find walls.as

package
{
	import flash.display.Sprite;

	public class Sandbox extends Sprite
	{

		public function Sandbox()
		{
			var gridWidth:int = 70;
			var gridHeight:int = 48;
			var gridTotal:int = gridWidth * gridHeight;


			var gridArray:Array = [];
			var edgeArray:Array = [];
			var i:int;
			
			for (i = 0; i < gridHeight; i++)
			{
				for (var j:int = 0; j < gridWidth; j++)
				{
					if(gridArray[i] == null) gridArray[i] = [];
					gridArray[i][j] = "?";
				}
				
			}

			var isEdge:Boolean;
			var currentColumn:int;
			var currentRow:int;
			
			//build "edge array" after the main 2d grid is created
			for (i = 0; i < gridTotal; i++, isEdge = false)
			{

				//this is what's going on below
//				var firstColumn:Boolean = (i % gridWidth) == 0;
//				var lastColumn:Boolean = (i % gridWidth) == (gridWidth -1);
//				var firstRow:Boolean = i < gridWidth;
//				var lastRow:Boolean = (gridWidth - i) < gridWidth;

				isEdge ||= ((i % gridWidth) == 0);
				isEdge ||= (i % gridWidth) == (gridWidth - 1);
				isEdge ||= i < gridWidth;
				isEdge ||= i > (gridTotal - gridWidth);
				if(isEdge)
				{
					currentColumn = i % gridWidth;
					currentRow = Math.floor(i / gridWidth);
					edgeArray.push(currentRow, currentColumn);
				}
				
			}

			//anytime later
			for (i = 0; i < edgeArray.length; i+=2)
			{
				var row:int = edgeArray[i];
				var column:int = edgeArray[i + 1];
				gridArray[row][column] = "#";
			}

			for (i = 0; i < gridArray.length; i++)
			{
				trace(i + " " + gridArray[i])
			}
		}
	}
}