Landscape GeoMipMapping

The goal is to be able to support some older device that lacks the VTF (Vertex Texture Fetch) hardware feature. In this case I found the "GeoMipMapping" to be the most suitable LOD algorithm. For the newer devices I would consider using the CDLOD algorithm. This video just shows some ruff implementation. There is still some work that needs to be done. There are still some seams visable. Still need to do some optimizations and implement some LOD morphing stuff.

The GeoMipMapping LOD algorithm is based on the document:
"Fast Terrain Rendering Using Geometrical MipMapping"
https://www.flipcode.com/archives/article_geomipmaps.pdf