Coordinate system transformations
Sometimes we need to translate, rotate, and resize drawings. For example, arcade games are based on the characters moving across the screen.
When we perform drawing using control points, the straightforward solution for translating, rotating, and resizing graphics is in applying desired transformations to control points using corresponding mathematical formulas. Such idea works, but sometimes leads to complicated formulas in the code (especially when we need to rotate graphics). The more elegant solution is in using coordinate system transformations. This is a method of temporarily changing the coordinate system during drawing, which lets you translate, rotate, and resize drawings without changing the drawing algorithm.
Note
The current coordinate system is represented in openFrameworks with a matrix. All coordinate system transformations are made by changing this matrix in some way. When openFrameworks draws something using the changed coordinate system, it...
