imgfile.c

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

                        All Rights Reserved

Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the above copyright notice appear in all copies and that
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distribution of the software without specific, written prior
permission.

While CWI is the initial source for this software, a modified version
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STICHTING MATHEMATISCH CENTRUM AND CNRI DISCLAIM ALL WARRANTIES WITH
REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
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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 "Python.h"

#include <gl/image.h>

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

/* Bunch of missing extern decls; keep gcc -Wall happy... */
extern void i_seterror();
extern void iclose();
extern void filterzoom();
extern void putrow();
extern void getrow();

static PyObject * 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 void
imgfile_error(str)
	char *str;
{
	PyErr_SetString(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)
				PyErr_SetFromErrno(ImgfileError);
			else
				PyErr_SetString(ImgfileError,
						"Can't open image file");
		}
		return NULL;
	}
	return image;
}

static PyObject *
imgfile_ttob(self, args)
	PyObject *self;
PyObject *args;
{
	int newval;
	PyObject *rv;
    
	if (!PyArg_Parse(args, "i", &newval))
		return NULL;
	rv = PyInt_FromLong(top_to_bottom);
	top_to_bottom = newval;
	return rv;
}

static PyObject *
imgfile_read(self, args)
	PyObject *self;
PyObject *args;
{
	char *fname;
	PyObject *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 ( !PyArg_Parse(args, "s", &fname) )
		return NULL;
    
	if ( (image = imgfile_open(fname)) == NULL )
		return NULL;
    
	if ( image->colormap != CM_NORMAL ) {
		iclose(image);
		PyErr_SetString(ImgfileError,
				"Can only handle CM_NORMAL images");
		return NULL;
	}
	if ( BPP(image->type) != 1 ) {
		iclose(image);
		PyErr_SetString(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);
		PyErr_SetString(ImgfileError,
				"Can only handle 1 or 3 byte pixels");
		return NULL;
	}
	if ( xsize > 8192 ) {
		iclose(image);
		PyErr_SetString(ImgfileError,
				"Can't handle image with > 8192 columns");
		return NULL;
	}

	if ( zsize == 3 ) zsize = 4;
	rv = PyString_FromStringAndSize((char *)NULL, xsize*ysize*zsize);
	if ( rv == NULL ) {
		iclose(image);
		return NULL;
	}
	cdatap = PyString_AsString(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 ) {
		Py_DECREF(rv);
		return NULL;
	}
	return rv;
}

static IMAGE *glob_image;
static long *glob_datap;
static int glob_width, glob_z, glob_ysize;

static void
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 void
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 void
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 void
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 PyObject *
imgfile_readscaled(self, args)
	PyObject *self;
PyObject *args;
{
	char *fname;
	PyObject *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 = 0;
	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 = PyTuple_Size(args);
	if ( cnt == 5 ) {
		extended = 1;
		if ( !PyArg_Parse(args, "(siisd)",
				  &fname, &xwtd, &ywtd, &filter, &blur) )
			return NULL;
	} else if ( cnt == 4 ) {
		extended = 1;
		if ( !PyArg_Parse(args, "(siis)",
				  &fname, &xwtd, &ywtd, &filter) )
			return NULL;
		blur = 1.0;
	} else if ( !PyArg_Parse(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 {
			PyErr_SetString(ImgfileError, "Unknown filter type");
			return NULL;
		}
	}
    
	if ( (image = imgfile_open(fname)) == NULL )
		return NULL;
    
	if ( image->colormap != CM_NORMAL ) {
		iclose(image);
		PyErr_SetString(ImgfileError,
				"Can only handle CM_NORMAL images");
		return NULL;
	}
	if ( BPP(image->type) != 1 ) {
		iclose(image);
		PyErr_SetString(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);
		PyErr_SetString(ImgfileError,
				"Can only handle 1 or 3 byte pixels");
		return NULL;
	}
	if ( xsize > 8192 ) {
		iclose(image);
		PyErr_SetString(ImgfileError,
				"Can't handle image with > 8192 columns");
		return NULL;
	}

	if ( zsize == 3 ) zsize = 4;
	rv = PyString_FromStringAndSize(NULL, xwtd*ywtd*zsize);
	if ( rv == NULL ) {
		iclose(image);
		return NULL;
	}
	PyFPE_START_PROTECT("readscaled", return 0)
	xfac = (float)xsize/(float)xwtd;
	yfac = (float)ysize/(float)ywtd;
	PyFPE_END_PROTECT(yfac)
	cdatap = PyString_AsString(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 ) {
		Py_DECREF(rv);
		return NULL;
	}
	return rv;
}

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

static PyObject *
imgfile_write(self, args)
	PyObject *self;
PyObject *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 ( !PyArg_Parse(args, "(ss#iii)",
			  &fname, &cdatap, &len, &xsize, &ysize, &zsize) )
		return NULL;
    
	if ( zsize != 1 && zsize != 3 ) {
		PyErr_SetString(ImgfileError,
				"Can only handle 1 or 3 byte pixels");
		return NULL;
	}
	if ( len != xsize * ysize * (zsize == 1 ? 1 : 4) ) {
		PyErr_SetString(ImgfileError, "Data does not match sizes");
		return NULL;
	}
	if ( xsize > 8192 ) {
		PyErr_SetString(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)
				PyErr_SetFromErrno(ImgfileError);
			else
				PyErr_SetString(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;
	Py_INCREF(Py_None);
	return Py_None;
    
}


static PyMethodDef imgfile_methods[] = {
	{ "getsizes",	imgfile_getsizes },
	{ "read",	imgfile_read },
	{ "readscaled",	imgfile_readscaled, 1},
	{ "write",	imgfile_write },
	{ "ttob",	imgfile_ttob },
	{ NULL,		NULL } /* Sentinel */
};


void
initimgfile()
{
	PyObject *m, *d;
	m = Py_InitModule("imgfile", imgfile_methods);
	d = PyModule_GetDict(m);
	ImgfileError = PyErr_NewException("imgfile.error", NULL, NULL);
	if (ImgfileError != NULL)
		PyDict_SetItemString(d, "error", ImgfileError);
}