Use line-{width,cap,join} attributes in svg context

draw2d.go

@@ -128,6 +128,14 @@ const (
 	SquareCap
 )
 
+func (cap LineCap) String() string {
+	return map[LineCap]string{
+		RoundCap: "round",
+		ButtCap: "cap",
+		SquareCap: "square",
+	}[cap]
+}
+
 // LineJoin is the style of segments joint
 type LineJoin int
 
@@ -140,6 +148,14 @@ const (
 	MiterJoin
 )
 
+func (join LineJoin) String() string {
+	return map[LineJoin]string{
+		RoundJoin: "round",
+		BevelJoin: "bevel",
+		MiterJoin: "miter",
+	}[join]
+}
+
 // StrokeStyle keeps stroke style attributes
 // that is used by the Stroke method of a Drawer
 type StrokeStyle struct {

draw2dsvg/gc.go

@@ -76,9 +76,16 @@ func (gc *GraphicContext) drawPaths (drawType drawType, paths ...*draw2d.Path) {
 		svgPaths[i].Desc = toSvgPathDesc(path)
 		if drawType & stroked == stroked {
 			svgPaths[i].Stroke = toSvgRGBA(gc.Current.StrokeColor)
+			svgPaths[i].StrokeWidth = toSvgLength(gc.Current.LineWidth)
+			svgPaths[i].StrokeLinecap = gc.Current.Cap.String()
+			svgPaths[i].StrokeLinejoin = gc.Current.Join.String()
+		} else {
+			svgPaths[i].Stroke = "none"
 		}
 		if drawType & filled == filled {
 			svgPaths[i].Fill = toSvgRGBA(gc.Current.FillColor)
+		} else {
+			svgPaths[i].Fill = "none"
 		}
 	}
 
@@ -89,7 +96,11 @@ func (gc *GraphicContext) drawPaths (drawType drawType, paths ...*draw2d.Path) {
 
 func toSvgRGBA (c color.Color) string { // TODO move elsewhere
 	r, g, b, a := c.RGBA()
-	return fmt.Sprintf("rgba(%v, %v, %v, %v)", r>>8, g>>8, b>>8, float64(a>>8)/255)
+	return fmt.Sprintf("rgba(%v, %v, %v, %.3f)", r>>8, g>>8, b>>8, float64(a>>8)/255)
+}
+
+func toSvgLength (l float64) string {
+	return fmt.Sprintf("%.4f", l)
 }
 
 func toSvgPathDesc (p *draw2d.Path) string { // TODO move elsewhere

draw2dsvg/svg.go

@@ -39,4 +39,7 @@ type Text struct {
 type FillStroke struct {
 	Fill string `xml:"fill,attr,omitempty"`
 	Stroke string `xml:"stroke,attr,omitempty"`
+	StrokeWidth string `xml:"stroke-width,attr,omitempty"`
+	StrokeLinecap string `xml:"stroke-linecap,attr,omitempty"`
+	StrokeLinejoin string `xml:"stroke-linejoin,attr,omitempty"`
 }