/*
  This code relies on the hand-assembly coded edgize, preplanarize,
  planarize and binitize functions.

  Preplanarize is called first - this caches the edgizing and planarizing
  repeated expressions into registers, and computes screen-space minimax
  x and y coordinates -

      rminx
      rminy
      rmaxx
      rmaxy
      rx23     \
      rx31       >  the recurring differences
      rx12     /
      rC       the divisor for preplanarizing
      rv1y
      rv2y
      rv3y
      rv4y     for quads
      rv1x
      rv2x
      rv3x
  and rv4x     for quads

  Total 16 fp regs

  To ease planarizing and z-buffering, we will keep vertex pointers in
  registers throughout -

      rv1
      rv2
      rv3
      rv4

  Total 4 int regs

  A subsequent call to edgeize_triangle edgizes the three edges
  correctly, in order, and will guarantee no DDA cracks. A similar edgize_quad
  needs implementing (so I need to reserve rvx4 and rvy4)
  After edgizing we proceed to planarize - this is done by chained calls to
  planarize_fn, passing in 3 fp registers which hold the v1 v2 v3 values to
  be planarized, and a pointer register to where A B C should be stored.

  Then binitize_fn is called, which uses the pre-computed minimax values to
  drop the macro value, coefficient start address and coefficient count into
  screen-bins.

  So, in general, a triangle drawing function will call

  preplanarize_fn ( float *coeffs, VERTEX *a, VERTEX *b, VERTEX *c, VERTEX *d )
  edgize_tri_fn   ( void )
  zbuffer_fn      ( void )
  planarize_fn    ( int opcode, )     many times
  binitize_fn     ()     to close

*/

#include <stdio.h>
#include <stdlib.h>
#include "pxpl5asm.h"

float *tri_zb_d_s ( float *coeffs, float *v1, float *v2, float *v3 )
{
  /* z-buffered, diffuse-lit, specular lit triangle */
  float *t=coeffs;

  preplanarize_fn ( coeffs, 0, v1, v2, v3, NULL );

  edgize_tri_fn ();
  zbuffer_fn    ();

  planarize_fn  ( 0x666, 3 );
  planarize_fn  ( 0x666, 4 );

  return safe_binitize_fn   ( 0x666, 4, 10 );
}

float *tri_zb_d_s_tex ( float *coeffs, float *v1, float *v2, float *v3 )
{
  /* z-buffered, diffuse-lit, specular lit, textured triangle */
  float *t=coeffs;

  preplanarize_fn ( coeffs, 0, v1, v2, v3, NULL );

  edgize_tri_fn ();
  zbuffer_fn    ();

  planarize_fn  ( 0x666, 3 );   /* diff */
  planarize_fn  ( 0x666, 4 );   /* spec */
  planarize_fn  ( 0x666, 5 );   /* u */
  planarize_fn  ( 0x666, 6 );   /* v */
  planarize_fn  ( 0x666, 7 );   /* homo */

  return safe_binitize_fn   ( 0x666, 4, 10 );
}

float *tri_zb_d_s_texm ( float *coeffs, float *v1, float *v2, float *v3 )
{
  /* z-buffered, diffuse-lit, specular lit, textured, mipped triangle */
  return NULL;
}