gistfile1.js

(function()
{
	var NEIGHBORS_DI = [0, 1, 1, 0, -1,-1];
	var NEIGHBORS_DJ = [
		[-1, -1, 0, 1, 0, -1],
		[-1, 0, 1, 1, 1, 0]
	];

	var NUM_NEIGHBORS = 6;

	var HexTile = function(radius)
	{	
		this.mX = 0; //Cell's left coordinate
		this.mY = 0; //Cell's top coordinate
		this.mI = 0; //Cell's horizontal grid coordinate
		this.mJ = 0; //Cell's vertical grid coordinate

		this.RADIUS = radius;
		this.WIDTH = this.RADIUS * 2;
		this.HEIGHT = parseInt(radius * Math.sqrt(3));
		this.SIDE = this.RADIUS * 3 / 2;

		this.CORNERS_DX = [
			this.RADIUS / 2,
			this.SIDE,
			this.WIDTH,
			this.SIDE,
			this.RADIUS / 2,
			0
		];

		this.CORNERS_DY = [
			0, 0, 
			this.HEIGHT / 2,
			this.HEIGHT, 
			this.HEIGHT, 
			this.HEIGHT / 2
		];

	}

	HexTile.prototype.getLeft = function()
	{
		return this.mX;
	}

	HexTile.prototype.getTop = function()
	{
		return this.mY;
	}

	HexTile.prototype.getCenterX = function()
	{
		return this.mX + this.RADIUS;
	}

	HexTile.prototype.getCenterY = function()
	{
		return this.mY + this.HEIGHT / 2;
	}

	HexTile.prototype.getIndexJ = function()
	{
		return this.mJ;
	}

	HexTile.prototype.getNeighbor = function(neighborId_x)
	{
		return this.mI + NEIGHBORS_DI[neighborId_x];
	}

	HexTile.prototype.getNeighborJ = function(neighborId_x)
	{
		return this.mJ + NEIGHBORS_DJ[this.mI % 2][neighborId_x];
	}

	HexTile.prototype.computeCorners = function(cornersX, cornersY)
	{
		for(var k = 0; k < NUM_NEIGHBORS; k++)
		{
			cornersX[k] = mX + this.CORNERS_DX[k];
			cornersY[k] = mY + this.CORNERS_DY[k];
		}

		return [cornersX, cornersY];
	}

	HexTile.prototype.setCellIndex = function(i, j)
	{
		this.mI = i;
		this.mJ = j;
		this.mX = i * this.SIDE;
		this.mY = this.HEIGHT * (2 * j + (i % 2)) / 2;
	}

	HexTile.prototype.setCellByPoint = function(x, y)
	{
		var ci = parseInt(Math.floor( parseFloat(x) / parseFloat(this.SIDE) ));
		var cx = x - this.SIDE * ci;
		var ty = y - (ci % 2) * this.HEIGHT / 2;
		var cj = parseInt(Math.floor(parseFloat(ty) / parseFloat(this.HEIGHT)));
		var cy = ty - this.HEIGHT * cj;

		if(cx > Math.abs(this.RADIUS / 2 - this.RADIUS * cy / this.HEIGHT))
		{
			this.setCellIndex(ci, cj);
		}
		else
		{
			this.setCellIndex(ci - 1, cj + (ci % 2) - ((cy < this.HEIGHT / 2) ? 1 : 0));
		}
	}

	HexMap = function(rows, columns)
	{
		this.rows = rows;
		this.columns = columns;
		this.$_radius = 16;
	}

	HexMap.prototype.drawGrid = function(canvas)
	{
		var posX;
		var posY;
		var coord;
		var self = this;

		for(var row = 0; row < this.rows; row++)
		{
			for(var col = 0; col < this.columns; col++)
			{
				posY = this.$_y_offset + row * this.$_radius;
				posX = (row & 1) * (this.$_hexsize + this.$_half_hexsize) + this.$_x_offset + 2 * col * (this.$_hexsize + this.$_half_hexsize);
				
				var tile = new HexTile(this.$_radius);
				tile.setCellIndex(col, row);
				this.drawHex(canvas, tile);
			}
		}
	}

	HexMap.prototype.findHex = function(position)
	{
		var mX = position[0];
		var mY = position[1];

		var tile = new HexTile(this.$_radius);
		tile.setCellByPoint(mX, mY);

		return tile;
	}

	HexMap.prototype.drawHex = function(canvas, tile, options)
	{
		var defaults = {
			fillStyle: 'black',
			strokeStyle: 'white',
			strokWidth: 2,
			x: tile.getCenterX() , y: tile.getCenterY(),
			radius: tile.RADIUS,
			sides: 6
		};

		var options = $.extend(defaults, options);
		canvas.drawPolygon(options);
	}
})();