text/v2: add Glyph.OriginOffset{X,Y}

Closes #3070

examples/text/main.go

@@ -21,7 +21,9 @@ import (
 	"math"
 
 	"github.com/hajimehoshi/ebiten/v2"
+	"github.com/hajimehoshi/ebiten/v2/ebitenutil"
 	"github.com/hajimehoshi/ebiten/v2/examples/resources/fonts"
+	"github.com/hajimehoshi/ebiten/v2/inpututil"
 	"github.com/hajimehoshi/ebiten/v2/text/v2"
 	"github.com/hajimehoshi/ebiten/v2/vector"
 )
@@ -58,10 +60,8 @@ func init() {
 }
 
 type Game struct {
-	counter        int
-	kanjiText      []rune
-	kanjiTextColor color.RGBA
-	glyphs         []text.Glyph
+	glyphs      []text.Glyph
+	showOrigins bool
 }
 
 func (g *Game) Update() error {
@@ -71,10 +71,15 @@ func (g *Game) Update() error {
 		op.LineSpacing = mplusNormalFace.Size * 1.5
 		g.glyphs = text.AppendGlyphs(g.glyphs, sampleText, mplusNormalFace, op)
 	}
+	if inpututil.IsKeyJustPressed(ebiten.KeyO) {
+		g.showOrigins = !g.showOrigins
+	}
 	return nil
 }
 
 func (g *Game) Draw(screen *ebiten.Image) {
+	ebitenutil.DebugPrint(screen, "Press O to show/hide origins")
+
 	gray := color.RGBA{0x80, 0x80, 0x80, 0xff}
 
 	{
@@ -147,6 +152,12 @@ func (g *Game) Draw(screen *ebiten.Image) {
 			op.ColorScale.Scale(r, g, b, 1)
 			screen.DrawImage(gl.Image, op)
 		}
+
+		if g.showOrigins {
+			for _, gl := range g.glyphs {
+				vector.DrawFilledCircle(screen, x+float32(gl.OriginX), y+float32(gl.OriginY), 2, color.RGBA{0xff, 0, 0, 0xff}, true)
+			}
+		}
 	}
 }
 

examples/texti18n/main.go

@@ -23,7 +23,9 @@ import (
 	"golang.org/x/text/language"
 
 	"github.com/hajimehoshi/ebiten/v2"
+	"github.com/hajimehoshi/ebiten/v2/ebitenutil"
 	"github.com/hajimehoshi/ebiten/v2/examples/resources/fonts"
+	"github.com/hajimehoshi/ebiten/v2/inpututil"
 	"github.com/hajimehoshi/ebiten/v2/text/v2"
 	"github.com/hajimehoshi/ebiten/v2/vector"
 )
@@ -109,13 +111,19 @@ const (
 )
 
 type Game struct {
+	showOrigins bool
 }
 
 func (g *Game) Update() error {
+	if inpututil.IsKeyJustPressed(ebiten.KeyO) {
+		g.showOrigins = !g.showOrigins
+	}
 	return nil
 }
 
 func (g *Game) Draw(screen *ebiten.Image) {
+	ebitenutil.DebugPrint(screen, "Press O to show/hide origins.\nRed points are the original origin positions.\nThe green points are the origin positions after applying the offset.")
+
 	gray := color.RGBA{0x80, 0x80, 0x80, 0xff}
 
 	{
@@ -126,13 +134,21 @@ func (g *Game) Draw(screen *ebiten.Image) {
 			Size:      24,
 			Language:  language.Arabic,
 		}
-		x, y := screenWidth-20, 40
+		x, y := screenWidth-20, 50
 		w, h := text.Measure(arabicText, f, 0)
 		// The left upper point is not x but x-w, since the text runs in the rigth-to-left direction.
 		vector.DrawFilledRect(screen, float32(x)-float32(w), float32(y), float32(w), float32(h), gray, false)
 		op := &text.DrawOptions{}
 		op.GeoM.Translate(float64(x), float64(y))
 		text.Draw(screen, arabicText, f, op)
+
+		if g.showOrigins {
+			op := &text.LayoutOptions{}
+			for _, g := range text.AppendGlyphs(nil, arabicText, f, op) {
+				vector.DrawFilledCircle(screen, float32(x)+float32(g.OriginX+g.OriginOffsetX), float32(y)+float32(g.OriginY+g.OriginOffsetY), 2, color.RGBA{0, 0xff, 0, 0xff}, true)
+				vector.DrawFilledCircle(screen, float32(x)+float32(g.OriginX), float32(y)+float32(g.OriginY), 2, color.RGBA{0xff, 0, 0, 0xff}, true)
+			}
+		}
 	}
 	{
 		const hindiText = "चूंकि मानव परिवार के सभी सदस्यों के जन्मजात गौरव और समान"
@@ -141,12 +157,20 @@ func (g *Game) Draw(screen *ebiten.Image) {
 			Size:     24,
 			Language: language.Hindi,
 		}
-		x, y := 20, 100
+		x, y := 20, 110
 		w, h := text.Measure(hindiText, f, 0)
 		vector.DrawFilledRect(screen, float32(x), float32(y), float32(w), float32(h), gray, false)
 		op := &text.DrawOptions{}
 		op.GeoM.Translate(float64(x), float64(y))
 		text.Draw(screen, hindiText, f, op)
+
+		if g.showOrigins {
+			op := &text.LayoutOptions{}
+			for _, g := range text.AppendGlyphs(nil, hindiText, f, op) {
+				vector.DrawFilledCircle(screen, float32(x)+float32(g.OriginX+g.OriginOffsetX), float32(y)+float32(g.OriginY+g.OriginOffsetY), 2, color.RGBA{0, 0xff, 0, 0xff}, true)
+				vector.DrawFilledCircle(screen, float32(x)+float32(g.OriginX), float32(y)+float32(g.OriginY), 2, color.RGBA{0xff, 0, 0, 0xff}, true)
+			}
+		}
 	}
 	{
 		const myanmarText = "လူခပ်သိမ်း၏ မျိုးရိုးဂုဏ်သိက္ခာနှင့်တကွ"
@@ -155,12 +179,20 @@ func (g *Game) Draw(screen *ebiten.Image) {
 			Size:     24,
 			Language: language.Burmese,
 		}
-		x, y := 20, 160
+		x, y := 20, 170
 		w, h := text.Measure(myanmarText, f, 0)
 		vector.DrawFilledRect(screen, float32(x), float32(y), float32(w), float32(h), gray, false)
 		op := &text.DrawOptions{}
 		op.GeoM.Translate(float64(x), float64(y))
 		text.Draw(screen, myanmarText, f, op)
+
+		if g.showOrigins {
+			op := &text.LayoutOptions{}
+			for _, g := range text.AppendGlyphs(nil, myanmarText, f, op) {
+				vector.DrawFilledCircle(screen, float32(x)+float32(g.OriginX+g.OriginOffsetX), float32(y)+float32(g.OriginY+g.OriginOffsetY), 2, color.RGBA{0, 0xff, 0, 0xff}, true)
+				vector.DrawFilledCircle(screen, float32(x)+float32(g.OriginX), float32(y)+float32(g.OriginY), 2, color.RGBA{0xff, 0, 0, 0xff}, true)
+			}
+		}
 	}
 	{
 		const thaiText = "โดยที่การยอมรับนับถือเกียรติศักดิ์ประจำตัว"
@@ -169,12 +201,20 @@ func (g *Game) Draw(screen *ebiten.Image) {
 			Size:     24,
 			Language: language.Thai,
 		}
-		x, y := 20, 220
+		x, y := 20, 230
 		w, h := text.Measure(thaiText, f, 0)
 		vector.DrawFilledRect(screen, float32(x), float32(y), float32(w), float32(h), gray, false)
 		op := &text.DrawOptions{}
 		op.GeoM.Translate(float64(x), float64(y))
 		text.Draw(screen, thaiText, f, op)
+
+		if g.showOrigins {
+			op := &text.LayoutOptions{}
+			for _, g := range text.AppendGlyphs(nil, thaiText, f, op) {
+				vector.DrawFilledCircle(screen, float32(x)+float32(g.OriginX+g.OriginOffsetX), float32(y)+float32(g.OriginY+g.OriginOffsetY), 2, color.RGBA{0, 0xff, 0, 0xff}, true)
+				vector.DrawFilledCircle(screen, float32(x)+float32(g.OriginX), float32(y)+float32(g.OriginY), 2, color.RGBA{0xff, 0, 0, 0xff}, true)
+			}
+		}
 	}
 	{
 		const mongolianText = "ᠬᠦᠮᠦᠨ ᠪᠦᠷ ᠲᠥᠷᠥᠵᠦ ᠮᠡᠨᠳᠡᠯᠡᠬᠦ\nᠡᠷᠬᠡ ᠴᠢᠯᠥᠭᠡ ᠲᠡᠢ᠂ ᠠᠳᠠᠯᠢᠬᠠᠨ"
@@ -187,13 +227,22 @@ func (g *Game) Draw(screen *ebiten.Image) {
 			Script: language.MustParseScript("Mong"),
 		}
 		const lineSpacing = 48
-		x, y := 20, 280
+		x, y := 20, 290
 		w, h := text.Measure(mongolianText, f, lineSpacing)
 		vector.DrawFilledRect(screen, float32(x), float32(y), float32(w), float32(h), gray, false)
 		op := &text.DrawOptions{}
 		op.GeoM.Translate(float64(x), float64(y))
 		op.LineSpacing = lineSpacing
 		text.Draw(screen, mongolianText, f, op)
+
+		if g.showOrigins {
+			op := &text.LayoutOptions{}
+			op.LineSpacing = lineSpacing
+			for _, g := range text.AppendGlyphs(nil, mongolianText, f, op) {
+				vector.DrawFilledCircle(screen, float32(x)+float32(g.OriginX+g.OriginOffsetX), float32(y)+float32(g.OriginY+g.OriginOffsetY), 2, color.RGBA{0, 0xff, 0, 0xff}, true)
+				vector.DrawFilledCircle(screen, float32(x)+float32(g.OriginX), float32(y)+float32(g.OriginY), 2, color.RGBA{0xff, 0, 0, 0xff}, true)
+			}
+		}
 	}
 	{
 		const japaneseText = "あのイーハトーヴォの\nすきとおった風、\n夏でも底に冷たさを\nもつ青いそら…\nあHello World.あ"
@@ -204,7 +253,7 @@ func (g *Game) Draw(screen *ebiten.Image) {
 			Language:  language.Japanese,
 		}
 		const lineSpacing = 48
-		x, y := screenWidth-20, 280
+		x, y := screenWidth-20, 290
 		w, h := text.Measure(japaneseText, f, lineSpacing)
 		// The left upper point is not x but x-w, since the text runs in the rigth-to-left direction as the secondary direction.
 		vector.DrawFilledRect(screen, float32(x)-float32(w), float32(y), float32(w), float32(h), gray, false)
@@ -212,6 +261,15 @@ func (g *Game) Draw(screen *ebiten.Image) {
 		op.GeoM.Translate(float64(x), float64(y))
 		op.LineSpacing = lineSpacing
 		text.Draw(screen, japaneseText, f, op)
+
+		if g.showOrigins {
+			op := &text.LayoutOptions{}
+			op.LineSpacing = lineSpacing
+			for _, g := range text.AppendGlyphs(nil, japaneseText, f, op) {
+				vector.DrawFilledCircle(screen, float32(x)+float32(g.OriginX), float32(y)+float32(g.OriginY), 2, color.RGBA{0xff, 0, 0, 0xff}, true)
+				vector.DrawFilledCircle(screen, float32(x)+float32(g.OriginX+g.OriginOffsetX), float32(y)+float32(g.OriginY+g.OriginOffsetY), 2, color.RGBA{0, 0xff, 0, 0xff}, true)
+			}
+		}
 	}
 }
 

text/v2/gotext.go

@@ -304,10 +304,11 @@ func (g *GoTextFace) appendGlyphsForLine(glyphs []Glyph, line string, indexOffse
 	}
 	_, gs := g.Source.shape(line, g)
 	for _, glyph := range gs {
-		img, imgX, imgY := g.glyphImage(glyph, origin.Add(fixed.Point26_6{
+		o := origin.Add(fixed.Point26_6{
 			X: glyph.shapingGlyph.XOffset,
 			Y: -glyph.shapingGlyph.YOffset,
-		}))
+		})
+		img, imgX, imgY := g.glyphImage(glyph, o)
 		// Append a glyph even if img is nil.
 		// This is necessary to return index information for control characters.
 		glyphs = append(glyphs, Glyph{
@@ -317,6 +318,10 @@ func (g *GoTextFace) appendGlyphsForLine(glyphs []Glyph, line string, indexOffse
 			Image:             img,
 			X:                 float64(imgX),
 			Y:                 float64(imgY),
+			OriginX:           fixed26_6ToFloat64(origin.X),
+			OriginY:           fixed26_6ToFloat64(origin.Y),
+			OriginOffsetX:     fixed26_6ToFloat64(glyph.shapingGlyph.XOffset),
+			OriginOffsetY:     fixed26_6ToFloat64(-glyph.shapingGlyph.YOffset),
 		})
 		origin = origin.Add(fixed.Point26_6{
 			X: glyph.shapingGlyph.XAdvance,

text/v2/gox.go

@@ -124,6 +124,10 @@ func (s *GoXFace) appendGlyphsForLine(glyphs []Glyph, line string, indexOffset i
 			Image:             img,
 			X:                 float64(imgX),
 			Y:                 float64(imgY),
+			OriginX:           fixed26_6ToFloat64(origin.X),
+			OriginY:           fixed26_6ToFloat64(origin.Y),
+			OriginOffsetX:     0,
+			OriginOffsetY:     0,
 		})
 		origin.X += a
 		prevR = r

text/v2/text.go

@@ -141,6 +141,20 @@ type Glyph struct {
 	// The position is determined in a sequence of characters given at AppendGlyphs.
 	// The position's origin is the first character's origin position.
 	Y float64
+
+	// OriginX is the X position of the origin of this glyph.
+	OriginX float64
+
+	// OriginY is the Y position of the origin of this glyph.
+	OriginY float64
+
+	// OriginOffsetX is the adjustment value to the X position of the origin of this glyph.
+	// OriginOffsetX is usually 0, but can be non-zero for some special glyphs or glyphs in the vertical text layout.
+	OriginOffsetX float64
+
+	// OriginOffsetY is the adjustment value to the Y position of the origin of this glyph.
+	// OriginOffsetY is usually 0, but can be non-zero for some special glyphs or glyphs in the vertical text layout.
+	OriginOffsetY float64
 }
 
 // Advance returns the advanced distance from the origin position when rendering the given text with the given face.
@@ -233,10 +247,7 @@ func Measure(text string, face Face, lineSpacingInPixels float64) (width, height
 // CacheGlyphs creates all such variations for one rune, while Draw and AppendGlyphs create only necessary glyphs.
 //
 // Draw and AppendGlyphs automatically create and cache necessary glyphs, so usually you don't have to call CacheGlyphs explicitly.
-// However, for example, when you call Draw for each rune of one big text, Draw tries to create the glyph cache and render it for each rune.
-// This is very inefficient because creating a glyph image and rendering it are different operations
-// (`(*ebiten.Image).WritePixels` and `(*ebiten.Image).DrawImage`) and can never be merged as one draw call.
-// CacheGlyphs creates necessary glyphs without rendering them so that these operations are likely merged into one draw call regardless of the size of the text.
+// If you really care about the performance, CacheGlyphs might be useful.
 //
 // CacheGlyphs is concurrent-safe.
 func CacheGlyphs(text string, face Face) {