irrlichtandClaude Opus 5
5a055c048d
pbio moves to git.bnd.wtf/irrlicht/pbio.git branch truecolor16: the framebuffer is now RGB565 u16, no palette. Assets are loaded from PNG via the png crate and quantized to RGB565 on load; transparency comes from the alpha channel as a per-tile opacity mask, so any color (black included) can be opaque. The TGA loader and the palette-order fragility are gone. overworld.png is the unmodified Mini-Medieval Overworld sheet (same 24-column layout as the old TGA, so map tile ids are unchanged); entities.png holds the player sprite extracted from the old entities.tga. Adds an ignored snapshot test that renders the first frame headlessly to a PNG for eyeballing the renderer without a window. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
3.0 KiB
Map Loader
Loads level data from a Tiled CSV export, replacing the old hardcoded build_world wall loop.
Implemented in sim/src/map.rs; wired into the world in sim/src/lib.rs::load_world.
Format
A bare comma-separated tile grid — Tiled's "CSV" layer export, stripped of the surrounding TMX/XML. No header, no dimensions. The loader derives them from the content:
- width = number of fields in the first row
- height = number of rows
The current test map lives at assets/map_test (30×30, tile ids 25 / 74 / 75 / 146).
A trailing comma per row is tolerated; ragged rows panic (they indicate a corrupt export).
Tile flip flags — the "negative numbers"
Tiled packs per-tile flip/rotation into the top 3 bits of each 32-bit GID. A flipped tile
therefore shows up in the CSV as a large negative decimal when read as i32. Example:
-2147483574 as u32 = 0x8000004A
│ └── 0x4A = 74 ← the real tile id
└────────── 0x80000000 = horizontal flip
| Bit | Mask | Meaning |
|---|---|---|
| 31 | 0x80000000 |
horizontal flip |
| 30 | 0x40000000 |
vertical flip |
| 29 | 0x20000000 |
diagonal flip (rot) |
The loader parses each field as i64, reinterprets the low 32 bits as u32, and strips the
flip flags with & 0x1FFF_FFFF, leaving the bare tile id. Flip orientation is discarded for
now — flipped tiles render unflipped. Real flipping would need a flip-aware blit_tile plus
the flags carried through the chunk palette; deferred to the camera/sprite pass (09).
Tile id ↔ tileset
Tile ids are used directly:
- Sim —
tile_flags(id)(inmap.rs) maps an id to gameplayTileFlags(collidable / opaque) via thesim::tile_collidablevocabulary. Hand-maintained; test values only. - Renderer — the id indexes straight into
overworld.png(game.rs). The tileset's tile order is the id space; keep the Tiled tileset andoverworld.pngin lockstep.
No firstgid subtraction: the authored ids already line up with overworld.png.
World assembly
load_world slices the map into 32×32 chunks via Chunk::generate, which builds each chunk's
6-bit palette automatically. The map's top-left tile sits at world (0, 0).
Edge border: a 30×30 map only fills part of chunk (0,0) (which spans tiles 0–31). Tiles
inside a loaded chunk but outside the authored map are emitted as an invisible solid border
(id 0, COLLIDABLE) so the walkable edge sits flush with the visible map rim rather than two
tiles past it at the chunk boundary. Beyond any loaded chunk, movement is blocked anyway by
sim.rs's map_or(true) (no chunk = world edge).
Not done yet
- Multiple layers (only a single tile layer is read)
- Tile properties from Tiled (collision comes from the hand-maintained
tile_flags, not the file) - Object layers (spawns, triggers)
- Tile flipping (orientation discarded — see above)