The tiles' photograph side is 0 when the map has none: no photograph or coarse photograph sections, no
decode, ter_o answers 0, and no coarse photograph texture - as such a map has always drawn. The cut and
terrain_tiles_bake no longer require one.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Heights as u16 over each 64 m tile's own minimum and step (a tile spanning 200 m steps 3 mm), normals
octahedral 8 + 8, the photograph RGB8, and the coarse level (2048: heights f32, normals, photograph)
- 30 + 32 + 48 + 16 + 8 + 12 MB, about 146 MB a map where the float tiles were 192 plus nothing coarse.
The writer puts the whole copy back to the quantized values as it goes, so the build's own queries,
the physics, the placements' bake and every machine read the same numbers; a tile read decodes them
into the pools the queries and the page pool already use.
terrain_tiles_bake(path, key, version, inputs_hash) writes a bake's file (ludic.base's LBAK header,
the tiles as its payload) from a made map; terrain_from_baked(path, key, version, half, ox, oz) opens
one at boot in place of terrain_use_dem / terrain_use_ortho, and terrain_init then generates nothing
(and bakes the sun's shadow from the coarse level unless terrain_shadow_from_bytes gave it). Without a
bake the cut writes the same format to <dir>/<key>.tiles and reads it back. The GPU's coarse level is
made from the file's coarse sections (the blit from the whole maps is gone).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
terrain_tiles_to(dir, key) before a map is made: once made, its heights, photograph and baked normals
are written tile by tile (64 m, TT_TEX) to <dir>/<key>.tiles - fresh every time, header last, so no
other generator's or a torn file is ever read - and the whole copies go. Every read goes through the
tile: resident, else read from the file there and then into a 2048-tile clock, so terrain_height,
terrain_height_smooth, terrain_ortho* and terrain_chunk_heights answer exactly what the whole copy
did (R3D_TT_CHECK: worst 0.0 m over 4000 points) whatever is resident - two machines and the boot's
placements agree to the bit. terrain_chunk_heights takes render3d_st mut for it.
terrain_height_near(read-only): the tile if it is in, else a coarse 2048^2 level (worst 0.91 m), never
the file - for line checks that must not take render3d_st mut. terrain_texel() is the texel size,
terrain_tiles_prefetch(x, z, r, budget) reads ahead, and a frame that reads more than 8 tiles says so
once. R3D_TERRAIN_TILES=<dir> turns it on for a run.
At the overlook with MallocLargeCache=0: 1731 MB off, 1658 MB on; 192 MB written in ~200 ms; the
frame unchanged (0 pixels over 8).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
