working on grid

package.json

@@ -8,7 +8,7 @@
     , "main"            : "./index.js"
     , "dependencies"    : {
       "heap" : "0.2.1"
-      , "node-simple-logger"          : ">= 0.1.0"
+      , "dev-logger"          : ">= 0.1.0"
     }
   , "devDependencies" : {
     "uglify-js"       : ">= 1.2.5"

src/grid.coffee

@@ -1,9 +1,24 @@
-logger = require "logger"
-Buffer = require "Buffer"
 
 
 class Grid
 
+
+  @bytesFrom2DArray : (width, height, array2d) ->
+    buf = new Buffer(Math.ceil(width * height / 8))
+    buf.fill(0) # fill all bits as false
+    for row, y in array2d
+      for col, x in row
+        if Boolean(col) # set bit only when true
+          index = y * width + x
+          byteIndex = Math.ceil(index / 8)
+          offset = index % 8
+          byte = buf[byteIndex]
+          byte = byte ^ 1 << offset
+          buf[byteIndex] = byte
+
+    return buf
+
+
   constructor: (@width, @height, @bytes) ->
     unless width > 0 and height > 0 and Buffer.isBuffer(bytes)
       throw new Error "bad arguments, width:#{width}, height:#{height}, bytes:#{bytes}"

src/tests/grid_test.coffee

@@ -0,0 +1,37 @@
+grid = require "../grid"
+
+
+describe "Static method in Grid", ->
+
+  it "should work" , ->
+
+    array2d = [
+      [1, 0, 0],
+      [0, 1, 0],
+      [0, 0, 1],
+      [1, 1, 0],
+      [1, 0, 0]
+    ]
+
+    width = 3
+
+    height = 5
+
+    buf = grid.bytesFrom2DArray(width, height, array2d)
+
+    console.log(buf.toString('hex'))
+
+    for i in [0...buf.length]
+      console.log "[grid_test] buf[i]:#{buf[i].toString(2)}"
+
+
+
+    #dump = ''
+
+    #for y in [0...height] by 1
+      #for x in [0...width] by 1
+
+
+
+
+

tests

@@ -0,0 +1 @@
+lib/tests/