ci,mod: bump go version and replace travis

[kortschak]

Please take a look.

[kortschak]

@sbinet I have a bunch of changes that are intended to get the rings package to pass (basically to use cmpimg), but I see

--- FAIL: TestScoresAxis (0.00s)
    --- FAIL: TestScoresAxis/axis-0 (0.00s)
panic: runtime error: invalid memory address or nil pointer dereference [recovered]
	panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x28 pc=0x63908b]

goroutine 7 [running]:
testing.tRunner.func1.2({0x6a2ee0, 0xde8a80})
	…/go/src/testing/testing.go:1734 +0x21c
testing.tRunner.func1()
	…/go/src/testing/testing.go:1737 +0x35e
panic({0x6a2ee0?, 0xde8a80?})
	…/go/src/runtime/panic.go:792 +0x132
gonum.org/v1/plot/vg/draw.(*Canvas).FillText(...)
	…/pkg/mod/gonum.org/v1/plot@v0.15.0/vg/draw/canvas.go:632
gonum.org/v1/exp/plotter/rings.(*Axis).drawAt(0xc00016a1e0, {{0x76cf70, 0xc0001473e0}, {{0x4014000000000000, 0x4014000000000000}, {0x4072c00000000000, 0x4072c00000000000}}}, {0xbff0000000000000?, 0xc0001112d8?}, {0xc00014a6e0, ...}, ...)
	…/src/gonum.org/v1/exp/plotter/rings/axis.go:158 +0xe8b
gonum.org/v1/exp/plotter/rings.(*Trace).Close(0xc000132210)
	…/src/gonum.org/v1/exp/plotter/rings/scores.go:286 +0x15f
gonum.org/v1/exp/plotter/rings.(*Scores).DrawAt(0xc0001600e0, {{0x76cf70, 0xc0001473e0}, {{0x4014000000000000, 0x4014000000000000}, {0x4072c00000000000, 0x4072c00000000000}}}, {0x0?, 0x0?})
	…/src/gonum.org/v1/exp/plotter/rings/scores.go:125 +0x23e
gonum.org/v1/exp/plotter/rings.(*Scores).Plot(0xc0001600e0, {{0x76cf70, 0xc0001473e0}, {{0x4014000000000000, 0x4014000000000000}, {0x4072c00000000000, 0x4072c00000000000}}}, 0x6f7cec?)
	…/src/gonum.org/v1/exp/plotter/rings/scores.go:131 +0x10e
gonum.org/v1/plot.(*Plot).Draw(0xc0001ee008, {{0x7f17ea1d7668, 0xc00007c420}, {{0x0, 0x0}, {0x4072c00000000000, 0x4072c00000000000}}})
	…/pkg/mod/gonum.org/v1/plot@v0.15.0/plot.go:173 +0xb9a
gonum.org/v1/plot.(*Plot).WriterTo(0xc0001ee008, 0xc0000164b0?, 0x4000000006c2068?, {0x6f030f?, 0x7f1830c94108?})
	…/pkg/mod/gonum.org/v1/plot@v0.15.0/plot.go:509 +0xf5
gonum.org/v1/exp/plotter/rings.checkImage(0xc000003c00, 0xc0001ee008)
	…/src/gonum.org/v1/exp/plotter/rings/rings_test.go:107 +0xde
gonum.org/v1/exp/plotter/rings.TestScoresAxis.func4(0xc000003c00)
	…/src/gonum.org/v1/exp/plotter/rings/axis_test.go:82 +0x226
testing.tRunner(0xc000003c00, 0xc000013c00)
	…/go/src/testing/testing.go:1792 +0xf4
created by testing.(*T).Run in goroutine 6
	…/go/src/testing/testing.go:1851 +0x413
FAIL	gonum.org/v1/exp/plotter/rings	0.008s
FAIL

so I obviously don't have everything smoothed over. Can you suggest what I might be missing? If this needs source, I'll make a second PR with the changes after this one is merged.

[sbinet]

ah, that's the big plot-font/cache migration.

I went back in my repo to see what were the mechanics of the migration.
I believe that's e.g.

• Gonum plot fonts go-hep/hep#843
• https://github.com/go-hep/hep/pull/843/files#diff-556c0720dc3b12ae2e6f9b232f33c7c3dfcf937f3cb9fa48ee0ced8174b54e60
• go-hep/hep@64a270d

I am running out of cycles for today, but I'll come back tomorrow w/ more.

here is a diff I think should point into the right direction:

diff --git a/plotter/rings/scale.go b/plotter/rings/scale.go
index 82e3f82..e1200e1 100644
--- a/plotter/rings/scale.go
+++ b/plotter/rings/scale.go
@@ -160,7 +160,13 @@ func (r *Scale) DrawAt(ca draw.Canvas, cen vg.Point) {
                                }
 
                                angle := Angle(iv-min)*scale + arc.Theta
-                               pt := cen.Add(Rectangular(angle, r.Radius+r.Tick.Length+r.Tick.Label.Font.Extents().Height))
+                               pt := cen.Add(Rectangular(
+                                       angle,
+                                       r.Radius+r.Tick.Length+r.Tick.Label.Handler.Extents(r.Tick.Label.Font).Height,
+                               ))
+
                                var (
                                        rot            Angle
                                        xalign, yalign float64
@@ -190,7 +196,10 @@ func (r *Scale) Plot(ca draw.Canvas, plt *plot.Plot) {
 func (r *Scale) GlyphBoxes(plt *plot.Plot) []plot.GlyphBox {
        grid := math.Max(float64(r.Grid.Inner), float64(r.Grid.Outer))
        radius := math.Max(float64(r.Radius+r.Tick.Length), grid)
-       radius = math.Max(radius, float64(r.Tick.Label.Font.Extents().Height*2))
+       radius = math.Max(radius, float64(
+               r.Tick.Label.Handler.Extents(r.Tick.Label.Font).Height*2,
+       ))
        return []plot.GlyphBox{{
                X: plt.X.Norm(r.X),
                Y: plt.Y.Norm(r.Y),

[sbinet]

I've created a draft PR w/ some of the API churn handled:

#67

but I've seen some labels movement, so there's possibly some "font descent" adjustment to look for...

[sbinet]

any reason why we don't use the gonum/tools package for testing imports, formatting et al ?

LGTM otherwise.

[sbinet]

shouldn't this be 1.23.0 ?

[kortschak]

Bumped.

[kortschak]

any reason why we don't use the gonum/tools package for testing imports, formatting et al ?

We have lower quality constraints here.