Method renderPixels

MicropolisCore/src/TileEngine/src/tileengine.cpp:638–733

void TileEngine::renderPixels(
    cairo_surface_t *destSurf,
    cairo_surface_t *cmapSurf,
    PyObject *tileFunction,
    PyObject *tileMap,
    int renderCol,
    int renderRow,
    int renderCols,
    int renderRows)
{
    if ((tileFunction != Py_None) &&
	!PyCallable_Check(tileFunction)) {
	PyErr_SetString(
	    PyExc_TypeError,
	    "expected tileFunction to be a callable function or None");
	return;
    }

    // The tileMap should be None, or an array of 4 byte integers,
    // mapping virtual tiles indices to absolute tile numbers.

    const int *tileMapData = NULL;
    unsigned int tileMapCount = 0;

    if (tileMap != Py_None) {

        if (!PySequence_Check(tileMap)) {
	    PyErr_SetString(
		PyExc_TypeError,
		"expected tileMap to be an array "
		"of 4 byte integers or None");
	    return;
	}

	tileMapCount = (unsigned int)PySequence_Size(tileMap);
	Py_ssize_t tileMapLength = 0;
	if (PyObject_AsReadBuffer(
	    tileMap,
	    (const void **)&tileMapData,
	    &tileMapLength) != 0) {
	    PyErr_SetString(
		PyExc_TypeError,
		"expected tileMap with read buffer");
	    return;
	}

	int tileMapDataCount = 
	    (int)tileMapLength / sizeof(unsigned int);

	if (tileMapDataCount != (int)tileMapCount) {
	  PyErr_SetString(
	    PyExc_TypeError,
	    "expected tileMap read buffer of 4 byte integers");
	  return;
	}
    }

    unsigned char *destData = cairo_image_surface_get_data(destSurf);