/**
 * Inline WGSL shader for the WebGPU physics benchmark.
 * Mirrors packages/engine/src/gpu/shaders/particle-physics.wgsl.
 * Keep in sync with the canonical shader.
 */
export declare const PARTICLE_PHYSICS_WGSL = "\nstruct Uniforms {\n  dt: f32,\n  gravity: f32,\n  groundY: f32,\n  restitution: f32,\n  friction: f32,\n  particleCount: u32,\n  _pad1: f32,\n  _pad2: f32,\n};\n\n@group(0) @binding(0) var<uniform> uniforms: Uniforms;\n\n@group(0) @binding(1) var<storage, read> positions_in: array<vec4<f32>>;\n@group(0) @binding(2) var<storage, read> velocities_in: array<vec4<f32>>;\n@group(0) @binding(3) var<storage, read> states_in: array<vec4<f32>>;\n\n@group(0) @binding(4) var<storage, read_write> positions_out: array<vec4<f32>>;\n@group(0) @binding(5) var<storage, read_write> velocities_out: array<vec4<f32>>;\n@group(0) @binding(6) var<storage, read_write> states_out: array<vec4<f32>>;\n\nconst SLEEP_VELOCITY_THRESHOLD: f32 = 0.01;\nconst SLEEP_FRAMES_REQUIRED: f32 = 10.0;\nconst COLLISION_DAMPING: f32 = 0.8;\n\nfn resolveGroundCollision(\n  position: vec3<f32>,\n  velocity: vec3<f32>,\n  radius: f32\n) -> vec4<f32> {\n  var pos = position;\n  var vel = velocity;\n  if (pos.y < uniforms.groundY + radius) {\n    pos.y = uniforms.groundY + radius;\n    vel.y = -vel.y * uniforms.restitution;\n    vel.x *= uniforms.friction;\n    vel.z *= uniforms.friction;\n    if (abs(vel.y) < 0.05) {\n      vel.y = 0.0;\n    }\n  }\n  return vec4<f32>(vel, f32(pos.y <= uniforms.groundY + radius + 0.01));\n}\n\nfn checkParticleCollision(\n  myIdx: u32,\n  myPos: vec3<f32>,\n  myVel: vec3<f32>,\n  myRadius: f32,\n  myMass: f32\n) -> vec3<f32> {\n  var resultVel = myVel;\n  let checkRadius: u32 = 100u;\n  let startIdx = max(0u, myIdx - checkRadius);\n  let endIdx = min(uniforms.particleCount, myIdx + checkRadius);\n  for (var i = startIdx; i < endIdx; i = i + 1u) {\n    if (i == myIdx) { continue; }\n    let otherPos = positions_in[i].xyz;\n    let otherRadius = positions_in[i].w;\n    let otherVel = velocities_in[i].xyz;\n    let otherMass = velocities_in[i].w;\n    let delta = myPos - otherPos;\n    let dist = length(delta);\n    let minDist = myRadius + otherRadius;\n    if (dist < minDist && dist > 0.0001) {\n      let normal = delta / dist;\n      let relVel = myVel - otherVel;\n      let velAlongNormal = dot(relVel, normal);\n      if (velAlongNormal < 0.0) {\n        let impulse = -(1.0 + COLLISION_DAMPING) * velAlongNormal / (1.0 / myMass + 1.0 / otherMass);\n        resultVel += impulse * normal / myMass;\n      }\n    }\n  }\n  return resultVel;\n}\n\n@compute @workgroup_size(256)\nfn main(@builtin(global_invocation_id) id: vec3<u32>) {\n  let idx = id.x;\n  if (idx >= uniforms.particleCount) { return; }\n\n  let pos_in = positions_in[idx];\n  let vel_in = velocities_in[idx];\n  let state_in = states_in[idx];\n\n  var pos = pos_in.xyz;\n  let radius = pos_in.w;\n  var vel = vel_in.xyz;\n  let mass = vel_in.w;\n  let active_flag = state_in.x;\n  let sleeping = state_in.y;\n  let health = state_in.z;\n  let userData = state_in.w;\n\n  if (active_flag < 0.5 || sleeping > 0.5) {\n    positions_out[idx] = pos_in;\n    velocities_out[idx] = vel_in;\n    states_out[idx] = state_in;\n    return;\n  }\n\n  vel.y -= uniforms.gravity * uniforms.dt;\n  pos += vel * uniforms.dt;\n\n  let groundResult = resolveGroundCollision(pos, vel, radius);\n  vel = groundResult.xyz;\n  let hitGround = groundResult.w;\n  if (hitGround > 0.5) {\n    pos.y = uniforms.groundY + radius;\n  }\n\n  vel = checkParticleCollision(idx, pos, vel, radius, mass);\n\n  var sleepCounter = userData;\n  let speed = length(vel);\n  if (speed < SLEEP_VELOCITY_THRESHOLD) {\n    sleepCounter += 1.0;\n  } else {\n    sleepCounter = 0.0;\n  }\n  var newSleeping = sleeping;\n  if (sleepCounter >= SLEEP_FRAMES_REQUIRED) {\n    newSleeping = 1.0;\n    vel = vec3<f32>(0.0, 0.0, 0.0);\n  }\n  if (hitGround > 0.5 && speed > 0.1) {\n    newSleeping = 0.0;\n    sleepCounter = 0.0;\n  }\n\n  positions_out[idx] = vec4<f32>(pos, radius);\n  velocities_out[idx] = vec4<f32>(vel, mass);\n  states_out[idx] = vec4<f32>(active_flag, newSleeping, health, sleepCounter);\n}\n";
//# sourceMappingURL=particle-physics-shader.d.ts.map