增加涡流修改器

src/core/particleEmitter.ts

@@ -6,7 +6,7 @@ import { pickImageResource, pickTrailResource, imageFrameState, imageFrameTextur
 import type { SceneCollider, EmitterConfig, ParticleState } from './particleTypes'
 import { defaultConfig, ensureEmitterConfig } from './particleConfig'
 import { BLEND_MAP, MAX_PARTICLES } from './particleConstants'
-import { lerp, finite, localToWorldMath, worldMathToLocal, localVelocityToWorldMath, worldVelocityToLocalMath, resolveColliderPoint, tFromLife, seededUnit, initialValue, overLifeValue, curveAt, mulberry32, hexToNumber, gradientColorAt } from './particleMath'
+import { lerp, finite, localToWorldMath, worldMathToLocal, localVelocityToWorldMath, worldVelocityToLocalMath, resolveColliderPoint, tFromLife, seededUnit, initialValue, overLifeValue, curveAt, mulberry32, hexToNumber, gradientColorAt, fieldFalloff, vortexAcceleration } from './particleMath'
 
 // 保留原有入口，现有调用方无需随内部拆分修改。
 export type * from './particleTypes'
@@ -258,9 +258,7 @@ export class ParticleEmitter extends Container {
         const dy = cfg.forceCenterY - particleWorldY
         const distance = Math.hypot(dx, dy)
         if (distance > 0.0001 && distance <= cfg.forceRadius) {
-          let falloff = 1
-          if (cfg.forceFalloff === 'linear') falloff = 1 - distance / cfg.forceRadius
-          else if (cfg.forceFalloff === 'inverse') falloff = Math.min(10, cfg.forceRadius / Math.max(distance, cfg.forceRadius * 0.1))
+          const falloff = fieldFalloff(cfg.forceFalloff, distance, cfg.forceRadius)
           const force = cfg.forceStrength * falloff * 10
           const accelWorldX = dx / distance * force
           const accelWorldY = dy / distance * force
@@ -270,6 +268,18 @@ export class ParticleEmitter extends Container {
           p.vy += (-sinRoot * accelScreenX + cosRoot * accelScreenY) / rootScaleY * dt
         }
       }
+      // 漩涡力在全局数学坐标中沿半径切线方向作用。
+      if (!p.collisionPaused && cfg.vortex && cfg.vortexStrength !== 0 && cfg.vortexRadius > 0) {
+        const world = localToWorldMath(cfg, p.x, p.y, this.simulationTransform)
+        const acceleration = vortexAcceleration(
+          world.x, world.y,
+          cfg.vortexCenterX, cfg.vortexCenterY,
+          cfg.vortexStrength, cfg.vortexRadius, cfg.vortexFalloff,
+        )
+        const localAcceleration = worldVelocityToLocalMath(cfg, acceleration.x, acceleration.y, this.simulationTransform)
+        p.vx += localAcceleration.x * dt
+        p.vy += localAcceleration.y * dt
+      }
       // 阻尼:速度按衰减系数逐渐减小
       if (!p.collisionPaused && cfg.damping > 0) {
         const f = Math.max(0, 1 - cfg.damping * dt)