source: golgotha/src/render/software/perspective_map_lit_c.cc @ 80 Tweet

/********************************************************************** <BR>
  This file is part of Crack dot Com's free source code release of
  Golgotha. <a href="http://www.crack.com/golgotha_release"> <BR> for
  information about compiling & licensing issues visit this URL</a> 
  <PRE> If that doesn't help, contact Jonathan Clark at 
  golgotha_source@usa.net (Subject should have "GOLG" in it) 
***********************************************************************/

#include "software/r1_software_globals.hh"
#include "software/inline_fpu.hh"

w32 *texture_perspective_lit_starter()
{
  w32 returnval;
  _asm
  {
    mov eax,OFFSET dumb_addr
dumb_addr:
    mov returnval,eax
  }
  return (w32 *)returnval;
}

void texture_scanline_perspective_lit(w16 *start_pixel,
                                      sw32 start_x,
                                      void *_left,//perspective_span *left,
                                      sw32 width)
{
  //temporary stuff for lighting calculations  
  w16 texel;  
  w32 t1,t2;
  w32 l_lookup;

  start_pixel = (w16 *)((w8 *)start_pixel + start_x);

  perspective_span *left = (perspective_span *)_left;
    
  left_z = 1.f / left->ooz;
  left_s = qftoi(left->soz * left_z) + cur_grads.s_adjust;
  left_t = qftoi(left->toz * left_z) + cur_grads.t_adjust;
  
  //dont forget the lighting
  left_l = left->l;
  
  sw32 had_subdivisions = width & (~15);

  num_subdivisions = width >> 4;
  num_leftover     = width & 15;
  
  if (num_subdivisions)
  {
    ooz_right = left->ooz + (cur_grads.doozdxspan);
    soz_right = left->soz + (cur_grads.dsozdxspan);
    toz_right = left->toz + (cur_grads.dtozdxspan);
    
    right_z = 1.f / ooz_right;

    while (num_subdivisions)
    {

      right_s = qftoi(soz_right * right_z) + cur_grads.s_adjust;
      if (right_s < 0)
        right_s = 0;
      else
      if (right_s > s_mask)
        right_s = s_mask;

      right_t = qftoi(toz_right * right_z) + cur_grads.t_adjust;
      if (right_t < 0)
        right_t = 0;
      else
      if (right_t > t_mask)
        right_t = t_mask;

      temp_dsdx = (right_s - left_s) >> 4;
      temp_dtdx = (right_t - left_t) >> 4;

      if (num_subdivisions!=1)
      {
        ooz_right += (cur_grads.doozdxspan);
        soz_right += (cur_grads.dsozdxspan);
        toz_right += (cur_grads.dtozdxspan);
        
        right_z = 1.f / ooz_right;
      }

      width_global = 16;

      while (width_global)
      {
        texel = *( r1_software_texture_ptr + (left_s>>16) + ((left_t>>16) << r1_software_twidth_log2) );
                
        l_lookup = left_l & (NUM_LIGHT_SHADES<<8);

        //lookup low bits
        t1 = ((w32 *)(0xDEADBEEF))[l_lookup + (texel & 0xFF)];

        //lookup high bits
        t2 = ((w32 *)(0xDEADBEEF)+ctable_size)[l_lookup + (texel>>8)];

        *start_pixel = (w16)(t1+t2);

        start_pixel++;

        left_s += temp_dsdx;
        left_t += temp_dtdx;
        left_l += dldx_fixed;

        width_global--;
      }
  
      left_s = right_s;
      left_t = right_t;
          
      num_subdivisions--;    
    }
  }
    
  if (num_leftover)
  {        
    if (num_leftover > 1)
    {
      if (had_subdivisions!=0)
      {
        ooz_right += (cur_grads.doozdx * num_leftover);
        soz_right += (cur_grads.dsozdx * num_leftover);
        toz_right += (cur_grads.dtozdx * num_leftover);
    
        right_z = 1.f / ooz_right;
      }
      else
      {
        ooz_right = left->ooz + (cur_grads.doozdx * num_leftover);
        soz_right = left->soz + (cur_grads.dsozdx * num_leftover);
        toz_right = left->toz + (cur_grads.dtozdx * num_leftover);
    
        right_z = 1.f / ooz_right;
      }

      right_s = qftoi(soz_right * right_z) + cur_grads.s_adjust;
      if (right_s < 0)
        right_s = 0;
      else
      if (right_s > s_mask)
        right_s = s_mask;

      right_t = qftoi(toz_right * right_z) + cur_grads.t_adjust;
      if (right_t < 0)
        right_t = 0;
      else
      if (right_t > t_mask)
        right_t = t_mask;

      temp_dsdx = qftoi((float)(right_s - left_s) * inverse_leftover_lookup[num_leftover]);
      temp_dtdx = qftoi((float)(right_t - left_t) * inverse_leftover_lookup[num_leftover]);

      while (num_leftover)
      {
        texel = *(r1_software_texture_ptr + (left_s>>16) + ((left_t>>16)<<r1_software_twidth_log2));
          
        l_lookup = left_l & (NUM_LIGHT_SHADES<<8);
  
        //lookup low bits
        t1 = ((w32 *)(0xDEADBEEF))[l_lookup + (texel & 0xFF)];

        //lookup high bits
        t2 = ((w32 *)(0xDEADBEEF)+ctable_size)[l_lookup + (texel>>8)];
  
        *start_pixel = (w16)(t1+t2);

        start_pixel++;

        left_s += temp_dsdx;
        left_t += temp_dtdx;
        left_l += dldx_fixed;
  
        num_leftover--;
      }
    }
    else
    {
      texel = *(r1_software_texture_ptr + (left_s>>16) + ((left_t>>16)<<r1_software_twidth_log2));
          
      l_lookup = left_l & (NUM_LIGHT_SHADES<<8);
  
      //lookup low bits
      t1 = ((w32 *)(0xDEADBEEF))[l_lookup + (texel & 0xFF)];

      //lookup high bits
      t2 = ((w32 *)(0xDEADBEEF)+ctable_size)[l_lookup + (texel>>8)];
  
      *start_pixel = (w16)(t1+t2);
    }
  }
}

w32 *texture_perspective_lit_sentinel()
{
  w32 returnval;
  _asm
  {
    mov eax,OFFSET dumb_addr
dumb_addr:
    mov returnval,eax
  }
  return (w32 *)returnval;
}

void insert_color_modify_address_low(w32 *address);
void insert_color_modify_address_high(w32 *address);
extern w32 color_modify_list[];
extern sw32 num_color_modifies;

void setup_color_modify_perspective_lit()
{
  w32 *stop = texture_perspective_lit_sentinel();

  w32 *search = texture_perspective_lit_starter();
  //start searching for 0xDEADBEEF
  while (search < stop)
  {
    //casting craziness
    search = (w32 *)((w8 *)search + 1);
    if (*search==0xDEADBEEF)
    {
      insert_color_modify_address_low(search);
    }
    else
    if (*search==(0xDEADBEEF + ctable_size_bytes))
    {
      insert_color_modify_address_high(search);
    }
  }
}