moving the OpenGL examples to the core

java/examples/OpenGL/Advanced/Particles/Particle.pde

@@ -0,0 +1,58 @@
+class Particle {
+
+  PVector velocity;
+  float lifespan = 255;
+  
+  PShape part;
+  float partSize;
+  
+  PVector gravity = new PVector(0,0.1);
+
+
+  Particle() {
+    partSize = random(10,60);
+    part = createShape(QUAD);
+    part.noStroke();
+    part.texture(sprite);
+    part.normal(0, 0, 1);
+    part.vertex(-partSize/2, -partSize/2, 0, 0);
+    part.vertex(+partSize/2, -partSize/2, sprite.width, 0);
+    part.vertex(+partSize/2, +partSize/2, sprite.width, sprite.height);
+    part.vertex(-partSize/2, +partSize/2, 0, sprite.height);
+    part.end();
+    
+    rebirth(width/2,height/2);
+    lifespan = random(255);
+  }
+
+  PShape getShape() {
+    return part;
+  }
+  
+  void rebirth(float x, float y) {
+    float a = random(TWO_PI);
+    float speed = random(0.5,4);
+    velocity = new PVector(cos(a), sin(a));
+    velocity.mult(speed);
+    lifespan = 255;   
+    part.resetMatrix();
+    part.translate(x, y); 
+  }
+  
+  boolean isDead() {
+    if (lifespan < 0) {
+     return true;
+    } else {
+     return false;
+    } 
+  }
+  
+
+  public void update() {
+    lifespan = lifespan - 1;
+    velocity.add(gravity);
+    
+    part.tint(255,lifespan);
+    part.translate(velocity.x, velocity.y);
+  }
+}