Playing around with SVG

utils/SVGPieChartPath.go

@@ -0,0 +1,27 @@
+package utils
+
+import (
+	"fmt"
+	"math"
+)
+
+// coords returns the coordinates for the given percentage.
+func coords(percent float64) (float64, float64) {
+	x := math.Cos(2 * math.Pi * percent)
+	y := math.Sin(2 * math.Pi * percent)
+	return x, y
+}
+
+// SVGSlicePath creates a path string for a slice in a pie chart.
+func SVGSlicePath(from float64, to float64) string {
+	x1, y1 := coords(from)
+	x2, y2 := coords(to)
+
+	largeArc := "0"
+
+	if to-from > 0.5 {
+		largeArc = "1"
+	}
+
+	return fmt.Sprintf("M %.2f %.2f A 1 1 0 %s 1 %.2f %.2f L 0 0", x1, y1, largeArc, x2, y2)
+}