op/clip: split clip operations into its own package

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

text/lru.go

@@ -3,7 +3,7 @@
 package text
 
 import (
-	"gioui.org/op/paint"
+	"gioui.org/op/clip"
 	"golang.org/x/image/math/fixed"
 )
 
@@ -26,7 +26,7 @@ type layoutElem struct {
 type path struct {
 	next, prev *path
 	key        pathKey
-	val        paint.ClipOp
+	val        clip.Op
 }
 
 type layoutKey struct {
@@ -81,16 +81,16 @@ func (l *layoutCache) insert(lt *layoutElem) {
 	lt.next.prev = lt
 }
 
-func (c *pathCache) Get(k pathKey) (paint.ClipOp, bool) {
+func (c *pathCache) Get(k pathKey) (clip.Op, bool) {
 	if v, ok := c.m[k]; ok {
 		c.remove(v)
 		c.insert(v)
 		return v.val, true
 	}
-	return paint.ClipOp{}, false
+	return clip.Op{}, false
 }
 
-func (c *pathCache) Put(k pathKey, v paint.ClipOp) {
+func (c *pathCache) Put(k pathKey, v clip.Op) {
 	if c.m == nil {
 		c.m = make(map[pathKey]*path)
 		c.head = new(path)

text/lru_test.go

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

text/shaper.go

@@ -5,7 +5,7 @@ package text
 import (
 	"unicode/utf8"
 
-	"gioui.org/op/paint"
+	"gioui.org/op/clip"
 	"gioui.org/unit"
 	"golang.org/x/image/math/fixed"
 )
@@ -46,7 +46,7 @@ func (s *Shaper) Layout(c unit.Converter, font Font, str string, opts LayoutOpti
 	return tf.layout(fixed.I(c.Px(font.Size)), str, opts)
 }
 
-func (s *Shaper) Shape(c unit.Converter, font Font, str String) paint.ClipOp {
+func (s *Shaper) Shape(c unit.Converter, font Font, str String) clip.Op {
 	tf := s.faceForFont(font)
 	return tf.shape(fixed.I(c.Px(font.Size)), str)
 }
@@ -99,9 +99,9 @@ func (t *face) layout(ppem fixed.Int26_6, str string, opts LayoutOptions) *Layou
 	return l
 }
 
-func (t *face) shape(ppem fixed.Int26_6, str String) paint.ClipOp {
+func (t *face) shape(ppem fixed.Int26_6, str String) clip.Op {
 	if t == nil {
-		return paint.ClipOp{}
+		return clip.Op{}
 	}
 	pk := pathKey{
 		ppem: ppem,

text/text.go

@@ -3,7 +3,7 @@
 package text
 
 import (
-	"gioui.org/op/paint"
+	"gioui.org/op/clip"
 	"gioui.org/unit"
 	"golang.org/x/image/math/fixed"
 )
@@ -61,7 +61,7 @@ type Font struct {
 // Face implements text layout and shaping for a particular font.
 type Face interface {
 	Layout(ppem fixed.Int26_6, str string, opts LayoutOptions) *Layout
-	Shape(ppem fixed.Int26_6, str String) paint.ClipOp
+	Shape(ppem fixed.Int26_6, str String) clip.Op
 }
 
 // Typeface identifies a particular typeface design. The empty