Preparing a perspective projection matrix

3D applications usually try to simulate the effect of how we perceive the world around us--objects in the distance seem smaller than the objects that are closer to us. To achieve this effect, we need to use a perspective projection matrix.

How to do it...

1. Prepare a variable of type float named aspect_ratio that will hold an aspect ratio of a renderable area (image's width divided by its height).
2. Create a variable of type float named field_of_view. Initialize it with an angle (in radians) of a vertical field of view of a camera.
3. Create a variable of type float named near_plane and initialize it with the distance from the camera's position to the near clipping plane.
4. Create a variable of type float named far_plane. Store the distance between a camera and the far clipping plane in the variable.
5. Calculate a value of 1.0f divided by a tangent of the half of the field_of_view (1.0f / tan(Deg2Rad(0.5f * field_of_view))) and store the result in a variable of type...