Orkuncakilkaya
72dbdca1f3
Our own shim (native/shim/jph_shim.cpp) over Jolt built from the pinned tag with cross-platform determinism and no fp contraction: shapes as handles (box, sphere, capsule, cylinder, dome, offset, heightfield, mesh), still/kinematic/dynamic bodies by id with real removal, rays, top_at and push (what CharacterGround asks), overlaps, buoyancy against the PhysWater port, contacts recorded in C and drained as PHYS_HIT / PHYS_SPLASH facts. Fixed 1/60 steps, at most four a frame. Nine tests against the real library, including a pile run twice to the bit. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
67 lines
2.6 KiB
Text
67 lines
2.6 KiB
Text
# system.ludic - the world stepped at a fixed rate in PH_SIMULATE, so frame rate never changes
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# the rules. It saves nothing: a thing at rest is saved by its owner and the world rebuilt on load.
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# as many fixed steps as the frame's time holds, at most ph_max_steps (a stall is not replayed)
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export function phys_tick(physics_st: mut PhysicsState, t: Tick) -> void { phys_advance(physics_st, t.dt) }
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export function phys_advance(physics_st: mut PhysicsState, dt: float) -> int {
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if physics_st.ph_world == null { return 0 }
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physics_st.ph_acc += dt
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var n = 0
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# a thousandth of a step of slack: 0.05 s is three steps even when float says 2.9999
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while physics_st.ph_acc + physics_st.ph_step * 0.001 >= physics_st.ph_step and n < physics_st.ph_max_steps {
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phys_step(physics_st)
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physics_st.ph_acc -= physics_st.ph_step
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n += 1
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}
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if physics_st.ph_acc > physics_st.ph_step or physics_st.ph_acc < 0.0 { physics_st.ph_acc = 0.0 }
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return n
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}
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# exactly one step: the water, Jolt, then the contacts that matter as facts
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export function phys_step(physics_st: mut PhysicsState) -> void {
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if physics_st.ph_world == null { return }
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ph_buffers(physics_st)
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ph_buoy_all(physics_st)
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jph_world_step(physics_st.ph_world, physics_st.ph_step, physics_st.ph_sub)
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physics_st.ph_steps += 1
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ph_contacts(physics_st)
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}
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export function phys_steps(physics_st: PhysicsState) -> int { return physics_st.ph_steps }
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# m/s2 down is negative
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export function phys_gravity(physics_st: mut PhysicsState, y: float) -> void { if physics_st.ph_world != null { jph_world_gravity(physics_st.ph_world, y) } }
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function ph_contacts(physics_st: mut PhysicsState) -> void {
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let n = jph_contacts_drain(physics_st.ph_world, physics_st.ph_ids, physics_st.ph_vals, PH_CAP)
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for i in 0 .. n {
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let speed = physics_st.ph_vals[i * 4 + 3]
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if speed >= physics_st.ph_hard {
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let f = new PhysFact
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f.what = PHYS_HIT
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f.a = physics_st.ph_ids[i * 2]
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f.b = physics_st.ph_ids[i * 2 + 1]
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f.x = physics_st.ph_vals[i * 4]
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f.y = physics_st.ph_vals[i * 4 + 1]
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f.z = physics_st.ph_vals[i * 4 + 2]
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f.speed = speed
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q_push(phys_facts(physics_st), f)
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}
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}
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}
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# contacts C had to drop because the buffer was full between two drains
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export function phys_contacts_lost(physics_st: PhysicsState) -> int {
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if physics_st.ph_world == null { return 0 }
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return jph_contacts_lost(physics_st.ph_world)
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}
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export function phys_reset(physics_st: mut PhysicsState) -> void { physics_st.ph_acc = 0.0 }
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export function phys_system() -> System {
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let s = system_new("physics", PH_SIMULATE)
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s.reset = fn phys_reset
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s.tick = fn phys_tick
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return s
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}
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