src/drawvrl5.c

   1
   2 #include <stdio.h>
   3 #include <conio.h> /* this is where Open Watcom hides the outp() etc. functions */
   4 #include <ctype.h>
   5 #include <stdlib.h>
   6 #include <unistd.h>
   7 #include <assert.h>
   8 #include <fcntl.h>
   9 #include <math.h>
  10 #include <dos.h>
  11
  12 #include <hw/cpu/cpu.h>
  13 #include <hw/dos/dos.h>
  14 #include <hw/vga/vga.h>
  15 #include <hw/vga/vrl.h>
  16
  17 static unsigned char palette[768];
  18
  19 int main(int argc,char **argv) {
  20         struct vrl1_vgax_header *vrl_header;
  21         vrl1_vgax_offset_t *vrl_lineoffs;
  22         unsigned char *buffer;
  23         unsigned int bufsz;
  24         int fd;
  25
  26         if (argc < 3) {
  27                 fprintf(stderr,"drawvrl <VRL file> <palette file>\n");
  28                 return 1;
  29         }
  30
  31         fd = open(argv[1],O_RDONLY|O_BINARY);
  32         if (fd < 0) {
  33                 fprintf(stderr,"Unable to open '%s'\n",argv[1]);
  34                 return 1;
  35         }
  36         {
  37                 unsigned long sz = lseek(fd,0,SEEK_END);
  38                 if (sz < sizeof(*vrl_header)) return 1;
  39                 if (sz >= 65535UL) return 1;
  40
  41                 bufsz = (unsigned int)sz;
  42                 buffer = malloc(bufsz);
  43                 if (buffer == NULL) return 1;
  44
  45                 lseek(fd,0,SEEK_SET);
  46                 if ((unsigned int)read(fd,buffer,bufsz) < bufsz) return 1;
  47
  48                 vrl_header = (struct vrl1_vgax_header*)buffer;
  49                 if (memcmp(vrl_header->vrl_sig,"VRL1",4) || memcmp(vrl_header->fmt_sig,"VGAX",4)) return 1;
  50                 if (vrl_header->width == 0 || vrl_header->height == 0) return 1;
  51         }
  52         close(fd);
  53
  54         probe_dos();
  55         if (!probe_vga()) {
  56                 printf("VGA probe failed\n");
  57                 return 1;
  58         }
  59         int10_setmode(19);
  60         update_state_from_vga();
  61         vga_enable_256color_modex(); // VGA mode X
  62         vga_state.vga_width = 320; // VGA lib currently does not update this
  63         vga_state.vga_height = 200; // VGA lib currently does not update this
  64
  65 #if 1 // 320x240 test mode: this is how Project 16 is using our code, enable for test case
  66         {
  67                 struct vga_mode_params cm;
  68
  69                 vga_read_crtc_mode(&cm);
  70
  71                 // 320x240 mode 60Hz
  72                 cm.vertical_total = 525;
  73                 cm.vertical_start_retrace = 0x1EA;
  74                 cm.vertical_end_retrace = 0x1EC;
  75                 cm.vertical_display_end = 480;
  76                 cm.vertical_blank_start = 489;
  77                 cm.vertical_blank_end = 517;
  78
  79                 vga_write_crtc_mode(&cm,0);
  80         }
  81         vga_state.vga_height = 240; // VGA lib currently does not update this
  82 #endif
  83
  84         /* load color palette */
  85         fd = open(argv[2],O_RDONLY|O_BINARY);
  86         if (fd >= 0) {
  87                 unsigned int i;
  88
  89                 read(fd,palette,768);
  90                 close(fd);
  91
  92                 vga_palette_lseek(0);
  93                 for (i=0;i < 256;i++) vga_palette_write(palette[(i*3)+0]>>2,palette[(i*3)+1]>>2,palette[(i*3)+2]>>2);
  94         }
  95
  96         /* preprocess the sprite to generate line offsets */
  97         vrl_lineoffs = vrl1_vgax_genlineoffsets(vrl_header,buffer+sizeof(*vrl_header),bufsz-sizeof(*vrl_header));
  98         if (vrl_lineoffs == NULL) return 1;
  99
 100         {
 101                 unsigned int i,j,o;
 102
 103                 /* fill screen with a distinctive pattern */
 104                 for (i=0;i < vga_state.vga_width;i++) {
 105                         o = i >> 2;
 106                         vga_write_sequencer(0x02/*map mask*/,1 << (i&3));
 107                         for (j=0;j < vga_state.vga_height;j++,o += vga_state.vga_stride)
 108                                 vga_state.vga_graphics_ram[o] = (i^j)&15; // VRL samples put all colors in first 15!
 109                 }
 110         }
 111         while (getch() != 13);
 112
 113         /* make distinctive pattern offscreen, render sprite, copy onscreen */
 114         {
 115                 const unsigned int offscreen_ofs = (vga_state.vga_stride * vga_state.vga_height);
 116                 unsigned int i,j,o,o2,x,y,rx,ry,w,h;
 117                 unsigned int overdraw = 1;      // how many pixels to "overdraw" so that moving sprites with edge pixels don't leave streaks.
 118                                                 // if the sprite's edge pixels are clear anyway, you can set this to 0.
 119                 VGA_RAM_PTR omemptr;
 120                 int xdir=1,ydir=1;
 121
 122                 /* starting coords. note: this technique is limited to x coordinates of multiple of 4 */
 123                 x = 0;
 124                 y = 0;
 125
 126                 /* do it */
 127                 omemptr = vga_state.vga_graphics_ram; // save original mem ptr
 128                 while (1) {
 129                         /* stop animating if the user hits ENTER */
 130                         if (kbhit()) {
 131                                 if (getch() == 13) break;
 132                         }
 133
 134                         /* render box bounds. y does not need modification, but x and width must be multiple of 4 */
 135                         if (x >= overdraw) rx = (x - overdraw) & (~3);
 136                         else rx = 0;
 137                         if (y >= overdraw) ry = (y - overdraw);
 138                         else ry = 0;
 139                         h = vrl_header->height + overdraw + y - ry;
 140                         w = (x + vrl_header->width + (overdraw*2) + 3/*round up*/ - rx) & (~3);
 141                         if ((rx+w) > vga_state.vga_width) w = vga_state.vga_width-rx;
 142                         if ((ry+h) > vga_state.vga_height) h = vga_state.vga_height-ry;
 143
 144                         /* replace VGA stride with our own and mem ptr. then sprite rendering at this stage is just (0,0) */
 145                         vga_state.vga_draw_stride_limit = (vga_state.vga_width + 3/*round up*/ - x) >> 2;
 146                         vga_state.vga_draw_stride = w >> 2;
 147                         vga_state.vga_graphics_ram = omemptr + offscreen_ofs;
 148
 149                         /* first draw pattern corresponding to that part of the screen. this COULD be optimized, obviously, but it's designed for study.
 150                          * also note we don't have to use the same stride as the display! */
 151                         for (i=rx;i < (rx+w);i++) {
 152                                 o = (i-rx) >> 2;
 153                                 vga_write_sequencer(0x02/*map mask*/,1 << (i&3));
 154                                 for (j=ry;j < (ry+h);j++,o += vga_state.vga_draw_stride)
 155                                         vga_state.vga_graphics_ram[o] = (i^j)&15; // VRL samples put all colors in first 15!
 156                         }
 157
 158                         /* then the sprite. note modding ram ptr means we just draw to (x&3,0) */
 159                         draw_vrl1_vgax_modex(x-rx,y-ry,vrl_header,vrl_lineoffs,buffer+sizeof(*vrl_header),bufsz-sizeof(*vrl_header));
 160
 161                         /* restore ptr */
 162                         vga_state.vga_graphics_ram = omemptr;
 163
 164                         /* block copy to visible RAM from offscreen */
 165                         vga_setup_wm1_block_copy();
 166                         o = offscreen_ofs; // source offscreen
 167                         o2 = (ry * vga_state.vga_stride) + (rx >> 2); // dest visible (original stride)
 168                         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);
 169                         /* must restore Write Mode 0/Read Mode 0 for this code to continue drawing normally */
 170                         vga_restore_rm0wm0();
 171
 172                         /* restore stride */
 173                         vga_state.vga_draw_stride_limit = vga_state.vga_draw_stride = vga_state.vga_stride;
 174
 175                         /* step */
 176                         x += xdir;
 177                         y += ydir;
 178                         if (x >= (vga_state.vga_width - 1) || x == 0)
 179                                 xdir = -xdir;
 180                         if (y >= (vga_state.vga_height - 1) || y == 0)
 181                                 ydir = -ydir;
 182                 }
 183         }
 184
 185         /* make distinctive pattern offscreen, render sprite, copy onscreen.
 186          * this time, we render the distinctive pattern to another offscreen location and just copy.
 187          * note this version is much faster too! */
 188         {
 189                 const unsigned int offscreen_ofs = (vga_state.vga_stride * vga_state.vga_height);
 190                 const unsigned int pattern_ofs = 0x10000UL - (vga_state.vga_stride * vga_state.vga_height);
 191                 unsigned int i,j,o,o2,x,y,rx,ry,w,h;
 192                 unsigned int overdraw = 1;      // how many pixels to "overdraw" so that moving sprites with edge pixels don't leave streaks.
 193                                                 // if the sprite's edge pixels are clear anyway, you can set this to 0.
 194                 VGA_RAM_PTR omemptr;
 195                 int xdir=1,ydir=1;
 196
 197                 /* fill pattern offset with a distinctive pattern */
 198                 for (i=0;i < vga_state.vga_width;i++) {
 199                         o = (i >> 2) + pattern_ofs;
 200                         vga_write_sequencer(0x02/*map mask*/,1 << (i&3));
 201                         for (j=0;j < vga_state.vga_height;j++,o += vga_state.vga_stride)
 202                                 vga_state.vga_graphics_ram[o] = (i^j)&15; // VRL samples put all colors in first 15!
 203                 }
 204
 205                 /* starting coords. note: this technique is limited to x coordinates of multiple of 4 */
 206                 x = 0;
 207                 y = 0;
 208
 209                 /* do it */
 210                 omemptr = vga_state.vga_graphics_ram; // save original mem ptr
 211                 while (1) {
 212                         /* stop animating if the user hits ENTER */
 213                         if (kbhit()) {
 214                                 if (getch() == 13) break;
 215                         }
 216
 217                         /* render box bounds. y does not need modification, but x and width must be multiple of 4 */
 218                         if (x >= overdraw) rx = (x - overdraw) & (~3);
 219                         else rx = 0;
 220                         if (y >= overdraw) ry = (y - overdraw);
 221                         else ry = 0;
 222                         h = vrl_header->height + overdraw + y - ry;
 223                         w = (x + vrl_header->width + (overdraw*2) + 3/*round up*/ - rx) & (~3);
 224                         if ((rx+w) > vga_state.vga_width) w = vga_state.vga_width-rx;
 225                         if ((ry+h) > vga_state.vga_height) h = vga_state.vga_height-ry;
 226
 227                         /* block copy pattern to where we will draw the sprite */
 228                         vga_setup_wm1_block_copy();
 229                         o2 = offscreen_ofs;
 230                         o = pattern_ofs + (ry * vga_state.vga_stride) + (rx >> 2); // source offscreen
 231                         for (i=0;i < h;i++,o += vga_state.vga_stride,o2 += (w >> 2)) vga_wm1_mem_block_copy(o2,o,w >> 2);
 232                         /* must restore Write Mode 0/Read Mode 0 for this code to continue drawing normally */
 233                         vga_restore_rm0wm0();
 234
 235                         /* replace VGA stride with our own and mem ptr. then sprite rendering at this stage is just (0,0) */
 236                         vga_state.vga_draw_stride_limit = (vga_state.vga_width + 3/*round up*/ - x) >> 2;
 237                         vga_state.vga_draw_stride = w >> 2;
 238                         vga_state.vga_graphics_ram = omemptr + offscreen_ofs;
 239
 240                         /* then the sprite. note modding ram ptr means we just draw to (x&3,0) */
 241                         draw_vrl1_vgax_modex(x-rx,y-ry,vrl_header,vrl_lineoffs,buffer+sizeof(*vrl_header),bufsz-sizeof(*vrl_header));
 242
 243                         /* restore ptr */
 244                         vga_state.vga_graphics_ram = omemptr;
 245
 246                         /* block copy to visible RAM from offscreen */
 247                         vga_setup_wm1_block_copy();
 248                         o = offscreen_ofs; // source offscreen
 249                         o2 = (ry * vga_state.vga_stride) + (rx >> 2); // dest visible (original stride)
 250                         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);
 251                         /* must restore Write Mode 0/Read Mode 0 for this code to continue drawing normally */
 252                         vga_restore_rm0wm0();
 253
 254                         /* restore stride */
 255                         vga_state.vga_draw_stride_limit = vga_state.vga_draw_stride = vga_state.vga_stride;
 256
 257                         /* step */
 258                         x += xdir;
 259                         y += ydir;
 260                         if (x >= (vga_state.vga_width - 1) || x == 0)
 261                                 xdir = -xdir;
 262                         if (y >= (vga_state.vga_height - 1) || y == 0)
 263                                 ydir = -ydir;
 264                 }
 265         }
 266
 267         /* another handy "demo" effect using VGA write mode 1.
 268          * we can take what's on screen and vertically squash it like an old analog TV set turning off. */
 269         {
 270                 unsigned int blank_line_ofs = (vga_state.vga_stride * vga_state.vga_height * 2);
 271                 unsigned int copy_ofs = (vga_state.vga_stride * vga_state.vga_height);
 272                 unsigned int display_ofs = 0x0000;
 273                 unsigned int i,y,soh,doh,dstart;
 274                 unsigned int dh_blankfill = 8;
 275                 unsigned int dh_step = 8;
 276                 uint32_t sh,dh,yf,ystep;
 277
 278                 /* copy active display (0) to offscreen buffer (0x4000) */
 279                 vga_state.vga_draw_stride_limit = vga_state.vga_draw_stride = vga_state.vga_stride;
 280                 vga_setup_wm1_block_copy();
 281                 vga_wm1_mem_block_copy(copy_ofs,display_ofs,vga_state.vga_stride * vga_state.vga_height);
 282                 vga_restore_rm0wm0();
 283
 284                 /* need a blank line as well */
 285                 for (i=0;i < vga_state.vga_stride;i++) vga_state.vga_graphics_ram[i+blank_line_ofs] = 0;
 286
 287                 sh = dh = vga_state.vga_height;
 288                 while (dh >= dh_step) {
 289                         /* stop animating if the user hits ENTER */
 290                         if (kbhit()) {
 291                                 if (getch() == 13) break;
 292                         }
 293
 294                         /* wait for vsync end */
 295                         vga_wait_for_vsync_end();
 296
 297                         /* what scalefactor to use for stretching? */
 298                         ystep = (0x10000UL * sh) / dh;
 299                         dstart = (vga_state.vga_height - dh) / 2; // center the squash effect on screen, otherwise it would squash to top of screen
 300                         doh = display_ofs;
 301                         soh = copy_ofs;
 302                         yf = 0;
 303                         y = 0;
 304
 305                         /* for performance, keep VGA in write mode 1 the entire render */
 306                         vga_setup_wm1_block_copy();
 307
 308                         /* blank lines */
 309                         if (dstart >= dh_blankfill) y = dstart - dh_blankfill;
 310                         else y = 0;
 311                         doh = vga_state.vga_stride * y;
 312
 313                         while (y < dstart) {
 314                                 vga_wm1_mem_block_copy(doh,blank_line_ofs,vga_state.vga_stride);
 315                                 doh += vga_state.vga_stride;
 316                                 y++;
 317                         }
 318
 319                         /* draw */
 320                         while (y < (dh+dstart)) {
 321                                 soh = copy_ofs + ((yf >> 16UL) * vga_state.vga_stride);
 322                                 vga_wm1_mem_block_copy(doh,soh,vga_state.vga_stride);
 323                                 doh += vga_state.vga_stride;
 324                                 yf += ystep;
 325                                 y++;
 326                         }
 327
 328                         /* blank lines */
 329                         while (y < vga_state.vga_height && y < (dh+dstart+dh_blankfill)) {
 330                                 vga_wm1_mem_block_copy(doh,blank_line_ofs,vga_state.vga_stride);
 331                                 doh += vga_state.vga_stride;
 332                                 y++;
 333                         }
 334
 335                         /* done */
 336                         vga_restore_rm0wm0();
 337
 338                         /* wait for vsync */
 339                         vga_wait_for_vsync();
 340
 341                         /* make it shrink */
 342                         dh -= dh_step;
 343                         if (dh < 40) dh_step = 1;
 344                 }
 345         }
 346
 347         int10_setmode(3);
 348         free(vrl_lineoffs);
 349         buffer = NULL;
 350         free(buffer);
 351         bufsz = 0;
 352         return 0;
 353 }
 354