Usenet 1994 January/usenetsourcesnewsgroupsinfomagicjanuary1994.iso/sources/misc/volume1/8709/5/suntops.c

C/C++ Source or Header | 1987-09-11 | 4.1 KB | 191 lines

/*
 * suntops -- convert Sun rasterfile to PostScript image
 */

#include <assert.h>
#include <rasterfile.h>
#include <stdio.h>

#include "suntops.h"

static void
xch(a, b)
    double         *a;
    double         *b;
{
    double          temp;

    temp = *a;
    *a = *b;
    *b = temp;
}

void
suntops(fpi, h_page, w_page, h_img, w_img, rotate, fpo)
    register FILE  *fpi;        /* rasterfile stdio pointer     */
    double          h_page;        /* PostScript page height     */
    double          w_page;        /* PostScript page width     */
    double          h_img;        /* PostScript image height     */
    double          w_img;        /* PostScript image width     */
    int             rotate;        /* ? rotate output image 90 deg     */
    register FILE  *fpo;        /* PostScript stdio pointer     */
{
    int             hexdig[16];    /* hexadecimal digit map     */
    double          aspect;        /* rasterfile aspect ratio     */
    register int    byte;        /* current rasterfile data byte     */
    register int   *hexp;        /* fast pointer to hexdig array     */
    struct rasterfile ras;        /* rasterfile header         */

 /*
  * read rasterfile header
  */
 /* NOSTRICT */
    if (fread((char *) (&ras), sizeof(ras), 1, fpi) != 1) {
        error("can't read rasterfile header");
    }

    if (ras.ras_magic != RAS_MAGIC) {
        error("input is not a Sun rasterfile");
    }
 /*
  * compute rasterfile aspect ratio
  */
    if (rotate) {
        xch(&h_img, &w_img);
        xch(&h_page, &w_page);
    }

    aspect = ras.ras_width;
    aspect /= ras.ras_height;
 /*
  * adjust PostScript image size to preserve aspect ratio
  */
    if (aspect >= w_img / h_img) {
        h_img = w_img / aspect;
    }
    else {
        w_img = h_img * aspect;
    }

    assert(h_page >= h_img);
    assert(w_page >= w_img);
 /*
  * rasterfile lines are padded to a multiple of 16 bits (see rasterfile(5));
  * adjust rasterfile line length accordingly
  *
  * initialize integer -> hexadecimal digit mapping
  */
    switch (ras.ras_depth) {

    case 1:
        if (ras.ras_width % 16 != 0) {
            ras.ras_width += 16 - ras.ras_width % 16;
        }
 /*
  * Sun black/white bitmap convention is opposite of PostScript, so reverse
  * int->hex map
  */
        hexdig[0] = 'f';
        hexdig[1] = 'e';
        hexdig[2] = 'd';
        hexdig[3] = 'c';
        hexdig[4] = 'b';
        hexdig[5] = 'a';
        hexdig[6] = '9';
        hexdig[7] = '8';
        hexdig[8] = '7';
        hexdig[9] = '6';
        hexdig[10] = '5';
        hexdig[11] = '4';
        hexdig[12] = '3';
        hexdig[13] = '2';
        hexdig[14] = '1';
        hexdig[15] = '0';

        break;

    case 8:
        ras.ras_width += ras.ras_width & 1;
 /*
  * normal int->hex map
  */
        hexdig[0] = '0';
        hexdig[1] = '1';
        hexdig[2] = '2';
        hexdig[3] = '3';
        hexdig[4] = '4';
        hexdig[5] = '5';
        hexdig[6] = '6';
        hexdig[7] = '7';
        hexdig[8] = '8';
        hexdig[9] = '9';
        hexdig[10] = 'a';
        hexdig[11] = 'b';
        hexdig[12] = 'c';
        hexdig[13] = 'd';
        hexdig[14] = 'e';
        hexdig[15] = 'f';

        break;

    default:
        error("bad rasterfile depth");
    }
 /*
  * PostScript header
  */
    (void) printf("%%!\n");
 /*
  * if "rotate" set then rotate PostScript image 90 degrees
  */
    if (rotate) {
        (void) printf("90 rotate\n");
        (void) printf("0 -%d translate\n", ITOP(h_page));
    }
 /*
  * center the PostScript image on the output page
  */
    (void) printf("%d %d translate\n",
              ITOP(((w_page - w_img) / 2.0) + XTRANS_FUDGE),
              ITOP((h_page - h_img) / 2.0));
    (void) printf("%d %d scale\n", ITOP(w_img), ITOP(h_img));
 /*
  * I/O buffer for readhexstring
  */
    (void) printf("/linebuf %d string def\n",
        ras.ras_width / (8 / ras.ras_depth));
 /*
  * set PostScript image parameters
  */
    (void) printf("%ld %ld %d\n",
              ras.ras_width, ras.ras_height, ras.ras_depth);
    (void) printf("[%ld 0 0 -%ld 0 %ld]\n",
              ras.ras_width, ras.ras_height, ras.ras_height);
    (void) printf("{currentfile linebuf readhexstring pop}\n");
 /*
  * image data follows
  */
    (void) printf("image\n");
 /*
  * convert rasterfile bytes to pairs of ASCII hexadecimal digits
  */
    hexp = hexdig;

    while ((byte = getc(fpi)) != EOF) {
        putc(hexp[HI_NYBBLE(byte)], fpo);
        putc(hexp[LO_NYBBLE(byte)], fpo);
    }

    if (ferror(fpi)) {
        error("input error");
    }

    if (ferror(fpo)) {
        error("output error");
    }
 /*
  * display PostScript image on output device
  */
    (void) fprintf(fpo, "showpage\n");
}