Orkuncakilkaya
0b149a6876
Phase 0 of the gameplay-controller work (#57): turn the static Collision.* overlap tests into a real physics-lite moving-body-with-collision layer that the platformer / shooter / NPC-AI / RPG families build on. New engine-owned system esys_move (runtime/native/systems_move.ludic), spliced and Update-phase-registered when a game declares `Body` (parse.ludic), standing entirely on the reflection ABI like the SpriteAnim / Motion / Light2D systems: - Body { vx, vy, gravity, max_fall, rx, ry, policy, on_ground, hit_wall, hit_ceiling } — Q16.16 velocity + engine-owned sub-pixel accumulators. - Collider { w, h, offx, offy, is_trigger, one_way, layer, mask, hit, entered, exited } — AABB shape off Position, layer/mask filtering, one-way + triggers. - Solids { tile, wall, oneway } — optional config entity enabling the tile-grid broadphase over the Map.* tilemap. esys_move integrates velocity + gravity, then resolves per-axis swept AABB against both solid Collider entities and the tile grid (no tunneling), handles one-way platforms (block only a downward landing), reports trigger/sensor overlaps without resolving, and sets on_ground / hit_wall / hit_ceiling for a controller to poll. No float, no hidden singletons, no runtime dispatch — integer + deterministic, so replay / lockstep / world_save hold. Contact is surfaced as polled flags (the SpriteAnim.event_fired shape), so a game raises its own CollisionResolved / TriggerEntered events with no engine coupling. Two self-asserting examples (entity + tile broadphase) wired into `x test`; docs added to the collision section. A build with no Body compiles byte-for-byte the same (bootstrap fixpoint + all golden renders unchanged). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2.7 KiB
| id | title | order |
|---|---|---|
| collision | Collision | 6 |
2D overlap tests on integer coordinates (pixels or tiles). Rectangles are (x, y, w, h) from the top-left; circles are (x, y, r). Each returns a bool. Squared distances are computed in 64-bit so large coordinates never overflow.
These are static boolean tests. For a moving body with real collision resolution, the engine ships a physics-lite movement system built on the same integer math — declare the well-known components and the engine advances them for you each frame, no handler wired:
property Body { vx, vy, gravity, max_fall, rx, ry, policy, on_ground, hit_wall, hit_ceiling }— velocity/accel state in Q16.16 fixed-point (vx/vy/gravity/max_fall), engine-owned sub-pixel accumulators (rx/ry), an integrationpolicy(0platformer with gravity,1top-down), and the derived contact flags the engine sets each frame.property Collider { w, h, offx, offy, is_trigger, one_way, layer, mask, hit, entered, exited }— an AABB shape offset from the entity'sPosition { x, y }, with layer/mask filtering, one-way-platform and trigger flags, and per-frame trigger outputs.property Solids { tile, wall, oneway }— an optional single config entity that turns on the tile-grid broadphase over theMaptilemap (tilepx size, the solidwallglyph, and an optional one-wayonewayglyph).
The engine-owned esys_move system (Update phase) integrates velocity and gravity into a tentative move, then resolves it with a per-axis swept AABB — against both solid Collider entities and the tile grid — so a fast body never tunnels through a wall. It handles one-way platforms (which block only a downward landing), reports trigger/sensor overlaps without resolving them, and sets on_ground / hit_wall / hit_ceiling for a controller to read. Everything is integer and deterministic, so movement reproduces exactly under replay, lockstep and world_save snapshots. Contact is surfaced as polled flags (the SpriteAnim.event_fired shape) rather than engine-emitted events, so a game raises its own CollisionResolved / TriggerEntered events from its handler with no coupling. This is the shared foundation the built-in gameplay controllers build on. Related: Grid, Map, Motion, @EngineSystem.