Issue 1113. Allow for Particle emitters that constantly have their particlesPerSec set to still emit (#1114)

richardTingle · stephengold · commit 04f771f7f989 · 2019-06-08T17:12:04.000-07:00
Previously if particlesPerSec was constantly set timeDifference could never grow large enough to emit a particle as timeDifference was reset to zero each time. This fixes that problem while still ensuring that timeDifference can't have grown very very large (leading to huge numbers of particles being emitted) by capping the timeDifference at the point where its just about to emit a particle. Discussed at https://hub.jmonkeyengine.org/t/particle-emitter-cannot-emit-particles-if-its-emissions-per-second-is-updated-every-frame/41930/2
diff --git a/jme3-core/src/main/java/com/jme3/effect/ParticleEmitter.java b/jme3-core/src/main/java/com/jme3/effect/ParticleEmitter.java
@@ -783,7 +783,7 @@ public float getParticlesPerSec() {
      */
     public void setParticlesPerSec(float particlesPerSec) {
         this.particlesPerSec = particlesPerSec;
-        timeDifference = 0;
+        timeDifference = Math.min(timeDifference,1f / particlesPerSec); //prevent large accumulated timeDifference from causing a huge number of particles to be emitted
     }
 
     /**

Original file line number	Diff line number	Diff line change
`@@ -783,7 +783,7 @@ public float getParticlesPerSec() {`
`783`	`783`	`*/`
`784`	`784`	`public void setParticlesPerSec(float particlesPerSec) {`
`785`	`785`	`this.particlesPerSec = particlesPerSec;`
`786`		`- timeDifference = 0;`
	`786`	`+ timeDifference = Math.min(timeDifference,1f / particlesPerSec); //prevent large accumulated timeDifference from causing a huge number of particles to be emitted`
`787`	`787`	`}`
`788`	`788`
`789`	`789`	`/**`