I have improved the available “plugs” for our compositing shaders mechanism and updated their documentation.

The overall goal was to make them friendly when you target only Phong shading, or want to switch between Phong and Gouraud shading.

• New PLUG_fragment_modify, simplest way to modify calculation after lighting, textures, fog are applied. This is also used now in the initial examples on Chapter 5. Extending the shaders with plugs.

• Clear warning when trying to use deprecated PLUG_texture_apply.

• Improved documentation about new things, and differences between Phong and Gouraud shading — PLUG_main_texture_apply, PLUG_texture_apply, PLUG_lighting_apply all necessarily behave a bit different depending on shading.

I have also updated Mountains of Fire (see also game page) a bit, to use new shader effects.