Isometric Tiles Math  Working with isometric tiles is a bit
trickier than a plain square grid. This tutorial is for beginner
game programmers looking to wrap their heads around isometric
math. Instead of simply handing you formulas, I intend to
explain what they do and how they should be used.  There are
many ways of handling isometric tiles but we're only going to
talk about one method. This happens to be the most commonly used
method. It's the way that isometry is handled in the Tiled map
editor, so it's definitely a good approach if you want to use
that tool.  Orthographic Projection  When working in isometric
project, your maps will still be a simple 2D array (or
equivalent) in memory -- just as if you were working in a
simpler orthographic projection (e.g. side or top view).  Our
grid in "map" coordinates -- how our array looks in memory,
Values are (map.x, map.y)  If you've worked with a regular
square grid before (which I recommend before trying isometric),
the math works out pretty simple. Drawing a t