src/tesuto.c

   1 #include <hw/cpu/cpu.h>
   2 #include <hw/dos/dos.h>
   3 #include <hw/vga/vga.h>
   4 #include <hw/vga/vrl.h>
   5 #include "src/tesuto.h"
   6
   7 global_game_variables_t gvar;
   8
   9 static unsigned char palette[768];
  10
  11 int main(int argc,char **argv) {
  12         struct vrl1_vgax_header *vrl_header;
  13         vrl1_vgax_offset_t *vrl_lineoffs;
  14         unsigned char *buffer;
  15         unsigned int bufsz;
  16         int fd;
  17
  18         if (argc < 3) {
  19                 fprintf(stderr,"drawvrl <VRL file> <palette file>\n");
  20                 return 1;
  21         }
  22
  23         fd = open(argv[1],O_RDONLY|O_BINARY);
  24         if (fd < 0) {
  25                 fprintf(stderr,"Unable to open '%s'\n",argv[1]);
  26                 return 1;
  27         }
  28         {
  29                 unsigned long sz = lseek(fd,0,SEEK_END);
  30                 if (sz < sizeof(*vrl_header)) return 1;
  31                 if (sz >= 65535UL) return 1;
  32
  33                 bufsz = (unsigned int)sz;
  34                 buffer = malloc(bufsz);
  35                 if (buffer == NULL) return 1;
  36
  37                 lseek(fd,0,SEEK_SET);
  38                 if ((unsigned int)read(fd,buffer,bufsz) < bufsz) return 1;
  39
  40                 vrl_header = (struct vrl1_vgax_header*)buffer;
  41                 if (memcmp(vrl_header->vrl_sig,"VRL1",4) || memcmp(vrl_header->fmt_sig,"VGAX",4)) return 1;
  42                 if (vrl_header->width == 0 || vrl_header->height == 0) return 1;
  43         }
  44         close(fd);
  45
  46         probe_dos();
  47         if (!probe_vga()) {
  48                 printf("VGA probe failed\n");
  49                 return 1;
  50         }
  51         int10_setmode(19);
  52         update_state_from_vga();
  53         //vga_enable_256color_modex(); // VGA mode X
  54         VGAmodeX(1, &gvar);
  55
  56         /* load color palette */
  57         fd = open(argv[2],O_RDONLY|O_BINARY);
  58         if (fd >= 0) {
  59                 unsigned int i;
  60
  61                 read(fd,palette,768);
  62                 close(fd);
  63
  64                 vga_palette_lseek(0);
  65                 for (i=0;i < 256;i++) vga_palette_write(palette[(i*3)+0]>>2,palette[(i*3)+1]>>2,palette[(i*3)+2]>>2);
  66         }
  67
  68         /* preprocess the sprite to generate line offsets */
  69         vrl_lineoffs = vrl1_vgax_genlineoffsets(vrl_header,buffer+sizeof(*vrl_header),bufsz-sizeof(*vrl_header));
  70         if (vrl_lineoffs == NULL) return 1;
  71
  72         {
  73                 unsigned int i,j,o;
  74
  75                 /* fill screen with a distinctive pattern */
  76                 for (i=0;i < 320;i++) {
  77                         o = i >> 2;
  78                         vga_write_sequencer(0x02/*map mask*/,1 << (i&3));
  79                         for (j=0;j < 240;j++,o += vga_state.vga_stride)
  80                                 vga_state.vga_graphics_ram[o] = (i^j)&15; // VRL samples put all colors in first 15!
  81                 }
  82         }
  83         while (getch() != 13);
  84
  85         /* make distinctive pattern offscreen, render sprite, copy onscreen */
  86         {
  87                 const unsigned int offscreen_ofs = 0x8000; /* middle of VGA RAM */
  88                 unsigned int i,j,o,o2,x,y,rx,ry,w,h;
  89                 unsigned int overdraw = 1;      // how many pixels to "overdraw" so that moving sprites with edge pixels don't leave streaks.
  90                                                 // if the sprite's edge pixels are clear anyway, you can set this to 0.
  91                 VGA_RAM_PTR omemptr;
  92                 int xdir=1,ydir=1;
  93
  94                 /* starting coords. note: this technique is limited to x coordinates of multiple of 4 */
  95                 x = 0;
  96                 y = 0;
  97
  98                 /* do it */
  99                 omemptr = vga_state.vga_graphics_ram; // save original mem ptr
 100                 while (1) {
 101                         /* stop animating if the user hits ENTER */
 102                         if (kbhit()) {
 103                                 if (getch() == 13) break;
 104                         }
 105
 106                         /* render box bounds. y does not need modification, but x and width must be multiple of 4 */
 107                         if (x >= overdraw) rx = (x - overdraw) & (~3);
 108                         else rx = 0;
 109                         if (y >= overdraw) ry = (y - overdraw);
 110                         else ry = 0;
 111                         h = vrl_header->height + overdraw + y - ry;
 112                         w = (x + vrl_header->width + (overdraw*2) + 3 - rx) & (~3);
 113                         if ((rx+w) > 320) w = 320-rx;
 114
 115                         /* replace VGA stride with our own and mem ptr. then sprite rendering at this stage is just (0,0) */
 116                         vga_state.vga_draw_stride = w >> 2;
 117                         vga_state.vga_graphics_ram = omemptr + offscreen_ofs;
 118
 119                         /* first draw pattern corresponding to that part of the screen. this COULD be optimized, obviously, but it's designed for study.
 120                          * also note we don't have to use the same stride as the display! */
 121                         for (i=rx;i < (rx+w);i++) {
 122                                 o = (i-rx) >> 2;
 123                                 vga_write_sequencer(0x02/*map mask*/,1 << (i&3));
 124                                 for (j=ry;j < (ry+h);j++,o += vga_state.vga_draw_stride)
 125                                         vga_state.vga_graphics_ram[o] = (i^j)&15; // VRL samples put all colors in first 15!
 126                         }
 127
 128                         /* then the sprite. note modding ram ptr means we just draw to (x&3,0) */
 129                         draw_vrl1_vgax_modex(x-rx,y-ry,vrl_header,vrl_lineoffs,buffer+sizeof(*vrl_header),bufsz-sizeof(*vrl_header));
 130
 131                         /* restore ptr */
 132                         vga_state.vga_graphics_ram = omemptr;
 133
 134                         /* block copy to visible RAM from offscreen */
 135                         // TODO: Maybe it would be better for VGA state to have "display stride" vs "draw stride" to avoid saving/restoring like this?
 136                         vga_setup_wm1_block_copy();
 137                         o = offscreen_ofs; // source offscreen
 138                         o2 = (ry * vga_state.vga_stride) + (rx >> 2); // dest visible (original stride)
 139                         for (i=0;i < h;i++,o += vga_state.vga_draw_stride,o2 += vga_state.vga_stride) vga_wm1_mem_block_copy(o2,o,w >> 2);
 140                         /* must restore Write Mode 0/Read Mode 0 for this code to continue drawing normally */
 141                         vga_restore_rm0wm0();
 142
 143                         /* restore stride */
 144                         vga_state.vga_draw_stride = vga_state.vga_stride;
 145
 146                         /* step */
 147                         x += xdir;
 148                         y += ydir;
 149                         if (x >= (319 - vrl_header->width) || x >= 319 || x == 0)
 150                                 xdir = -xdir;
 151                         if (y >= (239 - vrl_header->height) || y >= 239 || y == 0)
 152                                 ydir = -ydir;
 153                 }
 154         }
 155
 156         /* make distinctive pattern offscreen, render sprite, copy onscreen.
 157          * this time, we render the distinctive pattern to another offscreen location and just copy.
 158          * note this version is much faster too! */
 159         {
 160                 const unsigned int offscreen_ofs = 0x8000; /* middle of VGA RAM */
 161                 const unsigned int pattern_ofs = 0xC000;
 162                 unsigned int i,j,o,o2,x,y,rx,ry,w,h;
 163                 unsigned int overdraw = 1;      // how many pixels to "overdraw" so that moving sprites with edge pixels don't leave streaks.
 164                                                 // if the sprite's edge pixels are clear anyway, you can set this to 0.
 165                 VGA_RAM_PTR omemptr;
 166                 int xdir=1,ydir=1;
 167
 168                 /* fill pattern offset with a distinctive pattern */
 169                 for (i=0;i < 320;i++) {
 170                         o = (i >> 2) + pattern_ofs;
 171                         vga_write_sequencer(0x02/*map mask*/,1 << (i&3));
 172                         for (j=0;j < 240;j++,o += vga_state.vga_stride)
 173                                 vga_state.vga_graphics_ram[o] = (i^j)&15; // VRL samples put all colors in first 15!
 174                 }
 175
 176                 /* starting coords. note: this technique is limited to x coordinates of multiple of 4 */
 177                 x = 0;
 178                 y = 0;
 179
 180                 /* do it */
 181                 omemptr = vga_state.vga_graphics_ram; // save original mem ptr
 182                 while (1) {
 183                         /* stop animating if the user hits ENTER */
 184                         if (kbhit()) {
 185                                 if (getch() == 13) break;
 186                         }
 187
 188                         /* render box bounds. y does not need modification, but x and width must be multiple of 4 */
 189                         if (x >= overdraw) rx = (x - overdraw) & (~3);
 190                         else rx = 0;
 191                         if (y >= overdraw) ry = (y - overdraw);
 192                         else ry = 0;
 193                         h = vrl_header->height + overdraw + y - ry;
 194                         w = (x + vrl_header->width + (overdraw*2) + 3 - rx) & (~3);
 195                         if ((rx+w) > 320) w = 320-rx;
 196
 197                         /* block copy pattern to where we will draw the sprite */
 198                         vga_setup_wm1_block_copy();
 199                         o2 = offscreen_ofs;
 200                         o = pattern_ofs + (ry * vga_state.vga_stride) + (rx >> 2); // source offscreen
 201                         for (i=0;i < vrl_header->height;i++,o += vga_state.vga_stride,o2 += (w >> 2)) vga_wm1_mem_block_copy(o2,o,w >> 2);
 202                         /* must restore Write Mode 0/Read Mode 0 for this code to continue drawing normally */
 203                         vga_restore_rm0wm0();
 204
 205                         /* replace VGA stride with our own and mem ptr. then sprite rendering at this stage is just (0,0) */
 206                         vga_state.vga_draw_stride = w >> 2;
 207                         vga_state.vga_graphics_ram = omemptr + offscreen_ofs;
 208
 209                         /* then the sprite. note modding ram ptr means we just draw to (x&3,0) */
 210                         draw_vrl1_vgax_modex(x-rx,y-ry,vrl_header,vrl_lineoffs,buffer+sizeof(*vrl_header),bufsz-sizeof(*vrl_header));
 211
 212                         /* restore ptr */
 213                         vga_state.vga_graphics_ram = omemptr;
 214
 215                         /* block copy to visible RAM from offscreen */
 216                         // TODO: Maybe it would be better for VGA state to have "display stride" vs "draw stride" to avoid saving/restoring like this?
 217                         vga_setup_wm1_block_copy();
 218                         o = offscreen_ofs; // source offscreen
 219                         o2 = (ry * vga_state.vga_stride) + (rx >> 2); // dest visible (original stride)
 220                         for (i=0;i < vrl_header->height;i++,o += vga_state.vga_draw_stride,o2 += vga_state.vga_stride) vga_wm1_mem_block_copy(o2,o,w >> 2);
 221                         /* must restore Write Mode 0/Read Mode 0 for this code to continue drawing normally */
 222                         vga_restore_rm0wm0();
 223
 224                         /* restore stride */
 225                         vga_state.vga_draw_stride = vga_state.vga_stride;
 226
 227                         /* step */
 228                         x += xdir;
 229                         y += ydir;
 230                         if (x >= (319 - vrl_header->width) || x >= 319 || x == 0)
 231                                 xdir = -xdir;
 232                         if (y >= (239 - vrl_header->height) || y >= 239 || y == 0)
 233                                 ydir = -ydir;
 234                 }
 235         }
 236
 237         int10_setmode(3);
 238         //VGAmodeX(0, &gvar);
 239         free(vrl_lineoffs);
 240         buffer = NULL;
 241         free(buffer);
 242         bufsz = 0;
 243         return 0;
 244 }