java/examples/Library/Network/SharedCanvasServer/SharedCanvasServer.pde

@@ -0,0 +1,50 @@
+/**
+ * Shared Drawing Canvas (Server) 
+ * by Alexander R. Galloway. 
+ * 
+ * A server that shares a drawing canvas between two computers. 
+ * In order to open a socket connection, a server must select a 
+ * port on which to listen for incoming clients and through which 
+ * to communicate. Once the socket is established, a client may 
+ * connect to the server and send or receive commands and data.
+ * Get this program running and then start the Shared Drawing
+ * Canvas (Client) program so see how they interact.
+ */
+
+
+import processing.net.*;
+
+Server s;
+Client c;
+String input;
+int data[];
+
+void setup() 
+{
+  size(450, 255);
+  background(204);
+  stroke(0);
+  frameRate(5); // Slow it down a little
+  s = new Server(this, 12345); // Start a simple server on a port
+}
+
+void draw() 
+{
+  if (mousePressed == true) {
+    // Draw our line
+    stroke(255);
+    line(pmouseX, pmouseY, mouseX, mouseY);
+    // Send mouse coords to other person
+    s.write(pmouseX + " " + pmouseY + " " + mouseX + " " + mouseY + "\n");
+  }
+  // Receive data from client
+  c = s.available();
+  if (c != null) {
+    input = c.readString();
+    input = input.substring(0, input.indexOf("\n")); // Only up to the newline
+    data = int(split(input, ' ')); // Split values into an array
+    // Draw line using received coords
+    stroke(0);
+    line(data[0], data[1], data[2], data[3]);
+  }
+}