From 16d2a3ac0a07493f4f3f43beb6b00002a1869f44 Mon Sep 17 00:00:00 2001 From: Elias Naur Date: Mon, 13 Jan 2020 19:54:11 +0100 Subject: [PATCH] text: remove String, Layout and add Glyph In preparation for using Shaper with an io.Reader, rework the API to not refer to strings. In particular, introduce Glyph for holding the rune in addition to the advance. For fast traversing of the underlying text, add Len to Line with the UTF8 length. Layout is a useless wrapper around []Line; remove it while we're here. Signed-off-by: Elias Naur --- font/opentype/opentype.go | 58 +++++++++++++++++++-------------------- text/lru.go | 6 ++-- text/shaper.go | 37 ++++++++----------------- text/text.go | 21 ++++++-------- widget/editor.go | 48 ++++++++++++++++---------------- widget/label.go | 41 +++++++++++++-------------- 6 files changed, 95 insertions(+), 116 deletions(-) diff --git a/font/opentype/opentype.go b/font/opentype/opentype.go index 58dd4366..7dcee2b0 100644 --- a/font/opentype/opentype.go +++ b/font/opentype/opentype.go @@ -85,11 +85,11 @@ func (c *Collection) Font(i int) (*Font, error) { return &Font{font: fnt}, nil } -func (f *Font) Layout(ppem fixed.Int26_6, str string, opts text.LayoutOptions) *text.Layout { +func (f *Font) Layout(ppem fixed.Int26_6, str string, opts text.LayoutOptions) []text.Line { return layoutText(&f.buf, ppem, str, &opentype{Font: f.font, Hinting: font.HintingFull}, opts) } -func (f *Font) Shape(ppem fixed.Int26_6, str text.String) op.CallOp { +func (f *Font) Shape(ppem fixed.Int26_6, str []text.Glyph) op.CallOp { return textPath(&f.buf, ppem, &opentype{Font: f.font, Hinting: font.HintingFull}, str) } @@ -98,7 +98,7 @@ func (f *Font) Metrics(ppem fixed.Int26_6) font.Metrics { return o.Metrics(&f.buf, ppem) } -func layoutText(buf *sfnt.Buffer, ppem fixed.Int26_6, str string, f *opentype, opts text.LayoutOptions) *text.Layout { +func layoutText(buf *sfnt.Buffer, ppem fixed.Int26_6, str string, f *opentype, opts text.LayoutOptions) []text.Line { m := f.Metrics(buf, ppem) lineTmpl := text.Line{ Ascent: m.Ascent, @@ -110,18 +110,18 @@ func layoutText(buf *sfnt.Buffer, ppem fixed.Int26_6, str string, f *opentype, o var lines []text.Line maxDotX := fixed.I(opts.MaxWidth) type state struct { - r rune - advs []fixed.Int26_6 - adv fixed.Int26_6 - x fixed.Int26_6 - idx int - valid bool + r rune + layout []text.Glyph + adv fixed.Int26_6 + x fixed.Int26_6 + idx int + valid bool } var prev, word state endLine := func() { line := lineTmpl - line.Text.Advances = prev.advs - line.Text.String = str[:prev.idx] + line.Layout = prev.layout + line.Len = prev.idx line.Width = prev.x + prev.adv line.Bounds.Max.X += prev.x lines = append(lines, line) @@ -133,17 +133,17 @@ func layoutText(buf *sfnt.Buffer, ppem fixed.Int26_6, str string, f *opentype, o c, s := utf8.DecodeRuneInString(str[prev.idx:]) a, valid := f.GlyphAdvance(buf, ppem, c) next := state{ - r: c, - advs: prev.advs, - idx: prev.idx + s, - x: prev.x + prev.adv, - adv: a, - valid: valid, + r: c, + layout: prev.layout, + idx: prev.idx + s, + x: prev.x + prev.adv, + adv: a, + valid: valid, } if c == '\n' { // The newline is zero width; use the previous // character for line measurements. - prev.advs = append(prev.advs, 0) + prev.layout = append(prev.layout, text.Glyph{Rune: c, Advance: 0}) prev.idx = next.idx endLine() continue @@ -160,33 +160,32 @@ func layoutText(buf *sfnt.Buffer, ppem fixed.Int26_6, str string, f *opentype, o } next.x -= word.x + word.adv next.idx -= word.idx - next.advs = next.advs[len(word.advs):] + next.layout = next.layout[len(word.layout):] prev = word endLine() } else if k != 0 { - next.advs[len(next.advs)-1] += k + next.layout[len(next.layout)-1].Advance += k next.x += k } - next.advs = append(next.advs, next.adv) - if unicode.IsSpace(next.r) { + next.layout = append(next.layout, text.Glyph{Rune: c, Advance: next.adv}) + if unicode.IsSpace(c) { word = next } prev = next } endLine() - return &text.Layout{Lines: lines} + return lines } -func textPath(buf *sfnt.Buffer, ppem fixed.Int26_6, f *opentype, str text.String) op.CallOp { +func textPath(buf *sfnt.Buffer, ppem fixed.Int26_6, f *opentype, str []text.Glyph) op.CallOp { var lastPos f32.Point var builder clip.Path ops := new(op.Ops) var x fixed.Int26_6 - var advIdx int builder.Begin(ops) - for _, r := range str.String { - if !unicode.IsSpace(r) { - segs, ok := f.LoadGlyph(buf, ppem, r) + for _, g := range str { + if !unicode.IsSpace(g.Rune) { + segs, ok := f.LoadGlyph(buf, ppem, g.Rune) if !ok { continue } @@ -232,8 +231,7 @@ func textPath(buf *sfnt.Buffer, ppem fixed.Int26_6, f *opentype, str text.String } lastPos = lastPos.Add(lastArg) } - x += str.Advances[advIdx] - advIdx++ + x += g.Advance } builder.End().Add(ops) return op.CallOp{Ops: ops} diff --git a/text/lru.go b/text/lru.go index 343e7aee..3ff9b6d1 100644 --- a/text/lru.go +++ b/text/lru.go @@ -20,7 +20,7 @@ type pathCache struct { type layoutElem struct { next, prev *layoutElem key layoutKey - layout *Layout + layout []Line } type path struct { @@ -42,7 +42,7 @@ type pathKey struct { const maxSize = 1000 -func (l *layoutCache) Get(k layoutKey) (*Layout, bool) { +func (l *layoutCache) Get(k layoutKey) ([]Line, bool) { if lt, ok := l.m[k]; ok { l.remove(lt) l.insert(lt) @@ -51,7 +51,7 @@ func (l *layoutCache) Get(k layoutKey) (*Layout, bool) { return nil, false } -func (l *layoutCache) Put(k layoutKey, lt *Layout) { +func (l *layoutCache) Put(k layoutKey, lt []Line) { if l.m == nil { l.m = make(map[layoutKey]*layoutElem) l.head = new(layoutElem) diff --git a/text/shaper.go b/text/shaper.go index 39bc459b..d2cacb1d 100644 --- a/text/shaper.go +++ b/text/shaper.go @@ -3,8 +3,6 @@ package text import ( - "unicode/utf8" - "golang.org/x/image/font" "gioui.org/op" @@ -14,8 +12,10 @@ import ( // Shaper implements layout and shaping of text. type Shaper interface { - Layout(c unit.Converter, font Font, str string, opts LayoutOptions) *Layout - Shape(c unit.Converter, font Font, str String) op.CallOp + // Layout a text according to a set of options. + Layout(c unit.Converter, font Font, str string, opts LayoutOptions) []Line + // Shape a line of text previously laid out by Layout. + Shape(c unit.Converter, font Font, str string, layout []Glyph) op.CallOp Metrics(c unit.Converter, font Font) font.Metrics } @@ -50,14 +50,14 @@ func (s *FontRegistry) Register(font Font, tf Face) { } } -func (s *FontRegistry) Layout(c unit.Converter, font Font, str string, opts LayoutOptions) *Layout { +func (s *FontRegistry) Layout(c unit.Converter, font Font, str string, opts LayoutOptions) []Line { tf := s.faceForFont(font) return tf.layout(fixed.I(c.Px(font.Size)), str, opts) } -func (s *FontRegistry) Shape(c unit.Converter, font Font, str String) op.CallOp { +func (s *FontRegistry) Shape(c unit.Converter, font Font, str string, layout []Glyph) op.CallOp { tf := s.faceForFont(font) - return tf.shape(fixed.I(c.Px(font.Size)), str) + return tf.shape(fixed.I(c.Px(font.Size)), str, layout) } func (s *FontRegistry) Metrics(c unit.Converter, font Font) font.Metrics { @@ -96,9 +96,9 @@ func (s *FontRegistry) faceForFont(font Font) *face { return tf } -func (t *face) layout(ppem fixed.Int26_6, str string, opts LayoutOptions) *Layout { +func (t *face) layout(ppem fixed.Int26_6, str string, opts LayoutOptions) []Line { if t == nil { - return fallbackLayout(str) + return nil } lk := layoutKey{ ppem: ppem, @@ -113,18 +113,18 @@ 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) op.CallOp { +func (t *face) shape(ppem fixed.Int26_6, str string, layout []Glyph) op.CallOp { if t == nil { return op.CallOp{} } pk := pathKey{ ppem: ppem, - str: str.String, + str: str, } if clip, ok := t.pathCache.Get(pk); ok { return clip } - clip := t.face.Shape(ppem, str) + clip := t.face.Shape(ppem, layout) t.pathCache.Put(pk, clip) return clip } @@ -132,16 +132,3 @@ func (t *face) shape(ppem fixed.Int26_6, str String) op.CallOp { func (t *face) metrics(ppem fixed.Int26_6) font.Metrics { return t.face.Metrics(ppem) } - -func fallbackLayout(str string) *Layout { - l := &Layout{ - Lines: []Line{ - {Text: String{ - String: str, - }}, - }, - } - strlen := utf8.RuneCountInString(str) - l.Lines[0].Text.Advances = make([]fixed.Int26_6, strlen) - return l -} diff --git a/text/text.go b/text/text.go index 9f3c59e4..703a994d 100644 --- a/text/text.go +++ b/text/text.go @@ -11,7 +11,9 @@ import ( // A Line contains the measurements of a line of text. type Line struct { - Text String + Layout []Glyph + // Len is the length in UTF8 bytes of the line. + Len int // Width is the width of the line. Width fixed.Int26_6 // Ascent is the height above the baseline. @@ -23,16 +25,9 @@ type Line struct { Bounds fixed.Rectangle26_6 } -type String struct { - String string - // Advances contain the advance of each rune in String. - Advances []fixed.Int26_6 -} - -// A Layout contains the measurements of a body of text as -// a list of Lines. -type Layout struct { - Lines []Line +type Glyph struct { + Rune rune + Advance fixed.Int26_6 } // LayoutOptions specify the constraints of a text layout. @@ -59,8 +54,8 @@ 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) op.CallOp + Layout(ppem fixed.Int26_6, str string, opts LayoutOptions) []Line + Shape(ppem fixed.Int26_6, str []Glyph) op.CallOp Metrics(ppem fixed.Int26_6) font.Metrics } diff --git a/widget/editor.go b/widget/editor.go index 0ae7d359..aed6dd22 100644 --- a/widget/editor.go +++ b/widget/editor.go @@ -273,11 +273,13 @@ func (e *Editor) layout(gtx *layout.Context, sh text.Shaper) { } e.shapes = e.shapes[:0] for { - str, off, ok := it.Next() + start, end, layout, off, ok := it.Next() if !ok { break } - path := sh.Shape(gtx, e.font, str) + // TODO: remove + str := e.rr.String()[start:end] + path := sh.Shape(gtx, e.font, str, layout) e.shapes = append(e.shapes, line{off, path}) } @@ -433,15 +435,13 @@ func (e *Editor) moveCoord(c unit.Converter, pos image.Point) { func (e *Editor) layoutText(c unit.Converter, s text.Shaper, font text.Font) ([]text.Line, layout.Dimensions) { txt := e.rr.String() opts := text.LayoutOptions{MaxWidth: e.maxWidth} - textLayout := s.Layout(c, font, txt, opts) - lines := textLayout.Lines + lines := s.Layout(c, font, txt, opts) dims := linesDimens(lines) for i := 0; i < len(lines)-1; i++ { - s := lines[i].Text.String // To avoid layout flickering while editing, assume a soft newline takes // up all available space. - if len(s) > 0 { - r, _ := utf8.DecodeLastRuneInString(s) + if layout := lines[i].Layout; len(layout) > 0 { + r := layout[len(layout)-1].Rune if r != '\n' { dims.Size.X = e.maxWidth break @@ -459,21 +459,18 @@ loop: l := e.lines[carLine] y += (prevDesc + l.Ascent).Ceil() prevDesc = l.Descent - if carLine == len(e.lines)-1 || idx+len(l.Text.String) > e.rr.caret { - str := l.Text.String - for _, adv := range l.Text.Advances { + if carLine == len(e.lines)-1 || idx+len(l.Layout) > e.rr.caret { + for _, g := range l.Layout { if idx == e.rr.caret { break loop } - x += adv - _, s := utf8.DecodeRuneInString(str) - idx += s - str = str[s:] + x += g.Advance + idx += utf8.RuneLen(g.Rune) carCol++ } break } - idx += len(l.Text.String) + idx += l.Len } x += align(e.Alignment, e.lines[carLine].Width, e.viewSize.X) return @@ -553,11 +550,11 @@ func (e *Editor) moveToLine(carX fixed.Int26_6, carLine2 int) fixed.Int26_6 { // Move to start of line2. if carLine2 > carLine { for i := carLine; i < carLine2; i++ { - e.rr.caret += len(e.lines[i].Text.String) + e.rr.caret += e.lines[i].Len } } else { for i := carLine - 1; i >= carLine2; i-- { - e.rr.caret -= len(e.lines[i].Text.String) + e.rr.caret -= e.lines[i].Len } } } @@ -569,15 +566,15 @@ func (e *Editor) moveToLine(carX fixed.Int26_6, carLine2 int) fixed.Int26_6 { end = 1 } // Move to rune closest to previous horizontal position. - for i := 0; i < len(l2.Text.Advances)-end; i++ { - adv := l2.Text.Advances[i] + for i := 0; i < len(l2.Layout)-end; i++ { + g := l2.Layout[i] if carX2 >= carX { break } - if carX2+adv-carX >= carX-carX2 { + if carX2+g.Advance-carX >= carX-carX2 { break } - carX2 += adv + carX2 += g.Advance _, s := e.rr.runeAt(e.rr.caret) e.rr.caret += s } @@ -593,11 +590,11 @@ func (e *Editor) Move(distance int) { func (e *Editor) moveStart() { carLine, carCol, x, _ := e.layoutCaret() - advances := e.lines[carLine].Text.Advances + layout := e.lines[carLine].Layout for i := carCol - 1; i >= 0; i-- { _, s := e.rr.runeBefore(e.rr.caret) e.rr.caret -= s - x -= advances[i] + x -= layout[i].Advance } e.carXOff = -x } @@ -610,8 +607,9 @@ func (e *Editor) moveEnd() { if carLine < len(e.lines)-1 { end = 1 } - for i := carCol; i < len(l.Text.Advances)-end; i++ { - adv := l.Text.Advances[i] + layout := l.Layout + for i := carCol; i < len(layout)-end; i++ { + adv := layout[i].Advance _, s := e.rr.runeAt(e.rr.caret) e.rr.caret += s x += adv diff --git a/widget/label.go b/widget/label.go index 768ae797..7e9cd158 100644 --- a/widget/label.go +++ b/widget/label.go @@ -32,11 +32,12 @@ type lineIterator struct { Offset image.Point y, prevDesc fixed.Int26_6 + txtOff int } const inf = 1e6 -func (l *lineIterator) Next() (text.String, f32.Point, bool) { +func (l *lineIterator) Next() (int, int, []text.Glyph, f32.Point, bool) { for len(l.Lines) > 0 { line := l.Lines[0] l.Lines = l.Lines[1:] @@ -50,42 +51,41 @@ func (l *lineIterator) Next() (text.String, f32.Point, bool) { if (off.Y + line.Bounds.Min.Y).Floor() > l.Clip.Max.Y { break } + layout := line.Layout + start := l.txtOff + l.txtOff += line.Len if (off.Y + line.Bounds.Max.Y).Ceil() < l.Clip.Min.Y { continue } - str := line.Text - for len(str.Advances) > 0 { - adv := str.Advances[0] + for len(layout) > 0 { + g := layout[0] + adv := g.Advance if (off.X + adv + line.Bounds.Max.X - line.Width).Ceil() >= l.Clip.Min.X { break } off.X += adv - _, s := utf8.DecodeRuneInString(str.String) - str.String = str.String[s:] - str.Advances = str.Advances[1:] + layout = layout[1:] + start += utf8.RuneLen(g.Rune) } - n := 0 + end := start endx := off.X - for i, adv := range str.Advances { + for i, g := range layout { if (endx + line.Bounds.Min.X).Floor() > l.Clip.Max.X { - str.String = str.String[:n] - str.Advances = str.Advances[:i] + layout = layout[:i] break } - _, s := utf8.DecodeRuneInString(str.String[n:]) - n += s - endx += adv + end += utf8.RuneLen(g.Rune) + endx += g.Advance } offf := f32.Point{X: float32(off.X) / 64, Y: float32(off.Y) / 64} - return str, offf, true + return start, end, layout, offf, true } - return text.String{}, f32.Point{}, false + return 0, 0, nil, f32.Point{}, false } func (l Label) Layout(gtx *layout.Context, s text.Shaper, font text.Font, txt string) { cs := gtx.Constraints - textLayout := s.Layout(gtx, font, txt, text.LayoutOptions{MaxWidth: cs.Width.Max}) - lines := textLayout.Lines + lines := s.Layout(gtx, font, txt, text.LayoutOptions{MaxWidth: cs.Width.Max}) if max := l.MaxLines; max > 0 && len(lines) > max { lines = lines[:max] } @@ -100,7 +100,7 @@ func (l Label) Layout(gtx *layout.Context, s text.Shaper, font text.Font, txt st Width: dims.Size.X, } for { - str, off, ok := it.Next() + start, end, layout, off, ok := it.Next() if !ok { break } @@ -108,7 +108,8 @@ func (l Label) Layout(gtx *layout.Context, s text.Shaper, font text.Font, txt st var stack op.StackOp stack.Push(gtx.Ops) op.TransformOp{}.Offset(off).Add(gtx.Ops) - s.Shape(gtx, font, str).Add(gtx.Ops) + str := txt[start:end] + s.Shape(gtx, font, str, layout).Add(gtx.Ops) paint.PaintOp{Rect: lclip}.Add(gtx.Ops) stack.Pop() }