In this last section, we provide a simple explanation about the various mode settings in the gfx3.c sample program. First of all, the only thing specified for geometry mode is G_CULL_BACK. In other words, none of the shading functions are used. The combine mode is set to G_CC_DECALRGB. A detailed explanation of combine mode will be given in Chapter 4, so here we will only note that when the mode is set to G_CC_DECALRGB only the texture color and alpha value are used. That is why there is no need to specify G_SHADE for geometry mode.

The rendering mode is set to G_RM_OPA_SURF and G_RM_OPA_SURF2, as always. We will continue to use these settings until Chapter 5, so for now no explanation for the rendering mode will be provided.