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 1.2  2002/05/07 03:16:45  theoddone33
  11  * The Great Newline Fix
  12  *
  13  * Revision 1.1.1.1  2002/05/03 03:28:09  root
  14  * Initial import.
  15  *
  16  *
  17  * 2     10/07/98 10:53a Dave
  18  * Initial checkin.
  19  *
  20  * 1     10/07/98 10:49a Dave
  21  *
  22  * 1     3/25/98 8:07p John
  23  * Split software renderer into Win32 and DirectX
  24  *
  25  * $NoKeywords: $
  26  */
  27
  28 #include "osapi.h"
  29 #include "2d.h"
  30 #include "floating.h"
  31 #include "grsoft.h"
  32 #include "grinternal.h"
  33
  34 int gr_zcount=GR_Z_COUNT;
  35 int gr_zoffset=0;
  36
  37 uint *gr_zbuffer = NULL;
  38 int gr_zbuffer_w = 0;
  39 int gr_zbuffer_h = 0;
  40
  41 int gr_zbuffering = 0;
  42 int gr_zbuffering_mode = 0;
  43 int gr_global_zbuffering = 0;
  44
  45 // If mode is FALSE, turn zbuffer off the entire frame,
  46 // no matter what people pass to gr_zbuffer_set.
  47 void gr8_zbuffer_clear(int mode)
  48 {
  49         if ( mode )     {
  50                 gr_zbuffering = 1;
  51                 gr_zbuffering_mode = GR_ZBUFF_FULL;
  52                 gr_global_zbuffering = 1;
  53
  54                 if ( (!gr_zbuffer) || (gr_screen.max_w!=gr_zbuffer_w) || (gr_screen.max_h!=gr_zbuffer_h) )      {
  55                         //mprintf(( "Allocating a %d x %d zbuffer\n", gr_screen.max_w, gr_screen.max_h ));
  56                         if ( gr_zbuffer )       {
  57                                 free(gr_zbuffer);
  58                                 gr_zbuffer = NULL;
  59                         }
  60                         gr_zbuffer_w = gr_screen.max_w;
  61                         gr_zbuffer_h = gr_screen.max_h;
  62                         gr_zbuffer = (uint *)malloc(gr_zbuffer_w*gr_zbuffer_h*sizeof(uint));
  63                         if ( !gr_zbuffer )      {
  64                                 Error( LOCATION, "Couldn't allocate zbuffer\n" );
  65                                 gr_zbuffering = 0;
  66                                 return;
  67                         }
  68                         memset( gr_zbuffer, 0, gr_zbuffer_w*gr_zbuffer_h*sizeof(uint) );
  69                 }
  70
  71
  72                 gr_zcount++;
  73                 gr_zoffset += GR_Z_RANGE;
  74                 if ( gr_zcount >= (GR_Z_COUNT-16) )     {
  75                         //mprintf(( "Bing!\n" ));
  76                         memset( gr_zbuffer, 0, gr_zbuffer_w*gr_zbuffer_h*sizeof(uint) );
  77                         gr_zcount = 0;
  78                         gr_zoffset = GR_Z_RANGE*16;
  79                 }
  80         } else {
  81                 gr_zbuffering = 0;
  82                 gr_zbuffering_mode = GR_ZBUFF_NONE;
  83                 gr_global_zbuffering = 0;
  84         }
  85 }
  86
  87
  88 int gr8_zbuffer_get()
  89 {
  90         if ( !gr_global_zbuffering )    {
  91                 return GR_ZBUFF_NONE;
  92         }
  93         return gr_zbuffering_mode;
  94 }
  95
  96 int gr8_zbuffer_set(int mode)
  97 {
  98         if ( !gr_global_zbuffering )    {
  99                 gr_zbuffering = 0;
 100                 return GR_ZBUFF_NONE;
 101         }
 102
 103         int tmp = gr_zbuffering_mode;
 104
 105         gr_zbuffering_mode = mode;
 106
 107         if ( gr_zbuffering_mode == GR_ZBUFF_NONE )      {
 108                 gr_zbuffering = 0;
 109         } else {
 110                 gr_zbuffering = 1;
 111         }
 112         return tmp;
 113 }
 114