There is really no need to go into further detail about Fill mode and Copy mode. Both have a very simple pipeline structure and it should be clear how they are used. For the rest of this chapter we will focus on an explanation of the differences between 1-Cycle mode and 2-Cycle mode.

Actually, 1-Cycle mode is a richly functional mode that is sufficient for most of your rendering needs. Processing takes longer in 2-Cycle mode, so think of it as the mode you only use when there is something you cannot achieve with 1-Cycle mode. Next we will cover the things that 2-Cycle Mode can do that 1-Cycle Mode cannot.

-Use multi-tile textures (Combiner)

You need to set the RDP pipeline to 2-Cycle mode in order to put texels together from two textures in the Combiner, and to perform LOD-related texture mapping. We talk more about multi-texture tiles in Chapters 9 and 10.

-Combine a number of source colors (Combiner)

The Combiner can use the linear equation (a - b) * c + d to determine the pixel color and pixel alpha. But this expression is not sufficient if you want to make a calculation that reflects many more source colors (alphas). In this case, you would use 2-Cycle mode and perform (a - b) * c + d twice in order to calculate a more complicated pixel color (alpha). Later in this chapter, we will give an example of how to use this type of 2-Cycle mode.

-Fog function (Blender) & ordinary blending

You need to set the pipeline to 2-Cycle mode in order to enable the Fog function in the Blender and also perform blending. We will talk about Fog later in this chapter.