matplotlib Code

/*
 * The Python Imaging Library.
 * $Id$
 *
 */

/* This is needed for (at least) Tk 8.4.1, otherwise the signature of
** Tk_PhotoPutBlock changes.
*/
#define USE_COMPOSITELESS_PHOTO_PUT_BLOCK

#include <Python.h>
#include <cstdlib>
#include <cstdio>
#include <sstream>

#include "agg_basics.h"
#include "_backend_agg.h"
#include "agg_py_transforms.h"

extern "C"
{
#ifdef __APPLE__
#  ifdef TK_FRAMEWORK
#     include <Tcl/tcl.h>
#     include <Tk/tk.h>
#  else
#     include <tk.h>
#  endif
#else
#  include <tk.h>
#endif
}



typedef struct
{
    PyObject_HEAD
    Tcl_Interp* interp;
} TkappObject;

static int
PyAggImagePhoto(ClientData clientdata, Tcl_Interp* interp,
                int argc, char **argv)
{
    Tk_PhotoHandle photo;
    Tk_PhotoImageBlock block;
    PyObject* aggo;

    // vars for blitting
    PyObject* bboxo;

    unsigned long aggl, bboxl;
    bool has_bbox;
    agg::int8u *destbuffer;
    double l, b, r, t;
    int destx, desty, destwidth, destheight, deststride;
    //unsigned long tmp_ptr;

    long mode;
    long nval;
    if (Tk_MainWindow(interp) == NULL)
    {
        // Will throw a _tkinter.TclError with "this isn't a Tk application"
        return TCL_ERROR;
    }

    if (argc != 5)
    {
        Tcl_AppendResult(interp, "usage: ", argv[0],
                         " destPhoto srcImage", (char *) NULL);
        return TCL_ERROR;
    }

    /* get Tcl PhotoImage handle */
    photo = Tk_FindPhoto(interp, argv[1]);
    if (photo == NULL)
    {
        Tcl_AppendResult(interp, "destination photo must exist", (char *) NULL);
        return TCL_ERROR;
    }
    /* get array (or object that can be converted to array) pointer */
    if (sscanf(argv[2], "%lu", &aggl) != 1)
    {
        Tcl_AppendResult(interp, "error casting pointer", (char *) NULL);
        return TCL_ERROR;
    }
    aggo = (PyObject*)aggl;
    //aggo = (PyObject*)atol(argv[2]);

    //std::stringstream agg_ptr_ss;
    //agg_ptr_ss.str(argv[2]);
    //agg_ptr_ss >> tmp_ptr;
    //aggo = (PyObject*)tmp_ptr;
    RendererAgg *aggRenderer = (RendererAgg *)aggo;
    int srcheight = (int)aggRenderer->get_height();

    /* XXX insert aggRenderer type check */

    /* get array mode (0=mono, 1=rgb, 2=rgba) */
    mode = atol(argv[3]);
    if ((mode != 0) && (mode != 1) && (mode != 2))
    {
        Tcl_AppendResult(interp, "illegal image mode", (char *) NULL);
        return TCL_ERROR;
    }

    /* check for bbox/blitting */
    if (sscanf(argv[4], "%lu", &bboxl) != 1)
    {
        Tcl_AppendResult(interp, "error casting pointer", (char *) NULL);
        return TCL_ERROR;
    }
    bboxo = (PyObject*)bboxl;

    //bboxo = (PyObject*)atol(argv[4]);
    //std::stringstream bbox_ptr_ss;
    //bbox_ptr_ss.str(argv[4]);
    //bbox_ptr_ss >> tmp_ptr;
    //bboxo = (PyObject*)tmp_ptr;
    if (py_convert_bbox(bboxo, l, b, r, t))
    {
        has_bbox = true;

        destx = (int)l;
        desty = srcheight - (int)t;
        destwidth = (int)(r - l);
        destheight = (int)(t - b);
        deststride = 4 * destwidth;

        destbuffer = new agg::int8u[deststride*destheight];
        if (destbuffer == NULL)
        {
            throw Py::MemoryError("_tkagg could not allocate memory for destbuffer");
        }

        agg::rendering_buffer destrbuf;
        destrbuf.attach(destbuffer, destwidth, destheight, deststride);
        pixfmt destpf(destrbuf);
        renderer_base destrb(destpf);

        agg::rect_base<int> region(destx, desty, (int)r, srcheight - (int)b);
        destrb.copy_from(aggRenderer->renderingBuffer, &region,
                         -destx, -desty);
    }
    else
    {
        has_bbox = false;
        destbuffer = NULL;
        destx = desty = destwidth = destheight = deststride = 0;
    }

    /* setup tkblock */
    block.pixelSize = 1;
    if (mode == 0)
    {
        block.offset[0] = block.offset[1] = block.offset[2] = 0;
        nval = 1;
    }
    else
    {
        block.offset[0] = 0;
        block.offset[1] = 1;
        block.offset[2] = 2;
        if (mode == 1)
        {
            block.offset[3] = 0;
            block.pixelSize = 3;
            nval = 3;
        }
        else
        {
            block.offset[3] = 3;
            block.pixelSize = 4;
            nval = 4;
        }
    }

    if (has_bbox)
    {
        block.width  = destwidth;
        block.height = destheight;
        block.pitch = deststride;
        block.pixelPtr = destbuffer;

        Tk_PhotoPutBlock(photo, &block, destx, desty, destwidth, destheight);
        delete [] destbuffer;

    }
    else
    {
        block.width  = aggRenderer->get_width();
        block.height = aggRenderer->get_height();
        block.pitch = block.width * nval;
        block.pixelPtr =  aggRenderer->pixBuffer;

        /* Clear current contents */
        Tk_PhotoBlank(photo);
        /* Copy opaque block to photo image, and leave the rest to TK */
        Tk_PhotoPutBlock(photo, &block, 0, 0, block.width, block.height);
    }

    return TCL_OK;
}


static PyObject *
_pyobj_addr(PyObject* self, PyObject* args)
{
    PyObject *pyobj;
    if (!PyArg_ParseTuple(args, "O", &pyobj))
    {
        return NULL;
    }
    return Py_BuildValue("l", (long) pyobj);
}

static PyObject*
_tkinit(PyObject* self, PyObject* args)
{
    Tcl_Interp* interp;
    TkappObject* app;

    long arg;
    int is_interp;
    if (!PyArg_ParseTuple(args, "li", &arg, &is_interp))
    {
        return NULL;
    }

    if (is_interp)
    {
        interp = (Tcl_Interp*) arg;
    }
    else
    {
        /* Do it the hard way.  This will break if the TkappObject
           layout changes */
        app = (TkappObject*) arg;
        interp = app->interp;
    }

    /* This will bomb if interp is invalid... */

    Tcl_CreateCommand(interp, "PyAggImagePhoto",
                      (Tcl_CmdProc *) PyAggImagePhoto,
                      (ClientData) 0, (Tcl_CmdDeleteProc*) NULL);

    Py_INCREF(Py_None);
    return Py_None;
}

static PyMethodDef functions[] =
{
    /* Tkinter interface stuff */
    {"_pyobj_addr", (PyCFunction)_pyobj_addr, 1},
    {"tkinit", (PyCFunction)_tkinit, 1},
    {NULL, NULL} /* sentinel */
};

extern "C"
    DL_EXPORT(void) init_tkagg(void)
{
    import_array();

    Py_InitModule("_tkagg", functions);
}