Files
Andrew Kesterson 490e62dbbf Delete the sidescroller's collision, and let the library do it
collision.c was 383 lines that re-implemented akgl_physics_simulate's own
arithmetic, because movementlogicfunc runs before gravity, drag and the move
and so had to predict where the actor would end up. The whole file goes. What
replaces it is three lines in main.c, a shape on the player and the blob, and a
`collidable` property on the map's terrain layer -- which also retires
SS_TERRAIN_LAYER_ID, a compiled-in layer id that broke whenever somebody
reordered layers in Tiled.

grounded stays a probe rather than becoming a contact test. A contact says
something pushed back this step; grounded asks whether there is a floor to push
off, and that stays true through the frame after landing. The blob keeps its own
wall and ledge probes for the same reason: the resolver does not say which side
of the blob it was pushed from, and says nothing at all about a floor that is
missing.

The summary line now carries the player's resting position, because exiting 0
was not evidence that collision ran. It reports 136.0,160.0 grounded after 240
autoplay frames -- feet at y=192, flush on the surface of terrain row 12.

The tutorial's collision section is rewritten around the library's, keeping the
quarter-of-a-pixel story as what a predicting resolver costs. The docs harness
learns `json excerpt=`, so the map property the chapter quotes is checked
against the map.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KzBDV2fqgnUAcqCKqKvc71
2026-08-02 07:35:08 -04:00

16 KiB