src/graphics/grzbuffer.cpp

   1 /*
   2  * $Logfile: /Freespace2/code/Graphics/GrZbuffer.cpp $
   3  * $Revision$
   4  * $Date$
   5  * $Author$
   6  *
   7  * Code for the software renderer's zbuffer
   8  *
   9  * $Log$
  10  * Revision 1.1  2002/05/03 03:28:09  root
  11  * Initial revision
  12  *
  13  *
  14  * 2     10/07/98 10:53a Dave
  15  * Initial checkin.
  16  *
  17  * 1     10/07/98 10:49a Dave
  18  *
  19  * 1     3/25/98 8:07p John
  20  * Split software renderer into Win32 and DirectX
  21  *
  22  * $NoKeywords: $
  23  */
  24
  25 #include "osapi.h"
  26 #include "2d.h"
  27 #include "floating.h"
  28 #include "grsoft.h"
  29 #include "grinternal.h"
  30
  31 int gr_zcount=GR_Z_COUNT;
  32 int gr_zoffset=0;
  33
  34 uint *gr_zbuffer = NULL;
  35 int gr_zbuffer_w = 0;
  36 int gr_zbuffer_h = 0;
  37
  38 int gr_zbuffering = 0;
  39 int gr_zbuffering_mode = 0;
  40 int gr_global_zbuffering = 0;
  41
  42 // If mode is FALSE, turn zbuffer off the entire frame,
  43 // no matter what people pass to gr_zbuffer_set.
  44 void gr8_zbuffer_clear(int mode)
  45 {
  46         if ( mode )     {
  47                 gr_zbuffering = 1;
  48                 gr_zbuffering_mode = GR_ZBUFF_FULL;
  49                 gr_global_zbuffering = 1;
  50
  51                 if ( (!gr_zbuffer) || (gr_screen.max_w!=gr_zbuffer_w) || (gr_screen.max_h!=gr_zbuffer_h) )      {
  52                         //mprintf(( "Allocating a %d x %d zbuffer\n", gr_screen.max_w, gr_screen.max_h ));
  53                         if ( gr_zbuffer )       {
  54                                 free(gr_zbuffer);
  55                                 gr_zbuffer = NULL;
  56                         }
  57                         gr_zbuffer_w = gr_screen.max_w;
  58                         gr_zbuffer_h = gr_screen.max_h;
  59                         gr_zbuffer = (uint *)malloc(gr_zbuffer_w*gr_zbuffer_h*sizeof(uint));
  60                         if ( !gr_zbuffer )      {
  61                                 Error( LOCATION, "Couldn't allocate zbuffer\n" );
  62                                 gr_zbuffering = 0;
  63                                 return;
  64                         }
  65                         memset( gr_zbuffer, 0, gr_zbuffer_w*gr_zbuffer_h*sizeof(uint) );
  66                 }
  67
  68
  69                 gr_zcount++;
  70                 gr_zoffset += GR_Z_RANGE;
  71                 if ( gr_zcount >= (GR_Z_COUNT-16) )     {
  72                         //mprintf(( "Bing!\n" ));
  73                         memset( gr_zbuffer, 0, gr_zbuffer_w*gr_zbuffer_h*sizeof(uint) );
  74                         gr_zcount = 0;
  75                         gr_zoffset = GR_Z_RANGE*16;
  76                 }
  77         } else {
  78                 gr_zbuffering = 0;
  79                 gr_zbuffering_mode = GR_ZBUFF_NONE;
  80                 gr_global_zbuffering = 0;
  81         }
  82 }
  83
  84
  85 int gr8_zbuffer_get()
  86 {
  87         if ( !gr_global_zbuffering )    {
  88                 return GR_ZBUFF_NONE;
  89         }
  90         return gr_zbuffering_mode;
  91 }
  92
  93 int gr8_zbuffer_set(int mode)
  94 {
  95         if ( !gr_global_zbuffering )    {
  96                 gr_zbuffering = 0;
  97                 return GR_ZBUFF_NONE;
  98         }
  99
 100         int tmp = gr_zbuffering_mode;
 101
 102         gr_zbuffering_mode = mode;
 103
 104         if ( gr_zbuffering_mode == GR_ZBUFF_NONE )      {
 105                 gr_zbuffering = 0;
 106         } else {
 107                 gr_zbuffering = 1;
 108         }
 109         return tmp;
 110 }