/* clang --emit-llvm llvm_builtins.c |llvm-as |opt -std-compile-opts |llvm-dis */
/* clang --emit-llvm llvm_builtins.c |llvm-as |opt -std-compile-opts |llvm2cpp -for=Shader -gen-module -funcname=createBaseShader */
typedef __attribute__(( ocu_vector_type(4) )) float float4;

#if 0
//clang doesn't suppoer "struct->member" notation yet
struct vertex_header {
   unsigned clipmask:12;
   unsigned edgeflag:1;
   unsigned pad:3;
   unsigned vertex_id:16;

   float clip[4];

   float data[][4];
};

inline float
dot4(float4 a, float4 b)
{
   float4 c = a*b;
   return c.x + c.y + c.z + c.w;
}

inline unsigned
compute_clipmask(float4 clip, float4 (*plane), unsigned nr)
{
   unsigned mask = 0;
   unsigned i;

   for (i = 0; i < nr; i++) {
      if (dot4(clip, plane[i]) < 0)
         mask |= (1<<i);
   }

   return mask;
}

inline void collect_results(float4 *results, struct vertex_header *vOut,
                            float4 *planes, int nr_planes,
                            float4 scale, float4 trans,
                            int num_attribs)
{
   /* store results */
   unsigned slot;
   float x, y, z, w;

   /* Handle attr[0] (position) specially:
    */
   float4 res0 = results[0];
   float *clip = vOut->clip;
   x = clip[0] = res0.x;
   y = clip[1] = res0.y;
   z = clip[2] = res0.z;
   w = clip[3] = res0.w;

   vOut->clipmask = compute_clipmask(res0, planes, nr_planes);
   vOut->edgeflag = 1;

   /* divide by w */
   w = 1.0f / w;
   x *= w;
   y *= w;
   z *= w;
   res0.x = x; res0.y = y; res0.z = z; res0.w = 1;

   /* Viewport mapping */
   res0 = res0 * scale + trans;
   vOut->data[0][0] = res0.x;
   vOut->data[0][1] = res0.y;
   vOut->data[0][2] = res0.z;
   vOut->data[0][3] = w;

   /* Remaining attributes are packed into sequential post-transform
    * vertex attrib slots.
    * Skip 0 since we just did it above.
    * Subtract two because of the VERTEX_HEADER, CLIP_POS attribs.
    */
   for (slot = 1; slot < num_attribs - 2; slot++) {
      float4 vec = results[slot];
      vOut->data[slot][0] = vec.x;
      vOut->data[slot][1] = vec.y;
      vOut->data[slot][2] = vec.z;
      vOut->data[slot][3] = vec.w;

      printf("output %d: %f %f %f %f\n", slot,
             vOut->data[slot][0],
             vOut->data[slot][1],
             vOut->data[slot][2],
             vOut->data[slot][3]);
   }
}
#endif

void from_array(float4 (*res)[16], float (*ainputs)[16][4],
                int count, int num_attribs)
{
   for (int i = 0; i < count; ++i) {
      for (int j = 0; j < num_attribs; ++j) {
         float4 vec;
         vec.x = ainputs[i][j][0];
         vec.y = ainputs[i][j][1];
         vec.z = ainputs[i][j][2];
         vec.w = ainputs[i][j][3];
         printf("FRA(%d %d) %f %f %f %f\n", i, j, vec.x, vec.y, vec.z, vec.w);
         res[i][j] = vec;
      }
   }
}

void from_consts(float4 *res, float (*ainputs)[4],
                 int count)
{
   for (int i = 0; i < count; ++i) {
      float4 vec;
      vec.x = ainputs[i][0];
      vec.y = ainputs[i][1];
      vec.z = ainputs[i][2];
      vec.w = ainputs[i][3];
      printf("VCONST(%d) %f %f %f %f\n", i, vec.x, vec.y, vec.z, vec.w);
      res[i] = vec;
   }
}

void to_array(float (*dests)[4], float4 *in, int num_attribs)
{
   for (int i = 0; i < num_attribs; ++i) {
      float  *rd = dests[i];
      float4  ri = in[i];
      printf("DEST = %f %f %f %f\n", ri.x, ri.y, ri.z, ri.w);
      rd[0] = ri.x;
      rd[1] = ri.y;
      rd[2] = ri.z;
      rd[3] = ri.w;
   }
}

extern void execute_shader(float4 *dests, float4 *inputs,
                           float4 *consts);

void run_vertex_shader(float (*ainputs)[16][4],
                       float (*dests)[16][4],
                       float (*aconsts)[4],
                       int num_vertices,
                       int num_inputs,
                       int num_attribs,
                       int num_consts)
{
   float4  inputs[16*32*4][16];
   float4  consts[32];
   float4  results[16*32*4][16];

   printf("XXX LLVM run_vertex_shader vertices = %d, inputs = %d, consts = %d\n",
          num_vertices, num_inputs, num_consts);
   from_array(inputs, ainputs, num_vertices, num_inputs);
   from_consts(consts, aconsts, num_consts);
   printf("               after conversion\n");
   for (int i = 0; i < num_vertices; ++i) {
      float4 *in  = inputs[i];
      float4 *res = results[i];
      execute_shader(res, in, consts);
      printf("after executing shader\n");
      to_array(dests[i], res, num_attribs);
   }
}