text/v2: add AppendVectorPath

Closes #1937
Updates #2454

examples/fontvector/main.go

@@ -15,17 +15,15 @@
 package main
 
 import (
+	"bytes"
 	"image"
 	"image/color"
 	"log"
 	"math"
 
-	"golang.org/x/image/font"
-	"golang.org/x/image/font/sfnt"
-	"golang.org/x/image/math/fixed"
-
 	"github.com/hajimehoshi/ebiten/v2"
 	"github.com/hajimehoshi/ebiten/v2/examples/resources/fonts"
+	"github.com/hajimehoshi/ebiten/v2/text/v2"
 	"github.com/hajimehoshi/ebiten/v2/vector"
 )
 
@@ -46,13 +44,8 @@ const (
 	screenHeight = 480
 )
 
-func fixed26_6ToFloat32(x fixed.Int26_6) float32 {
-	return float32(x>>6) + float32(x&((1<<6)-1))/float32(1<<6)
-}
-
 type Game struct {
-	segments sfnt.Segments
+	path     vector.Path
-	bounds   fixed.Rectangle26_6
 	vertices []ebiten.Vertex
 	indices  []uint16
 
@@ -60,83 +53,37 @@ type Game struct {
 }
 
 func (g *Game) Update() error {
+	if g.tick == 0 {
+		s, err := text.NewGoTextFaceSource(bytes.NewReader(fonts.MPlus1pRegular_ttf))
+		if err != nil {
+			return err
+		}
+		op := &text.LayoutOptions{}
+		op.LineSpacingInPixels = 100
+		text.AppendVectorPath(&g.path, "あいうえお\nかきくけこ", &text.GoTextFace{
+			Source: s,
+			Size:   100,
+		}, op)
+	}
+
 	g.tick++
 
-	if g.segments == nil {
-		ppem := fixed.I(300)
-
-		f, err := sfnt.Parse(fonts.MPlus1pRegular_ttf)
-		if err != nil {
-			return err
-		}
-
-		var b sfnt.Buffer
-		idx, err := f.GlyphIndex(&b, 'あ')
-		if err != nil {
-			return err
-		}
-
-		segments, err := f.LoadGlyph(&b, idx, ppem, nil)
-		if err != nil {
-			return err
-		}
-		g.segments = segments
-
-		bounds, err := f.Bounds(&b, ppem, font.HintingNone)
-		if err != nil {
-			return err
-		}
-		g.bounds = bounds
-	}
 	return nil
 }
 
 func (g *Game) Draw(screen *ebiten.Image) {
-	var path vector.Path
-	for _, seg := range g.segments {
-		switch seg.Op {
-		case sfnt.SegmentOpMoveTo:
-			path.MoveTo(
-				fixed26_6ToFloat32(seg.Args[0].X),
-				fixed26_6ToFloat32(seg.Args[0].Y),
-			)
-		case sfnt.SegmentOpLineTo:
-			path.LineTo(
-				fixed26_6ToFloat32(seg.Args[0].X),
-				fixed26_6ToFloat32(seg.Args[0].Y),
-			)
-		case sfnt.SegmentOpQuadTo:
-			path.QuadTo(
-				fixed26_6ToFloat32(seg.Args[0].X),
-				fixed26_6ToFloat32(seg.Args[0].Y),
-				fixed26_6ToFloat32(seg.Args[1].X),
-				fixed26_6ToFloat32(seg.Args[1].Y),
-			)
-		case sfnt.SegmentOpCubeTo:
-			path.CubicTo(
-				fixed26_6ToFloat32(seg.Args[0].X),
-				fixed26_6ToFloat32(seg.Args[0].Y),
-				fixed26_6ToFloat32(seg.Args[1].X),
-				fixed26_6ToFloat32(seg.Args[1].Y),
-				fixed26_6ToFloat32(seg.Args[2].X),
-				fixed26_6ToFloat32(seg.Args[2].Y),
-			)
-		}
-	}
-	path.Close()
-
 	g.vertices = g.vertices[:0]
 	g.indices = g.indices[:0]
 
 	op := &vector.StrokeOptions{}
-	op.Width = 7*(float32(math.Sin(float64(g.tick)*2*math.Pi/180))+1) + 1
+	op.Width = 2*(float32(math.Sin(float64(g.tick)*2*math.Pi/180))+1) + 1
 	op.LineJoin = vector.LineJoinRound
 	op.LineCap = vector.LineCapRound
-	g.vertices, g.indices = path.AppendVerticesAndIndicesForStroke(g.vertices, g.indices, op)
+	g.vertices, g.indices = g.path.AppendVerticesAndIndicesForStroke(g.vertices, g.indices, op)
 
 	for i := range g.vertices {
-		g.vertices[i].DstX += screenWidth/2 - fixed26_6ToFloat32(g.bounds.Max.X+g.bounds.Min.X)/2
+		g.vertices[i].DstX += 50
-		g.vertices[i].DstY += screenHeight/2 - fixed26_6ToFloat32(g.bounds.Max.Y+g.bounds.Min.Y)/2
+		g.vertices[i].DstY += 50
 		g.vertices[i].SrcX = 1
 		g.vertices[i].SrcY = 1
 	}

text/v2/gotext.go

@@ -29,6 +29,7 @@ import (
 	"golang.org/x/text/language"
 
 	"github.com/hajimehoshi/ebiten/v2"
+	"github.com/hajimehoshi/ebiten/v2/vector"
 )
 
 var _ Face = (*GoTextFace)(nil)
@@ -286,14 +287,13 @@ func (g *GoTextFace) advance(text string) float64 {
 	return fixed26_6ToFloat64(output.Advance)
 }
 
-// appendGlyphs implements Face.
+// appendGlyphsForLine implements Face.
-func (g *GoTextFace) appendGlyphs(glyphs []Glyph, text string, indexOffset int, originX, originY float64) []Glyph {
+func (g *GoTextFace) appendGlyphsForLine(glyphs []Glyph, line string, indexOffset int, originX, originY float64) []Glyph {
-	_, gs := g.Source.shape(text, g)
-
 	origin := fixed.Point26_6{
 		X: float64ToFixed26_6(originX),
 		Y: float64ToFixed26_6(originY),
 	}
+	_, gs := g.Source.shape(line, g)
 	for _, glyph := range gs {
 		img, imgX, imgY := g.glyphImage(glyph, origin)
 		if img != nil {
@@ -344,6 +344,22 @@ func (g *GoTextFace) glyphImage(glyph glyph, origin fixed.Point26_6) (*ebiten.Im
 	return img, imgX, imgY
 }
 
+// appendVectorPathForLine implements Face.
+func (g *GoTextFace) appendVectorPathForLine(path *vector.Path, line string, originX, originY float64) {
+	origin := fixed.Point26_6{
+		X: float64ToFixed26_6(originX),
+		Y: float64ToFixed26_6(originY),
+	}
+	_, gs := g.Source.shape(line, g)
+	for _, glyph := range gs {
+		appendVectorPathFromSegments(path, glyph.scaledSegments, fixed26_6ToFloat32(origin.X), fixed26_6ToFloat32(origin.Y))
+		origin = origin.Add(fixed.Point26_6{
+			X: glyph.shapingGlyph.XAdvance,
+			Y: -glyph.shapingGlyph.YAdvance,
+		})
+	}
+}
+
 // direction implements Face.
 func (g *GoTextFace) direction() Direction {
 	return g.Direction

text/v2/gotextseg.go

@@ -21,9 +21,10 @@ import (
 
 	"github.com/go-text/typesetting/opentype/api"
 	"golang.org/x/image/math/fixed"
-	"golang.org/x/image/vector"
+	gvector "golang.org/x/image/vector"
 
 	"github.com/hajimehoshi/ebiten/v2"
+	"github.com/hajimehoshi/ebiten/v2/vector"
 )
 
 func segmentsToBounds(segs []api.Segment) fixed.Rectangle26_6 {
@@ -94,7 +95,7 @@ func segmentsToImage(segs []api.Segment, subpixelOffset fixed.Point26_6, glyphBo
 	biasX := fixed26_6ToFloat32(-glyphBounds.Min.X + subpixelOffset.X)
 	biasY := fixed26_6ToFloat32(-glyphBounds.Min.Y + subpixelOffset.Y)
 
-	rast := vector.NewRasterizer(w, h)
+	rast := gvector.NewRasterizer(w, h)
 	rast.DrawOp = draw.Src
 	for _, seg := range segs {
 		switch seg.Op {
@@ -120,3 +121,26 @@ func segmentsToImage(segs []api.Segment, subpixelOffset fixed.Point26_6, glyphBo
 	rast.Draw(dst, dst.Bounds(), image.Opaque, image.Point{})
 	return ebiten.NewImageFromImage(dst)
 }
+
+func appendVectorPathFromSegments(path *vector.Path, segs []api.Segment, x, y float32) {
+	for _, seg := range segs {
+		switch seg.Op {
+		case api.SegmentOpMoveTo:
+			path.MoveTo(seg.Args[0].X+x, seg.Args[0].Y+y)
+		case api.SegmentOpLineTo:
+			path.LineTo(seg.Args[0].X+x, seg.Args[0].Y+y)
+		case api.SegmentOpQuadTo:
+			path.QuadTo(
+				seg.Args[0].X+x, seg.Args[0].Y+y,
+				seg.Args[1].X+x, seg.Args[1].Y+y,
+			)
+		case api.SegmentOpCubeTo:
+			path.CubicTo(
+				seg.Args[0].X+x, seg.Args[0].Y+y,
+				seg.Args[1].X+x, seg.Args[1].Y+y,
+				seg.Args[2].X+x, seg.Args[2].Y+y,
+			)
+		}
+	}
+	path.Close()
+}

text/v2/layout.go

@@ -18,6 +18,7 @@ import (
 	"strings"
 
 	"github.com/hajimehoshi/ebiten/v2"
+	"github.com/hajimehoshi/ebiten/v2/vector"
 )
 
 // Align is the alignment that determines how to put a text.
@@ -125,15 +126,32 @@ func AppendGlyphs(glyphs []Glyph, text string, face Face, options *LayoutOptions
 	return appendGlyphs(glyphs, text, face, 0, 0, options)
 }
 
+// AppndVectorPath appends a vector path for glyphs to the given path.
+//
+// AppendVectorPath works only when face is *GoTextFace so far. For other types, AppendVectorPath does nothing.
+func AppendVectorPath(path *vector.Path, text string, face Face, options *LayoutOptions) {
+	forEachLine(text, face, options, func(line string, indexOffset int, originX, originY float64) {
+		face.appendVectorPathForLine(path, line, originX, originY)
+	})
+}
+
 // appendGlyphs appends glyphs to the given slice and returns a slice.
 //
 // appendGlyphs assumes the text is rendered with the position (x, y).
 // (x, y) might affect the subpixel rendering results.
 func appendGlyphs(glyphs []Glyph, text string, face Face, x, y float64, options *LayoutOptions) []Glyph {
-	if text == "" {
+	forEachLine(text, face, options, func(line string, indexOffset int, originX, originY float64) {
+		glyphs = face.appendGlyphsForLine(glyphs, line, indexOffset, originX+x, originY+y)
+	})
 	return glyphs
 }
 
+// forEachLine interates lines.
+func forEachLine(text string, face Face, options *LayoutOptions, f func(text string, indexOffset int, originX, originY float64)) {
+	if text == "" {
+		return
+	}
+
 	if options == nil {
 		options = &LayoutOptions{}
 	}
@@ -232,7 +250,7 @@ func appendGlyphs(glyphs []Glyph, text string, face Face, x, y float64, options
 			}
 		}
 
-		glyphs = face.appendGlyphs(glyphs, line, indexOffset, originX+offsetX+x, originY+offsetY+y)
+		f(line, indexOffset, originX+offsetX, originY+offsetY)
 
 		if !found {
 			break
@@ -253,8 +271,6 @@ func appendGlyphs(glyphs []Glyph, text string, face Face, x, y float64, options
 			originX -= options.LineSpacingInPixels
 		}
 	}
-
-	return glyphs
 }
 
 type horizontalAlign int

text/v2/std.go

@@ -22,6 +22,7 @@ import (
 	"golang.org/x/image/math/fixed"
 
 	"github.com/hajimehoshi/ebiten/v2"
+	"github.com/hajimehoshi/ebiten/v2/vector"
 )
 
 var _ Face = (*StdFace)(nil)
@@ -84,8 +85,8 @@ func (s *StdFace) advance(text string) float64 {
 	return fixed26_6ToFloat64(font.MeasureString(s.f, text))
 }
 
-// appendGlyphs implements Face.
+// appendGlyphsForLine implements Face.
-func (s *StdFace) appendGlyphs(glyphs []Glyph, text string, indexOffset int, originX, originY float64) []Glyph {
+func (s *StdFace) appendGlyphsForLine(glyphs []Glyph, line string, indexOffset int, originX, originY float64) []Glyph {
 	s.copyCheck()
 
 	origin := fixed.Point26_6{
@@ -94,7 +95,7 @@ func (s *StdFace) appendGlyphs(glyphs []Glyph, text string, indexOffset int, ori
 	}
 	prevR := rune(-1)
 
-	for i, r := range text {
+	for i, r := range line {
 		if prevR >= 0 {
 			origin.X += s.f.Kern(prevR, r)
 		}
@@ -102,7 +103,7 @@ func (s *StdFace) appendGlyphs(glyphs []Glyph, text string, indexOffset int, ori
 		if img != nil {
 			// Adjust the position to the integers.
 			// The current glyph images assume that they are rendered on integer positions so far.
-			_, size := utf8.DecodeRuneInString(text[i:])
+			_, size := utf8.DecodeRuneInString(line[i:])
 			glyphs = append(glyphs, Glyph{
 				StartIndexInBytes: indexOffset + i,
 				EndIndexInBytes:   indexOffset + i + size,
@@ -173,6 +174,10 @@ func (s *StdFace) direction() Direction {
 	return DirectionLeftToRight
 }
 
+// appendVectorPathForLine implements Face.
+func (s *StdFace) appendVectorPathForLine(path *vector.Path, text string, originX, originY float64) {
+}
+
 // Metrics implelements Face.
 func (s *StdFace) private() {
 }

text/v2/text.go

@@ -24,6 +24,7 @@ import (
 	"golang.org/x/image/math/fixed"
 
 	"github.com/hajimehoshi/ebiten/v2"
+	"github.com/hajimehoshi/ebiten/v2/vector"
 )
 
 // Face is an interface representing a font face. The implementations are only GoTextFace and StdFace.
@@ -38,7 +39,8 @@ type Face interface {
 
 	advance(text string) float64
 
-	appendGlyphs(glyphs []Glyph, text string, indexOffset int, originX, originY float64) []Glyph
+	appendGlyphsForLine(glyphs []Glyph, line string, indexOffset int, originX, originY float64) []Glyph
+	appendVectorPathForLine(path *vector.Path, text string, originX, originY float64)
 
 	direction() Direction