Two triangles are to be rendered on screen. The vertices have been transformed to two-dimensional screen-space and are all within the viewing area. Each vertex has position and colour attributes. a) A number of techniques exist for rasterising a triangle. Describe, in step-by-step fashion, one such technique for deciding which pixels are to be rendered as part of the triangle. [12 marks] b) Identify one advantage or disadvantage of the technique you have described over other techniques. State clearly whether it is an advantage or disadvantage and explain why. [4 marks]