flattener: Remove Close() from interface

The prior commit switched Close() to function correctly, but upon reflection it was decided that communicating this state was not likely to be useful.  Instead having the flattern handle the `LineTo` logic reduces the overall complexity and how often this must be handled.

Overall, this is much simpler.

chartdraw/drawing/dasher.go

@@ -32,11 +32,6 @@ func (dasher *DashVertexConverter) MoveTo(x, y float64) {
 	dasher.currentDash = 0
 }
 
-// Close implements the pathbuilder interface.
-func (dasher *DashVertexConverter) Close() {
-	dasher.next.Close()
-}
-
 // End implements the pathbuilder interface.
 func (dasher *DashVertexConverter) End() {
 	dasher.next.End()

chartdraw/drawing/demux_flattener.go

@@ -19,13 +19,6 @@ func (dc DemuxFlattener) LineTo(x, y float64) {
 	}
 }
 
-// Close implements the path builder interface.
-func (dc DemuxFlattener) Close() {
-	for _, flattener := range dc.Flatteners {
-		flattener.Close()
-	}
-}
-
 // End implements the path builder interface.
 func (dc DemuxFlattener) End() {
 	for _, flattener := range dc.Flatteners {

chartdraw/drawing/flattener.go

@@ -12,21 +12,22 @@ type Flattener interface {
 	MoveTo(x, y float64)
 	// LineTo Draw a line from the current position to the point (x, y)
 	LineTo(x, y float64)
-	// Close add the most recent starting point to close the path to create a polygon
-	Close()
 	// End mark the current line as finished so we can draw caps
 	End()
 }
 
 // Flatten convert curves into straight segments keeping join segments info
 func Flatten(path *Path, flattener Flattener, scale float64) {
+	// First Point
+	var startX, startY float64
 	// Current Point
 	var x, y float64
 	var i int
 	for _, cmp := range path.Components {
 		switch cmp {
 		case MoveToComponent:
 			x, y = path.Points[i], path.Points[i+1]
+			startX, startY = x, y
 			if i != 0 {
 				flattener.End()
 			}
@@ -52,23 +53,21 @@ func Flatten(path *Path, flattener Flattener, scale float64) {
 			flattener.LineTo(x, y)
 			i += 6
 		case CloseComponent:
-			flattener.Close()
+			if x != startX || y != startY {
+				flattener.LineTo(startX, startY)
+			}
 		}
 	}
 	flattener.End()
 }
 
 // SegmentedPath is a path of disparate point sections.
 type SegmentedPath struct {
-	startX float64
-	startY float64
 	Points []float64
 }
 
 // MoveTo implements the path interface.
 func (p *SegmentedPath) MoveTo(x, y float64) {
-	p.startX = x
-	p.startY = y
 	p.Points = append(p.Points, x, y)
 }
 
@@ -77,14 +76,6 @@ func (p *SegmentedPath) LineTo(x, y float64) {
 	p.Points = append(p.Points, x, y)
 }
 
-// Close implements the path interface.
-func (p *SegmentedPath) Close() {
-	pointLen := len(p.Points)
-	if pointLen > 1 && (p.Points[pointLen-2] != p.startX || p.Points[pointLen-1] != p.startY) {
-		p.Points = append(p.Points, p.startX, p.startY)
-	}
-}
-
 // End implements the path interface.
 func (p *SegmentedPath) End() {
 	// Nothing to do

chartdraw/drawing/free_type_path.go

@@ -7,27 +7,18 @@ import (
 
 // FtLineBuilder is a builder for freetype raster glyphs.
 type FtLineBuilder struct {
-	startX float64
-	startY float64
-	Adder  raster.Adder
+	Adder raster.Adder
 }
 
 // MoveTo implements the path builder interface.
-func (liner *FtLineBuilder) MoveTo(x, y float64) {
-	liner.startX = x
-	liner.startY = y
+func (liner FtLineBuilder) MoveTo(x, y float64) {
 	liner.Adder.Start(fixed.Point26_6{X: fixed.Int26_6(x * 64), Y: fixed.Int26_6(y * 64)})
 }
 
 // LineTo implements the path builder interface.
-func (liner *FtLineBuilder) LineTo(x, y float64) {
+func (liner FtLineBuilder) LineTo(x, y float64) {
 	liner.Adder.Add1(fixed.Point26_6{X: fixed.Int26_6(x * 64), Y: fixed.Int26_6(y * 64)})
 }
 
-// Close implements the path builder interface.
-func (liner *FtLineBuilder) Close() {
-	liner.LineTo(liner.startX, liner.startY)
-}
-
 // End implements the path builder interface.
-func (liner *FtLineBuilder) End() {}
+func (liner FtLineBuilder) End() {}

chartdraw/drawing/raster_graphic_context.go

@@ -226,7 +226,7 @@ func (rgc *RasterGraphicContext) Stroke(paths ...*Path) {
 
 	rgc.strokeRasterizer.UseNonZeroWinding = true
 
-	stroker := NewLineStroker(rgc.current.Cap, Transformer{Tr: rgc.current.Tr, Flattener: &FtLineBuilder{Adder: rgc.strokeRasterizer}})
+	stroker := NewLineStroker(rgc.current.Cap, Transformer{Tr: rgc.current.Tr, Flattener: FtLineBuilder{Adder: rgc.strokeRasterizer}})
 	stroker.HalfLineWidth = rgc.current.LineWidth / 2
 
 	var liner Flattener
@@ -298,7 +298,7 @@ func (rgc *RasterGraphicContext) Fill(paths ...*Path) {
 
 	rgc.fillRasterizer.UseNonZeroWinding = rgc.current.FillRule == FillRuleWinding
 
-	flattener := Transformer{Tr: rgc.current.Tr, Flattener: &FtLineBuilder{Adder: rgc.fillRasterizer}}
+	flattener := Transformer{Tr: rgc.current.Tr, Flattener: FtLineBuilder{Adder: rgc.fillRasterizer}}
 	for _, p := range paths {
 		Flatten(p, flattener, rgc.current.Tr.GetScale())
 	}
@@ -323,9 +323,9 @@ func (rgc *RasterGraphicContext) FillStroke(paths ...*Path) {
 	rgc.fillRasterizer.UseNonZeroWinding = rgc.current.FillRule == FillRuleWinding
 	rgc.strokeRasterizer.UseNonZeroWinding = true
 
-	flattener := Transformer{Tr: rgc.current.Tr, Flattener: &FtLineBuilder{Adder: rgc.fillRasterizer}}
+	flattener := Transformer{Tr: rgc.current.Tr, Flattener: FtLineBuilder{Adder: rgc.fillRasterizer}}
 
-	stroker := NewLineStroker(rgc.current.Cap, Transformer{Tr: rgc.current.Tr, Flattener: &FtLineBuilder{Adder: rgc.strokeRasterizer}})
+	stroker := NewLineStroker(rgc.current.Cap, Transformer{Tr: rgc.current.Tr, Flattener: FtLineBuilder{Adder: rgc.strokeRasterizer}})
 	stroker.HalfLineWidth = rgc.current.LineWidth / 2
 
 	var liner Flattener

chartdraw/drawing/stroker.go

@@ -44,13 +44,6 @@ func (l *LineStroker) line(x1, y1, x2, y2 float64) {
 	}
 }
 
-// Close implements the path builder interface.
-func (l *LineStroker) Close() {
-	if len(l.vertices) > 1 && (l.vertices[0] != l.rewind[0] || l.vertices[1] != l.rewind[1]) {
-		l.appendVertex(l.vertices[0], l.vertices[1], l.rewind[0], l.rewind[1])
-	}
-}
-
 // End implements the path builder interface.
 func (l *LineStroker) End() {
 	if len(l.vertices) > 1 {

chartdraw/drawing/transformer.go

@@ -23,11 +23,6 @@ func (t Transformer) LineTo(x, y float64) {
 	t.Flattener.LineTo(u, v)
 }
 
-// Close implements the path builder interface.
-func (t Transformer) Close() {
-	t.Flattener.Close()
-}
-
 // End implements the path builder interface.
 func (t Transformer) End() {
 	t.Flattener.End()