loadras.c

来自「细胞自动机的一个源代码」· C语言 代码 · 共 178 行

/*procedure to put raster file into byte/int array*/
#include <stdio.h>
#include <sys/file.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include "loadras.h"

int getrasheader(struct rasterheader *rashead, int from) {
  int i, j, k, n;
  char rbuf[4], buf[4];
  /*  char magic[4] = {0x59a66a95};*/

  n=read(from, buf, 4);
  for (j=0; j<4; j++) {
    rbuf[j] = buf[4-j-1];
    rashead->ras_magic[j]=buf[j];
  }
  k = (int)*( (int *)rbuf);
  rashead->irasmagic=k;

  n=read(from, buf, 4);
  for (j=0; j<4; j++) {
    rbuf[j] = buf[4-j-1];
    rashead->ras_width[j]=buf[j];
  }
  k = (int)*( (int *)rbuf);
  rashead->iraswidth=k;

  n=read(from, buf, 4);
  for (j=0; j<4; j++) {
    rbuf[j] = buf[4-j-1];
    rashead->ras_height[j]=buf[j];
  }
  k = (int)*( (int *)rbuf);
  rashead->irasheight=k;

  n=read(from, buf, 4);
  for (j=0; j<4; j++) {
    rbuf[j] = buf[4-j-1];
    rashead->ras_depth[j]=buf[j];
  }
  k = (int)*( (int *)rbuf);
  rashead->irasdepth=k;

  n=read(from, buf, 4);
  for (j=0; j<4; j++) {
    rbuf[j] = buf[4-j-1];
    rashead->ras_length[j]=buf[j];
  }
  k = (int)*( (int *)rbuf);
  rashead->iraslength=k;

  n=read(from, buf, 4);
  for (j=0; j<4; j++) {
    rbuf[j] = buf[4-j-1];
    rashead->ras_type[j]=buf[j];
  }
  k = (int)*( (int *)rbuf);
  rashead->irastype=k;

  n=read(from, buf, 4);
  for (j=0; j<4; j++) {
    rbuf[j] = buf[4-j-1];
    rashead->ras_maptype[j]=buf[j];
  }
  k = (int)*( (int *)rbuf);
  rashead->irasmaptype=k;

  n=read(from, buf, 4);
  for (j=0; j<4; j++) {
    rbuf[j] = buf[4-j-1];
    rashead->ras_maplength[j]=buf[j];
  }
  k = (int)*( (int *)rbuf);
  rashead->irasmaplength=k;

}

/*AS FAR AS I KNOW, THIS WILL ONLY WORK ON
  INTEL MACHINES.  BE WARNED*/
int writeras(struct aberas *src, char *fn) {
  int i, j, k;
  int to;
  char buf[4], rbuf[4];

  if ((to = open(fn,
		 O_WRONLY|O_CREAT|O_TRUNC,
		 S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH))<0) {
    perror(fn);
    return(-1);
  }

  write(to, src->header.ras_magic, 4);
  write(to, src->header.ras_width, 4);
  write(to, src->header.ras_height, 4);
  write(to, src->header.ras_depth, 4);
  write(to, src->header.ras_length, 4);
  write(to, src->header.ras_type, 4);
  write(to, src->header.ras_maptype, 4);
  write(to, src->header.ras_maplength, 4);

  k=src->header.iraswidth * src->header.irasheight;
  for (i=0; i<k; i++) {
    write(to, (char *)(&(src->brgba[i*4])), 3);
  }

  close(to);

}

int loadras(struct aberas *dest, char *filename) {
  int i, j, k;
  int from;
  char buf[4], rbuf[4];

  if ((from = open(filename, O_RDONLY))<0) {
    perror(filename);
    exit(1);
  }

  getrasheader(&dest->header, from);

  k = 4*((dest->header.iraswidth) * (dest->header.irasheight));

  dest->brgba = (unsigned char *) malloc(k);

  dest->height=dest->header.irasheight;
  dest->width=dest->header.iraswidth;

  k = ((dest->header.iraswidth) * (dest->header.irasheight));  

  /* mother fucking raster files pad odd widths with a byte! */

  for (i=0; i<k; i++) { 
    read(from, buf, 3);
    dest->brgba[i*4]=(unsigned char)buf[2];
    dest->brgba[(i*4)+1]=(unsigned char)buf[1];
    dest->brgba[(i*4)+2]=(unsigned char)buf[0];
    dest->brgba[(i*4)+3]=255;

    if (((dest->header.iraswidth)%2)==1) {
      if (((i+1)%(dest->header.iraswidth))==0) {
	//if width is odd, and we've read a full
	//width, line, throw away padded byte
	read(from, buf, 1);
      }
    }
  }

  return(1);
}

/*
void main(int argc, char **argv) {
  int i, j, k;
  struct aberas t;

  char fn[80] = {"blargh"};

  if (argc!=2) exit(1);
  loadras(&t, argv[1]);

  printf("\n\n%i\n", t.header.irasmagic);
  printf("%i\n", t.header.iraswidth);
  printf("%i\n", t.header.irasheight);
  printf("%i\n", t.header.irasdepth);
  printf("%i\n", t.header.iraslength);
  printf("%i\n", t.header.irastype);
  printf("%i\n", t.header.irasmaptype);
  printf("%i\n", t.header.irasmaplength);

  free(t.brgba);

}
*/