Parse MOPY per-triangle flags in WMO groups and exclude detail/decorative
triangles (flag 0x04) from collision detection. This prevents invisible
walls from objects like gears and railings in WMO interiors.
Add WotLK area trigger IDs 2173/2175 to extended-range tram triggers.
Two WMO rendering fixes:
1. Glass batch merging: BatchKey didn't include isWindow, so window and
non-window batches sharing the same texture got merged together. If
the window batch was processed first, the entire merged batch (lamp
base, iron frame, etc.) rendered as transparent glass. Add isWindow
to the batch key so glass/non-glass batches stay separate.
2. LOD group culling: WMO groups named with "LOD" are distance-only
impostor geometry (e.g. cathedral tower extension, hill tower). They
should only render beyond 200 units. Store raw MOGN chunk for
offset-based name lookup, detect "lod" in group names during load,
and skip LOD groups in both main and shadow passes when camera is
within range.
Portal-based visibility culling for WMO rendering (disabled by default,
needs debugging for complex WMOs like Stormwind). Skip character creation
screen when characters already exist in single-player mode.
- Add loading screen system with stb_image for JPEG loading
- Two loading screen images (orc and dwarf) randomly selected
- Display loading screen while terrain data loads
- Cache WMO inverse matrices to reduce per-frame computation
- Stub WMO liquid rendering (needs coordinate system fix)
- Update spawn point to Stormwind Trade District
The MOHD header structure was missing the nTextures field at the start,
causing all subsequent field reads to be offset by 4 bytes. This corrupted
bounding box values and caused floor geometry to be incorrectly culled.
