Merge pull request 'Refactor line styling' (#7) from line_styling into master

.golangci.yml

@@ -6,10 +6,9 @@ linters:
     - nlreturn          # covered by wsl cuddle rules
     - nonamedreturns    # named returns are accepted
     - mnd
-    - gomnd
     # deprecated
     - exhaustruct
-    - execinquery
+    - tenv
 
 severity:
   default-severity: major

pkg/pattern/path/path.go

@@ -2,33 +2,25 @@
 package path
 
 import (
-	"image/color"
-
 	"git.wtrh.nl/patterns/gopatterns/pkg/pattern/point"
 	"github.com/tdewolff/canvas"
 )
 
 // Path defines a set of straight lines through points.
 type Path struct {
-	points    []point.Point
-	thickness float64
-	color     color.RGBA
+	points []point.Point
+	style  Style
 }
 
 // NewPath returns a new [Path].
-func NewPath(points ...point.Point) *Path {
-	black := canvas.Black
-	return &Path{points: points, color: black, thickness: 0.2}
-}
-
-// NewPathWithStyle returns a new [Path] with the specified thickness and color.
-func NewPathWithStyle(thickness float64, color color.RGBA, points ...point.Point) Path {
-	return Path{points: points, color: color, thickness: thickness}
+func NewPath(points []point.Point, style Style) *Path {
+	return &Path{points: points, style: style}
 }
 
-// SetThickness updates the tickness of the line
-func (p *Path) SetThickness(thickness float64) {
-	p.thickness = thickness
+// WithStyle updates the style of the Path.
+func (p *Path) WithStyle(Style Style) *Path {
+	p.style = Style
+	return p
 }
 
 // Draw the path to the provided [canvas.Canvas].
@@ -38,17 +30,7 @@ func (p *Path) Draw(c *canvas.Canvas) error {
 		polyline.Add(next.Vector().Values())
 	}
 
-	c.RenderPath(polyline.ToPath(),
-		canvas.Style{
-			Fill:         canvas.Paint{},
-			Stroke:       canvas.Paint{Color: p.color},
-			StrokeWidth:  p.thickness,
-			StrokeCapper: canvas.RoundCap,
-			StrokeJoiner: canvas.BevelJoin,
-			DashOffset:   0,
-			Dashes:       nil,
-			FillRule:     0,
-		}, canvas.Identity)
+	c.RenderPath(polyline.ToPath(), p.style.ToCanvas(), canvas.Identity)
 
 	return nil
 }

pkg/pattern/path/splines.go

@@ -2,7 +2,6 @@ package path
 
 import (
 	"fmt"
-
 	"git.wtrh.nl/patterns/gopatterns/pkg/pattern/point"
 	"github.com/tdewolff/canvas"
 	splines "gitlab.com/Achilleshiel/gosplines"
@@ -16,42 +15,48 @@ type Spline struct {
 	start, end point.Point
 }
 
+type SplineOpts struct {
+	Start, End point.Point
+	Points     []point.Point
+	Style      Style
+}
+
 // NewSpline returns a new spline through points. Start and end points can be provided as
 // the start and stop direction of the spline. When start or end point arguments are left nil there
 // are no constraints on the direction.
-func NewSpline(start, end point.Point, points ...point.Point) Spline {
+func NewSpline(opts SplineOpts) Spline {
 	s := Spline{
-		Path:  NewPath(points...),
-		start: start,
-		end:   end,
+		Path:  NewPath(opts.Points, opts.Style),
+		start: opts.Start,
+		end:   opts.End,
 	}
 
-	if start == nil && len(points) > 1 {
-		s.start = points[0]
+	if opts.Start == nil && len(opts.Points) > 1 {
+		s.start = opts.Points[0]
 	}
 
-	if end == nil && len(points) > 1 {
-		s.end = points[len(points)-1]
+	if opts.End == nil && len(opts.Points) > 1 {
+		s.end = opts.Points[len(opts.Points)-1]
 	}
 
 	return s
 }
 
 // Draw the spline to the provided [canvas.Canvas].
-func (p Spline) Draw(c *canvas.Canvas) error {
-	if len(p.points) < 2 {
+func (s Spline) Draw(c *canvas.Canvas) error {
+	if len(s.points) < 2 {
 		return nil
 	}
 
-	x := make([]float64, len(p.points))
-	y := make([]float64, len(p.points))
+	x := make([]float64, len(s.points))
+	y := make([]float64, len(s.points))
 
-	for i, point := range p.points {
-		x[i], y[i] = point.Vector().Values()
+	for i, p := range s.points {
+		x[i], y[i] = p.Vector().Values()
 	}
 
-	diffStart := p.start.Vector().Subtract(p.points[0].Vector())
-	diffEnd := p.points[len(p.points)-1].Vector().Subtract(p.end.Vector())
+	diffStart := s.start.Vector().Subtract(s.points[0].Vector())
+	diffEnd := s.points[len(s.points)-1].Vector().Subtract(s.end.Vector())
 
 	xCoefficient, err := splines.SolveSplineWithConstraint(x, diffStart.X, diffEnd.X)
 	if err != nil {
@@ -66,8 +71,8 @@ func (p Spline) Draw(c *canvas.Canvas) error {
 	points := make([]point.Point, 0, len(x)*resolution)
 	stepSize := 1.0 / float64(resolution-1)
 
-	for i := range len(p.points) - 1 {
-		points = append(points, p.points[i])
+	for i := range len(s.points) - 1 {
+		points = append(points, s.points[i])
 
 		for t := stepSize; t < 1.0; t += stepSize {
 			xCalculated := xCoefficient[i].Calculate(t)
@@ -76,10 +81,9 @@ func (p Spline) Draw(c *canvas.Canvas) error {
 		}
 	}
 
-	points = append(points, p.points[len(p.points)-1])
+	points = append(points, s.points[len(s.points)-1])
 
-	path := NewPath(points...)
-	path.SetThickness(p.thickness)
+	path := NewPath(points, s.style)
 
 	if err = path.Draw(c); err != nil {
 		return fmt.Errorf("draw spline points to canvas: %w", err)

pkg/pattern/path/style.go

@@ -0,0 +1,33 @@
+package path
+
+import (
+	"image/color"
+
+	"github.com/tdewolff/canvas"
+)
+
+type Style struct {
+	Thickness float64
+	Color     color.RGBA
+	Dashes    []float64
+}
+
+func (s Style) ToCanvas() canvas.Style {
+	return canvas.Style{
+		Fill:         canvas.Paint{},
+		Stroke:       canvas.Paint{Color: s.Color},
+		StrokeWidth:  s.Thickness,
+		StrokeCapper: canvas.RoundCap,
+		StrokeJoiner: canvas.BevelJoin,
+		DashOffset:   0,
+		Dashes:       s.Dashes,
+		FillRule:     0,
+	}
+}
+
+func NewDefaultStyle() Style {
+	return Style{
+		Thickness: 0.2,
+		Color:     canvas.Black,
+	}
+}

pkg/pattern/pattern.go

@@ -11,7 +11,7 @@ import (
 	"gopkg.in/Knetic/govaluate.v3"
 )
 
-// Pattern contains all the points, lines and dimensions to draw a pattern to a canvas.
+// The Pattern contains all the points, lines and dimensions to draw a pattern to a canvas.
 type Pattern struct {
 	points     map[point.ID]point.Point
 	lines      []pathDrawer
@@ -34,7 +34,7 @@ func (p *Pattern) AddLine(line pathDrawer) {
 }
 
 // GetPoints returns a slice with points for the given IDs.
-func (p *Pattern) GetPoints(id ...point.ID) []point.Point {
+func (p *Pattern) GetPoints(id []point.ID) []point.Point {
 	points := make([]point.Point, 0, len(id))
 	for _, i := range id {
 		points = append(points, p.GetPoint(i))

pkg/pattern/template/line.go

@@ -28,29 +28,29 @@ type Curve struct {
 
 // Build adds the line to the provided [pattern.Pattern].
 func (l Line) Build(pat *pattern.Pattern) error {
-	points := pat.GetPoints(l.Through...)
+	points := pat.GetPoints(l.Through)
 	for _, p := range points {
 		p.SetDraw()
 	}
 
-	switch {
-	case l.Curve != nil:
-		startPoint := pat.GetPoint(l.Curve.Start)
-		endPoint := pat.GetPoint(l.Curve.End)
-		spline := path.NewSpline(startPoint, endPoint, points...)
+	style := path.NewDefaultStyle()
 
-		if l.Style != nil && l.Style.Thickness != nil {
-			spline.SetThickness(*l.Style.Thickness)
-		}
+	if l.Style != nil && l.Style.Thickness != nil {
+		style.Thickness = *l.Style.Thickness
+	}
 
-		pat.AddLine(spline)
+	switch {
+	case l.Curve != nil:
+		pat.AddLine(
+			path.NewSpline(path.SplineOpts{
+				Start:  pat.GetPoint(l.Curve.Start),
+				End:    pat.GetPoint(l.Curve.End),
+				Points: points,
+				Style:  style,
+			}),
+		)
 	default:
-		newPath := path.NewPath(points...)
-		if l.Style != nil && l.Style.Thickness != nil {
-			newPath.SetThickness(*l.Style.Thickness)
-		}
-
-		pat.AddLine(newPath)
+		pat.AddLine(path.NewPath(points, style))
 	}
 
 	return nil