1 files changed, 92 insertions, 0 deletions
diff --git a/engine/src/core/com/jme3/effect/influencers/DefaultParticleInfluencer.java b/engine/src/core/com/jme3/effect/influencers/DefaultParticleInfluencer.java
new file mode 100644
index 0000000..80f52d9
--- /dev/null
+++ b/engine/src/core/com/jme3/effect/influencers/DefaultParticleInfluencer.java
@@ -0,0 +1,92 @@
+package com.jme3.effect.influencers;
+
+import com.jme3.effect.Particle;
+import com.jme3.effect.shapes.EmitterShape;
+import com.jme3.export.InputCapsule;
+import com.jme3.export.JmeExporter;
+import com.jme3.export.JmeImporter;
+import com.jme3.export.OutputCapsule;
+import com.jme3.math.FastMath;
+import com.jme3.math.Vector3f;
+import java.io.IOException;
+
+/**
+ * This emitter influences the particles so that they move all in the same direction.
+ * The direction may vary a little if the velocity variation is non zero.
+ * This influencer is default for the particle emitter.
+ * @author Marcin Roguski (Kaelthas)
+ */
+public class DefaultParticleInfluencer implements ParticleInfluencer {
+
+    /** Temporary variable used to help with calculations. */
+    protected transient Vector3f temp = new Vector3f();
+    /** The initial velocity of the particles. */
+    protected Vector3f startVelocity = new Vector3f();
+    /** The velocity's variation of the particles. */
+    protected float velocityVariation = 0.2f;
+
+    @Override
+    public void influenceParticle(Particle particle, EmitterShape emitterShape) {
+        emitterShape.getRandomPoint(particle.position);
+        this.applyVelocityVariation(particle);
+    }
+
+    /**
+     * This method applies the variation to the particle with already set velocity.
+     * @param particle
+     *        the particle to be affected
+     */
+    protected void applyVelocityVariation(Particle particle) {
+    	particle.velocity.set(startVelocity);
+        temp.set(FastMath.nextRandomFloat(), FastMath.nextRandomFloat(), FastMath.nextRandomFloat());
+        temp.multLocal(2f);
+        temp.subtractLocal(1f, 1f, 1f);
+        temp.multLocal(startVelocity.length());
+        particle.velocity.interpolate(temp, velocityVariation);
+    }
+
+    @Override
+    public void write(JmeExporter ex) throws IOException {
+        OutputCapsule oc = ex.getCapsule(this);
+        oc.write(startVelocity, "startVelocity", Vector3f.ZERO);
+        oc.write(velocityVariation, "variation", 0.2f);
+    }
+
+    @Override
+    public void read(JmeImporter im) throws IOException {
+        InputCapsule ic = im.getCapsule(this);
+        startVelocity = (Vector3f) ic.readSavable("startVelocity", Vector3f.ZERO.clone());
+        velocityVariation = ic.readFloat("variation", 0.2f);
+    }
+
+    @Override
+    public ParticleInfluencer clone() {
+        try {
+            DefaultParticleInfluencer clone = (DefaultParticleInfluencer) super.clone();
+            clone.startVelocity = startVelocity.clone();
+            return clone;
+        } catch (CloneNotSupportedException e) {
+            throw new AssertionError();
+        }
+    }
+
+    @Override
+    public void setInitialVelocity(Vector3f initialVelocity) {
+        this.startVelocity.set(initialVelocity);
+    }
+
+    @Override
+    public Vector3f getInitialVelocity() {
+        return startVelocity;
+    }
+
+    @Override
+    public void setVelocityVariation(float variation) {
+        this.velocityVariation = variation;
+    }
+
+    @Override
+    public float getVelocityVariation() {
+        return velocityVariation;
+    }
+}