add doc

README.md

@@ -251,7 +251,7 @@ These examples incubate dotSCAD and dotSCAD refactors these examples. See [examp
 - [mz_square_get](https://openhome.cc/eGossip/OpenSCAD/lib2x-mz_square_get.html)
 - [mz_square_walls](https://openhome.cc/eGossip/OpenSCAD/lib2x-mz_square_walls.html)
 - [mz_hex_walls](https://openhome.cc/eGossip/OpenSCAD/lib2x-mz_hex_walls.html)
-- mz_square_initialize
+- [mz_square_initialize](https://openhome.cc/eGossip/OpenSCAD/lib2x-mz_square_initialize.html)
 - mz_hamiltonian
 
 ----

docs/lib2x-mz_square_initialize.md

@@ -0,0 +1,84 @@
+# mz_square_initialize
+
+It's a helper for initializing cell data of a maze. 
+
+**Since:** 2.5
+
+## Parameters
+
+- `rows` : The rows of the maze.
+- `columns` : The columns of the maze.
+- `mask` : The mask for a maze. A list of 0s and 1s. Cells makred as 0 won't be traveled.
+
+## Examples
+    
+	use <maze/mz_square_initialize.scad>;
+	use <maze/mz_square_cells.scad>;
+	use <maze/mz_square_walls.scad>;
+	use <polyline2d.scad>;
+
+	rows = 10;
+	columns = 10;
+	cell_width = 5;
+	wall_thickness = 2;
+
+    init_cells = mz_square_initialize(rows, columns);
+	cells = mz_square_cells(rows, columns, init_cells = init_cells);
+	walls = mz_square_walls(cells, rows, columns, cell_width);
+
+	for(wall = walls) {
+		polyline2d(wall, wall_thickness, joinStyle = "JOIN_MITER");
+	}
+	
+![mz_square_initialize](images/lib2x-mz_square_initialize-1.JPG)
+
+    use <maze/mz_square_cells.scad>;
+    use <maze/mz_square_walls.scad>;
+    use <maze/mz_square_initialize.scad>;
+    use <polyline2d.scad>;
+
+    mask = [
+        [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
+        [0, 0, 1, 1, 0, 0, 0, 1, 1, 0, 0],
+        [0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0],
+        [0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0],
+        [0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0],
+        [0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0],
+        [0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0],
+        [0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0],
+        [0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0],
+        [0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0],
+        [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
+    ];
+    start = [3, 3];
+    cell_width = 5;
+    wall_thickness = 2;
+
+    rows = len(mask);
+    columns = len(mask[0]);
+    init_cells = mz_square_initialize(mask = mask);
+    cells = mz_square_cells(rows, columns, start, init_cells);
+    walls = mz_square_walls(cells, rows, columns, cell_width, false, false);
+
+    // Maze
+    for(wall = walls) {
+        polyline2d(wall, wall_thickness, joinStyle = "JOIN_MITER");
+    }
+
+    // Mask
+    mask_width = cell_width + wall_thickness;
+    translate([-wall_thickness / 2, -wall_thickness / 2])
+    for(i = [0:rows - 1]) {
+        for(j = [0:columns - 1]) {
+                if(mask[i][j] == 0) {
+                    translate([cell_width * j, cell_width * (rows - i - 1)])
+                        square(mask_width);
+                }
+        }
+    }
+	
+![mz_square_initialize](images/lib2x-mz_square_initialize-2.JPG)
+
+ I provide a tool [img2binary](https://github.com/JustinSDK/img2binary) for converting an image into 0 and 1. 0 is for black and 1 is for white. You may use it to create a mask from an image. The mask of [maze_masking](https://github.com/JustinSDK/dotSCAD/blob/master/examples/maze/maze_masking.scad) is an example.
+
+![mz_square_initialize](images/lib2x-mz_square_initialize-3.JPG)

src/maze/mz_square_initialize.scad

@@ -1,3 +1,13 @@
+/**
+* mz_square_initialize.scad
+*
+* @copyright Justin Lin, 2020
+* @license https://opensource.org/licenses/lgpl-3.0.html
+*
+* @see https://openhome.cc/eGossip/OpenSCAD/lib2x-mz_square_initialize.html
+*
+**/
+
 use <_impl/_mz_initialize.scad>;
 
 function mz_square_initialize(rows, columns, mask) =