mdw@git.distorted.org.uk Git - mup/blob - mup/mupdisp/dos.c

   1
   2 /* Copyright (c) 1995, 1998 by Arkkra Enterprises */
   3 /* All rights reserved */
   4
   5 /* Functions for displaying Mup/Ghostscript output on screen using
   6  * Watcom C */
   7
   8 #ifdef __WATCOMC__
   9 #include "mupdisp.h"
  10 #include <graph.h>
  11 #include <stdlib.h>
  12 #include <malloc.h>
  13 #include <stdio.h>
  14 #include <conio.h>
  15 #include <fcntl.h>
  16 #include <io.h>
  17
  18 /* hard code X and Y sizes for the moment */
  19 #define XSIZE           640
  20 #define YSIZE           480
  21
  22 /* image to be calloc'ed has 6 header bytes, then each row consecutively */
  23 #define BITS2BYTES(bits)        (((bits) + 7) / 8)      /* round upwards */
  24 #define SIZEIMAGE       (6 + ((long)BITS2BYTES(XSIZE)*4) * (long)YSIZE)
  25 static char *Image;
  26
  27 static void zapblock P((char *area, long size));
  28 \f
  29
  30 /* initialize graphics driver, etc */
  31
  32 void
  33 dos_setup()
  34
  35 {
  36         struct videoconfig vidinfo;
  37
  38
  39         /* initalize best graphics mode */
  40         if (_setvideomode(_VRES16COLOR) == 0) {
  41                 fprintf(stderr, "can't set graphics mode\n");
  42                 generalcleanup(1);
  43         }
  44
  45         _getvideoconfig(&vidinfo);
  46
  47         if (vidinfo.numxpixels != XSIZE || vidinfo.numypixels != YSIZE) {
  48                 _setvideomode(_DEFAULTMODE);
  49                 fprintf(stderr, "video mode %dx%d not supported\n",
  50                                 vidinfo.numxpixels, vidinfo.numypixels);
  51                 generalcleanup(0);
  52         }
  53
  54         /*
  55          * Allocate the image buffer.  Note that both parameters must be less
  56          * than 65536, but the total size (product) can be greater.  The +1
  57          * is to allow room for the header bytes (and then some).
  58          */
  59         Image = (char *)calloc(BITS2BYTES(YSIZE)*4 + 1, XSIZE);
  60         if (Image == NULL) {
  61                 _setvideomode(_DEFAULTMODE);
  62                 fprintf(stderr, "can't allocate image buffer\n");
  63                 generalcleanup(0);
  64         }
  65
  66         /* set aspect ratio adjust */
  67         Conf_info_p->adjust = 1.375 * (double) vidinfo.numypixels
  68                                         / (double) vidinfo.numxpixels;
  69         Conf_info_p->vlines = vidinfo.numypixels;
  70
  71         /* set screen to all white */
  72         _setbkcolor(_BRIGHTWHITE);
  73         _clearscreen(_GCLEARSCREEN);
  74 }
  75 \f
  76
  77 /* before exiting, clean up graphics, then call the general cleanup routine */
  78
  79 void
  80 dos_cleanup(int status)
  81 {
  82          _setvideomode(_DEFAULTMODE);
  83          generalcleanup(status);
  84 }
  85 \f
  86
  87 /* draw a screen worth of the bitmap, starting at specified raster line */
  88
  89 void
  90 dos_draw(line, small)
  91
  92 int line;       /* start at this raster line */
  93 int small;      /* YES or NO for small or large page image */
  94
  95 {
  96         int r;                          /* row index */
  97         long offset;                    /* into bitmap file */
  98         int fd;                         /* file descriptor */
  99         int himage_bytes;               /* horizontal image bytes */
 100         char *row_ptr;                  /* point at a row of the image */
 101         int n;                          /* loop variable */
 102
 103
 104         /* make sure we have a valid page to draw */
 105         if (Currpage_p == (struct Pginfo *) 0) {
 106                 ( *(Conf_info_p->error) ) ("page # out of range");
 107                 return;
 108         }
 109
 110         /* figure out where in the bitmap file this page is */
 111         offset = Currpage_p->seqnum * BYTES_PER_PAGE;
 112         fd = gen1file(small);
 113         lseek(fd, offset + (long)line * BYTES_PER_LINE, SEEK_SET);
 114
 115         /* zero out the image buffer */
 116         zapblock(Image, SIZEIMAGE);
 117
 118         /* number of bytes representing one horizontal row in full page image */
 119         himage_bytes = BITS2BYTES(XSIZE) * 4;
 120
 121         /* set the header bytes in the image */
 122         Image[0] = XSIZE % 256;
 123         Image[1] = XSIZE / 256;
 124         Image[2] = YSIZE % 256;
 125         Image[3] = YSIZE / 256;
 126         Image[4] = 4;
 127         Image[5] = 0;
 128
 129         /* set screen to all white */
 130         _setbkcolor(_BRIGHTWHITE);
 131         _clearscreen(_GCLEARSCREEN);
 132
 133         /* for each row */
 134         for (r = 0; r < Conf_info_p->vlines; r++) {
 135                 /* read it directly into the image */
 136                 row_ptr = &Image[ 6 + r * himage_bytes ];
 137                 if (read(fd, row_ptr, BYTES_PER_LINE) != BYTES_PER_LINE) {
 138                         break;
 139                 }
 140
 141                 if (small) {
 142                         /* black out the unused strip on the right */
 143                         for (n = BITS_PER_LINE; n < XSIZE; n++)
 144                                 row_ptr[n/8] |= 1 << (7 - n%8);
 145                 }
 146         }
 147         /* put at upper left corner, (0, 0) */
 148         _putimage(0, 0, Image, _GPSET);
 149 }
 150 \f
 151
 152 /* for now we just beep on errors */
 153 /*ARGSUSED*/
 154 void
 155 dos_error(msg)
 156
 157 char *msg;
 158
 159 {
 160         putc('\7', stderr);
 161 }
 162 \f
 163
 164 /* for user interface, call command processor for each character read */
 165
 166 void
 167 dos_user_interf()
 168
 169 {
 170         int c;
 171         int special = 0;        /* 1 = got a null, which is first character
 172                                  * of special key sequence */
 173         for ( ; ; ) {
 174                 c = getch();
 175                 if (c == '\0') {
 176                         special = 1;
 177                         continue;
 178                 }
 179                 if (special == 1) {
 180                         switch (c) {
 181                         case 0x49:
 182                                 /* PgUp key */
 183                                 c = 'p';
 184                                 break;
 185                         case 0x51:
 186                                 /* PgDown key */
 187                                 c = 'n';
 188                                 break;
 189                         case 0x48:
 190                                 /* Up arrow key */
 191                                 c = 'b';
 192                                 break;
 193                         case 0x50:
 194                                 /* Down arrow key */
 195                                 c = 'f';
 196                                 break;
 197                         default:
 198                                 special = 0;
 199                                 continue;
 200                         }
 201                 }
 202                 do_cmd(c);
 203                 special = 0;
 204         }
 205 }
 206 \f
 207
 208 /* display a raster centered on window */
 209
 210 void
 211 dos_raster(bitmap, width, height)
 212
 213 unsigned char *bitmap;  /* what to display */
 214 int width, height;      /* of bitmap, width is in bytes */
 215
 216 {
 217         int r, c;       /* row and column indices */
 218         int b;          /* index through bits */
 219         int x, y;       /* upper left corner of where to put bitmap,
 220                          * x in bytes */
 221         int himage_bytes;       /* bytes needed for one row in image */
 222         int n;          /* loop variable */
 223         char *row_ptr;  /* point at a row of the image */
 224
 225
 226         himage_bytes = 4 * width;
 227
 228         /* figure out how to center on screen */
 229         x = (BYTES_PER_LINE - width) / 2 * 8;
 230         y = (Conf_info_p->vlines - height) / 2;
 231
 232         /* zero out the image buffer */
 233         zapblock(Image, SIZEIMAGE);
 234
 235         /* set the header bytes in the image */
 236         Image[0] = (width * 8) % 256;
 237         Image[1] = (width * 8) / 256;
 238         Image[2] = height % 256;
 239         Image[3] = height / 256;
 240         Image[4] = 4;
 241         Image[5] = 0;
 242
 243         /* for each row */
 244         for (r = 0; r < height; r++) {
 245                 row_ptr = &Image[ 6 + r * himage_bytes ];
 246                 for (c = 0; c < width; c++) {
 247                         for (b = 0; b < 8; b++) {
 248                                 if (bitmap[r*width+c] & (1 << (7-b))) {
 249                                         /* white (15); set 4 copies of bit */
 250                                         for (n = 0; n < 4; n++)
 251                                                 row_ptr[n*width + c] |=
 252                                                         (1 << (7-b));
 253                                 } else {
 254                                         /* black (8); set only the first */
 255                                         row_ptr[c] |= (1 << (7-b));
 256                                 }
 257                         }
 258                 }
 259         }
 260
 261         _putimage(x, y, Image, _GPSET);
 262 }
 263 \f
 264 /* zero out a block of memory that may be bigger than 32K */
 265
 266 #define BLOCKSIZE       0x3fff
 267
 268 static void
 269 zapblock(area, size)
 270
 271 char *area;
 272 long size;
 273
 274 {
 275         long k;
 276
 277         /*
 278          * memset's third parm is "unsigned int", so we can't do the whole
 279          * area at once.
 280          */
 281         for (k = 0; k < size; k += BLOCKSIZE) {
 282                 if (size - k >= BLOCKSIZE)
 283                         (void)memset(&area[k], 0, BLOCKSIZE);
 284                 else
 285                         (void)memset(&area[k], 0, size - k);
 286         }
 287 }
 288
 289 #else
 290
 291 /* some compilers don't like empty files, so if __WATCOMC__ isn't defined,
 292  * put something here to keep those compilers happy */
 293 static short dummy;
 294
 295 #endif