1 files changed, 135 insertions, 0 deletions
diff --git a/Godeps/_workspace/src/code.google.com/p/draw2d/draw2d/stroker.go b/Godeps/_workspace/src/code.google.com/p/draw2d/draw2d/stroker.go
new file mode 100644
index 000000000..9331187f6
--- /dev/null
+++ b/Godeps/_workspace/src/code.google.com/p/draw2d/draw2d/stroker.go
@@ -0,0 +1,135 @@
+// Copyright 2010 The draw2d Authors. All rights reserved.
+// created: 13/12/2010 by Laurent Le Goff
+
+package draw2d
+
+type Cap int
+
+const (
+	RoundCap Cap = iota
+	ButtCap
+	SquareCap
+)
+
+type Join int
+
+const (
+	BevelJoin Join = iota
+	RoundJoin
+	MiterJoin
+)
+
+type LineStroker struct {
+	Next          VertexConverter
+	HalfLineWidth float64
+	Cap           Cap
+	Join          Join
+	vertices      []float64
+	rewind        []float64
+	x, y, nx, ny  float64
+	command       VertexCommand
+}
+
+func NewLineStroker(c Cap, j Join, converter VertexConverter) *LineStroker {
+	l := new(LineStroker)
+	l.Next = converter
+	l.HalfLineWidth = 0.5
+	l.vertices = make([]float64, 0, 256)
+	l.rewind = make([]float64, 0, 256)
+	l.Cap = c
+	l.Join = j
+	l.command = VertexNoCommand
+	return l
+}
+
+func (l *LineStroker) NextCommand(command VertexCommand) {
+	l.command = command
+	if command == VertexStopCommand {
+		l.Next.NextCommand(VertexStartCommand)
+		for i, j := 0, 1; j < len(l.vertices); i, j = i+2, j+2 {
+			l.Next.Vertex(l.vertices[i], l.vertices[j])
+			l.Next.NextCommand(VertexNoCommand)
+		}
+		for i, j := len(l.rewind)-2, len(l.rewind)-1; j > 0; i, j = i-2, j-2 {
+			l.Next.NextCommand(VertexNoCommand)
+			l.Next.Vertex(l.rewind[i], l.rewind[j])
+		}
+		if len(l.vertices) > 1 {
+			l.Next.NextCommand(VertexNoCommand)
+			l.Next.Vertex(l.vertices[0], l.vertices[1])
+		}
+		l.Next.NextCommand(VertexStopCommand)
+		// reinit vertices	
+		l.vertices = l.vertices[0:0]
+		l.rewind = l.rewind[0:0]
+		l.x, l.y, l.nx, l.ny = 0, 0, 0, 0
+	}
+}
+
+func (l *LineStroker) Vertex(x, y float64) {
+	switch l.command {
+	case VertexNoCommand:
+		l.line(l.x, l.y, x, y)
+	case VertexJoinCommand:
+		l.joinLine(l.x, l.y, l.nx, l.ny, x, y)
+	case VertexStartCommand:
+		l.x, l.y = x, y
+	case VertexCloseCommand:
+		l.line(l.x, l.y, x, y)
+		l.joinLine(l.x, l.y, l.nx, l.ny, x, y)
+		l.closePolygon()
+	}
+	l.command = VertexNoCommand
+}
+
+func (l *LineStroker) appendVertex(vertices ...float64) {
+	s := len(vertices) / 2
+	if len(l.vertices)+s >= cap(l.vertices) {
+		v := make([]float64, len(l.vertices), cap(l.vertices)+128)
+		copy(v, l.vertices)
+		l.vertices = v
+		v = make([]float64, len(l.rewind), cap(l.rewind)+128)
+		copy(v, l.rewind)
+		l.rewind = v
+	}
+
+	copy(l.vertices[len(l.vertices):len(l.vertices)+s], vertices[:s])
+	l.vertices = l.vertices[0 : len(l.vertices)+s]
+	copy(l.rewind[len(l.rewind):len(l.rewind)+s], vertices[s:])
+	l.rewind = l.rewind[0 : len(l.rewind)+s]
+
+}
+
+func (l *LineStroker) closePolygon() {
+	if len(l.vertices) > 1 {
+		l.appendVertex(l.vertices[0], l.vertices[1], l.rewind[0], l.rewind[1])
+	}
+}
+
+func (l *LineStroker) line(x1, y1, x2, y2 float64) {
+	dx := (x2 - x1)
+	dy := (y2 - y1)
+	d := vectorDistance(dx, dy)
+	if d != 0 {
+		nx := dy * l.HalfLineWidth / d
+		ny := -(dx * l.HalfLineWidth / d)
+		l.appendVertex(x1+nx, y1+ny, x2+nx, y2+ny, x1-nx, y1-ny, x2-nx, y2-ny)
+		l.x, l.y, l.nx, l.ny = x2, y2, nx, ny
+	}
+}
+
+func (l *LineStroker) joinLine(x1, y1, nx1, ny1, x2, y2 float64) {
+	dx := (x2 - x1)
+	dy := (y2 - y1)
+	d := vectorDistance(dx, dy)
+
+	if d != 0 {
+		nx := dy * l.HalfLineWidth / d
+		ny := -(dx * l.HalfLineWidth / d)
+		/*	l.join(x1, y1, x1 + nx, y1 - ny, nx, ny, x1 + ny2, y1 + nx2, nx2, ny2)
+			l.join(x1, y1, x1 - ny1, y1 - nx1, nx1, ny1, x1 - ny2, y1 - nx2, nx2, ny2)*/
+
+		l.appendVertex(x1+nx, y1+ny, x2+nx, y2+ny, x1-nx, y1-ny, x2-nx, y2-ny)
+		l.x, l.y, l.nx, l.ny = x2, y2, nx, ny
+	}
+}