all: correctly handle descent in glyphbox of text symbols

Fixes #649.
gonum · Dec 18, 2020 · 89f7b11 · 89f7b11
1 parent 35049c6
commit 89f7b11
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Showing 67 changed files with 927 additions and 336 deletions.
diff --git a/legend.go b/legend.go
@@ -106,7 +106,7 @@ func (l *Legend) Draw(c draw.Canvas) {
 	iconx += l.XOffs
 
 	descent := sty.Font.Extents().Descent
-	enth := l.entryHeight() + descent
+	enth := l.entryHeight()
 	y := c.Max.Y - enth
 	if !l.Top {
 		y = c.Min.Y + (enth+l.Padding)*(vg.Length(len(l.entries))-1)
@@ -131,7 +131,7 @@ func (l *Legend) Draw(c draw.Canvas) {
 		for _, t := range e.thumbs {
 			t.Thumbnail(icon)
 		}
-		yoffs := (enth - sty.Rectangle(e.text).Max.Y) / 2
+		yoffs := (enth + descent - sty.Rectangle(e.text).Max.Y) / 2
 		yoffs += yoff
 		c.FillText(sty, vg.Point{X: textx, Y: icon.Min.Y + yoffs}, e.text)
 		icon.Min.Y -= enth + l.Padding

diff --git a/plotter/label_example_test.go → plotter/labels_example_test.go b/plotter/label_example_test.go → plotter/labels_example_test.go
diff --git a/plotter/labels_test.go b/plotter/labels_test.go
@@ -5,12 +5,125 @@
 package plotter_test
 
 import (
+	"image/color"
 	"testing"
 
+	"gonum.org/v1/plot"
 	"gonum.org/v1/plot/cmpimg"
+	"gonum.org/v1/plot/plotter"
+	"gonum.org/v1/plot/vg"
+	"gonum.org/v1/plot/vg/draw"
 )
 
 func TestLabels(t *testing.T) {
 	cmpimg.CheckPlot(ExampleLabels, t, "labels.png")
 	cmpimg.CheckPlot(ExampleLabels_inCanvasCoordinates, t, "labels_cnv_coords.png")
 }
+
+// TestLabelsWithGlyphBoxes tests the position of the glyphbox around
+// a block of text, checking whether we correctly take into account
+// the descent+ascent of a glyph.
+func TestLabelsWithGlyphBoxes(t *testing.T) {
+	cmpimg.CheckPlot(
+		func() {
+			const fontSize = 24
+
+			p, err := plot.New()
+			if err != nil {
+				t.Fatalf("could not create plot: %+v", err)
+			}
+
+			p.Title.Text = "Labels"
+			p.X.Min = -1
+			p.X.Max = +1
+			p.Y.Min = -1
+			p.Y.Max = +1
+
+			const (
+				left   = 0.00
+				middle = 0.02
+				right  = 0.04
+			)
+
+			labels, err := plotter.NewLabels(plotter.XYLabels{
+				XYs: []plotter.XY{
+					{X: -0.8 + left, Y: -0.5},   // Aq + y-align bottom
+					{X: -0.6 + middle, Y: -0.5}, // Aq + y-align center
+					{X: -0.4 + right, Y: -0.5},  // Aq + y-align top
+
+					{X: -0.8 + left, Y: +0.5}, // ditto for Aq\nAq
+					{X: -0.6 + middle, Y: +0.5},
+					{X: -0.4 + right, Y: +0.5},
+
+					{X: +0.0 + left, Y: +0}, // ditto for Bg\nBg\nBg
+					{X: +0.2 + middle, Y: +0},
+					{X: +0.4 + right, Y: +0},
+				},
+				Labels: []string{
+					"Aq", "Aq", "Aq",
+					"Aq\nAq", "Aq\nAq", "Aq\nAq",
+
+					"Bg\nBg\nBg",
+					"Bg\nBg\nBg",
+					"Bg\nBg\nBg",
+				},
+			})
+			if err != nil {
+				t.Fatalf("could not creates labels plotter: %+v", err)
+			}
+			for i := range labels.TextStyle {
+				sty := &labels.TextStyle[i]
+				sty.Font.Size = vg.Length(fontSize)
+			}
+			labels.TextStyle[0].YAlign = draw.YBottom
+			labels.TextStyle[1].YAlign = draw.YCenter
+			labels.TextStyle[2].YAlign = draw.YTop
+
+			labels.TextStyle[3].YAlign = draw.YBottom
+			labels.TextStyle[4].YAlign = draw.YCenter
+			labels.TextStyle[5].YAlign = draw.YTop
+
+			labels.TextStyle[6].YAlign = draw.YBottom
+			labels.TextStyle[7].YAlign = draw.YCenter
+			labels.TextStyle[8].YAlign = draw.YTop
+
+			lred, err := plotter.NewLabels(plotter.XYLabels{
+				XYs: []plotter.XY{
+					{X: -0.8 + left, Y: +0.5},
+					{X: +0.0 + left, Y: +0},
+				},
+				Labels: []string{
+					"Aq", "Bg",
+				},
+			})
+			if err != nil {
+				t.Fatalf("could not creates labels plotter: %+v", err)
+			}
+			for i := range lred.TextStyle {
+				sty := &lred.TextStyle[i]
+				sty.Font.Size = vg.Length(fontSize)
+				sty.Color = color.RGBA{R: 255, A: 255}
+				sty.YAlign = draw.YBottom
+			}
+
+			m5 := plotter.NewFunction(func(float64) float64 { return -0.5 })
+			m5.LineStyle.Color = color.RGBA{R: 255, A: 255}
+
+			l0 := plotter.NewFunction(func(float64) float64 { return 0 })
+			l0.LineStyle.Color = color.RGBA{G: 255, A: 255}
+
+			p5 := plotter.NewFunction(func(float64) float64 { return +0.5 })
+			p5.LineStyle.Color = color.RGBA{B: 255, A: 255}
+
+			p.Add(labels, lred, m5, l0, p5)
+			p.Add(plotter.NewGrid())
+			p.Add(plotter.NewGlyphBoxes())
+
+			err = p.Save(10*vg.Centimeter, 10*vg.Centimeter, "testdata/labels_glyphboxes.png")
+			if err != nil {
+				t.Fatalf("could save plot: %+v", err)
+			}
+		},
+		t, "labels_glyphboxes.png",
+	)
+}
diff --git a/plotter/testdata/barChart_positiveNegative_golden.png b/plotter/testdata/barChart_positiveNegative_golden.png
diff --git a/plotter/testdata/clippedFilledLine_golden.png b/plotter/testdata/clippedFilledLine_golden.png
diff --git a/plotter/testdata/colorBarVertical_golden.png b/plotter/testdata/colorBarVertical_golden.png
diff --git a/plotter/testdata/contour_golden.svg b/plotter/testdata/contour_golden.svg
diff --git a/plotter/testdata/field_golden.png b/plotter/testdata/field_golden.png
diff --git a/plotter/testdata/functions_golden.png b/plotter/testdata/functions_golden.png
diff --git a/plotter/testdata/groupedQuartPlot_golden.png b/plotter/testdata/groupedQuartPlot_golden.png
diff --git a/plotter/testdata/horizontalBoxPlot_golden.png b/plotter/testdata/horizontalBoxPlot_golden.png
diff --git a/plotter/testdata/horizontalQuartPlot_golden.png b/plotter/testdata/horizontalQuartPlot_golden.png
diff --git a/plotter/testdata/image_plot_golden.png b/plotter/testdata/image_plot_golden.png
diff --git a/plotter/testdata/image_plot_log_golden.png b/plotter/testdata/image_plot_log_golden.png
diff --git a/plotter/testdata/labels_cnv_coords_golden.png b/plotter/testdata/labels_cnv_coords_golden.png
diff --git a/plotter/testdata/labels_glyphboxes_golden.png b/plotter/testdata/labels_glyphboxes_golden.png
diff --git a/plotter/testdata/labels_golden.png b/plotter/testdata/labels_golden.png
diff --git a/plotter/testdata/plotLogo_golden.png b/plotter/testdata/plotLogo_golden.png
diff --git a/plotter/testdata/polygon_hexagons_golden.png b/plotter/testdata/polygon_hexagons_golden.png
diff --git a/plotter/testdata/polygon_holes_golden.eps b/plotter/testdata/polygon_holes_golden.eps
@@ -2,7 +2,7 @@
 %%Creator gonum.org/v1/plot/vg/vgeps
 %%Title: 
 %%BoundingBox: 0 0 100 100
-%%CreationDate: 2020-11-02 12:45:40.941971207 +1030 ACDT m=+2.016279260
+%%CreationDate: 2020-12-14 16:10:53.813225989 +0100 CET m=+3.425219129
 %%Orientation: Portrait
 %%EndComments
 
@@ -57,79 +57,79 @@ stroke
 gsave
 90 rotate
 /Times-Roman findfont 12 scalefont setfont
-57.323 -11.555 moveto
+58.839 -11.555 moveto
 (Y) show
 grestore
 19.055 41.946 moveto
 (0) show
-19.055 58.45 moveto
+19.055 59.967 moveto
 (2) show
-19.055 74.955 moveto
+19.055 77.987 moveto
 (4) show
 newpath
 26.555 45.151 moveto
 34.555 45.151 lineto
 stroke
 newpath
-26.555 61.656 moveto
-34.555 61.656 lineto
+26.555 63.172 moveto
+34.555 63.172 lineto
 stroke
 newpath
-26.555 78.161 moveto
-34.555 78.161 lineto
+26.555 81.193 moveto
+34.555 81.193 lineto
 stroke
 newpath
-30.555 53.404 moveto
-34.555 53.404 lineto
+30.555 54.162 moveto
+34.555 54.162 lineto
 stroke
 newpath
-30.555 69.908 moveto
-34.555 69.908 lineto
+30.555 72.182 moveto
+34.555 72.182 lineto
 stroke
 newpath
 34.555 45.151 moveto
-34.555 78.161 lineto
+34.555 81.193 lineto
 stroke
 0 0 1 setrgbcolor
 newpath
 40.305 45.151 moveto
 97.5 45.151 lineto
-97.5 78.161 lineto
-40.305 78.161 lineto
+97.5 81.193 lineto
+40.305 81.193 lineto
 closepath
-47.454 49.278 moveto
-61.753 49.278 lineto
-61.753 57.53 lineto
-47.454 57.53 lineto
+47.454 49.657 moveto
+61.753 49.657 lineto
+61.753 58.667 lineto
+47.454 58.667 lineto
 closepath
-90.351 65.782 moveto
-76.052 65.782 lineto
-76.052 74.034 lineto
-90.351 74.034 lineto
+90.351 67.677 moveto
+76.052 67.677 lineto
+76.052 76.688 lineto
+90.351 76.688 lineto
 closepath
 fill
 0 0 0 setrgbcolor
 1 setlinewidth
 newpath
 40.305 45.151 moveto
 97.5 45.151 lineto
-97.5 78.161 lineto
-40.305 78.161 lineto
+97.5 81.193 lineto
+40.305 81.193 lineto
 40.305 45.151 lineto
 stroke
 newpath
-47.454 49.278 moveto
-61.753 49.278 lineto
-61.753 57.53 lineto
-47.454 57.53 lineto
-47.454 49.278 lineto
+47.454 49.657 moveto
+61.753 49.657 lineto
+61.753 58.667 lineto
+47.454 58.667 lineto
+47.454 49.657 lineto
 stroke
 newpath
-90.351 65.782 moveto
-76.052 65.782 lineto
-76.052 74.034 lineto
-90.351 74.034 lineto
-90.351 65.782 lineto
+90.351 67.677 moveto
+76.052 67.677 lineto
+76.052 76.688 lineto
+90.351 76.688 lineto
+90.351 67.677 lineto
 stroke
 0 0 1 setrgbcolor
 newpath

diff --git a/plotter/testdata/polygon_holes_golden.pdf b/plotter/testdata/polygon_holes_golden.pdf
diff --git a/plotter/testdata/polygon_holes_golden.png b/plotter/testdata/polygon_holes_golden.png
diff --git a/plotter/testdata/polygon_holes_golden.svg b/plotter/testdata/polygon_holes_golden.svg
diff --git a/plotter/testdata/precision_golden.png b/plotter/testdata/precision_golden.png
diff --git a/plotter/testdata/rasterHeatMap_golden.png b/plotter/testdata/rasterHeatMap_golden.png
diff --git a/plotter/testdata/rotation_golden.png b/plotter/testdata/rotation_golden.png
diff --git a/plotter/testdata/sankeyGrouped_golden.png b/plotter/testdata/sankeyGrouped_golden.png
diff --git a/plotter/testdata/sankeySimple_golden.png b/plotter/testdata/sankeySimple_golden.png
diff --git a/plotter/testdata/step_golden.png b/plotter/testdata/step_golden.png
diff --git a/plotter/testdata/verticalBarChart_golden.png b/plotter/testdata/verticalBarChart_golden.png
diff --git a/plotter/testdata/verticalBoxPlot_golden.png b/plotter/testdata/verticalBoxPlot_golden.png
diff --git a/plotter/testdata/verticalQuartPlot_golden.png b/plotter/testdata/verticalQuartPlot_golden.png
diff --git a/testdata/align_golden.png b/testdata/align_golden.png
diff --git a/testdata/axis_labels_golden.png b/testdata/axis_labels_golden.png
diff --git a/testdata/axis_padding_00_golden.png b/testdata/axis_padding_00_golden.png
diff --git a/testdata/axis_padding_05_golden.png b/testdata/axis_padding_05_golden.png
diff --git a/testdata/axis_padding_10_golden.png b/testdata/axis_padding_10_golden.png
diff --git a/testdata/legend_standalone_golden.png b/testdata/legend_standalone_golden.png
diff --git a/vg/draw/text.go b/vg/draw/text.go
@@ -74,16 +74,17 @@ func (sty TextStyle) Height(txt string) vg.Length {
 		return vg.Length(0)
 	}
 	e := sty.Font.Extents()
-	return e.Height*vg.Length(nl-1) + e.Ascent - e.Descent
+	return e.Height * vg.Length(nl)
 }
 
 // Rectangle returns a rectangle giving the bounds of
 // this text assuming that it is drawn at (0, 0).
 func (sty TextStyle) Rectangle(txt string) vg.Rectangle {
+	e := sty.Font.Extents()
 	w := sty.Width(txt)
 	h := sty.Height(txt)
 	xoff := vg.Length(sty.XAlign) * w
-	yoff := vg.Length(sty.YAlign) * h
+	yoff := vg.Length(sty.YAlign)*h + e.Descent
 	// lower left corner
 	p1 := rotatePoint(sty.Rotation, vg.Point{X: xoff, Y: yoff})
 	// upper left corner

diff --git a/vg/testdata/cosine_golden.png b/vg/testdata/cosine_golden.png
diff --git a/vg/testdata/sine_golden.png b/vg/testdata/sine_golden.png
diff --git a/vg/testdata/width_-1.jpg b/vg/testdata/width_-1.jpg
diff --git a/vg/testdata/width_-1.pdf b/vg/testdata/width_-1.pdf
diff --git a/vg/testdata/width_-1.png b/vg/testdata/width_-1.png
diff --git a/vg/testdata/width_-1.svg b/vg/testdata/width_-1.svg
diff --git a/vg/testdata/width_-1.tiff b/vg/testdata/width_-1.tiff
diff --git a/vg/testdata/width_0.jpg b/vg/testdata/width_0.jpg
diff --git a/vg/testdata/width_0.pdf b/vg/testdata/width_0.pdf
diff --git a/vg/testdata/width_0.png b/vg/testdata/width_0.png