Modules/imgfile.c

/***********************************************************
Copyright 1991, 1992 by Stichting Mathematisch Centrum, Amsterdam, The
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/* IMGFILE module - Interface to sgi libimg */

/*XXXX This modele should be done better at some point. It should return
** an object of image file class, and have routines to manipulate these
** image files in a neater way (so you can get rgb images off a greyscale
** file, for instance, or do a straight display without having to get the
** image bits into python, etc).
*/

#include "allobjects.h"
#include "modsupport.h"

#include <gl/image.h>

/* #include "sigtype.h" */

static object * ImgfileError;

static char gfname[1024];
static IMAGE *image;

static int error_called;

static imgfile_error(str)
    char *str;
{
    err_setstr(ImgfileError, str);
    error_called = 1;
    return;	/* To imglib, which will return a failure indictaor */
}

static
imgfile_open(args)
    object *args;
{
    char *fname;
    
    if ( !getargs(args, "s", &fname) )
      return 0;
    i_seterror(imgfile_error);
    error_called = 0;
    if ( image != NULL && strcmp(fname, gfname) != 0 ) {
	iclose(image);
	image = NULL;
	gfname[0] = '\0';
    }
    if ( (image=iopen(fname, "r")) == NULL ) {
	/* Error may already be set by imgfile_error */
	if ( !error_called )
	  err_setstr(ImgfileError, "Cannot open image file");
	return 0;
    }
    strcpy(gfname, fname);
    return 1;    
}

static object *
imgfile_read(self, args)
    object *self;
    object *args;
{
    char *fname;
    object *rv;
    int xsize, ysize, zsize;
    char *cdatap;
    long *idatap;
    static short rs[8192], gs[8192], bs[8192];
    int x, y;
    
    if ( !imgfile_open(args) )
      return NULL;
    
    if ( image->colormap != CM_NORMAL ) {
	err_setstr(ImgfileError, "Can only handle CM_NORMAL images");
	return NULL;
    }
    if ( BPP(image->type) != 1 ) {
	err_setstr(ImgfileError, "Cannot handle imgfiles with bpp!=1");
	return NULL;
    }
    xsize = image->xsize;
    ysize = image->ysize;
    zsize = image->zsize;
    if ( zsize != 1 && zsize != 3) {
	err_setstr(ImgfileError, "Can only handle 1 or 3 byte pixels");
	return NULL;
    }

    if ( zsize == 3 ) zsize = 4;
    rv = newsizedstringobject(NULL, xsize*ysize*zsize);
    if ( rv == NULL )
      return NULL;
    cdatap = getstringvalue(rv);
    idatap = (long *)cdatap;
    for ( y=0; y < ysize && !error_called; y++ ) {
	if ( zsize == 1 ) {
	    getrow(image, rs, y, 0);
	    for(x=0; x<xsize; x++ )
	      *cdatap++ = rs[x];
	} else {
	    getrow(image, rs, y, 0);
	    getrow(image, gs, y, 1);
	    getrow(image, bs, y, 2);
	    for(x=0; x<xsize; x++ )
	      *idatap++ = (rs[x] & 0xff)     |
		         ((gs[x] & 0xff)<<8) |
		         ((bs[x] & 0xff)<<16);
	}
    }
    if ( error_called ) {
	DECREF(rv);
	return NULL;
    }
    return rv;
}

static object *
imgfile_getsizes(self, args)
    object *self;
    object *args;
{
    char *fname;
    object *rv;
    
    if ( !imgfile_open(args) )
      return NULL;
    rv = newtupleobject(3);
    if ( rv == NULL )
      return NULL;
    settupleitem(rv, 0, newintobject(image->xsize));
    settupleitem(rv, 1, newintobject(image->ysize));
    settupleitem(rv, 2, newintobject(image->zsize));
    return rv;
}


static struct methodlist imgfile_methods[] = {
    { "getsizes", imgfile_getsizes },
    { "read",     imgfile_read },
    { 0,          0 }
};


void
initimgfile()
{
	object *m, *d;
	m = initmodule("imgfile", imgfile_methods);
	d = getmoduledict(m);
	ImgfileError = newstringobject("imgfile.error");
	if ( ImgfileError == NULL || dictinsert(d,"error",ImgfileError) )
	    fatal("can't define imgfile.error");
}