Basic path implementation

draw2dsvg/gc.go

@@ -4,9 +4,11 @@
 package draw2dsvg
 
 import (
+	"fmt"
 	"image"
-	"bytes"
 	"image/color"
+	"strings"
+	"bytes"
 	"github.com/llgcode/draw2d"
 	"github.com/llgcode/draw2d/draw2dbase"
 )
@@ -17,6 +19,12 @@ const (
 var (
 )
 
+type drawType int
+const (
+	filled drawType = 1 << iota
+	stroked
+)
+
 type SVG bytes.Buffer
 
 func NewSvg() *Svg {
@@ -35,76 +43,100 @@ func NewGraphicContext(svg *Svg) *GraphicContext {
 	return gc
 }
 
-// TODO implement all following methods
+// Clear fills the current canvas with a default transparent color
+func (gc *GraphicContext) Clear() {
+	gc.svg.Groups = nil
+	gc.svg.Groups = append(gc.svg.Groups, Group{
+		// TODO add background color?
+	})
+}
 
-// BeginPath creates a new path
+// Stroke strokes the paths with the color specified by SetStrokeColor
-func (gc *GraphicContext) BeginPath() {
+func (gc *GraphicContext) Stroke(paths ...*draw2d.Path) {
+	gc.drawPaths(stroked, paths...)
+	gc.Current.Path.Clear()
+}
+// Fill fills the paths with the color specified by SetFillColor
+func (gc *GraphicContext) Fill(paths ...*draw2d.Path) {
+	gc.drawPaths(filled, paths...)
+	gc.Current.Path.Clear()
+}
+// FillStroke first fills the paths and than strokes them
+func (gc *GraphicContext) FillStroke(paths ...*draw2d.Path) {
+	gc.drawPaths(filled | stroked, paths...)
+	gc.Current.Path.Clear()
+}
 
-}
+func (gc *GraphicContext) drawPaths (drawType drawType, paths ...*draw2d.Path) {
-// GetPath copies the current path, then returns it
+	paths = append(paths, gc.Current.Path)
-func (gc *GraphicContext) GetPath() draw2d.Path {
-	return draw2d.Path{}
-}
-// GetMatrixTransform returns the current transformation matrix
-func (gc *GraphicContext) GetMatrixTransform() draw2d.Matrix {
-	return draw2d.Matrix{}
-}
-// SetMatrixTransform sets the current transformation matrix
-func (gc *GraphicContext) SetMatrixTransform(tr draw2d.Matrix) {
 
-}
+	svgPaths := make([]Path, len(paths))
-// ComposeMatrixTransform composes the current transformation matrix with tr
-func (gc *GraphicContext) ComposeMatrixTransform(tr draw2d.Matrix) {
 
-}
+	for i, path := range paths {
-// Rotate applies a rotation to the current transformation matrix. angle is in radian.
+		svgPaths[i].Desc = toSvgPathDesc(path)
-func (gc *GraphicContext) Rotate(angle float64) {
+		if drawType & stroked == stroked {
+			svgPaths[i].Stroke = toSvgRGBA(gc.Current.StrokeColor)
+		}
+		if drawType & filled == filled {
+			svgPaths[i].Fill = toSvgRGBA(gc.Current.FillColor)
+		}
+	}
 
+	gc.svg.Groups = append(gc.svg.Groups, Group{
+		Paths: svgPaths,
+	})
 }
-// Translate applies a translation to the current transformation matrix.
-func (gc *GraphicContext) Translate(tx, ty float64) {
 
+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)
 }
-// Scale applies a scale to the current transformation matrix.
-func (gc *GraphicContext) Scale(sx, sy float64) {
 
+func toSvgPathDesc (p *draw2d.Path) string { // TODO move elsewhere
+	parts := make([]string, len(p.Components))
+	i := 0
+	for j, cmp := range p.Components {
+		switch cmp {
+		case draw2d.MoveToCmp:
+			parts[j] = fmt.Sprintf("M %v %v", p.Points[i], p.Points[i+1])
+			i += 2
+		case draw2d.LineToCmp:
+			parts[j] = fmt.Sprintf("L %v %v", p.Points[i], p.Points[i+1])
+			i += 2
+		case draw2d.QuadCurveToCmp:
+			parts[j] = fmt.Sprintf("Q %v %v %v %v", p.Points[i], p.Points[i+1], p.Points[i+2], p.Points[i+3])
+			i += 4
+		case draw2d.CubicCurveToCmp:
+			parts[j] = fmt.Sprintf("C %v %v %v %v %v %v", p.Points[i], p.Points[i+1], p.Points[i+2], p.Points[i+3], p.Points[i+4], p.Points[i+5])
+			i += 6
+		case draw2d.ArcToCmp:
+			large := 0
+			sweep := 0
+			if p.Points[i+4] - p.Points[i+5] > 0 { // TODO this is probably not correct
+				large = 1
+				sweep = 1
+			}
+			// rx ry x-axis-rotation large-arc-flag sweep-flag x y
+			parts[j] = fmt.Sprintf("A %v %v %v %v %v %v %v",
+				p.Points[i+2], // rx
+				p.Points[i+3], // ry
+				0, // x-axis-rotation
+				large, // large-arc-flag
+				sweep, // // sweep-flag
+				p.Points[i], // x // TODO this is center of arc not an endpont
+				p.Points[i+1], // y // TODO -//-
+			)
+			i += 6
+		case draw2d.CloseCmp:
+			parts[j] = "Z"
+		}
+	}
+	println("parts", parts)
+	return strings.Join(parts, " ")
 }
-// SetStrokeColor sets the current stroke color
+///////////////////////////////////////
-func (gc *GraphicContext) SetStrokeColor(c color.Color) {
+// TODO implement following methods (or remove if not neccesary)
 
-}
-// SetFillColor sets the current fill color
-func (gc *GraphicContext) SetFillColor(c color.Color) {
-
-}
-// SetFillRule sets the current fill rule
-func (gc *GraphicContext) SetFillRule(f draw2d.FillRule) {
-
-}
-// SetLineWidth sets the current line width
-func (gc *GraphicContext) SetLineWidth(lineWidth float64) {
-
-}
-// SetLineCap sets the current line cap
-func (gc *GraphicContext) SetLineCap(cap draw2d.LineCap) {
-
-}
-// SetLineJoin sets the current line join
-func (gc *GraphicContext) SetLineJoin(join draw2d.LineJoin) {
-
-}
-// SetLineDash sets the current dash
-func (gc *GraphicContext) SetLineDash(dash []float64, dashOffset float64) {
-
-}
-// SetFontSize sets the current font size
-func (gc *GraphicContext) SetFontSize(fontSize float64) {
-
-}
-// GetFontSize gets the current font size
-func (gc *GraphicContext) GetFontSize() float64 {
-	return 0
-}
 // SetFontData sets the current FontData
 func (gc *GraphicContext) SetFontData(fontData draw2d.FontData) {
 
@@ -128,10 +160,6 @@ func (gc *GraphicContext) Save() {
 // Restore remove the current context and restore the last one
 func (gc *GraphicContext) Restore() {
 
-}
-// Clear fills the current canvas with a default transparent color
-func (gc *GraphicContext) Clear() {
-
 }
 // ClearRect fills the specified rectangle with a default transparent color
 func (gc *GraphicContext) ClearRect(x1, y1, x2, y2 int) {
@@ -169,15 +197,3 @@ func (gc *GraphicContext) StrokeString(text string) (cursor float64) {
 func (gc *GraphicContext) StrokeStringAt(text string, x, y float64) (cursor float64) {
 	return 0
 }
-// Stroke strokes the paths with the color specified by SetStrokeColor
-func (gc *GraphicContext) Stroke(paths ...*draw2d.Path) {
-
-}
-// Fill fills the paths with the color specified by SetFillColor
-func (gc *GraphicContext) Fill(paths ...*draw2d.Path) {
-
-}
-// FillStroke first fills the paths and than strokes them
-func (gc *GraphicContext) FillStroke(paths ...*draw2d.Path) {
-
-}

draw2dsvg/svg.go

@@ -7,6 +7,8 @@ import (
 	"encoding/xml"
 )
 
+/* svg elements */
+
 type Svg struct {
 	XMLName xml.Name `xml:"svg"`
 	Xmlns string `xml:"xmlns,attr"`
@@ -14,16 +16,27 @@ type Svg struct {
 }
 
 type Group struct {
+	FillStroke
 	Groups []Group `xml:"g"`
 	Paths []Path `xml:"path"`
 	Texts []Text `xml:"text"`
 }
 
 type Path struct {
-	Data string `xml:"d,attr"`
+	FillStroke
+	Desc string `xml:"d,attr"`
 }
 
 type Text struct {
+	FillStroke
 	Text string `xml:",innerxml"`
 	Style string `xml:",attr,omitempty"`
+}
+
+
+/* shared attrs */
+
+type FillStroke struct {
+	Fill string `xml:"fill,attr,omitempty"`
+	Stroke string `xml:"stroke,attr,omitempty"`
 }

draw2dsvg/xml_test.go

@@ -13,7 +13,7 @@ import (
 
 // Test basic encoding of svg/xml elements
 func TestXml(t *testing.T) {
-	
+
 	svg := NewSvg()
 	svg.Groups = []Group{Group{
 		Groups: []Group{
@@ -25,7 +25,7 @@ func TestXml(t *testing.T) {
 			Text{Text: "world", Style: "opacity: 0.5"}, // text with style
 		},
 		Paths: []Path{
-			Path{Data: "M100,200 C100,100 250,100 250,200 S400,300 400,200"}, // simple path
+			Path{Desc: "M100,200 C100,100 250,100 250,200 S400,300 400,200"}, // simple path
 			Path{}, // empty path
 		},
 	}}