Hansong Zhang (zhangh++at++cs.unc.edu)
Mon, 27 May 1996 14:47:00 -0400 (EDT)
I have another question on interpolation of texels.
What I'm doing is:
(1) draw in a 256x256 window a (0,0)-(255,255) square onto which
the 256x256 texture is mapped
(2) load the 256x256 image in the window into the texture with
fbsubtexload(); loop to (1), i.e. draw the sqaure with the
framebuffer image as a texture map.
I expected a static image of the texture map loaded from a file; and
such I got when TX_MINFILTER is TX_POINT, TX_TRILINEAR etc. But when
TX_MINFILTER is TX_BILINEAR, I got an animation with the texture
gradually blurred and shrinking to the middle of the window. I think
this shouldn't happen since I'm neither minifying or magnifying the
texture. Could anybody explain this to me? Thanks much,
My texture and geometry coordinates are:
float texcoords[4][2] = {{0,0},{1,0},{1,1},{0,1}};
float coords[4][2] = {{0,0},{255,0},{255,255},{0,255}};
And the code is:
for (i=0; i<LOOPS; i++) {
bgnpolygon();
for (j=0; j<4; j++) {
t2f(texcoords[j]);
v2f(coords[j]);
}
endpolygon();
gflush();
fbsubtexload(0,0, TX_TEXTURE_0, SPOT, 0.0f, 1.0f, 0.0f, 1.0f, 0);
}
Thanks,
Hansong
>
> rany++at++netvision.net.il writes:
> >If I remember correctly, the 'flags' argument in the fbsubtexload() command
> >- which you set to 1, tells fbsubtexload(0 to act in one of a several
> >special cases. flags=1 means that the texture chunk you are loading is a 8
> >bit intensity texture tile of size 64x64. Try settiong 'flags' to zero.
>
> Actually, that's the interpretation of the flags argument to subtexload();
> the flags to fbsubtexload are not used.
>
> The manpage hints that fbsubtexload() is for use with textures that have
> been defined with TX_FAST_DEFINE; try adding that to the list of properties
> in texdef2d().
>
> Simon
>
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