Modules/imgfile.c

/* IMGFILE module - Interface to sgi libimage */

/* XXX This module 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(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(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(PyObject *self, PyObject *args)
{
    int newval;
    PyObject *rv;

    if (!PyArg_ParseTuple(args, "i:ttob", &newval))
        return NULL;
    rv = PyInt_FromLong(top_to_bottom);
    top_to_bottom = newval;
    return rv;
}

static PyObject *
imgfile_read(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_ParseTuple(args, "s:read", &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(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(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(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(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 *image, int xsize, int ysize, int zsize,
       long *datap, int xnew, int 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(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;
    IMAGE *image;
    char *filter;
    double blur = 1.0;
    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 = PyTuple_Size(args) >= 4;
    if ( !PyArg_ParseTuple(args, "sii|sd",
                           &fname, &xwtd, &ywtd, &filter, &blur) )
        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(PyObject *self, PyObject *args)
{
    char *fname;
    PyObject *rv;
    IMAGE *image;

    if ( !PyArg_ParseTuple(args, "s:getsizes", &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(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_ParseTuple(args, "ss#iii:write",
                      &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, METH_VARARGS },
    { "read",           imgfile_read, METH_VARARGS },
    { "readscaled",     imgfile_readscaled, METH_VARARGS},
    { "write",          imgfile_write, METH_VARARGS },
    { "ttob",           imgfile_ttob, METH_VARARGS },
    { NULL,             NULL } /* Sentinel */
};


void
initimgfile(void)
{
    PyObject *m, *d;

    if (PyErr_WarnPy3k("the imgfile module has been removed in "
                       "Python 3.0", 2) < 0)
        return;

    m = Py_InitModule("imgfile", imgfile_methods);
    if (m == NULL)
        return;
    d = PyModule_GetDict(m);
    ImgfileError = PyErr_NewException("imgfile.error", NULL, NULL);
    if (ImgfileError != NULL)
        PyDict_SetItemString(d, "error", ImgfileError);
}