a defined interface => they can handle it well..
should be doable in opengl, too, checking all first glTexImage() loops on a tex-id. then again, ati is known to not care that much about opengl in terms of optimisation.

as i said. i don't KNOW. but its definitely a possibility, so a fine guess.

 

[Clootie]

and possibly, they can even detect you load it from file, and check then, too.. in dx, this loading is a defined interface => they can handle it well..

D3DXCreateTextureFromFile is build in app code, there is NO WAY to driver to know how texture is loaded. Driver is only requested to lock texture and return acessible by CPU memory block.