graph/layout: reduce code duplication in layout tests

graph/layout/eades_example_test.go

@@ -1,4 +1,4 @@
-// Copyright ©2021 The Gonum Authors. All rights reserved.
+// Copyright ©2019 The Gonum Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file
 

graph/layout/eades_test.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package layout
+package layout_test
 
 import (
 	"path/filepath"
@@ -15,6 +15,8 @@ import (
 	"gonum.org/v1/gonum/spatial/r2"
 	"gonum.org/v1/plot"
 	"gonum.org/v1/plot/vg"
+
+	. "gonum.org/v1/gonum/graph/layout"
 )
 
 var eadesR2Tests = []struct {

graph/layout/isomap_386_test.go

@@ -4,7 +4,7 @@
 
 // +build 386
 
-package layout
+package layout_test
 
 // Change the testdata path for calculations done on 386.
 func init() {

graph/layout/isomap_arm64_test.go

@@ -4,7 +4,7 @@
 
 // +build arm64
 
-package layout
+package layout_test
 
 // Change the testdata path for calculations done on arm64.
 func init() {

graph/layout/isomap_noasm_test.go

@@ -4,7 +4,7 @@
 
 // +build noasm gccgo safe
 
-package layout
+package layout_test
 
 // Change the testdata path for calculations done without assembly kernels.
 func init() {

graph/layout/isomap_test.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package layout
+package layout_test
 
 import (
 	"path/filepath"
@@ -13,6 +13,8 @@ import (
 	"gonum.org/v1/gonum/spatial/r2"
 	"gonum.org/v1/plot"
 	"gonum.org/v1/plot/vg"
+
+	. "gonum.org/v1/gonum/graph/layout"
 )
 
 var (

graph/layout/layout_test.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package layout
+package layout_test
 
 import (
 	"bytes"

graph/layout/plotter_test.go

@@ -1,145 +0,0 @@
-// Copyright ©2019 The Gonum Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package layout
-
-import (
-	"fmt"
-	"image/color"
-	"math"
-
-	"gonum.org/v1/plot"
-	"gonum.org/v1/plot/plotter"
-	"gonum.org/v1/plot/vg"
-	"gonum.org/v1/plot/vg/draw"
-)
-
-const radius = vg.Length(15)
-
-// render implements the plot.Plotter interface for graphs.
-type render struct {
-	GraphR2
-}
-
-func (p render) Plot(c draw.Canvas, plt *plot.Plot) {
-	nodes := p.GraphR2.Nodes()
-	if nodes.Len() == 0 {
-		return
-	}
-	var (
-		xys plotter.XYs
-		ids []string
-	)
-	if nodes.Len() >= 0 {
-		xys = make(plotter.XYs, 0, nodes.Len())
-		ids = make([]string, 0, nodes.Len())
-	}
-	for nodes.Next() {
-		u := nodes.Node()
-		uid := u.ID()
-		ur2 := p.GraphR2.LayoutNodeR2(uid)
-		xys = append(xys, plotter.XY(ur2.Coord2))
-		ids = append(ids, fmt.Sprint(uid))
-		to := p.GraphR2.From(uid)
-		for to.Next() {
-			v := to.Node()
-			vid := v.ID()
-			vr2 := p.GraphR2.LayoutNodeR2(vid)
-
-			l, err := plotter.NewLine(plotter.XYs{plotter.XY(ur2.Coord2), plotter.XY(vr2.Coord2)})
-			if err != nil {
-				panic(err)
-			}
-			l.Plot(c, plt)
-			if err != nil {
-				panic(err)
-			}
-		}
-	}
-
-	n, err := plotter.NewScatter(xys)
-	if err != nil {
-		panic(err)
-	}
-	n.GlyphStyle.Shape = nodeGlyph{}
-	n.GlyphStyle.Radius = radius
-	n.Plot(c, plt)
-
-	l, err := plotter.NewLabels(plotter.XYLabels{XYs: xys, Labels: ids})
-	if err != nil {
-		panic(err)
-	}
-	fnt, err := vg.MakeFont(plot.DefaultFont, vg.Points(18))
-	if err != nil {
-		panic(err)
-	}
-	for i := range l.TextStyle {
-		l.TextStyle[i] = draw.TextStyle{Font: fnt, XAlign: draw.XCenter, YAlign: -0.25}
-	}
-
-	l.Plot(c, plt)
-}
-
-// DataRange returns the minimum and maximum X and Y values
-func (p render) DataRange() (xmin, xmax, ymin, ymax float64) {
-	nodes := p.GraphR2.Nodes()
-	if nodes.Len() == 0 {
-		return
-	}
-	var xys plotter.XYs
-	if nodes.Len() >= 0 {
-		xys = make(plotter.XYs, 0, nodes.Len())
-	}
-	for nodes.Next() {
-		u := nodes.Node()
-		uid := u.ID()
-		ur2 := p.GraphR2.LayoutNodeR2(uid)
-		xys = append(xys, plotter.XY(ur2.Coord2))
-	}
-	return plotter.XYRange(xys)
-}
-
-// GlyphBoxes returns a slice of plot.GlyphBoxes, implementing the
-// plot.GlyphBoxer interface.
-func (p render) GlyphBoxes(plt *plot.Plot) []plot.GlyphBox {
-	nodes := p.GraphR2.Nodes()
-	if nodes.Len() == 0 {
-		return nil
-	}
-	var b []plot.GlyphBox
-	if nodes.Len() >= 0 {
-		b = make([]plot.GlyphBox, 0, nodes.Len())
-	}
-	for i := 0; nodes.Next(); i++ {
-		u := nodes.Node()
-		uid := u.ID()
-		ur2 := p.GraphR2.LayoutNodeR2(uid)
-
-		b = append(b, plot.GlyphBox{})
-		b[i].X = plt.X.Norm(ur2.Coord2.X)
-		b[i].Y = plt.Y.Norm(ur2.Coord2.Y)
-		r := radius
-		b[i].Rectangle = vg.Rectangle{
-			Min: vg.Point{X: -r, Y: -r},
-			Max: vg.Point{X: +r, Y: +r},
-		}
-	}
-	return b
-}
-
-// nodeGlyph is a glyph that draws a filled circle.
-type nodeGlyph struct{}
-
-// DrawGlyph implements the GlyphDrawer interface.
-func (nodeGlyph) DrawGlyph(c *draw.Canvas, sty draw.GlyphStyle, pt vg.Point) {
-	var p vg.Path
-	c.Push()
-	c.SetColor(color.White)
-	p.Move(vg.Point{X: pt.X + sty.Radius, Y: pt.Y})
-	p.Arc(pt, sty.Radius, 0, 2*math.Pi)
-	p.Close()
-	c.Fill(p)
-	c.Pop()
-	c.Stroke(p)
-}