We have seen a lot so far. How to draw and color an object, then we added and animated a second object. But there remain two large issues in this model.
First, we see that we are drawing directly into the normalized device coordinates. While it is possible work in a world where all coordinates are bound by ±1, it is at best artificial and clumsy.
Also, looking at the second triangle we see that it is exactly the same size as the first triangle, despite being more distant.
These issues lead us to our final major topic, perspective projection.