a012e3f65a0d

--- a/package.lisp	Wed Jun 08 12:07:35 2016 +0000
+++ b/package.lisp	Wed Jun 08 12:30:15 2016 +0000
@@ -49,6 +49,8 @@
     #:cell-west
     #:cell-col
     #:cell-row
+    #:cell-active
+    #:cell-active-group
     #:grid
     #:grid-cols
     #:grid-rows

--- a/src/demo.lisp	Wed Jun 08 12:07:35 2016 +0000
+++ b/src/demo.lisp	Wed Jun 08 12:30:15 2016 +0000
@@ -50,6 +50,12 @@
 (defparameter *end-pen*
   (make-pen :fill (rgb 1.000 0.733 0.424)))
 
+(defparameter *active-pen*
+  (make-pen :fill (rgb 0.731 0.550 0.758)))
+
+(defparameter *active-group-pen*
+  (make-pen :fill (rgb 0.427 0.322 0.443)))
+
 
 (defun draw-maze (instance)
   (with-slots (grid start end path longest-path show-longest show-colors)
@@ -82,6 +88,13 @@
           (with-pen *end-pen*
             (when start (draw-cell start))
             (when end (draw-cell end)))
+          (grid-loop-cells cell grid
+            (with-pen *active-group-pen*
+              (when (cell-active-group cell)
+                (draw-cell cell)))
+            (with-pen *active-pen*
+              (when (cell-active cell)
+                (draw-cell cell))))
           (with-pen *wall-pen*
             (grid-loop-cells cell grid
               (let ((x1 (cell-x cell))
@@ -111,7 +124,7 @@
      (frame 0)
      (log " ")
      ;; Variables
-     (grid (make-grid 20 20))
+     (grid (make-grid 25 25))
      (gen (funcall *generator* grid))
      (finished-generating nil)
      (distances nil)
@@ -128,7 +141,7 @@
     ;;
     (draw-maze sketch::instance)
     (if (and (not finished-generating)
-             (dividesp frame 1))
+             (dividesp frame 4))
       (when (funcall gen)
         (setf finished-generating t
               longest-path (find-longest-path grid))))

--- a/src/generation.lisp	Wed Jun 08 12:07:35 2016 +0000
+++ b/src/generation.lisp	Wed Jun 08 12:30:15 2016 +0000
@@ -2,15 +2,18 @@
 
 (defgenerator binary-tree-generator (grid)
   (grid-loop-cells cell grid
+    (setf (cell-active cell) t)
     (let ((other (random-elt (full-list (cell-north cell)
                                         (cell-east cell)))))
       (when other
         (cell-link cell other)))
-    (yield)))
+    (yield)
+    (setf (cell-active cell) nil)))
 
 (defun binary-tree (grid)
   (do-generator (_ (binary-tree-generator grid))))
 
+
 (defgenerator sidewinder-generator (grid)
   (grid-loop-rows row grid
     (loop :with run = nil
@@ -20,16 +23,25 @@
           :for should-close = (or at-east-bound
                                   (and (not at-north-bound)
                                        (randomp)))
-          :do (progn
-                (push cell run)
-                (if should-close
-                  (let* ((member (random-elt run))
-                         (member-north (cell-north member)))
-                    (when member-north
-                      (cell-link member member-north))
-                    (setf run nil))
-                  (cell-link cell (cell-east cell)))
-                (yield)))))
+          :do
+          (progn
+            (setf (cell-active-group cell) t
+                  (cell-active cell) t)
+            (push cell run)
+            (if should-close
+              (let* ((member (random-elt run))
+                     (member-north (cell-north member)))
+                (when member-north
+                  (setf (cell-active member) t)
+                  (cell-link member member-north))
+                (yield)
+                (setf (cell-active member) nil)
+                (loop :for c :in run :do (setf (cell-active-group c) nil))
+                (setf run nil))
+              (progn
+                (cell-link cell (cell-east cell))
+                (yield)))
+            (setf (cell-active cell) nil)))))
 
 (defun sidewinder (grid)
   (do-generator (_ (sidewinder-generator grid))))

--- a/src/grid.lisp	Wed Jun 08 12:07:35 2016 +0000
+++ b/src/grid.lisp	Wed Jun 08 12:30:15 2016 +0000
@@ -8,6 +8,8 @@
    (south :accessor cell-south :initform nil)
    (east :accessor cell-east :initform nil)
    (west :accessor cell-west :initform nil)
+   (active :accessor cell-active :initform nil)
+   (active-group :accessor cell-active-group :initform nil)
    (links :accessor cell-links :initform nil)))