[Bug 14762] GeforceFX series: fullscreen PP effect issues / RECT texcoord fixup

[wine-bugs at winehq.org]

http://bugs.winehq.org/show_bug.cgi?id=14762





--- Comment #44 from Stefan Dösinger <stefandoesinger at gmx.at>  2008-12-04 18:42:41 ---
Yes, this is the problem:

/* can we safely assume that the cast works here? */
const IWineD3DSurfaceImpl *surf =
(IWineD3DSurfaceImpl*)stateBlock->textures[i];
const float tex_dim[2] = {surf->currentDesc.Width, surf->currentDesc.Height};

The cast is not safe, because a texture is not a surface. It is a container
that contains one or more surfaces(or volumes, in case of a 3D texture).

I also noticed this:
if(arg->opcode_token & WINED3DSI_TEXLD_BIAS) {
    ...
+    /* what to do here when texrect is enabled? */
    shader_addline(arg->buffer, "%s(Psampler%u, %s, %s)%s);\n",
}

I'd argue that this should never happen, because D3DSI_TEXLD_BIAS specifies a
level of detail bias to use a different mipmap sublevel(see below), which
doesn't make much sense with RECT textures since they only have one level
anyway. However, it could happen that D3D supports this, and simply ignores the
LOD Bias in this case. I think this is a candidate for a test case.

FYI:
A 1024x1024 2D texture can for example contain 10 surfaces, which are then
usually called mipmap sublevels. The first one has 1024x1024 pixels, the 2nd
512x512, then 256x256 etc. Depending on the level of detail needed when
sampling from the texture, different a different mipmap is read. This reduces
filtering artifacts because the artist can draw the smaller mipmaps separately
and optimize the content for looking well instead of relying on strictly
mathematical filtering algorithms. (Ever played an old game where fences,
bricks or other recursive patterns start flickering or show other odd effects?)

Don't worry: You don't have to care about mipmaps here. Why?

There are also cube textures. Those essentially 6 2D textures(possibly with
mipmaps) arranged in a cubic layout. When sampling from such a texture, you sit
in the center of the cube, and a 3D direction vector points to a texel. This is
often used for drawing reflections.

If you do need a surface in this code


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