C to assembly conversion help

Hello, I am having trouble converting this function to assembly because i barely know assembly, so i need some help.  Below is the C function(bout 20 lines) and after that is what i have started on(I know its all wrong). So let me explain the variables below:

is_cached - is hit a lot more often
n - is from 0 to 319
tex - is char *
tex_row_table - is int [258]
swim_u & swim_v - is int [256]
g_mip - is int either 0,1,2,3
wid * ht - are int

#include "s.h"
#include "fix.h"
#include "tm.h"

void draw_affine(int n, char *dest, fix u, fix v, fix du, fix dv)
{
   if (is_cached) {
      while (n--) {
         int iu = u >> 16;
         int iv = v >> 16;
         *dest++ = tex[tex_row_table[iv+1] + iu];
         u += du;
         v += dv;
      }
   } else {  
      while (n--) {
         int iu = ((u + (swim_u[(((v<<g_mip) >> 16) & 0xff)] >> g_mip)) >> 16) & wid;
         int iv = ((v + (swim_v[(((u<<g_mip) >> 16) & 0xff)] >> g_mip)) >> 16) & ht;
         *dest++ = tex[tex_row_table[iv+1] + iu];
         u += du;
         v += dv;
      }
   }
}

this is what i have for assembly; (just for some sorta skeleton ;)

      .file "affine.asm"
      .medium
      .486

_global draw_affine

draw_affine:

      mov si,n
      les di,dest
      mov eax,u
      mov ebx,v
      mov ecx,du
      mov edx,dv
      mov ax,tex_row_table
      cmpl is_cached,0
      je scandone

scanloop:
            
      add ax,eax
      add ax,ebx
      adc bx,ax
      mov bx,tex
      mov ah,[bx]
      mov es:[di],ah
      add eax,ecx
      add ebx,edx
      dec si
      jnz scanloop

scandone:

      ret

so im sure a lot, a lot of that is wrong so thats why i need help, i also only attempted the if(is_cached).  This should be enough points for this, and any other questions email me at benco@gisco.net.

Thanx a lot in advance