It is implemented as a post-processing effect. The hack for the
projection transform matrix has been removed, because now the image is
flipped upside down in the post-processing stage.
Major differences from DrawDungeon.hll are:
- DGN, DTX, TES are loaded from individual files, not from a DLF archive
- 2D map functions are not used
- (unimplemented) Spinning motion of event markers
- (unimplemented) Additional 3D object types (polygon models and roofs)
Before this, all objects that share a texture were drawn at once.
Objects were not depth-sorted, so if a transparent object was drawn
first, objects behind it were not drawn.
After this, dungeon is drawn for each cell, sorted by distance from
the camera position. To reduce the number of cells to be drawn, PVS
(Potentially Visible Set) stored in dgn files is used.
kichikuou