1 files changed, 55 insertions, 0 deletions
diff --git a/Godeps/_workspace/src/code.google.com/p/draw2d/draw2d/raster/line.go b/Godeps/_workspace/src/code.google.com/p/draw2d/draw2d/raster/line.go
new file mode 100644
index 000000000..6f6d8863f
--- /dev/null
+++ b/Godeps/_workspace/src/code.google.com/p/draw2d/draw2d/raster/line.go
@@ -0,0 +1,55 @@
+// Copyright 2011 The draw2d Authors. All rights reserved.
+// created: 27/05/2011 by Laurent Le Goff
+package raster
+
+import (
+	"image/color"
+	"image/draw"
+)
+
+func abs(i int) int {
+	if i < 0 {
+		return -i
+	}
+	return i
+}
+
+func PolylineBresenham(img draw.Image, c color.Color, s ...float64) {
+	for i := 2; i < len(s); i += 2 {
+		Bresenham(img, c, int(s[i-2]+0.5), int(s[i-1]+0.5), int(s[i]+0.5), int(s[i+1]+0.5))
+	}
+}
+
+func Bresenham(img draw.Image, color color.Color, x0, y0, x1, y1 int) {
+	dx := abs(x1 - x0)
+	dy := abs(y1 - y0)
+	var sx, sy int
+	if x0 < x1 {
+		sx = 1
+	} else {
+		sx = -1
+	}
+	if y0 < y1 {
+		sy = 1
+	} else {
+		sy = -1
+	}
+	err := dx - dy
+
+	var e2 int
+	for {
+		img.Set(x0, y0, color)
+		if x0 == x1 && y0 == y1 {
+			return
+		}
+		e2 = 2 * err
+		if e2 > -dy {
+			err = err - dy
+			x0 = x0 + sx
+		}
+		if e2 < dx {
+			err = err + dx
+			y0 = y0 + sy
+		}
+	}
+}