all: remove descent padding from horizontal axis

axis.go

@@ -235,7 +235,6 @@ type horizontalAxis struct {
 // size returns the height of the axis.
 func (a horizontalAxis) size() (h vg.Length) {
 	if a.Label.Text != "" { // We assume that the label isn't rotated.
-		h += a.Label.TextStyle.FontExtents().Descent
 		h += a.Label.TextStyle.Height(a.Label.Text)
 		h += a.Label.Padding
 	}

cmpimg/checkplot.go

@@ -29,6 +29,8 @@ func goldenPath(path string) string {
 // For image.Image formats, a base64 encoded png representation is output to
 // the testing log when a difference is identified.
 func CheckPlot(ExampleFunc func(), t *testing.T, filenames ...string) {
+	t.Helper()
+
 	CheckPlotApprox(ExampleFunc, t, 0, filenames...)
 }
 

palette/moreland/convert.go

@@ -17,9 +17,9 @@ type rgb struct {
 // cieXYZ returns a CIE XYZ color representation of the receiver.
 func (c rgb) cieXYZ() cieXYZ {
 	return cieXYZ{
-		X: 0.4124*c.R + 0.3576*c.G + 0.1805*c.B,
-		Y: 0.2126*c.R + 0.7152*c.G + 0.0722*c.B,
-		Z: 0.0193*c.R + 0.1192*c.G + 0.9505*c.B,
+		X: float64(0.4124*c.R) + float64(0.3576*c.G) + float64(0.1805*c.B),
+		Y: float64(0.2126*c.R) + float64(0.7152*c.G) + float64(0.0722*c.B),
+		Z: float64(0.0193*c.R) + float64(0.1192*c.G) + float64(0.9505*c.B),
 	}
 }
 
@@ -29,7 +29,7 @@ func (c rgb) sRGBA(alpha float64) sRGBA {
 	// f converts from a linear RGB component to an sRGB component.
 	f := func(v float64) float64 {
 		if v > 0.0031308 {
-			return 1.055*math.Pow(v, 1/2.4) - 0.055
+			return float64(1.055*math.Pow(v, 1/2.4)) - 0.055
 		}
 		return 12.92 * v
 	}
@@ -51,9 +51,9 @@ type cieXYZ struct {
 // rgb returns a linear RGB representation of the receiver.
 func (c cieXYZ) rgb() rgb {
 	return rgb{
-		R: c.X*3.2406 + c.Y*-1.5372 + c.Z*-0.4986,
-		G: c.X*-0.9689 + c.Y*1.8758 + c.Z*0.0415,
-		B: c.X*0.0557 + c.Y*-0.204 + c.Z*1.057,
+		R: float64(c.X*3.2406) + float64(c.Y*-1.5372) + float64(c.Z*-0.4986),
+		G: float64(c.X*-0.9689) + float64(c.Y*1.8758) + float64(c.Z*0.0415),
+		B: float64(c.X*0.0557) + float64(c.Y*-0.204) + float64(c.Z*1.057),
 	}
 }
 
@@ -64,14 +64,14 @@ func (c cieXYZ) cieLAB() cieLAB {
 		if v > 0.008856 {
 			return math.Pow(v, 1.0/3.0)
 		}
-		return 7.787*v + 16.0/116.0
+		return float64(7.787*v) + float64(16.0/116.0)
 	}
 
 	tempX := f(c.X / 0.9505)
 	tempY := f(c.Y)
 	tempZ := f(c.Z / 1.089)
 	return cieLAB{
-		L: (116.0 * tempY) - 16.0,
+		L: float64(116.0*tempY) - 16.0,
 		A: 500.0 * (tempX - tempY),
 		B: 200 * (tempY - tempZ),
 	}

palette/moreland/luminance.go

@@ -95,9 +95,9 @@ func (l *luminance) At(v float64) (color.Color, error) {
 	c2 := l.colors[i]
 	frac := (scalar - l.scalars[i-1]) / (l.scalars[i] - l.scalars[i-1])
 	o := cieLAB{
-		L: frac*(c2.L-c1.L) + c1.L,
-		A: frac*(c2.A-c1.A) + c1.A,
-		B: frac*(c2.B-c1.B) + c1.B,
+		L: float64(frac*(c2.L-c1.L)) + float64(c1.L),
+		A: float64(frac*(c2.A-c1.A)) + float64(c1.A),
+		B: float64(frac*(c2.B-c1.B)) + float64(c1.B),
 	}.cieXYZ().rgb().sRGBA(l.alpha)
 	o.clamp()
 	return o, nil
@@ -179,7 +179,7 @@ func (l luminance) Palette(n int) palette.Palette {
 	var v float64
 	c := make([]color.Color, n)
 	for i := 0; i < n; i++ {
-		v = l.min + delta*float64(i)
+		v = l.min + float64(delta*float64(i))
 		var err error
 		c[i], err = l.At(v)
 		if err != nil {

palette/moreland/smooth.go

@@ -145,20 +145,20 @@ func (p *smoothDiverging) interpolateMSHDiverging(scalar, convergePoint float64)
 		// interpolation factor
 		interp := scalar / convergePoint
 		return msh{
-			M: (p.convergeM-p.start.M)*interp + p.start.M,
+			M: float64((p.convergeM-p.start.M)*interp) + p.start.M,
 			S: p.start.S * (1 - interp),
-			H: p.start.H + startHTwist*interp,
+			H: p.start.H + float64(startHTwist*interp),
 		}
 	}
 	// interpolation factors
 	interp1 := (scalar - 1) / (convergePoint - 1)
 	interp2 := (scalar/convergePoint - 1)
 	var H float64
 	if scalar > convergePoint {
-		H = p.end.H + endHTwist*interp1
+		H = p.end.H + float64(endHTwist*interp1)
 	}
 	return msh{
-		M: (p.convergeM-p.end.M)*interp1 + p.end.M,
+		M: float64((p.convergeM-p.end.M)*interp1) + p.end.M,
 		S: p.end.S * interp2,
 		H: H,
 	}
@@ -173,7 +173,7 @@ func (p smoothDiverging) Palette(n int) palette.Palette {
 	delta := (p.max - p.min) / float64(n-1)
 	c := make([]color.Color, n)
 	for i := range c {
-		v := p.min + delta*float64(i)
+		v := p.min + float64(delta*float64(i))
 		var err error
 		c[i], err = p.At(v)
 		if err != nil {

plot_test.go

@@ -10,6 +10,7 @@ import (
 	"image/color"
 	"math"
 	"os"
+	"runtime"
 	"testing"
 	"time"
 
@@ -182,9 +183,9 @@ func TestDrawGlyphBoxes(t *testing.T) {
 			t.Fatalf("error: %+v", err)
 		}
 
-		err = os.WriteFile("testdata/glyphbox.png", buf.Bytes(), 0644)
+		err = os.WriteFile("testdata/glyphbox_"+runtime.GOARCH+".png", buf.Bytes(), 0644)
 		if err != nil {
 			t.Fatalf("could not save plot: %+v", err)
 		}
-	}, t, "glyphbox.png")
+	}, t, "glyphbox_"+runtime.GOARCH+".png")
 }

plotter/barchart_example_test.go

@@ -7,6 +7,7 @@ package plotter_test
 import (
 	"image/color"
 	"log"
+	"runtime"
 
 	"golang.org/x/exp/rand"
 
@@ -43,7 +44,7 @@ func ExampleBarChart() {
 	}
 	p2.Add(horizontalBarChart)
 	p2.NominalY(horizontalLabels...)
-	err = p2.Save(100, 100, "testdata/horizontalBarChart.png")
+	err = p2.Save(100, 100, "testdata/horizontalBarChart_"+runtime.GOARCH+".png")
 	if err != nil {
 		log.Panic(err)
 	}

plotter/barchart_test.go

@@ -5,14 +5,15 @@
 package plotter_test
 
 import (
+	"runtime"
 	"testing"
 
 	"gonum.org/v1/plot/cmpimg"
 )
 
 func TestBarChart(t *testing.T) {
 	cmpimg.CheckPlot(ExampleBarChart, t, "verticalBarChart.png",
-		"horizontalBarChart.png", "barChart2.png",
+		"horizontalBarChart_"+runtime.GOARCH+".png", "barChart2.png",
 		"stackedBarChart.png")
 }
 

plotter/contour_example_test.go

@@ -7,6 +7,7 @@ package plotter_test
 import (
 	"log"
 	"math"
+	"runtime"
 	"testing"
 
 	"golang.org/x/exp/rand"
@@ -51,7 +52,7 @@ func ExampleContour() {
 
 	p.Add(c)
 
-	err := p.Save(10*vg.Centimeter, 10*vg.Centimeter, "testdata/contour.png")
+	err := p.Save(10*vg.Centimeter, 10*vg.Centimeter, "testdata/contour_"+runtime.GOARCH+".png")
 	if err != nil {
 		log.Fatalf("could not save plot: %+v", err)
 	}
@@ -77,5 +78,5 @@ func (g unitGrid) Y(r int) float64 {
 }
 
 func TestContour(t *testing.T) {
-	cmpimg.CheckPlotApprox(ExampleContour, t, 0.01, "contour.png")
+	cmpimg.CheckPlotApprox(ExampleContour, t, 0.01, "contour_"+runtime.GOARCH+".png")
 }

plotter/labels_test.go

@@ -6,6 +6,7 @@ package plotter_test
 
 import (
 	"image/color"
+	"runtime"
 	"testing"
 
 	"gonum.org/v1/plot"
@@ -145,11 +146,11 @@ func TestLabelsWithGlyphBoxes(t *testing.T) {
 			p.Add(plotter.NewGrid())
 			p.Add(plotter.NewGlyphBoxes())
 
-			err = p.Save(10*vg.Centimeter, 10*vg.Centimeter, "testdata/labels_glyphboxes.png")
+			err = p.Save(10*vg.Centimeter, 10*vg.Centimeter, "testdata/labels_glyphboxes_"+runtime.GOARCH+".png")
 			if err != nil {
-				t.Fatalf("could save plot: %+v", err)
+				t.Fatalf("could not save plot: %+v", err)
 			}
 		},
-		t, "labels_glyphboxes.png",
+		t, "labels_glyphboxes_"+runtime.GOARCH+".png",
 	)
 }

plotter/precision_test.go

@@ -6,6 +6,7 @@ package plotter_test
 
 import (
 	"log"
+	"runtime"
 	"testing"
 
 	"gonum.org/v1/plot"
@@ -14,7 +15,7 @@ import (
 )
 
 func TestFloatPrecision(t *testing.T) {
-	const fname = "precision.png"
+	const fname = "precision_" + runtime.GOARCH + ".png"
 
 	cmpimg.CheckPlot(func() {
 		p := plot.New()

plotter/rotation_example_test.go

@@ -8,6 +8,7 @@ import (
 	"image/color"
 	"log"
 	"math"
+	"runtime"
 
 	"gonum.org/v1/plot"
 	"gonum.org/v1/plot/plotter"
@@ -92,7 +93,7 @@ func Example_rotation() {
 	p.Y.Tick.Label.XAlign = draw.XCenter
 	p.Y.Tick.Label.YAlign = draw.YBottom
 
-	err = p.Save(200, 150, "testdata/rotation.png")
+	err = p.Save(200, 150, "testdata/rotation_"+runtime.GOARCH+".png")
 	if err != nil {
 		log.Panic(err)
 	}

plotter/rotation_test.go

@@ -5,11 +5,12 @@
 package plotter_test
 
 import (
+	"runtime"
 	"testing"
 
 	"gonum.org/v1/plot/cmpimg"
 )
 
 func TestRotation(t *testing.T) {
-	cmpimg.CheckPlot(Example_rotation, t, "rotation.png")
+	cmpimg.CheckPlot(Example_rotation, t, "rotation_"+runtime.GOARCH+".png")
 }

plotter/sankey_example_test.go

@@ -9,6 +9,7 @@ import (
 	"image/color"
 	"log"
 	"os"
+	"runtime"
 
 	"gonum.org/v1/plot"
 	"gonum.org/v1/plot/plotter"
@@ -396,7 +397,7 @@ func ExampleSankey_grouped() {
 
 	p.Draw(dc)
 	pngimg := vgimg.PngCanvas{Canvas: c}
-	f, err := os.Create("testdata/sankeyGrouped.png")
+	f, err := os.Create("testdata/sankeyGrouped_" + runtime.GOARCH + ".png")
 	if err != nil {
 		log.Panic(err)
 	}

plotter/sankey_test.go

@@ -5,6 +5,7 @@
 package plotter_test
 
 import (
+	"runtime"
 	"testing"
 
 	"gonum.org/v1/plot"
@@ -20,7 +21,7 @@ func TestSankey_simple(t *testing.T) {
 }
 
 func TestSankey_grouped(t *testing.T) {
-	cmpimg.CheckPlot(ExampleSankey_grouped, t, "sankeyGrouped.png")
+	cmpimg.CheckPlot(ExampleSankey_grouped, t, "sankeyGrouped_"+runtime.GOARCH+".png")
 }
 
 // This test checks whether the Sankey plotter makes any changes to