let fern grow upward

lindenmayer-system/lindenmeyer-system.html

@@ -136,7 +136,7 @@ function sierpinski() {
  function barnsley_fern() {
      project.clear();
      var r = generate(
-         'IXF'.split(''),
+         'iIXF'.split(''),
          [
              ['X'.split(''), 'F+[[X]-X]-F[-FX]+X'.split('')],
              ['F'.split(''), 'FF'.split('')]
@@ -149,7 +149,8 @@ function sierpinski() {
          r,
          {
              'F': draw_forward(),
-             'I': draw_angle_init(25/180 * Math.PI),
+             'i': draw_set_dir(Math.PI),
+             'I': draw_angle_init(25/180 * Math.PI  + Math.random() * 0.2),
              '-': draw_angle_turn(-1),
              '+': draw_angle_turn(1),
              '[': draw_state_push(),
@@ -157,7 +158,7 @@ function sierpinski() {
          }
      );
      p.scale(2);
-     p.translate(new Point(200, 200));
+     p.translate(new Point(200, 300));
      p.strokeWidth = 1;
      p.strokeColor = '#ff00ff';
  }

lindenmayer-system/lindenmeyer-system.js

@@ -45,7 +45,7 @@ function generate(start, rules, iterations) {
 
 function draw_initstate(p, state) {
     if(!('dir' in state)) {
-        state.dir = 0;//Math.PI/2;
+        state.dir = 0;
     }
     if(!('curpath' in state)) {
         p.addChild(new paper.Path());
@@ -54,6 +54,13 @@ function draw_initstate(p, state) {
 }
 
 
+function draw_set_dir(dir) {
+    return function(p, state) {
+        state.dir = dir;
+    }
+}
+
+
 function draw_forward() {
     return function(p, state) {
         draw_initstate(p, state);