// branch_renderer.js - Rendering of branch DAGs on the client side

//

// Copyright 2008 Dirkjan Ochtman <dirkjan AT ochtman DOT nl>

// Copyright 2006 Alexander Schremmer <alex AT alexanderweb DOT de>

//

// derived from code written by Scott James Remnant <scott@ubuntu.com>

// Copyright 2005 Canonical Ltd.

//

// This software may be used and distributed according to the terms

// of the GNU General Public License, incorporated herein by reference.

var colors = [

	[ 1.0, 0.0, 0.0 ],

	[ 1.0, 1.0, 0.0 ],

	[ 0.0, 1.0, 0.0 ],

	[ 0.0, 1.0, 1.0 ],

	[ 0.0, 0.0, 1.0 ],

	[ 1.0, 0.0, 1.0 ]

];

function Graph() {

	this.canvas = document.getElementById('graph');

	if (navigator.userAgent.indexOf('MSIE') >= 0) this.canvas = window.G_vmlCanvasManager.initElement(this.canvas);

	this.ctx = this.canvas.getContext('2d');

	this.ctx.strokeStyle = 'rgb(0, 0, 0)';

	this.ctx.fillStyle = 'rgb(0, 0, 0)';

	this.cur = [0, 0];

	this.line_width = 3;

	this.bg = [0, 4];

	this.cell = [2, 0];

	this.columns = 0;

	this.revlink = '';

	this.scale = function(height) {

		this.bg_height = height;

		this.box_size = Math.floor(this.bg_height / 1.2);

		this.cell_height = this.box_size;

	}

	function colorPart(num) {

		num *= 255

		num = num < 0 ? 0 : num;

		num = num > 255 ? 255 : num;

		var digits = Math.round(num).toString(16);

		if (num < 16) {

			return '0' + digits;

		} else {

			return digits;

		}

	}

	this.setColor = function(color, bg, fg) {

		// Set the colour.

		//

		// Picks a distinct colour based on an internal wheel; the bg

		// parameter provides the value that should be assigned to the 'zero'

		// colours and the fg parameter provides the multiplier that should be

		// applied to the foreground colours.

		color %= colors.length;

		var red = (colors[color][0] * fg) || bg;

		var green = (colors[color][1] * fg) || bg;

		var blue = (colors[color][2] * fg) || bg;

		red = Math.round(red * 255);

		green = Math.round(green * 255);

		blue = Math.round(blue * 255);

		var s = 'rgb(' + red + ', ' + green + ', ' + blue + ')';

		this.ctx.strokeStyle = s;

		this.ctx.fillStyle = s;

		return s;

	}

	this.render = function(data) {

		for (var i in data) {

			var parity = i % 2;

			this.cell[1] += this.bg_height;

			this.bg[1] += this.bg_height;

			var cur = data[i];

			var node = cur[1];

			var edges = cur[2];

			var fold = false;

			for (var j in edges) {

				line = edges[j];

				start = line[0];

				end = line[1];

				color = line[2];

				if (end > this.columns) {

					this.columns += 1;

				} else if (start == this.columns && start > end) {

					var fold = true;

				}

				x0 = this.cell[0] + this.box_size * start + this.box_size / 2;

				y0 = this.bg[1] - this.bg_height / 2;

				x1 = this.cell[0] + this.box_size * end + this.box_size / 2;

				y1 = this.bg[1] + this.bg_height / 2;

				this.edge(x0, y0, x1, y1, color);

			}

			// Draw the revision node in the right column

			column = node[0]

			color = node[1]

			radius = this.box_size / 8;

			x = this.cell[0] + this.box_size * column + this.box_size / 2;

			y = this.bg[1] - this.bg_height / 2;

			this.vertex(x, y, color, parity, cur);

			if (fold) this.columns -= 1;

		}

	}

}