Added week4 sketches

Author: Marc Bickel

FirstGravitySketch/FirstGravitySketch.pde

@@ -0,0 +1,13 @@
+Mover mover;
+void settings() {
+size(800, 200);
+}
+void setup() {
+mover = new Mover();
+}
+void draw() {
+background(255);
+mover.update();
+mover.checkEdges();
+mover.display();
+}

FirstGravitySketch/mover.pde

@@ -0,0 +1,38 @@
+class Mover {
+PVector location;
+PVector velocity;
+PVector gravity = new PVector(0, 0.1);
+float reboundCoeff = 0.8f;
+Mover() {
+location = new PVector(width/2f, height/2f);
+velocity = new PVector(1f, 1f);
+}
+void update() {
+location.add(velocity);
+velocity.add(gravity);
+}
+void display() {
+stroke(0);
+strokeWeight(2);
+fill(127);
+ellipse(location.x, location.y, 48, 48);
+}
+void checkEdges() {
+if (location.x + 24 > width) {
+velocity.x = velocity.x * -1 * reboundCoeff;
+location.x = width - 24;
+}
+else if (location.x - 24 < 0) {
+velocity.x = velocity.x * -1* reboundCoeff;
+location.x = 24;
+}
+if (location.y + 24 > height) {
+velocity.y = velocity.y * -1 * reboundCoeff;
+location.y = height - 24;
+}
+else if (location.y - 24 < 0) {
+velocity.y = velocity.y * -1 * reboundCoeff;
+location.y = 24;
+}
+}
+}

NiceLittleDraw/NiceLittleDraw.pde

@@ -0,0 +1,28 @@
+// The Nature of Code
+// Daniel Shiffman
+// http://natureofcode.com
+PVector location;
+PVector velocity;
+void setup() {
+size(200, 200);
+background(255);
+location = new PVector(100, 100);
+velocity = new PVector(2.5, 5);
+}
+void draw() {
+noStroke();
+fill(255, 10); // 10 is the level of opacity (to get the "trace" effect)
+rect(0, 0, width, height);
+// Add the current speed to the location.
+location.add(velocity);
+if ((location.x > width) || (location.x < 0)) {
+velocity.x = velocity.x * -1;
+}
+if ((location.y > height) || (location.y < 0)) {
+velocity.y = velocity.y * -1;
+}
+// Display circle at its location
+stroke(0);
+fill(175);
+ellipse(location.x, location.y, 16, 16);
+}