adds startingAngle and fullCircle properties to gauge

spec/arc-spec.js

@@ -97,4 +97,62 @@ describe('c3 chart arc', function () {
 
     });
 
+    describe('show gauge', function () {
+
+        it('should update args to have a 180 degree gauge', function () {
+            args = {
+                gauge: {
+                    width: 10,
+                    max: 10,
+                    expand: true
+                },
+                data: {
+                    columns: [
+                        ['data', 8]
+                    ],
+                    type: 'gauge'
+                }
+            };
+            expect(true).toBeTruthy();
+        });
+
+        it('should have correct d for Pi radian gauge', function () {
+            var chartArc = d3.select('.c3-chart-arcs'),
+                data = chartArc.select('.c3-chart-arc.c3-target.c3-target-data')
+                    .select('g.c3-shapes.c3-shapes-data.c3-arcs.c3-arcs-data')
+                    .select('path.c3-shape.c3-shape.c3-arc.c3-arc-data');
+
+            expect(data.attr('d')).toMatch('M-304,-3.7229262694079536e-14A304,304 0 0,1 245.94116628998404,-178.68671669691184L237.85099634623455,-172.8088641739871A294,294 0 0,0 -294,-3.6004615894932184e-14Z');
+        });
+
+        it('should update args to have a 2 Pi radian gauge that starts at Pi/2', function() {
+            args = {
+                gauge: {
+                    width: 10,
+                    max: 10,
+                    expand: true,
+                    fullCircle: true
+                },
+                data: {
+                    columns: [
+                        ['data', 8]
+                    ],
+                    type: 'gauge',
+                    fullCircle: true,
+                    startingAngle: Math.PI/2
+                }
+            };
+            expect(true).toBeTruthy();
+        });
+
+        it('should have correct d for 2 Pi radian gauge starting at Pi/2', function() {
+            var chartArc = d3.select('.c3-chart-arcs'),
+                data = chartArc.select('.c3-chart-arc.c3-target.c3-target-data')
+                    .select('g.c3-shapes.c3-shapes-data.c3-arcs.c3-arcs-data')
+                    .select('path.c3-shape.c3-shape.c3-arc.c3-arc-data');
+
+            expect(data.attr('d')).toMatch('M-304,-3.7229262694079536e-14A304,304 0 0,1 245.94116628998404,-178.68671669691184L237.85099634623455,-172.8088641739871A294,294 0 0,0 -294,-3.6004615894932184e-14Z');
+        });
+    });
+
 });

src/arc.js

@@ -50,9 +50,9 @@ c3_chart_internal_fn.updateAngle = function (d) {
     if ($$.isGaugeType(d.data)) {
         gMin = config.gauge_min;
         gMax = config.gauge_max;
-        gTic = (Math.PI) / (gMax - gMin);
+        gTic = (Math.PI * (config.gauge_fullCircle ? 2 : 1)) / (gMax - gMin);
         gValue = d.value < gMin ? 0 : d.value < gMax ? d.value - gMin : (gMax - gMin);
-        d.startAngle = -1 * (Math.PI / 2);
+        d.startAngle = config.gauge_startingAngle;
         d.endAngle = d.startAngle + gTic * gValue;
     }
     return found ? d : null;
@@ -103,7 +103,8 @@ c3_chart_internal_fn.transformForArcLabel = function (d) {
 
 c3_chart_internal_fn.getArcRatio = function (d) {
     var $$ = this,
-        whole = $$.hasType('gauge') ? Math.PI : (Math.PI * 2);
+        config = $$.config,
+        whole = Math.PI * ($$.hasType('gauge') && !config.gauge_fullCircle ? 1 : 2);
     return d ? (d.endAngle - d.startAngle) / whole : null;
 };
 
@@ -278,7 +279,7 @@ c3_chart_internal_fn.redrawArc = function (duration, durationForExit, withTransf
         .style("opacity", 0)
         .each(function (d) {
             if ($$.isGaugeType(d.data)) {
-                d.startAngle = d.endAngle = -1 * (Math.PI / 2);
+                d.startAngle = d.endAngle = config.gauge_startingAngle;
             }
             this._current = d;
         });
@@ -388,8 +389,8 @@ c3_chart_internal_fn.redrawArc = function (duration, durationForExit, withTransf
             .attr("d", function () {
                 var d = {
                     data: [{value: config.gauge_max}],
-                    startAngle: -1 * (Math.PI / 2),
-                    endAngle: Math.PI / 2
+                    startAngle: config.gauge_startingAngle,
+                    endAngle: -1 * config.gauge_startingAngle
                 };
                 return $$.getArc(d, true, true);
             });
@@ -397,11 +398,11 @@ c3_chart_internal_fn.redrawArc = function (duration, durationForExit, withTransf
             .attr("dy", ".75em")
             .text(config.gauge_label_show ? config.gauge_units : '');
         $$.arcs.select('.' + CLASS.chartArcsGaugeMin)
-            .attr("dx", -1 * ($$.innerRadius + (($$.radius - $$.innerRadius) / 2)) + "px")
+            .attr("dx", -1 * ($$.innerRadius + (($$.radius - $$.innerRadius) / (config.gauge_fullCircle ? 1 : 2))) + "px")
             .attr("dy", "1.2em")
             .text(config.gauge_label_show ? config.gauge_min : '');
         $$.arcs.select('.' + CLASS.chartArcsGaugeMax)
-            .attr("dx", $$.innerRadius + (($$.radius - $$.innerRadius) / 2) + "px")
+            .attr("dx", $$.innerRadius + (($$.radius - $$.innerRadius) / (config.gauge_fullCircle ? 1 : 2)) + "px")
             .attr("dy", "1.2em")
             .text(config.gauge_label_show ? config.gauge_max : '');
     }

src/config.js

@@ -173,10 +173,12 @@ c3_chart_internal_fn.getDefaultConfig = function () {
         pie_expand: {},
         pie_expand_duration: 50,
         // gauge
+        gauge_fullCircle: false,
         gauge_label_show: true,
         gauge_label_format: undefined,
         gauge_min: 0,
         gauge_max: 100,
+        gauge_startingAngle: -1 * Math.PI/2,
         gauge_units: undefined,
         gauge_width: undefined,
         gauge_expand: {},

src/core.js

@@ -419,7 +419,7 @@ c3_chart_internal_fn.updateSizes = function () {
     // for arc
     $$.arcWidth = $$.width - ($$.isLegendRight ? legendWidth + 10 : 0);
     $$.arcHeight = $$.height - ($$.isLegendRight ? 0 : 10);
-    if ($$.hasType('gauge')) {
+    if ($$.hasType('gauge') && !config.gauge_fullCircle) {
         $$.arcHeight += $$.height - $$.getGaugeLabelHeight();
     }
     if ($$.updateRadius) { $$.updateRadius(); }

src/size.js

@@ -5,7 +5,7 @@ c3_chart_internal_fn.getCurrentWidth = function () {
 c3_chart_internal_fn.getCurrentHeight = function () {
     var $$ = this, config = $$.config,
         h = config.size_height ? config.size_height : $$.getParentHeight();
-    return h > 0 ? h : 320 / ($$.hasType('gauge') ? 2 : 1);
+    return h > 0 ? h : 320 / ($$.hasType('gauge') && !config.gauge_fullCircle ? 2 : 1); 
 };
 c3_chart_internal_fn.getCurrentPaddingTop = function () {
     var $$ = this,