I would like to draw a chart in OpenGL similar to the donut graph at the bottom-right of this example. I have experience with drawing 2D charts such as the main chart in the example but what confuses me about the one I want to draw is the correct type of primitive to use when drawing the 3D chart. I have considered using GL_QUAD_STRIP and GL_POLYGON but neither seem quite right for the task. Where should I begin? I will be using JOGL with Java to draw the chart, if that helps at all. Also, I don't necessarily need to extrude certain slices of the chart as shown in the example.