From 77193dd7073bfb1d2d2bdd64eff7d1c11beda1ac Mon Sep 17 00:00:00 2001
From: Stephen Birarda <commit@birarda.com>
Date: Mon, 23 Sep 2013 09:56:07 -0700
Subject: [PATCH] change the placeholder javascript to be 32x32 game of life

---
 .../resources/web/assignment/placeholder.js   | 121 ++++++++++++++++++
 1 file changed, 121 insertions(+)

diff --git a/domain-server/resources/web/assignment/placeholder.js b/domain-server/resources/web/assignment/placeholder.js
index 93f90b7b30..e351f5e2b7 100644
--- a/domain-server/resources/web/assignment/placeholder.js
+++ b/domain-server/resources/web/assignment/placeholder.js
@@ -2,4 +2,125 @@
 
 // The following is an example of Conway's Game of Life (http://en.wikipedia.org/wiki/Conway's_Game_of_Life)
 
+var NUMBER_OF_CELLS_EACH_DIMENSION = 32;
+var NUMBER_OF_CELLS = NUMBER_OF_CELLS_EACH_DIMENSION * NUMBER_OF_CELLS_EACH_DIMENSION;
 
+var currentCells = [];
+var nextCells = [];
+
+var METER_LENGTH = 1 / TREE_SCALE;
+var cellScale = (8 * METER_LENGTH) / NUMBER_OF_CELLS_EACH_DIMENSION; 
+
+print("TREE_SCALE = " + TREE_SCALE + "\n");
+
+// randomly populate the cell start values
+for (var i = 0; i < NUMBER_OF_CELLS_EACH_DIMENSION; i++) {
+  // create the array to hold this row
+  currentCells[i] = [];
+  
+  // create the array to hold this row in the nextCells array
+  nextCells[i] = [];
+  
+  for (var j = 0; j < NUMBER_OF_CELLS_EACH_DIMENSION; j++) {
+     currentCells[i][j] = Math.floor(Math.random() * 2);
+     
+     // put the same value in the nextCells array for first board draw
+     nextCells[i][j] = currentCells[i][j];
+  }
+}
+
+function isNeighbourAlive(i, j) {
+  if (i < 0 || i >= NUMBER_OF_CELLS_EACH_DIMENSION 
+      || i < 0 || j >= NUMBER_OF_CELLS_EACH_DIMENSION) {
+    return 0;
+  } else {
+    return currentCells[i][j];
+  }
+}
+
+function updateCells() {
+  var i = 0;
+  var j = 0;
+  
+  for (i = 0; i < NUMBER_OF_CELLS_EACH_DIMENSION; i++) {
+    for (j = 0; j < NUMBER_OF_CELLS_EACH_DIMENSION; j++) {
+      // figure out the number of live neighbours for the i-j cell
+      var liveNeighbours = 
+        isNeighbourAlive(i + 1, j - 1) + isNeighbourAlive(i + 1, j) + isNeighbourAlive(i + 1, j + 1) +
+        isNeighbourAlive(i, j - 1) + isNeighbourAlive(i, j + 1) +
+        isNeighbourAlive(i - 1, j - 1) + isNeighbourAlive(i - 1, j) + isNeighbourAlive(i - 1, j + 1);
+      
+      if (currentCells[i][j]) {
+        // live cell
+        
+        if (liveNeighbours < 2) {
+          // rule #1 - under-population - this cell will die
+          // mark it zero to mark the change
+          nextCells[i][j] = 0;
+        } else if (liveNeighbours < 4) {
+          // rule #2 - this cell lives
+          // mark it -1 to mark no change
+          nextCells[i][j] = -1;
+        } else {
+          // rule #3 - overcrowding - this cell dies
+          // mark it zero to mark the change
+          nextCells[i][j] = 0;
+        }
+      } else {
+        // dead cell
+        if (liveNeighbours == 3) {
+          // rule #4 - reproduction - this cell revives
+          // mark it one to mark the change
+          nextCells[i][j] = 1;
+        } else {
+          // this cell stays dead
+          // mark it -1 for no change
+          nextCells[i][j] = -1;
+        }
+      }    
+    }
+  }
+  
+  for (i = 0; i < NUMBER_OF_CELLS_EACH_DIMENSION; i++) {
+    for (j = 0; j < NUMBER_OF_CELLS_EACH_DIMENSION; j++) {
+      if (nextCells[i][j] != -1) {
+        // there has been a change to this cell, change the value in the currentCells array
+        currentCells[i][j] = nextCells[i][j];
+      }
+    }
+  }
+}
+
+function sendNextCells() {
+  for (var i = 0; i < NUMBER_OF_CELLS_EACH_DIMENSION; i++) {
+    for (var j = 0; j < NUMBER_OF_CELLS_EACH_DIMENSION; j++) {
+      if (nextCells[i][j] != -1) {
+        // there has been a change to the state of this cell, send it
+        
+        // find the x and y position for this voxel, z = 0
+        var x = j * cellScale;
+        var y = i * cellScale;
+
+        // queue a packet to add a voxel for the new cell
+        var color = (nextCells[i][j] == 1) ? 255 : 1;
+        Voxels.queueDestructiveVoxelAdd(x, y, 0, cellScale, color, color, color);
+      }
+    }
+  } 
+}
+
+var sentFirstBoard = false;
+
+function step() {
+  if (sentFirstBoard) {
+    // we've already sent the first full board, perform a step in time
+    updateCells();
+  } else {
+    // this will be our first board send
+    sentFirstBoard = true;
+  }
+  
+  sendNextCells();  
+}
+
+Agent.willSendVisualDataCallback.connect(step);
\ No newline at end of file