first commit

1 files changed, 36 insertions, 0 deletions

diff --git a/Godeps/_workspace/src/code.google.com/p/draw2d/draw2d/curve/arc.go b/Godeps/_workspace/src/code.google.com/p/draw2d/draw2d/curve/arc.go
new file mode 100644
index 000000000..92850e979
--- /dev/null
+++ b/Godeps/_workspace/src/code.google.com/p/draw2d/draw2d/curve/arc.go
@@ -0,0 +1,36 @@
+// Copyright 2010 The draw2d Authors. All rights reserved.
+// created: 21/11/2010 by Laurent Le Goff
+package curve
+
+import (
+	"math"
+)
+
+func SegmentArc(t LineTracer, x, y, rx, ry, start, angle, scale float64) {
+	end := start + angle
+	clockWise := true
+	if angle < 0 {
+		clockWise = false
+	}
+	ra := (math.Abs(rx) + math.Abs(ry)) / 2
+	da := math.Acos(ra/(ra+0.125/scale)) * 2
+	//normalize
+	if !clockWise {
+		da = -da
+	}
+	angle = start + da
+	var curX, curY float64
+	for {
+		if (angle < end-da/4) != clockWise {
+			curX = x + math.Cos(end)*rx
+			curY = y + math.Sin(end)*ry
+			break;
+		}
+		curX = x + math.Cos(angle)*rx
+		curY = y + math.Sin(angle)*ry
+
+		angle += da
+		t.LineTo(curX, curY)
+	}
+	t.LineTo(curX, curY)
+}