Equations and Shapes

In this game you will have to pick a side of a polygon that in your opinion will be the longest after the points that make up these sides have traveled a specified amount of space along the axes of the Cartesian coordinate system. Every point has a corresponding equation along the graph of which it moves. The equations on the right are colored accordingly to the color of the points (A - yellow, B - red, C - blue, D - green, E - purple) and are placed from top to bottom in the alphabetical order (that is a(x) at the top, e(x) at the bottom). The game might be buggy, so any feedback would be appreciated. Thank you for playing!

HOW TO PLAY: number keys (1-5) circle between sides of the polygon; w,a,s,d - move the camera; space - start plotting graphs and/or advance to the next level

UPDATE: since some users' browsers don't allow downloading .exe files I've packed both the executable and the source code in a .rar file.  Also I've fixed a small typo in the code that made triangles extremely rare (only in the .rar version). I hope this isn't against the rules to make such small adjustments after the deadline. I can always return to the previous version by deleting the .rar file since the other 2 files weren't changed.