Tetris Piece Rotation Algorithm

Question

What are the best algorithms (and explanations) for representing and rotating the pieces of a tetris game? I always find the piece rotation and representation schemes confu

Answer 1

In Ruby, at least, you can actually use matrices. Represent your piece shapes as nested arrays of arrays like [[0,1],[0,2],[0,3]]

require 'matrix'
shape = shape.map{|arr|(Matrix[arr] * Matrix[[0,-1],[1,0]]).to_a.flatten}

However, I agree that hard-coding the shapes is feasible since there are 7 shapes and 4 states for each = 28 lines and it will never be any more than that.

For more on this see my blog post at https://content.pivotal.io/blog/the-simplest-thing-that-could-possibly-work-in-tetris and a completely working implementation (with minor bugs) at https://github.com/andrewfader/Tetronimo