Earth Rendering

It's a simple tutrial about Rendering Earth using OpenGL ust for fun.I implemented it three years ago and the main framework is used to test some interested technology until today,such as antialiased line, vector text rendering, polygon filling test and so on. I will release some implementations on the furture;   this example display a earth background map and have a terrain effect using bump map technology; while mouse wheel and left key press can rotate and scale the "earth".