    /**
     * Line charts
     */
    $.fn.sparkline.line = line = createClass($.fn.sparkline._base, {
        type: 'line',

        init: function (el, values, options, width, height) {
            line._super.init.call(this, el, values, options, width, height);
            this.vertices = [];
            this.regionMap = [];
            this.xvalues = [];
            this.yvalues = [];
            this.yminmax = [];
            this.hightlightSpotId = null;
            this.lastShapeId = null;
            this.initTarget();
        },

        getRegion: function (el, x, y) {
            var i,
                regionMap = this.regionMap; // maps regions to value positions
            for (i = regionMap.length; i--;) {
                if (regionMap[i] !== null && x >= regionMap[i][0] && x <= regionMap[i][1]) {
                    return regionMap[i][2];
                }
            }
            return undefined;
        },

        getCurrentRegionFields: function () {
            var currentRegion = this.currentRegion;
            return {
                isNull: this.yvalues[currentRegion] === null,
                x: this.xvalues[currentRegion],
                y: this.yvalues[currentRegion],
                color: this.options.get('lineColor'),
                fillColor: this.options.get('fillColor'),
                offset: currentRegion
            };
        },

        renderHighlight: function () {
            var currentRegion = this.currentRegion,
                target = this.target,
                vertex = this.vertices[currentRegion],
                options = this.options,
                spotRadius = options.get('spotRadius'),
                highlightSpotColor = options.get('highlightSpotColor'),
                highlightLineColor = options.get('highlightLineColor'),
                highlightSpot, highlightLine;

            if (!vertex) {
                return;
            }
            if (spotRadius && highlightSpotColor) {
                highlightSpot = target.drawCircle(vertex[0], vertex[1],
                    spotRadius, undefined, highlightSpotColor);
                this.highlightSpotId = highlightSpot.id;
                target.insertAfterShape(this.lastShapeId, highlightSpot);
            }
            if (highlightLineColor) {
                highlightLine = target.drawLine(vertex[0], this.canvasTop, vertex[0],
                    this.canvasTop + this.canvasHeight, highlightLineColor);
                this.highlightLineId = highlightLine.id;
                target.insertAfterShape(this.lastShapeId, highlightLine);
            }
        },

        removeHighlight: function () {
            var target = this.target;
            if (this.highlightSpotId) {
                target.removeShapeId(this.highlightSpotId);
                this.highlightSpotId = null;
            }
            if (this.highlightLineId) {
                target.removeShapeId(this.highlightLineId);
                this.highlightLineId = null;
            }
        },

        scanValues: function () {
            var values = this.values,
                valcount = values.length,
                xvalues = this.xvalues,
                yvalues = this.yvalues,
                yminmax = this.yminmax,
                i, val, isStr, isArray, sp;
            for (i = 0; i < valcount; i++) {
                val = values[i];
                isStr = typeof(values[i]) === 'string';
                isArray = typeof(values[i]) === 'object' && values[i] instanceof Array;
                sp = isStr && values[i].split(':');
                if (isStr && sp.length === 2) { // x:y
                    xvalues.push(Number(sp[0]));
                    yvalues.push(Number(sp[1]));
                    yminmax.push(Number(sp[1]));
                } else if (isArray) {
                    xvalues.push(val[0]);
                    yvalues.push(val[1]);
                    yminmax.push(val[1]);
                } else {
                    xvalues.push(i);
                    if (values[i] === null || values[i] === 'null') {
                        yvalues.push(null);
                    } else {
                        yvalues.push(Number(val));
                        yminmax.push(Number(val));
                    }
                }
            }
            if (this.options.get('xvalues')) {
                xvalues = this.options.get('xvalues');
            }

            this.maxy = this.maxyorg = Math.max.apply(Math, yminmax);
            this.miny = this.minyorg = Math.min.apply(Math, yminmax);

            this.maxx = Math.max.apply(Math, xvalues);
            this.minx = Math.min.apply(Math, xvalues);

            this.xvalues = xvalues;
            this.yvalues = yvalues;
            this.yminmax = yminmax;

        },

        processRangeOptions: function () {
            var options = this.options,
                normalRangeMin = options.get('normalRangeMin'),
                normalRangeMax = options.get('normalRangeMax');

            if (normalRangeMin !== undefined) {
                if (normalRangeMin < this.miny) {
                    this.miny = normalRangeMin;
                }
                if (normalRangeMax > this.maxy) {
                    this.maxy = normalRangeMax;
                }
            }
            if (options.get('chartRangeMin') !== undefined && (options.get('chartRangeClip') || options.get('chartRangeMin') < this.miny)) {
                this.miny = options.get('chartRangeMin');
            }
            if (options.get('chartRangeMax') !== undefined && (options.get('chartRangeClip') || options.get('chartRangeMax') > this.maxy)) {
                this.maxy = options.get('chartRangeMax');
            }
            if (options.get('chartRangeMinX') !== undefined && (options.get('chartRangeClipX') || options.get('chartRangeMinX') < this.minx)) {
                this.minx = options.get('chartRangeMinX');
            }
            if (options.get('chartRangeMaxX') !== undefined && (options.get('chartRangeClipX') || options.get('chartRangeMaxX') > this.maxx)) {
                this.maxx = options.get('chartRangeMaxX');
            }

        },

        drawNormalRange: function (canvasLeft, canvasTop, canvasHeight, canvasWidth, rangey) {
            var normalRangeMin = this.options.get('normalRangeMin'),
                normalRangeMax = this.options.get('normalRangeMax'),
                ytop = canvasTop + Math.round(canvasHeight - (canvasHeight * ((normalRangeMax - this.miny) / rangey))),
                height = Math.round((canvasHeight * (normalRangeMax - normalRangeMin)) / rangey);
            this.target.drawRect(canvasLeft, ytop, canvasWidth, height, undefined, this.options.get('normalRangeColor')).append();
        },

        render: function () {
            var options = this.options,
                target = this.target,
                canvasWidth = this.canvasWidth,
                canvasHeight = this.canvasHeight,
                vertices = this.vertices,
                spotRadius = options.get('spotRadius'),
                regionMap = this.regionMap,
                rangex, rangey, yvallast,
                canvasTop, canvasLeft,
                vertex, path, paths, x, y, xnext, xpos, xposnext,
                last, next, yvalcount, lineShapes, fillShapes, plen,
                valueSpots, hlSpotsEnabled, color, xvalues, yvalues, i;

            if (!line._super.render.call(this)) {
                return;
            }

            this.scanValues();
            this.processRangeOptions();

            xvalues = this.xvalues;
            yvalues = this.yvalues;

            if (!this.yminmax.length || this.yvalues.length < 2) {
                // empty or all null valuess
                return;
            }

            canvasTop = canvasLeft = 0;

            rangex = this.maxx - this.minx === 0 ? 1 : this.maxx - this.minx;
            rangey = this.maxy - this.miny === 0 ? 1 : this.maxy - this.miny;
            yvallast = this.yvalues.length - 1;

            if (spotRadius && (canvasWidth < (spotRadius * 4) || canvasHeight < (spotRadius * 4))) {
                spotRadius = 0;
            }
            if (spotRadius) {
                // adjust the canvas size as required so that spots will fit
                hlSpotsEnabled = options.get('highlightSpotColor') &&  !options.get('disableInteraction');
                if (hlSpotsEnabled || options.get('minSpotColor') || (options.get('spotColor') && yvalues[yvallast] === this.miny)) {
                    canvasHeight -= Math.ceil(spotRadius);
                }
                if (hlSpotsEnabled || options.get('maxSpotColor') || (options.get('spotColor') && yvalues[yvallast] === this.maxy)) {
                    canvasHeight -= Math.ceil(spotRadius);
                    canvasTop += Math.ceil(spotRadius);
                }
                if (hlSpotsEnabled ||
                     ((options.get('minSpotColor') || options.get('maxSpotColor')) && (yvalues[0] === this.miny || yvalues[0] === this.maxy))) {
                    canvasLeft += Math.ceil(spotRadius);
                    canvasWidth -= Math.ceil(spotRadius);
                }
                if (hlSpotsEnabled || options.get('spotColor') ||
                    (options.get('minSpotColor') || options.get('maxSpotColor') &&
                        (yvalues[yvallast] === this.miny || yvalues[yvallast] === this.maxy))) {
                    canvasWidth -= Math.ceil(spotRadius);
                }
            }


            canvasHeight--;

            if (options.get('normalRangeMin') !== undefined && !options.get('drawNormalOnTop')) {
                this.drawNormalRange(canvasLeft, canvasTop, canvasHeight, canvasWidth, rangey);
            }

            path = [];
            paths = [path];
            last = next = null;
            yvalcount = yvalues.length;
            for (i = 0; i < yvalcount; i++) {
                x = xvalues[i];
                xnext = xvalues[i + 1];
                y = yvalues[i];
                xpos = canvasLeft + Math.round((x - this.minx) * (canvasWidth / rangex));
                xposnext = i < yvalcount - 1 ? canvasLeft + Math.round((xnext - this.minx) * (canvasWidth / rangex)) : canvasWidth;
                next = xpos + ((xposnext - xpos) / 2);
                regionMap[i] = [last || 0, next, i];
                last = next;
                if (y === null) {
                    if (i) {
                        if (yvalues[i - 1] !== null) {
                            path = [];
                            paths.push(path);
                        }
                        vertices.push(null);
                    }
                } else {
                    if (y < this.miny) {
                        y = this.miny;
                    }
                    if (y > this.maxy) {
                        y = this.maxy;
                    }
                    if (!path.length) {
                        // previous value was null
                        path.push([xpos, canvasTop + canvasHeight]);
                    }
                    vertex = [xpos, canvasTop + Math.round(canvasHeight - (canvasHeight * ((y - this.miny) / rangey)))];
                    path.push(vertex);
                    vertices.push(vertex);
                }
            }

            lineShapes = [];
            fillShapes = [];
            plen = paths.length;
            for (i = 0; i < plen; i++) {
                path = paths[i];
                if (path.length) {
                    if (options.get('fillColor')) {
                        path.push([path[path.length - 1][0], (canvasTop + canvasHeight)]);
                        fillShapes.push(path.slice(0));
                        path.pop();
                    }
                    // if there's only a single point in this path, then we want to display it
                    // as a vertical line which means we keep path[0]  as is
                    if (path.length > 2) {
                        // else we want the first value
                        path[0] = [path[0][0], path[1][1]];
                    }
                    lineShapes.push(path);
                }
            }

            // draw the fill first, then optionally the normal range, then the line on top of that
            plen = fillShapes.length;
            for (i = 0; i < plen; i++) {
                target.drawShape(fillShapes[i],
                    options.get('fillColor'), options.get('fillColor')).append();
            }

            if (options.get('normalRangeMin') !== undefined && options.get('drawNormalOnTop')) {
                this.drawNormalRange(canvasLeft, canvasTop, canvasHeight, canvasWidth, rangey);
            }

            plen = lineShapes.length;
            for (i = 0; i < plen; i++) {
                target.drawShape(lineShapes[i], options.get('lineColor'), undefined,
                    options.get('lineWidth')).append();
            }

            if (spotRadius && options.get('valueSpots')) {
                valueSpots = options.get('valueSpots');
                if (valueSpots.get === undefined) {
                    valueSpots = new RangeMap(valueSpots);
                }
                for (i = 0; i < yvalcount; i++) {
                    color = valueSpots.get(yvalues[i]);
                    if (color) {
                        target.drawCircle(canvasLeft + Math.round((xvalues[i] - this.minx) * (canvasWidth / rangex)),
                            canvasTop + Math.round(canvasHeight - (canvasHeight * ((yvalues[i] - this.miny) / rangey))),
                            spotRadius, undefined,
                            color).append();
                    }
                }

            }
            if (spotRadius && options.get('spotColor') && yvalues[yvallast] !== null) {
                target.drawCircle(canvasLeft + Math.round((xvalues[xvalues.length - 1] - this.minx) * (canvasWidth / rangex)),
                    canvasTop + Math.round(canvasHeight - (canvasHeight * ((yvalues[yvallast] - this.miny) / rangey))),
                    spotRadius, undefined,
                    options.get('spotColor')).append();
            }
            if (this.maxy !== this.minyorg) {
                if (spotRadius && options.get('minSpotColor')) {
                    x = xvalues[$.inArray(this.minyorg, yvalues)];
                    target.drawCircle(canvasLeft + Math.round((x - this.minx) * (canvasWidth / rangex)),
                        canvasTop + Math.round(canvasHeight - (canvasHeight * ((this.minyorg - this.miny) / rangey))),
                        spotRadius, undefined,
                        options.get('minSpotColor')).append();
                }
                if (spotRadius && options.get('maxSpotColor')) {
                    x = xvalues[$.inArray(this.maxyorg, yvalues)];
                    target.drawCircle(canvasLeft + Math.round((x - this.minx) * (canvasWidth / rangex)),
                        canvasTop + Math.round(canvasHeight - (canvasHeight * ((this.maxyorg - this.miny) / rangey))),
                        spotRadius, undefined,
                        options.get('maxSpotColor')).append();
                }
            }

            this.lastShapeId = target.getLastShapeId();
            this.canvasTop = canvasTop;
            target.render();
        }
    });
