ok, so i read wikipedia's thoughts about mode 7 and i am even more confused.

can someone explain this please?

mostly about the matrices.

"Planar texture maps using Mode 7 graphics are generated by transforming screen coordinates to background coordinates using a 2D affine transformation,


umm??? VVV
    \begin{bmatrix} x' \\ y' \\ 1 \end{bmatrix} = \begin{bmatrix} a & b & x_0 \\ c & d & x_0 \\ 0 & 0 & 1 \end{bmatrix} \begin{bmatrix} x - x_0 \\ y - y_0 \\ 1 \end{bmatrix}

where a, b, c, and d are the transformation coefficients; x and y are the screen offset; x_0 and y_0 are the origin offset; and x' and y' are the transformed coordinates. All arithmetic is carried out on 16-bit signed fixed point numbers, while all offsets are limited to 13 bits. The radix point is between bits 7 and 8.

Affine transformations only allow for displacement, scaling, and shearing effects. Many games create additional effects through creative manipulation of the transformation matrix parameters on a scanline by scanline basis. In this way pseudo-perspective, curved surface, and distortion effects can be achieved"

Please elaborate, I may have an idea...
But I can't really understand it yet. 

I worked out all the math on paper (it involved lots of similar triangles )

The thing to remember is that to figure out what each pixel is, you have to cast a ray through each screen pixel (as if there was a floating screen in the virtual space). This is how raytracing works, but this has much simpler math because you're only intersecting with a flat plane.

so in for a car on a straight road, how would you figure out how the road shows up on a screen?

me too! 

I beleive the program is in F-Zero subforum, however, its in ASM

If you want to see the Axe version I made a while back, you can download the source code here but it doesn't have rotation.  One confusing optimization that programs like these use though is to remove the multiplication in the main loop and replace it with an addition.

ok, could i edit the code to have rotation?

If you want to see the Axe version I made a while back, you can download the source code here but it doesn't have rotation.  One confusing optimization that programs like these use though is to remove the multiplication in the main loop and replace it with an addition.

One confusing optimization that programs like these use though is to remove the multiplication in the main loop and replace it with an addition.

How exactly would you do that with addition?