op/paint: return ClipOp from Path.End

Instead of adding an implicit ClipOp, return a ClipOp ready to use, freeing the
caller from recording a macro.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

op/op.go

@@ -210,17 +210,22 @@ func (o *Ops) Write(op []byte, refs ...interface{}) {
 		}
 		o.auxLen += len(op)
 	default:
-		if o.inAux {
-			o.inAux = false
-			bo := binary.LittleEndian
-			bo.PutUint32(o.data[o.auxOff+1:], uint32(o.auxLen))
-		}
+		o.endAux()
 	}
 	o.write(op, refs...)
 }
 
-func (d *Ops) pc() pc {
-	return pc{data: len(d.data), refs: len(d.refs)}
+func (o *Ops) endAux() {
+	if !o.inAux {
+		return
+	}
+	o.inAux = false
+	bo := binary.LittleEndian
+	bo.PutUint32(o.data[o.auxOff+1:], uint32(o.auxLen))
+}
+
+func (o *Ops) pc() pc {
+	return pc{data: len(o.data), refs: len(o.refs)}
 }
 
 // Record a macro of operations.
@@ -242,6 +247,7 @@ func (m *MacroOp) Stop() {
 	if !m.recording {
 		panic("not recording")
 	}
+	m.ops.endAux()
 	m.ops.macroDepth--
 	m.recording = false
 	m.fill()

op/paint/path.go

@@ -25,14 +25,17 @@ type Path struct {
 	pen       f32.Point
 	bounds    f32.Rectangle
 	hasBounds bool
+	macro     op.MacroOp
 }
 
 // ClipOp sets the current clip path.
 type ClipOp struct {
+	macro  op.MacroOp
 	bounds f32.Rectangle
 }
 
 func (p ClipOp) Add(o *op.Ops) {
+	p.macro.Add(o)
 	data := make([]byte, opconst.TypeClipLen)
 	data[0] = byte(opconst.TypeClip)
 	bo := binary.LittleEndian
@@ -46,6 +49,7 @@ func (p ClipOp) Add(o *op.Ops) {
 // Begin the path, storing the path data and final ClipOp into ops.
 func (p *Path) Begin(ops *op.Ops) {
 	p.ops = ops
+	p.macro.Record(ops)
 }
 
 // MoveTo moves the pen to the given position.
@@ -280,11 +284,12 @@ func (p *Path) simpleQuadTo(ctrl, to f32.Point) {
 	p.pen = to
 }
 
-// End the path and add the resulting ClipOp to
-// the operation list passed to Init.
-func (p *Path) End() {
+// End the path and return the resulting ClipOp.
+func (p *Path) End() ClipOp {
 	p.end()
-	ClipOp{
+	p.macro.Stop()
+	return ClipOp{
+		macro:  p.macro,
 		bounds: p.bounds,
-	}.Add(p.ops)
+	}
 }

text/measure.go

@@ -7,7 +7,7 @@ import (
 	"image"
 
 	"gioui.org/layout"
-	"gioui.org/op"
+	"gioui.org/op/paint"
 	"golang.org/x/image/math/fixed"
 )
 
@@ -64,8 +64,8 @@ type Family interface {
 	// Layout returns the text layout for a string given a set of
 	// options.
 	Layout(face Face, size float32, s string, opts LayoutOptions) *Layout
-	// Path returns the ClipOp outline of a text recorded in a macro.
-	Shape(face Face, size float32, s String) op.MacroOp
+	// Path returns the ClipOp outline of a text.
+	Shape(face Face, size float32, s String) paint.ClipOp
 }
 
 type Alignment uint8

text/shape/lru.go

@@ -3,7 +3,7 @@
 package shape
 
 import (
-	"gioui.org/op"
+	"gioui.org/op/paint"
 	"gioui.org/text"
 	"golang.org/x/image/font/sfnt"
 	"golang.org/x/image/math/fixed"
@@ -28,7 +28,7 @@ type layout struct {
 type path struct {
 	next, prev *path
 	key        pathKey
-	val        op.MacroOp
+	val        paint.ClipOp
 }
 
 type layoutKey struct {
@@ -85,16 +85,16 @@ func (l *layoutCache) insert(lt *layout) {
 	lt.next.prev = lt
 }
 
-func (c *pathCache) Get(k pathKey) (op.MacroOp, bool) {
+func (c *pathCache) Get(k pathKey) (paint.ClipOp, bool) {
 	if v, ok := c.m[k]; ok {
 		c.remove(v)
 		c.insert(v)
 		return v.val, true
 	}
-	return op.MacroOp{}, false
+	return paint.ClipOp{}, false
 }
 
-func (c *pathCache) Put(k pathKey, v op.MacroOp) {
+func (c *pathCache) Put(k pathKey, v paint.ClipOp) {
 	if c.m == nil {
 		c.m = make(map[pathKey]*path)
 		c.head = new(path)

text/shape/lru_test.go

@@ -6,7 +6,7 @@ import (
 	"strconv"
 	"testing"
 
-	"gioui.org/op"
+	"gioui.org/op/paint"
 )
 
 func TestLayoutLRU(t *testing.T) {
@@ -24,7 +24,7 @@ func TestLayoutLRU(t *testing.T) {
 func TestuPathLRU(t *testing.T) {
 	c := new(pathCache)
 	put := func(i int) {
-		c.Put(pathKey{str: strconv.Itoa(i)}, op.MacroOp{})
+		c.Put(pathKey{str: strconv.Itoa(i)}, paint.ClipOp{})
 	}
 	get := func(i int) bool {
 		_, ok := c.Get(pathKey{str: strconv.Itoa(i)})

text/shape/measure.go

@@ -64,7 +64,7 @@ func (f *Family) Layout(face text.Face, size float32, str string, opts text.Layo
 	return l
 }
 
-func (f *Family) Shape(face text.Face, size float32, str text.String) op.MacroOp {
+func (f *Family) Shape(face text.Face, size float32, str text.String) paint.ClipOp {
 	fnt := f.fontFor(face)
 	ppem := fixed.Int26_6(size * 64)
 	pk := pathKey{
@@ -169,14 +169,12 @@ func layoutText(buf *sfnt.Buffer, ppem fixed.Int26_6, str string, f *opentype, o
 	return &text.Layout{Lines: lines}
 }
 
-func textPath(buf *sfnt.Buffer, ppem fixed.Int26_6, f *opentype, str text.String) op.MacroOp {
+func textPath(buf *sfnt.Buffer, ppem fixed.Int26_6, f *opentype, str text.String) paint.ClipOp {
 	var lastPos f32.Point
 	var builder paint.Path
 	ops := new(op.Ops)
 	var x fixed.Int26_6
 	var advIdx int
-	var m op.MacroOp
-	m.Record(ops)
 	builder.Begin(ops)
 	for _, r := range str.String {
 		if !unicode.IsSpace(r) {
@@ -229,7 +227,5 @@ func textPath(buf *sfnt.Buffer, ppem fixed.Int26_6, f *opentype, str text.String
 		x += str.Advances[advIdx]
 		advIdx++
 	}
-	builder.End()
-	m.Stop()
-	return m
+	return builder.End()
 }