cpython/Modules/imgfile.c

/***********************************************************
Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
The Netherlands.

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documentation for any purpose and without fee is hereby granted,
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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).
**
** Warning: this module is very non-reentrant (esp. the readscaled stuff)
*/

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

#include <gl/image.h>
#include <errno.h>

#include "/usr/people/4Dgifts/iristools/include/izoom.h"

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

static int top_to_bottom;	/* True if we want top-to-bottom images */

/* 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 indicator */
}


/* 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_ttob(self, args)
    object *self;
    object *args;
{
    int newval;
    object *rv;
    
    if (!getargs(args, "i", &newval))
      return NULL;
    rv = newintobject(top_to_bottom);
    top_to_bottom = newval;
    return rv;
}

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;
    int yfirst, ylast, ystep;

    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;

    if (top_to_bottom) {
	yfirst = ysize-1;
	ylast = -1;
	ystep = -1;
    } else {
	yfirst = 0;
	ylast = ysize;
	ystep = 1;
    }
    for ( y=yfirst; y != ylast && !error_called; y += ystep ) {
	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 IMAGE *glob_image;
static long *glob_datap;
static int glob_width, glob_z, glob_ysize;

static
xs_get(buf, y)
    short *buf;
    int y;
{
    if (top_to_bottom)
      getrow(glob_image, buf, (glob_ysize-1-y), glob_z);
    else
      getrow(glob_image, buf, y, glob_z);
}

static
xs_put_c(buf, y)
    short *buf;
    int y;
{
    char *datap = (char *)glob_datap + y*glob_width;
    int width = glob_width;

    while ( width-- )
      *datap++ = (*buf++) & 0xff;
}

static
xs_put_0(buf, y)
    short *buf;
    int y;
{
    long *datap = glob_datap + y*glob_width;
    int width = glob_width;

    while ( width-- )
      *datap++ = (*buf++) & 0xff;
}
static
xs_put_12(buf, y)
    short *buf;
    int y;
{
    long *datap = glob_datap + y*glob_width;
    int width = glob_width;

    while ( width-- )
      *datap++ |= ((*buf++) & 0xff) << (glob_z*8);
}

static void
xscale(image, xsize, ysize, zsize, datap, xnew, ynew, fmode, blur)
    IMAGE *image;
    int xsize, ysize, zsize;
    long *datap;
    int xnew, ynew;
    int fmode;
    double blur;
{
    glob_image = image;
    glob_datap = datap;
    glob_width = xnew;
    glob_ysize = ysize;
    if ( zsize == 1 ) {
	glob_z = 0;
	filterzoom(xs_get, xs_put_c, xsize, ysize, xnew, ynew, fmode, blur);
    } else {
	glob_z = 0;
	filterzoom(xs_get, xs_put_0, xsize, ysize, xnew, ynew, fmode, blur);
	glob_z = 1;
	filterzoom(xs_get, xs_put_12, xsize, ysize, xnew, ynew, fmode, blur);
	glob_z = 2;
	filterzoom(xs_get, xs_put_12, xsize, ysize, xnew, ynew, fmode, blur);
    }
}


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;
    char *filter;
    double blur;
    int extended;
    int fmode;
    int yfirst, ylast, ystep;

    /*
     ** Parse args. Funny, since arg 4 and 5 are optional
     ** (filter name and blur factor). Also, 4 or 5 arguments indicates
     ** extended scale algorithm in stead of simple-minded pixel drop/dup.
     */
    extended = 0;
    cnt = gettuplesize(args);
    if ( cnt == 5 ) {
	extended = 1;
	if ( !getargs(args, "(siisd)", &fname, &xwtd, &ywtd, &filter, &blur) )
	  return NULL;
    } else if ( cnt == 4 ) {
	extended = 1;
	if ( !getargs(args, "(siis)", &fname, &xwtd, &ywtd, &filter) )
	  return NULL;
	blur = 1.0;
    } else if ( !getargs(args, "(sii)", &fname, &xwtd, &ywtd) )
      return NULL;

    /*
     ** Check parameters, open file and check type, rows, etc.
     */
    if ( extended ) {
	if ( strcmp(filter, "impulse") == 0 ) fmode = IMPULSE;
	else if ( strcmp( filter, "box") == 0 ) fmode = BOX;
	else if ( strcmp( filter, "triangle") == 0 ) fmode = TRIANGLE;
	else if ( strcmp( filter, "quadratic") == 0 ) fmode = QUADRATIC;
	else if ( strcmp( filter, "gaussian") == 0 ) fmode = GAUSSIAN;
	else {
	    err_setstr(ImgfileError, "Unknown filter type");
	    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;

    if ( extended ) {
	xscale(image, xsize, ysize, zsize, idatap, xwtd, ywtd, fmode, blur);
    } else {
	if (top_to_bottom) {
	    yfirst = ywtd-1;
	    ylast = -1;
	    ystep = -1;
	} else {
	    yfirst = 0;
	    ylast = ywtd;
	    ystep = 1;
	}
	for ( y=yfirst; y != ylast && !error_called; y += ystep ) {
	    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;
    int yfirst, ylast, ystep;


    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;
    
    if (top_to_bottom) {
	yfirst = ysize-1;
	ylast = -1;
	ystep = -1;
    } else {
	yfirst = 0;
	ylast = ysize;
	ystep = 1;
    }
    for ( y=yfirst; y != ylast && !error_called; y += ystep ) {
	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, 1},
    { "write",		imgfile_write },
    { "ttob",		imgfile_ttob },
    { 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");
}