forked from joejulian/gio
Chris Waldon
1e5a3696f5
This commit introduces a new text shaping infrastructure powered by Benoit Kugler's Go source-port of harfbuzz. This shaper can properly display complex scripts and RTL text. This commit changes the signature of the text.Shaper function, which is a breaking API change. The new functionality is available via opentype.ParseHarfbuzz, which configures a text.Shaper leveraging the new backend. References: https://todo.sr.ht/~eliasnaur/gio/146 Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
126 lines
2.2 KiB
Go
126 lines
2.2 KiB
Go
// SPDX-License-Identifier: Unlicense OR MIT
|
|
|
|
package text
|
|
|
|
import (
|
|
"gioui.org/io/system"
|
|
"gioui.org/op/clip"
|
|
"golang.org/x/image/math/fixed"
|
|
)
|
|
|
|
type layoutCache struct {
|
|
m map[layoutKey]*layoutElem
|
|
head, tail *layoutElem
|
|
}
|
|
|
|
type pathCache struct {
|
|
m map[pathKey]*path
|
|
head, tail *path
|
|
}
|
|
|
|
type layoutElem struct {
|
|
next, prev *layoutElem
|
|
key layoutKey
|
|
layout []Line
|
|
}
|
|
|
|
type path struct {
|
|
next, prev *path
|
|
key pathKey
|
|
val clip.PathSpec
|
|
layout Layout
|
|
}
|
|
|
|
type layoutKey struct {
|
|
ppem fixed.Int26_6
|
|
maxWidth int
|
|
str string
|
|
locale system.Locale
|
|
}
|
|
|
|
type pathKey struct {
|
|
ppem fixed.Int26_6
|
|
str string
|
|
gidHash uint64
|
|
}
|
|
|
|
const maxSize = 1000
|
|
|
|
func (l *layoutCache) Get(k layoutKey) ([]Line, bool) {
|
|
if lt, ok := l.m[k]; ok {
|
|
l.remove(lt)
|
|
l.insert(lt)
|
|
return lt.layout, true
|
|
}
|
|
return nil, false
|
|
}
|
|
|
|
func (l *layoutCache) Put(k layoutKey, lt []Line) {
|
|
if l.m == nil {
|
|
l.m = make(map[layoutKey]*layoutElem)
|
|
l.head = new(layoutElem)
|
|
l.tail = new(layoutElem)
|
|
l.head.prev = l.tail
|
|
l.tail.next = l.head
|
|
}
|
|
val := &layoutElem{key: k, layout: lt}
|
|
l.m[k] = val
|
|
l.insert(val)
|
|
if len(l.m) > maxSize {
|
|
oldest := l.tail.next
|
|
l.remove(oldest)
|
|
delete(l.m, oldest.key)
|
|
}
|
|
}
|
|
|
|
func (l *layoutCache) remove(lt *layoutElem) {
|
|
lt.next.prev = lt.prev
|
|
lt.prev.next = lt.next
|
|
}
|
|
|
|
func (l *layoutCache) insert(lt *layoutElem) {
|
|
lt.next = l.head
|
|
lt.prev = l.head.prev
|
|
lt.prev.next = lt
|
|
lt.next.prev = lt
|
|
}
|
|
|
|
func (c *pathCache) Get(k pathKey, l Layout) (clip.PathSpec, bool) {
|
|
if v, ok := c.m[k]; ok && l.equals(v.layout) {
|
|
c.remove(v)
|
|
c.insert(v)
|
|
return v.val, true
|
|
}
|
|
return clip.PathSpec{}, false
|
|
}
|
|
|
|
func (c *pathCache) Put(k pathKey, l Layout, v clip.PathSpec) {
|
|
if c.m == nil {
|
|
c.m = make(map[pathKey]*path)
|
|
c.head = new(path)
|
|
c.tail = new(path)
|
|
c.head.prev = c.tail
|
|
c.tail.next = c.head
|
|
}
|
|
val := &path{key: k, val: v, layout: l}
|
|
c.m[k] = val
|
|
c.insert(val)
|
|
if len(c.m) > maxSize {
|
|
oldest := c.tail.next
|
|
c.remove(oldest)
|
|
delete(c.m, oldest.key)
|
|
}
|
|
}
|
|
|
|
func (c *pathCache) remove(v *path) {
|
|
v.next.prev = v.prev
|
|
v.prev.next = v.next
|
|
}
|
|
|
|
func (c *pathCache) insert(v *path) {
|
|
v.next = c.head
|
|
v.prev = c.head.prev
|
|
v.prev.next = v
|
|
v.next.prev = v
|
|
}
|