add

Author: AlexGyver

README.md

@@ -52,7 +52,8 @@
 + **simplePID_advanced** - функция пид + ограничения
 
 ### processing - примеры на Processing
-+ **first_lesson** - [Урок #1](https://youtu.be/2fs1tuUUJRM) 
++ **first_lesson** - [Урок #1](https://youtu.be/2fs1tuUUJRM)
++ **physics** - [Урок #2](https://youtu.be/78N0t5BxQyY)
 
 ### soft_pwm_lesson - программный ШИМ
 + [Видос](https://youtu.be/UvxOwSfa3Zg) 

processing/physics/physics.pde

@@ -0,0 +1,114 @@
+import controlP5.*;
+ControlP5 cp5;
+
+PVector pos, vel;
+int r = 25;
+
+void setup() {
+  size (640, 480);
+  frameRate(200);
+  pos = new PVector(width/2, height/2);
+  vel = PVector.random2D().mult(5);
+
+  cp5 = new ControlP5(this);
+  addSld("size", 5, 50, 5);
+  addSld("grav", 0, 5, 0);
+  addSld("speed", 5, 30, 5);
+  addSld("damp", 0, 1, 1);
+  addSld("drag", 0, 0.001, 0);
+  addSld("water", 0, 0.001, 0);
+  addSld("dense", 0, 0.001, 0);
+
+  cp5.addButton("reset")
+    .setPosition(120, 10)
+    .setSize(100, 20)    
+    ;
+
+  cp5.addToggle("toggle")
+    .setPosition(120, 40)
+    .setSize(50, 20)    
+    .setMode(ControlP5.SWITCH)
+    ;
+}
+
+void reset() {
+  vel = PVector.random2D();
+  pos = new PVector(width/2, height/2);
+  vel.normalize();
+  vel.mult(getSlider("speed"));
+}
+
+void draw() {
+  background(255);
+  float r = getSlider("size");
+  boolean waterExists = cp5.get(Toggle.class, "toggle").getState();
+
+  PVector acc = new PVector();
+  acc.set(0, getSlider("grav"));
+
+  float dens = 0;
+  float drag = getSlider("drag");
+  if (waterExists && pos.y > height*2/3) {
+    dens = getSlider("dense");
+    drag = getSlider("water");
+  }
+  acc.y -= r*r*r * dens;
+
+  PVector accV = new PVector();
+  accV = vel.copy();
+  accV.normalize();
+  accV.mult(-drag * r * r);  
+
+  acc.add(accV);
+  acc.y -= r*r*r * dens;
+  
+  vel.add(acc);
+  pos.add(vel); 
+
+  if (pos.x < r) {        
+    vel.x = -vel.x;
+    vel.mult(getSlider("damp"));
+    pos.x = r;
+  }
+  if (pos.x > width-r) {    
+    vel.x = -vel.x;
+    vel.mult(getSlider("damp"));
+    pos.x = width-r;
+  }
+
+  if (pos.y < r) {
+    vel.y = -vel.y;
+    vel.mult(getSlider("damp"));
+    pos.y = r;
+  }
+
+  if (pos.y > height-r) {
+    vel.y = -vel.y;
+    vel.mult(getSlider("damp"));
+    pos.y = height-r;
+  }
+
+  noStroke();
+  fill(#83DDFF);
+  if (waterExists) rect(0, height*2/3, width, height/3);
+  fill(0);  
+  circle(pos.x, pos.y, 2*r);
+}
+
+// ===================================================================
+
+int offset = 10;
+void addSld(String str, float min, float max, float init) {
+  cp5.addSlider(str)
+    .setPosition(10, offset)
+    .setSize(100, 20)
+    .setRange(min, max)
+    .setValue(init)
+    .getCaptionLabel().setPaddingX(-30);
+  ;
+  offset += 25;
+}
+
+float getSlider(String str) {
+  return cp5.get(Slider.class, str).getValue();
+}