text,widget,opentype: change text.Face.Shape to return a clip.PathSpec

With this change, the Shape function returns a clip.PathSpec
instead of a clip.Outline op. It is then possible to create
a clip.Outline or clip.Stroke op to fill the text path or
draw its stroke.

Signed-off-by: Christophe Meessen <meessen@cppm.in2p3.fr>

text/lru.go

@@ -26,7 +26,7 @@ type layoutElem struct {
 type path struct {
 	next, prev *path
 	key        pathKey
-	val        clip.Op
+	val        clip.PathSpec
 }
 
 type layoutKey struct {
@@ -81,16 +81,16 @@ func (l *layoutCache) insert(lt *layoutElem) {
 	lt.next.prev = lt
 }
 
-func (c *pathCache) Get(k pathKey) (clip.Op, bool) {
+func (c *pathCache) Get(k pathKey) (clip.PathSpec, bool) {
 	if v, ok := c.m[k]; ok {
 		c.remove(v)
 		c.insert(v)
 		return v.val, true
 	}
-	return clip.Op{}, false
+	return clip.PathSpec{}, false
 }
 
-func (c *pathCache) Put(k pathKey, v clip.Op) {
+func (c *pathCache) Put(k pathKey, v clip.PathSpec) {
 	if c.m == nil {
 		c.m = make(map[pathKey]*path)
 		c.head = new(path)

text/lru_test.go

@@ -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)}, clip.Op{})
+		c.Put(pathKey{str: strconv.Itoa(i)}, clip.PathSpec{})
 	}
 	get := func(i int) bool {
 		_, ok := c.Get(pathKey{str: strconv.Itoa(i)})

text/shaper.go

@@ -18,7 +18,7 @@ type Shaper interface {
 	// LayoutString is Layout for strings.
 	LayoutString(font Font, size fixed.Int26_6, maxWidth int, str string) []Line
 	// Shape a line of text and return a clipping operation for its outline.
-	Shape(font Font, size fixed.Int26_6, layout Layout) clip.Op
+	Shape(font Font, size fixed.Int26_6, layout Layout) clip.PathSpec
 }
 
 // A FontFace is a Font and a matching Face.
@@ -121,7 +121,7 @@ func (c *Cache) LayoutString(font Font, size fixed.Int26_6, maxWidth int, str st
 
 // Shape is a caching implementation of the Shaper interface. Shape assumes that the layout
 // argument is unchanged from a call to Layout or LayoutString.
-func (c *Cache) Shape(font Font, size fixed.Int26_6, layout Layout) clip.Op {
+func (c *Cache) Shape(font Font, size fixed.Int26_6, layout Layout) clip.PathSpec {
 	cache := c.lookup(font)
 	return cache.shape(size, layout)
 }
@@ -143,9 +143,9 @@ func (f *faceCache) layout(ppem fixed.Int26_6, maxWidth int, str string) []Line
 	return l
 }
 
-func (f *faceCache) shape(ppem fixed.Int26_6, layout Layout) clip.Op {
+func (f *faceCache) shape(ppem fixed.Int26_6, layout Layout) clip.PathSpec {
 	if f == nil {
-		return clip.Op{}
+		return clip.PathSpec{}
 	}
 	pk := pathKey{
 		ppem: ppem,

text/text.go

@@ -48,7 +48,7 @@ type Font struct {
 // methods must be safe for concurrent use.
 type Face interface {
 	Layout(ppem fixed.Int26_6, maxWidth int, txt io.Reader) ([]Line, error)
-	Shape(ppem fixed.Int26_6, str Layout) clip.Op
+	Shape(ppem fixed.Int26_6, str Layout) clip.PathSpec
 }
 
 // Typeface identifies a particular typeface design. The empty