|Country polygons, state and |
river polylines, and city points (billboards)
|Country polygons and river polylines|
This chapter begins with two short sections on sources of vector data and on avoiding z-fighting between vector data and the globe it is drawn on. The bulk of the chapter is then in these three sections:
- Layouts: strips, loops, and indexed lines.
- Batching and static vertex buffers.
- Rendering wide lines using a geometry shader [code].
- Shaders for rendering outlined (two color) lines [code].
- Overview of raster techniques for polygon rendering.
- A pipeline for geometry-based polygon rendering, including:
Of course, the chapter contains much more than the above bullets but these are the highlights. Now, I'm off to write the chapter on moving much of this work (disk/network access, triangulation, texture atlas packing, GL resource creation) off the main thread. Since most the code for this is already done, I'm hoping this is a pretty easy chapter to write.