Minecraft Forums

Quote from Keybounce»

The biggest thing you'd want to do is find the routine in the code that handles the pistons pushing, and make that routine call your code instead of doing its own stuff.

That's a non-trivial thing. In the easiest case -- there is one method that does this and nothing else -- you simply use ASM to put, at the beginning of the method, the equivalent of "return myMethod(argument list)".

In any case, you have to figure out what bytecode corresponds to the method call, where to insert it into the method, and then how to do so. There's at least two ways (I think) to do it; locating the where for anything but that simple case is painful; and the compiling to java assembly takes some learning.

My suggestion: Get help from others that have already done this.

I'm not going to mess with this, then. I've looked through the piston code enough to know that there's three or more methods I need to override (pistons do a pre-check and a move in separate methods, and these are called from two different methods). Much more work that I'm going to put in to a mod that's been mothballed for over a year.