Merge pull request #126 from carlrobert/master

Random maze generation using a Drone

src/main/js/plugins/drone/contrib/mazegen.js

@@ -0,0 +1,107 @@
+// Maze generation based on http://rosettacode.org/wiki/Maze_generation#JavaScript
+
+var Drone = require('../drone').Drone;
+
+function maze_make(x,y) {
+  var n=x*y-1;
+  if (n<0) {
+    echo("illegal maze dimensions");
+    return ({x: 0, y: 0});
+  }
+  var horiz=[]; for (var j= 0; j<x+1; j++) horiz[j]= [];
+  var verti=[]; for (var j= 0; j<y+1; j++) verti[j]= [];
+  var here= [Math.floor(Math.random()*x), Math.floor(Math.random()*y)];
+  var path= [here];
+  var unvisited= [];
+  for (var j= 0; j<x+2; j++) {
+    unvisited[j]= [];
+    for (var k= 0; k<y+1; k++)
+      unvisited[j].push(j>0 && j<x+1 && k>0 && (j != here[0]+1 || k != here[1]+1));
+  }
+  while (0<n) {
+    var potential= [[here[0]+1, here[1]], [here[0],here[1]+1],
+        [here[0]-1, here[1]], [here[0],here[1]-1]];
+    var neighbors= [];
+    for (var j= 0; j < 4; j++)
+      if (unvisited[potential[j][0]+1][potential[j][1]+1])
+        neighbors.push(potential[j]);
+    if (neighbors.length) {
+      n= n-1;
+      next= neighbors[Math.floor(Math.random()*neighbors.length)];
+      unvisited[next[0]+1][next[1]+1]= false;
+      if (next[0] == here[0])
+        horiz[next[0]][(next[1]+here[1]-1)/2]= true;
+      else 
+        verti[(next[0]+here[0]-1)/2][next[1]]= true;
+      path.push(here= next);
+    } else 
+      here= path.pop();
+  }
+  return ({x: x, y: y, horiz: horiz, verti: verti});
+}
+
+function maze_display(m) {
+  var text= [];
+  for (var j= 0; j<m.x*2+1; j++) {
+    var line= [];
+    if (0 == j%2)
+      for (var k=0; k<m.y*4+1; k++)
+        if (0 == k%4) 
+          line[k]= '+';
+        else
+          if (j>0 && m.verti[j/2-1][Math.floor(k/4)])
+            line[k]= ' ';
+          else
+            line[k]= '-';
+    else
+      for (var k=0; k<m.y*4+1; k++)
+        if (0 == k%4)
+          if (k>0 && m.horiz[(j-1)/2][k/4-1])
+            line[k]= ' ';
+          else
+            line[k]= '|';
+        else
+          line[k]= ' ';
+    if (0 == j) line[1]= line[2]= line[3]= ' ';
+    if (m.x*2-1 == j) line[4*m.y]= ' ';
+    text.push(line.join('')+' \r\n'); // TWEAKED: space added to get an even number of columns
+  }
+  return text.join('');
+}
+
+// ScriptCraft stuff starts here
+// Helper function to parse the ASCII art into Drone actions
+// You might also consider creating a new maze_display but for now this will do the work
+function maze_draw(maze_string, d) {
+  // d is the Drone to use
+  d.up().chkpt('maze-start');
+  for (var j = 0; j < maze_string.length; j += 2) {
+    switch(maze_string.substr(j, 2)) {
+    case '  ':
+      d.box(0).fwd(); // Make sure to empty this position
+      break;
+    case '\r\n':
+      d.move('maze-start');
+      d.right().chkpt('maze-start');
+      break;
+    default: // '+ ', '+-', '--', '| '
+      if (j == 0) {
+        d.box(blocks.glowstone); // highlight the maze entry and exit
+      } else if (j == maze_string.length - 4) {
+        d.box(blocks.glass);
+      } else {
+        d.box(blocks.oak);
+      }
+      d.fwd();
+    }
+  }
+}
+
+// User-facing code starts here
+// Example: Try /js amazing(5,7)
+Drone.extend('amazing', function(size_x, size_y) {
+  m = maze_make(size_x, size_y);
+  if (m.x > 0 && m.y > 0) {
+    maze_draw(maze_display(m), this);
+  }
+});