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Sunday, July 23, 2006

Code generator works

Code generator for the Renderman shading language compiler I'm writing for a masters thesis works. The world is one (small) step closer to raytracing graphic cards ;-). So now it can go all the way through, from source code to abstract syntax tree to assembly to pretty picture. So it can compile this thing:

color silly(point P; point Eye; color near_color; color far_color)
   vector ray = P-Eye;
   float ray_dist = sqrt(ray.ray);
   if(ray_dist < 0)
       ray_dist = 0;
   if(ray_dist > 1)
       ray_dist = 1;

   color c = near_color + (far_color-near_color) * ray_dist;

   return c;
To this assembly:
   dp3 R2.w,,
   mov_rsq R15.w, R2.w
   mov_rcp R15.w, S.w
   add R15, 0.0, -S.w + jmp 4 xyzw (>0)
   mov R3.w, S.w
   add R15, R3.w, -1.0 + jmp 7 xyzw (>0)
   mul,, R3.w
   mov R3.w, 1.0
   jmp 9
   mov R3.w, 0.0
   jmp 8
For now it only supports functions which pretend to be shaders, not "real" surface shaders. And more about our cool hardware here.

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