base.js

var Class = require('../../core/class');
var Transform = require('../../core/transform');
var Color = require('../../core/color');
var Node = require('./node');
var DOM = require('./dom');

var precision = 100;

var defaultBox = { left: 0, top: 0, width: 500, height: 500 };

module.exports = Class(Node, {

	element_initialize: Node.prototype.initialize,

	initialize: function(tag){
		this.element_initialize(tag);
		var element = this.element;
		
		var skew = this.skewElement = DOM.createElement('skew');
		skew.on = true;
		element.appendChild(skew);

		var fill = this.fillElement = DOM.createElement('fill');
		fill.on = false;
		element.appendChild(fill);
		
		var stroke = this.strokeElement = DOM.createElement('stroke');
		stroke.on = false;
		element.appendChild(stroke);
	},
	
	/* transform */
	
	_transform: function(){
		var container = this.parentNode;
		
		// Active Transformation Matrix
		var m = container ? new Transform(container._activeTransform).transform(this) : this;
		
		// Box in shape user space
		
		var box = this._boxCoords || this._size || defaultBox;
		
		var originX = box.left || 0,
			originY = box.top || 0,
			width = box.width || 1,
			height = box.height || 1;
				
		// Flipped
	    var flip = m.yx / m.xx > m.yy / m.xy;
		if (m.xx < 0 ? m.xy >= 0 : m.xy < 0) flip = !flip;
		flip = flip ? -1 : 1;
		
		m = new Transform().scale(flip, 1).transform(m);
		
		// Rotation is approximated based on the transform
		var rotation = Math.atan2(-m.xy, m.yy) * 180 / Math.PI;
		
		// Reverse the rotation, leaving the final transform in box space
		var rad = rotation * Math.PI / 180, sin = Math.sin(rad), cos = Math.cos(rad);
		
		var transform = new Transform(
			(m.xx * cos - m.xy * sin),
			(m.yx * cos - m.yy * sin) * flip,
			(m.xy * cos + m.xx * sin) * flip,
			(m.yy * cos + m.yx * sin)
		);

		var rotationTransform = new Transform().rotate(rotation, 0, 0);

		var shapeToBox = new Transform().rotate(-rotation, 0, 0).transform(m).moveTo(0,0);

		// Scale box after reversing rotation
		width *= Math.abs(shapeToBox.xx);
		height *= Math.abs(shapeToBox.yy);
		
		// Place box
		var left = m.x, top = m.y;
		
		// Compensate for offset by center origin rotation
		var vx = -width / 2, vy = -height / 2;
		var point = rotationTransform.point(vx, vy);
		left -= point.x - vx;
		top -= point.y - vy;
		
		// Adjust box position based on offset
		var rsm = new Transform(m).moveTo(0,0);
		point = rsm.point(originX, originY);
		left += point.x;
		top += point.y;
		
		if (flip < 0) left = -left - width;
		
		// Place transformation origin
		var point0 = rsm.point(-originX, -originY);
		var point1 = rotationTransform.point(width, height);
		var point2 = rotationTransform.point(width, 0);
		var point3 = rotationTransform.point(0, height);
		
		var minX = Math.min(0, point1.x, point2.x, point3.x),
		    maxX = Math.max(0, point1.x, point2.x, point3.x),
		    minY = Math.min(0, point1.y, point2.y, point3.y),
		    maxY = Math.max(0, point1.y, point2.y, point3.y);
		
		var transformOriginX = (point0.x - point1.x / 2) / (maxX - minX) * flip,
		    transformOriginY = (point0.y - point1.y / 2) / (maxY - minY);
		
		// Adjust the origin
		point = shapeToBox.point(originX, originY);
		originX = point.x;
		originY = point.y;
		
		// Scale stroke
		var strokeWidth = this._strokeWidth;
		if (strokeWidth){
			// Scale is the hypothenus between the two vectors
			// TODO: Use area calculation instead
			var vx = m.xx + m.xy, vy = m.yy + m.yx;
			strokeWidth *= Math.sqrt(vx * vx + vy * vy) / Math.sqrt(2);
		}
		
		// convert to multiplied precision space
		originX *= precision;
		originY *= precision;
		left *= precision;
		top *= precision;
		width *= precision;
		height *= precision;
		
		// Set box
		var element = this.element;
		element.coordorigin = originX + ',' + originY;
		element.coordsize = width + ',' + height;
		element.style.left = left + 'px';
		element.style.top = top + 'px';
		element.style.width = width;
		element.style.height = height;
		element.style.rotation = rotation.toFixed(8);
		element.style.flip = flip < 0 ? 'x' : '';
		
		// Set transform
		var skew = this.skewElement;
		skew.matrix = [transform.xx.toFixed(4), transform.xy.toFixed(4), transform.yx.toFixed(4), transform.yy.toFixed(4), 0, 0];
		skew.origin = transformOriginX + ',' + transformOriginY;

		// Set stroke
		this.strokeElement.weight = strokeWidth + 'px';
	},
	
	/* styles */

	_createGradient: function(style, stops){
		var fill = this.fillElement;

		// Temporarily eject the fill from the DOM
		this.element.removeChild(fill);

		fill.type = style;
		fill.method = 'none';
		fill.rotate = true;

		var colors = [], color1, color2;

		var addColor = function(offset, color){
			color = Color.detach(color);
			if (color1 == null) color1 = color2 = color;
			else color2 = color;
			colors.push(offset + ' ' + color[0]);
		};

		// Enumerate stops, assumes offsets are enumerated in order
		if ('length' in stops) for (var i = 0, l = stops.length - 1; i <= l; i++) addColor(i / l, stops[i]);
		else for (var offset in stops) addColor(offset, stops[offset]);
		
		fill.color = color1[0];
		fill.color2 = color2[0];
		
		//if (fill.colors) fill.colors.value = colors; else
		fill.colors = colors;

		// Opacity order gets flipped when color stops are specified
		fill.opacity = color2[1];
		fill['ao:opacity2'] = color1[1];

		fill.on = true;
		this.element.appendChild(fill);
		return fill;
	},
	
	_setColor: function(type, color){
		var element = type == 'fill' ? this.fillElement : this.strokeElement;
		if (color == null){
			element.on = false;
		} else {
			color = Color.detach(color);
			element.color = color[0];
			element.opacity = color[1];
			element.on = true;
		}
	},
	
	fill: function(color){
		if (arguments.length > 1){
			this.fillLinear(arguments);
		} else {
			this._boxCoords = defaultBox;
			var fill = this.fillElement;
			fill.type = 'solid';
			fill.color2 = '';
			fill['ao:opacity2'] = '';
			if (fill.colors) fill.colors.value = '';
			this._setColor('fill', color);
		}
		return this;
	},

	fillRadial: function(stops, focusX, focusY, radiusX, radiusY, centerX, centerY){
		var fill = this._createGradient('gradientradial', stops);
		if (focusX == null) focusX = this.left + this.width * 0.5;
		if (focusY == null) focusY = this.top + this.height * 0.5;
		if (radiusY == null) radiusY = radiusX || (this.height * 0.5);
		if (radiusX == null) radiusX = this.width * 0.5;
		if (centerX == null) centerX = focusX;
		if (centerY == null) centerY = focusY;
		
		centerX += centerX - focusX;
		centerY += centerY - focusY;
		
		var box = this._boxCoords = {
			left: centerX - radiusX * 2,
			top: centerY - radiusY * 2,
			width: radiusX * 4,
			height: radiusY * 4
		};
		focusX -= box.left;
		focusY -= box.top;
		focusX /= box.width;
		focusY /= box.height;

		fill.focussize = '0 0';
		fill.focusposition = focusX + ',' + focusY;
		fill.focus = '50%';
		
		this._transform();
		
		return this;
	},

	fillLinear: function(stops, x1, y1, x2, y2){
		var fill = this._createGradient('gradient', stops);
		fill.focus = '100%';
		if (arguments.length == 5){
			var w = Math.abs(x2 - x1), h = Math.abs(y2 - y1);
			this._boxCoords = {
				left: Math.min(x1, x2),
				top: Math.min(y1, y2),
				width: w < 1 ? h : w,
				height: h < 1 ? w : h
			};
			fill.angle = (360 + Math.atan2((x2 - x1) / h, (y2 - y1) / w) * 180 / Math.PI) % 360;
		} else {
			this._boxCoords = null;
			fill.angle = (x1 == null) ? 0 : (90 + x1) % 360;
		}
		this._transform();
		return this;
	},

	fillImage: function(url, width, height, left, top, color1, color2){
		var fill = this.fillElement;
		if (color1 != null){
			color1 = Color.detach(color1);
			if (color2 != null) color2 = Color.detach(color2);
			fill.type = 'pattern';
			fill.color = color1[0];
			fill.color2 = color2 == null ? color1[0] : color2[0];
			fill.opacity = color2 == null ? 0 : color2[1];
			fill['ao:opacity2'] = color1[1];
		} else {
			fill.type = 'tile';
			fill.color = '';
			fill.color2 = '';
			fill.opacity = 1;
			fill['ao:opacity2'] = 1;
		}
		if (fill.colors) fill.colors.value = '';
		fill.rotate = true;
		fill.src = url;
		
		fill.size = '1,1';
		fill.position = '0,0';
		fill.origin = '0,0';
		fill.aspect = 'ignore'; // ignore, atleast, atmost
		fill.on = true;

		if (!left) left = 0;
		if (!top) top = 0;
		this._boxCoords = width ? { left: left + 0.5, top: top + 0.5, width: width, height: height } : null;
		this._transform();
		return this;
	},

	/* stroke */
	
	stroke: function(color, width, cap, join){
		var stroke = this.strokeElement;
		this._strokeWidth = (width != null) ? width : 1;
		stroke.weight = (width != null) ? width + 'px' : 1;
		stroke.endcap = (cap != null) ? ((cap == 'butt') ? 'flat' : cap) : 'round';
		stroke.joinstyle = (join != null) ? join : 'round';

		this._setColor('stroke', color);
		return this;
	}

});