Creating a particle system using instanced meshes

To give more geometric detail to each particle in a particle system, we can draw entire meshes instead of single quads. Instanced rendering is a convenient and efficient way to draw several copies of a particular object. OpenGL provides support for instanced rendering through the functions glDrawArraysInstanced and glDrawElementsInstanced.

In this example, we'll modify the particle system introduced in the previous recipes. Rather than drawing single quads, we'll render a more complex object in the place of each particle. The following image shows an example where each particle is rendered as a shaded torus:

We covered the basics of instanced rendering in the previous recipes, so you may want to review those before reading this one. To draw full meshes, we'll use the same basic technique, with some minor changes.  

We'll also add another attribute to control the rotation of each particle so that each can independently spin at a random rotational...