Modules/imgfile.c

/***********************************************************
Copyright 1991, 1992 by Stichting Mathematisch Centrum, Amsterdam, The
Netherlands.

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******************************************************************/

/* IMGFILE module - Interface to sgi libimage */

/* XXX 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 <errno.h>

static object * ImgfileError; /* Exception we raise for various trouble */


/* The image library does not always call the error hander :-(,
   therefore we have a global variable indicating that it was called.
   It is cleared by imgfile_open(). */

static int error_called;


/* The error handler */

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


/* Open an image file and return a pointer to it.
   Make sure we raise an exception if we fail. */

static IMAGE *
imgfile_open(fname)
    char *fname;
{
    IMAGE *image;
    i_seterror(imgfile_error);
    error_called = 0;
    errno = 0;
    if ( (image = iopen(fname, "r")) == NULL ) {
	/* Error may already be set by imgfile_error */
	if ( !error_called ) {
	    if (errno)
	        err_errno(ImgfileError);
	    else
	        err_setstr(ImgfileError, "Can't open image file");
        }
	return NULL;
    }
    return image;
}


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;
    IMAGE *image;
    
    if ( !getargs(args, "s", &fname) )
      return NULL;
    
    if ( (image = imgfile_open(fname)) == NULL )
      return NULL;
    
    if ( image->colormap != CM_NORMAL ) {
	iclose(image);
	err_setstr(ImgfileError, "Can only handle CM_NORMAL images");
	return NULL;
    }
    if ( BPP(image->type) != 1 ) {
	iclose(image);
	err_setstr(ImgfileError, "Can't handle imgfiles with bpp!=1");
	return NULL;
    }
    xsize = image->xsize;
    ysize = image->ysize;
    zsize = image->zsize;
    if ( zsize != 1 && zsize != 3) {
	iclose(image);
	err_setstr(ImgfileError, "Can only handle 1 or 3 byte pixels");
	return NULL;
    }
    if ( xsize > 8192 ) {
	iclose(image);
	err_setstr(ImgfileError, "Can't handle image with > 8192 columns");
	return NULL;
    }

    if ( zsize == 3 ) zsize = 4;
    rv = newsizedstringobject((char *)NULL, xsize*ysize*zsize);
    if ( rv == NULL ) {
      iclose(image);
      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);
	}
    }
    iclose(image);
    if ( error_called ) {
	DECREF(rv);
	return NULL;
    }
    return rv;
}


static object *
imgfile_readscaled(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;
    int xwtd, ywtd, xorig, yorig;
    float xfac, yfac;
    int cnt;
    IMAGE *image;
    
    if ( !getargs(args, "(sii)", &fname, &xwtd, &ywtd) )
      return NULL;

    if ( (image = imgfile_open(fname)) == NULL )
      return NULL;
    
    if ( image->colormap != CM_NORMAL ) {
	iclose(image);
	err_setstr(ImgfileError, "Can only handle CM_NORMAL images");
	return NULL;
    }
    if ( BPP(image->type) != 1 ) {
	iclose(image);
	err_setstr(ImgfileError, "Can't handle imgfiles with bpp!=1");
	return NULL;
    }
    xsize = image->xsize;
    ysize = image->ysize;
    zsize = image->zsize;
    if ( zsize != 1 && zsize != 3) {
	iclose(image);
	err_setstr(ImgfileError, "Can only handle 1 or 3 byte pixels");
	return NULL;
    }
    if ( xsize > 8192 ) {
	iclose(image);
	err_setstr(ImgfileError, "Can't handle image with > 8192 columns");
	return NULL;
    }

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


static object *
imgfile_getsizes(self, args)
    object *self;
    object *args;
{
    char *fname;
    object *rv;
    IMAGE *image;
    
    if ( !getargs(args, "s", &fname) )
      return NULL;
    
    if ( (image = imgfile_open(fname)) == NULL )
      return NULL;
    rv = mkvalue("(iii)", image->xsize, image->ysize, image->zsize);
    iclose(image);
    return rv;
}


static object *
imgfile_write(self, args)
    object *self;
    object *args;
{
    IMAGE *image;
    char *fname;
    int xsize, ysize, zsize, len;
    char *cdatap;
    long *idatap;
    short rs[8192], gs[8192], bs[8192];
    short r, g, b;
    long rgb;
    int x, y;

    if ( !getargs(args, "(ss#iii)",
		  &fname, &cdatap, &len, &xsize, &ysize, &zsize) )
      return NULL;
    
    if ( zsize != 1 && zsize != 3 ) {
	err_setstr(ImgfileError, "Can only handle 1 or 3 byte pixels");
	return NULL;
    }
    if ( len != xsize * ysize * (zsize == 1 ? 1 : 4) ) {
	err_setstr(ImgfileError, "Data does not match sizes");
	return NULL;
    }
    if ( xsize > 8192 ) {
	err_setstr(ImgfileError, "Can't handle image with > 8192 columns");
	return NULL;
    }

    error_called = 0;
    errno = 0;
    image =iopen(fname, "w", RLE(1), 3, xsize, ysize, zsize);
    if ( image == 0 ) {
	if ( ! error_called ) {
	    if (errno)
		err_errno(ImgfileError);
	    else
	        err_setstr(ImgfileError, "Can't create image file");
	}
	return NULL;
    }

    idatap = (long *)cdatap;
    
    for( y=0; y<ysize && !error_called; y++ ) {
	if ( zsize == 1 ) {
	    for( x=0; x<xsize; x++ )
	      rs[x] = *cdatap++;
	    putrow(image, rs, y, 0);
	} else {
	    for( x=0; x<xsize; x++ ) {
		rgb = *idatap++;
		r = rgb & 0xff;
		g = (rgb >> 8 ) & 0xff;
		b = (rgb >> 16 ) & 0xff;
		rs[x] = r;
		gs[x] = g;
		bs[x] = b;
	    }
	    putrow(image, rs, y, 0);
	    putrow(image, gs, y, 1);
	    putrow(image, bs, y, 2);
	}
    }
    iclose(image);
    if ( error_called )
      return NULL;
    INCREF(None);
    return None;
    
}


static struct methodlist imgfile_methods[] = {
    { "getsizes",	imgfile_getsizes },
    { "read",		imgfile_read },
    { "readscaled",	imgfile_readscaled },
    { "write",		imgfile_write },
    { NULL,		NULL } /* Sentinel */
};


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");
}