op/clip: automatically close Path in Outlines

Unclosed path segments in Path will be automatically
closed by a line.

Fixes: https://todo.sr.ht/~eliasnaur/gio/320
Signed-off-by: Pierre Curto <pierre.curto@gmail.com>

gpu/internal/rendertest/render_test.go

@@ -357,6 +357,60 @@ func TestImageRGBA(t *testing.T) {
 	})
 }
 
+func TestGapsInPath(t *testing.T) {
+	ops := new(op.Ops)
+	var p clip.Path
+	p.Begin(ops)
+	// Unclosed square 1
+	p.MoveTo(f32.Point{X: 10})
+	p.LineTo(f32.Point{X: 40})
+	p.LineTo(f32.Point{X: 40, Y: 30})
+	p.LineTo(f32.Point{X: 10, Y: 30})
+
+	// Unclosed square 2
+	p.MoveTo(f32.Point{X: 50})
+	p.LineTo(f32.Point{X: 80})
+	p.LineTo(f32.Point{X: 80, Y: 30})
+	p.LineTo(f32.Point{X: 50, Y: 30})
+
+	spec := p.End()
+
+	t.Run("Stroke", func(t *testing.T) {
+		run(t,
+			func(ops *op.Ops) {
+				stack := clip.Stroke{
+					Path:  spec,
+					Width: 2,
+				}.Op().Push(ops)
+				paint.ColorOp{Color: color.NRGBA{R: 255, A: 255}}.Add(ops)
+				paint.PaintOp{}.Add(ops)
+				stack.Pop()
+			},
+			func(r result) {
+				r.expect(10, 20, color.RGBA{})
+				r.expect(50, 20, color.RGBA{})
+			},
+		)
+	})
+
+	t.Run("Outline", func(t *testing.T) {
+		run(t,
+			func(ops *op.Ops) {
+				stack := clip.Outline{Path: spec}.Op().Push(ops)
+				paint.ColorOp{Color: color.NRGBA{R: 255, A: 255}}.Add(ops)
+				paint.PaintOp{}.Add(ops)
+				stack.Pop()
+			},
+			func(r result) {
+				r.expect(10, 20, colornames.Red)
+				r.expect(20, 20, colornames.Red)
+				r.expect(50, 20, colornames.Red)
+				r.expect(60, 20, colornames.Red)
+			},
+		)
+	})
+}
+
 // lerp calculates linear interpolation with color b and p.
 func lerp(a, b f32color.RGBA, p float32) f32color.RGBA {
 	return f32color.RGBA{

gpu/internal/rendertest/util_test.go

@@ -11,6 +11,7 @@ import (
 	"image/draw"
 	"image/png"
 	"io/ioutil"
+	"os"
 	"path/filepath"
 	"strconv"
 	"testing"
@@ -143,11 +144,20 @@ func multiRun(t *testing.T, frames ...frameT) {
 
 func verifyRef(t *testing.T, img *image.RGBA, frame int) (ok bool) {
 	// ensure identical to ref data
-	path := filepath.Join("refs", t.Name()+".png")
-	if frame != 0 {
-		path = filepath.Join("refs", t.Name()+"_"+strconv.Itoa(frame)+".png")
+	var path string
+	if frame == 0 {
+		path = t.Name()
+	} else {
+		path = t.Name() + "_" + strconv.Itoa(frame)
 	}
+	path = filepath.Join("refs", path+".png")
 	if *dumpImages {
+		if err := os.MkdirAll(filepath.Dir(path), 0766); err != nil {
+			if !os.IsExist(err) {
+				t.Error(err)
+				return
+			}
+		}
 		saveImage(t, path, img)
 		return true
 	}