montagev_rgba
Tcl_Obj* imageTopObj
Tcl_Obj* imageBottomObj

/*
 * Place the two images adjacent to each other in the result, from top to
 * bottom. The images have to have the same width.
 */

crimp_image*     result;
crimp_image*     imageTop;
crimp_image*     imageBottom;
int x, y;

crimp_input (imageTopObj,    imageTop,    rgba);
crimp_input (imageBottomObj, imageBottom, rgba);

if (!crimp_eq_width (imageTop, imageBottom)) {
    Tcl_SetResult(interp, "image widths do not match", TCL_STATIC);
    return TCL_ERROR;
}

result = crimp_new_rgba (imageTop->w, imageTop->h + imageBottom->h);

for (y = 0; y < imageTop->h; y++) {
    for (x = 0; x < result->w; x++) {

	R (result, x, y) = R (imageTop, x, y);
	G (result, x, y) = G (imageTop, x, y);
	B (result, x, y) = B (imageTop, x, y);
	A (result, x, y) = A (imageTop, x, y);
    }
}

for (y = 0; y < imageBottom->h; y++) {
    for (x = 0; x < result->w; x++) {

	R (result, x, imageTop->h + y) = R (imageBottom, x, y);
	G (result, x, imageTop->h + y) = G (imageBottom, x, y);
	B (result, x, imageTop->h + y) = B (imageBottom, x, y);
	A (result, x, imageTop->h + y) = A (imageBottom, x, y);
    }
}

Tcl_SetObjResult(interp, crimp_new_image_obj (result));
return TCL_OK;

/* vim: set sts=4 sw=4 tw=80 et ft=c: */
/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */