Combat contact and projectiles

Combat is rectangle overlap plus action timing. It is intentionally understandable enough to inspect in the C source and strong enough to make spacing meaningful.

Try it: trade on purpose.

Choose matching fighters in P1 VS P2, face them together, and begin jabs on the same update. Both sparks mean both active rectangles overlapped.

A hitbox exists only during an active window

Jab visuals have three phases. Generated character data supplies total duration, phase boundaries, and inclusive active ticks; jab_is_active() computes elapsed ticks from the remaining timer. Mario, Tommy, and Rizer use 9 ticks with contact on elapsed ticks 3–5. Simon uses 15 with contact on 5–9. Tommy’s special is a 12-tick kick active on 4–7.

The code tests a 16×32 defender body against an 8-pixel-high attack rectangle in front of the attacker. Jab reach is 10/20/12/14 pixels for Mario/Simon/Tommy/Rizer. Tommy’s kick extends 24 pixels. Art can overhang these rectangles; visual pixels do not redefine collision.

Trades are a frame-order property

update_battle() calls detect_melee_hit(0) and detect_melee_hit(1) before either call to apply_melee_hit(). Both attacks therefore use the same action state. If both are active and overlap, each lands. Once a hit is applied, it clears the target’s timers, so a later startup never becomes contact by accident.

On every hit, the runtime sets ten ticks of hitstun, cancels jab/special, adds damage, applies launch velocity, starts a five-tick spark, and sends a sound cue. The source’s apply_hit() is the authoritative list.

Projectiles are separate moving entities

Mario spawns a fireball at 3 horizontal pixels per update, lifetime 40, with a fixed low bounce. Simon’s axe starts at vertical velocity -9, moves 2 pixels horizontally, gains downward velocity until 6, and lives 55 updates. Rizer’s bullet moves straight at 4 and lives 30. Each owner may have at most one active projectile, and the global pool is bounded, which caps per-frame work.

Projectile visuals are not collision geometry: each collision is an 8×8 projectile rectangle against the same fighter body. A live projectile survives its owner entering hitstun because update_projectiles() runs independently after melee resolution.

Does a long-looking whip always hit?

No. The runtime tests the authored reach rectangle. Art can overhang it without changing collision.

Source data chooses cadence, not every rule

Character TOML files author frame sequence, duration, and active window. For example, Simon’s character file gives the whip’s timing, while C supplies the shared body dimensions, reach table, damage, and resolution sequence. The generated state graph is validated data; it is not a generic state-machine interpreter running the fight.