From e5cb7eed836d80e017a19ea3ef04469a6646a84a Mon Sep 17 00:00:00 2001
From: Daniel Shiffman <daniel@shiffman.net>
Date: Mon, 18 Mar 2013 16:16:24 -0400
Subject: [PATCH] a new proposed example demonstrating morphing from one shape
 to another

---
 java/examples/Topics/Motion/Morph/Morph.pde | 63 +++++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100644 java/examples/Topics/Motion/Morph/Morph.pde

diff --git a/java/examples/Topics/Motion/Morph/Morph.pde b/java/examples/Topics/Motion/Morph/Morph.pde
new file mode 100644
index 000000000..1c6a65f81
--- /dev/null
+++ b/java/examples/Topics/Motion/Morph/Morph.pde
@@ -0,0 +1,63 @@
+/**
+ * Morph. 
+ * 
+ * Changing one shape into another by interpolating
+ * vertices from one to another
+ */
+
+ArrayList<PVector> circle = new ArrayList<PVector>();
+ArrayList<PVector> square = new ArrayList<PVector>();
+
+ArrayList<PVector> morph = new ArrayList<PVector>();
+
+boolean state = false;
+
+void setup() {
+  size(640, 360);
+
+  for (int angle = 0; angle < 360; angle += 9) {
+    PVector v = PVector.fromAngle(radians(angle-135));
+    v.mult(100);
+    circle.add(v);
+    morph.add(new PVector());
+  }
+
+  for (int x = -50; x < 50; x += 10) {
+    square.add(new PVector(x, -50));
+  }
+  for (int y = -50; y < 50; y += 10) {
+    square.add(new PVector(50, y));
+  }
+  for (int x = 50; x > -50; x -= 10) {
+    square.add(new PVector(x, 50));
+  }
+  for (int y = 50; y > -50; y -= 10) {
+    square.add(new PVector(-50, y));
+  }
+}
+
+void draw() {
+  background(51);
+
+  for (int i = 0; i < circle.size(); i++) {
+    PVector v1;
+    if (state) v1 = circle.get(i);
+    else v1 = square.get(i);
+    PVector v2 = morph.get(i);
+    v2.lerp(v1, 0.1);
+    float d = PVector.dist(v1, v2);
+    if (d < 0.01) {
+      state = !state;
+    }
+  }
+
+  translate(width/2, height/2);
+  beginShape();
+  noFill();
+  stroke(255);
+  for (PVector v : morph) {
+    vertex(v.x, v.y);
+  }
+  endShape(CLOSE);
+}
+