From 5e8d969034591df390339c99b17d7ce9c27a72f3 Mon Sep 17 00:00:00 2001
From: Zyko <13394516+Zyko0@users.noreply.github.com>
Date: Sat, 27 Jul 2024 17:41:53 +0200
Subject: [PATCH 1/2] PoC text/v2 glyph atlas

---
 go.mod                      |  3 ++-
 go.sum                      | 10 ++++++++++
 text/v2/atlas.go            | 32 ++++++++++++++++++++++++++++++++
 text/v2/glyph.go            | 11 +++++++----
 text/v2/gotext.go           | 14 ++++++++++----
 text/v2/gotextfacesource.go |  5 ++---
 text/v2/gotextseg.go        | 19 ++++++++++++++++---
 text/v2/gox.go              | 18 +++++++++++-------
 text/v2/layout.go           | 17 +++++++++++++----
 text/v2/text.go             |  6 ++++++
 10 files changed, 109 insertions(+), 26 deletions(-)
 create mode 100644 text/v2/atlas.go

diff --git a/go.mod b/go.mod
index ac8c82711..b8914bd5d 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module github.com/hajimehoshi/ebiten/v2
 
-go 1.19
+go 1.21.1
 
 require (
 	github.com/ebitengine/gomobile v0.0.0-20240518074828-e86332849895
@@ -23,6 +23,7 @@ require (
 )
 
 require (
+	github.com/Zyko0/Ebiary/atlas v0.0.0-20240727152911-c0be754219b9 // indirect
 	github.com/jfreymuth/vorbis v1.0.2 // indirect
 	github.com/pierrec/lz4/v4 v4.1.21 // indirect
 	golang.org/x/mod v0.19.0 // indirect
diff --git a/go.sum b/go.sum
index 7131682fc..44de873b2 100644
--- a/go.sum
+++ b/go.sum
@@ -1,3 +1,13 @@
+github.com/Zyko0/Ebiary/atlas v0.0.0-20240715185308-15c9f3ed18e4 h1:hw0xjh6636KyizJh10Akyym5q+gJT/JZaG5YoOECpCo=
+github.com/Zyko0/Ebiary/atlas v0.0.0-20240715185308-15c9f3ed18e4/go.mod h1:TqaiWLulZjjwPydGAqz6EqHELgtnn/swD/0PlPovCp8=
+github.com/Zyko0/Ebiary/atlas v0.0.0-20240727132256-058f84c22395 h1:4kBG4iBHZD8ZnwzYarhCYhBP3bTwTRXHYqjo/TxAvUI=
+github.com/Zyko0/Ebiary/atlas v0.0.0-20240727132256-058f84c22395/go.mod h1:3Uar+fYP2hzgYiXkoReBociscUtpaBMXvjAEjph13pk=
+github.com/Zyko0/Ebiary/atlas v0.0.0-20240727143531-e678f4f326f6 h1:sRjhOIw0+bqFvKOw+cUmIw0LFkhbo95KlKeIDupVp6c=
+github.com/Zyko0/Ebiary/atlas v0.0.0-20240727143531-e678f4f326f6/go.mod h1:3Uar+fYP2hzgYiXkoReBociscUtpaBMXvjAEjph13pk=
+github.com/Zyko0/Ebiary/atlas v0.0.0-20240727145901-a622e72da2b1 h1:Tv7NzEiyRLfo2PJNo+IQRf0VdCskblash/RGnSZsQJQ=
+github.com/Zyko0/Ebiary/atlas v0.0.0-20240727145901-a622e72da2b1/go.mod h1:3Uar+fYP2hzgYiXkoReBociscUtpaBMXvjAEjph13pk=
+github.com/Zyko0/Ebiary/atlas v0.0.0-20240727152911-c0be754219b9 h1:qfCLi8fCRFO3zVs9c60Ey2xJa+8VfVRKJlgbQVjYfpk=
+github.com/Zyko0/Ebiary/atlas v0.0.0-20240727152911-c0be754219b9/go.mod h1:3Uar+fYP2hzgYiXkoReBociscUtpaBMXvjAEjph13pk=
 github.com/ebitengine/gomobile v0.0.0-20240518074828-e86332849895 h1:48bCqKTuD7Z0UovDfvpCn7wZ0GUZ+yosIteNDthn3FU=
 github.com/ebitengine/gomobile v0.0.0-20240518074828-e86332849895/go.mod h1:XZdLv05c5hOZm3fM2NlJ92FyEZjnslcMcNRrhxs8+8M=
 github.com/ebitengine/hideconsole v1.0.0 h1:5J4U0kXF+pv/DhiXt5/lTz0eO5ogJ1iXb8Yj1yReDqE=
diff --git a/text/v2/atlas.go b/text/v2/atlas.go
new file mode 100644
index 000000000..ad7c47fac
--- /dev/null
+++ b/text/v2/atlas.go
@@ -0,0 +1,32 @@
+package text
+
+import (
+	"github.com/Zyko0/Ebiary/atlas"
+)
+
+type glyphAtlas struct {
+	atlas *atlas.Atlas
+}
+
+func newGlyphAtlas() *glyphAtlas {
+	return &glyphAtlas{
+		// Note: 128x128 is arbitrary, maybe a better value can be inferred
+		// from the font size or something
+		atlas: atlas.New(128, 128, nil),
+	}
+}
+
+func (g *glyphAtlas) NewImage(w, h int) *atlas.Image {
+	if img := g.atlas.NewImage(w, h); img != nil {
+		return img
+	}
+
+	// Grow atlas
+	old := g.atlas.Image()
+
+	aw, ah := g.atlas.Bounds().Dx()*2, g.atlas.Bounds().Dy()*2
+	g.atlas = atlas.New(aw, ah, nil)
+	g.atlas.Image().DrawImage(old, nil)
+
+	return g.NewImage(w, h)
+}
diff --git a/text/v2/glyph.go b/text/v2/glyph.go
index cdf03df26..9af846af6 100644
--- a/text/v2/glyph.go
+++ b/text/v2/glyph.go
@@ -18,7 +18,7 @@ import (
 	"math"
 	"sync"
 
-	"github.com/hajimehoshi/ebiten/v2"
+	"github.com/Zyko0/Ebiary/atlas"
 	"github.com/hajimehoshi/ebiten/v2/internal/hook"
 )
 
@@ -38,17 +38,18 @@ func init() {
 }
 
 type glyphImageCacheEntry struct {
-	image *ebiten.Image
+	image *atlas.Image
 	atime int64
 }
 
 type glyphImageCache[Key comparable] struct {
+	atlas *glyphAtlas
 	cache map[Key]*glyphImageCacheEntry
 	atime int64
 	m     sync.Mutex
 }
 
-func (g *glyphImageCache[Key]) getOrCreate(face Face, key Key, create func() *ebiten.Image) *ebiten.Image {
+func (g *glyphImageCache[Key]) getOrCreate(face Face, key Key, create func(a *glyphAtlas) *atlas.Image) *atlas.Image {
 	g.m.Lock()
 	defer g.m.Unlock()
 
@@ -61,10 +62,11 @@ func (g *glyphImageCache[Key]) getOrCreate(face Face, key Key, create func() *eb
 	}
 
 	if g.cache == nil {
+		g.atlas = newGlyphAtlas()
 		g.cache = map[Key]*glyphImageCacheEntry{}
 	}
 
-	img := create()
+	img := create(g.atlas)
 	e = &glyphImageCacheEntry{
 		image: img,
 	}
@@ -91,6 +93,7 @@ func (g *glyphImageCache[Key]) getOrCreate(face Face, key Key, create func() *eb
 					continue
 				}
 				delete(g.cache, key)
+				g.atlas.atlas.Free(e.image)
 			}
 		}
 	}
diff --git a/text/v2/gotext.go b/text/v2/gotext.go
index 7b42576dd..9fb81869a 100644
--- a/text/v2/gotext.go
+++ b/text/v2/gotext.go
@@ -19,6 +19,7 @@ import (
 	"encoding/binary"
 	"fmt"
 
+	"github.com/Zyko0/Ebiary/atlas"
 	"github.com/go-text/typesetting/di"
 	glanguage "github.com/go-text/typesetting/language"
 	"github.com/go-text/typesetting/opentype/api/font"
@@ -310,11 +311,16 @@ func (g *GoTextFace) appendGlyphsForLine(glyphs []Glyph, line string, indexOffse
 		}))
 		// Append a glyph even if img is nil.
 		// This is necessary to return index information for control characters.
+		var ebitenImage *ebiten.Image
+		if img != nil {
+			ebitenImage = img.Image()
+		}
 		glyphs = append(glyphs, Glyph{
+			img:               img,
 			StartIndexInBytes: indexOffset + glyph.startIndex,
 			EndIndexInBytes:   indexOffset + glyph.endIndex,
 			GID:               uint32(glyph.shapingGlyph.GlyphID),
-			Image:             img,
+			Image:             ebitenImage,
 			X:                 float64(imgX),
 			Y:                 float64(imgY),
 		})
@@ -327,7 +333,7 @@ func (g *GoTextFace) appendGlyphsForLine(glyphs []Glyph, line string, indexOffse
 	return glyphs
 }
 
-func (g *GoTextFace) glyphImage(glyph glyph, origin fixed.Point26_6) (*ebiten.Image, int, int) {
+func (g *GoTextFace) glyphImage(glyph glyph, origin fixed.Point26_6) (*atlas.Image, int, int) {
 	if g.direction().isHorizontal() {
 		origin.X = adjustGranularity(origin.X, g)
 		origin.Y &^= ((1 << 6) - 1)
@@ -347,8 +353,8 @@ func (g *GoTextFace) glyphImage(glyph glyph, origin fixed.Point26_6) (*ebiten.Im
 		yoffset:    subpixelOffset.Y,
 		variations: g.ensureVariationsString(),
 	}
-	img := g.Source.getOrCreateGlyphImage(g, key, func() *ebiten.Image {
-		return segmentsToImage(glyph.scaledSegments, subpixelOffset, b)
+	img := g.Source.getOrCreateGlyphImage(g, key, func(a *glyphAtlas) *atlas.Image {
+		return segmentsToImage(a, glyph.scaledSegments, subpixelOffset, b)
 	})
 
 	imgX := (origin.X + b.Min.X).Floor()
diff --git a/text/v2/gotextfacesource.go b/text/v2/gotextfacesource.go
index 3e84adde6..9c15789f0 100644
--- a/text/v2/gotextfacesource.go
+++ b/text/v2/gotextfacesource.go
@@ -19,6 +19,7 @@ import (
 	"io"
 	"sync"
 
+	"github.com/Zyko0/Ebiary/atlas"
 	"github.com/go-text/typesetting/font"
 	"github.com/go-text/typesetting/language"
 	"github.com/go-text/typesetting/opentype/api"
@@ -26,8 +27,6 @@ import (
 	"github.com/go-text/typesetting/opentype/loader"
 	"github.com/go-text/typesetting/shaping"
 	"golang.org/x/image/math/fixed"
-
-	"github.com/hajimehoshi/ebiten/v2"
 )
 
 type goTextOutputCacheKey struct {
@@ -282,7 +281,7 @@ func (g *GoTextFaceSource) scale(size float64) float64 {
 	return size / float64(g.f.Upem())
 }
 
-func (g *GoTextFaceSource) getOrCreateGlyphImage(goTextFace *GoTextFace, key goTextGlyphImageCacheKey, create func() *ebiten.Image) *ebiten.Image {
+func (g *GoTextFaceSource) getOrCreateGlyphImage(goTextFace *GoTextFace, key goTextGlyphImageCacheKey, create func(a *glyphAtlas) *atlas.Image) *atlas.Image {
 	if g.glyphImageCache == nil {
 		g.glyphImageCache = map[float64]*glyphImageCache[goTextGlyphImageCacheKey]{}
 	}
diff --git a/text/v2/gotextseg.go b/text/v2/gotextseg.go
index 4875bb4ba..3d7fa9e9d 100644
--- a/text/v2/gotextseg.go
+++ b/text/v2/gotextseg.go
@@ -16,12 +16,15 @@ package text
 
 import (
 	"image"
+	"image/color"
 	"image/draw"
 	"math"
 
+	"github.com/Zyko0/Ebiary/atlas"
+	gvector "golang.org/x/image/vector"
+
 	"github.com/go-text/typesetting/opentype/api"
 	"golang.org/x/image/math/fixed"
-	gvector "golang.org/x/image/vector"
 
 	"github.com/hajimehoshi/ebiten/v2"
 	"github.com/hajimehoshi/ebiten/v2/vector"
@@ -75,7 +78,14 @@ func segmentsToBounds(segs []api.Segment) fixed.Rectangle26_6 {
 	}
 }
 
-func segmentsToImage(segs []api.Segment, subpixelOffset fixed.Point26_6, glyphBounds fixed.Rectangle26_6) *ebiten.Image {
+var whiteImage = ebiten.NewImage(3, 3)
+
+func init() {
+	whiteImage.Fill(color.White)
+	//whiteImage.Set(1, 1, color.White)
+}
+
+func segmentsToImage(a *glyphAtlas, segs []api.Segment, subpixelOffset fixed.Point26_6, glyphBounds fixed.Rectangle26_6) *atlas.Image {
 	if len(segs) == 0 {
 		return nil
 	}
@@ -122,7 +132,10 @@ func segmentsToImage(segs []api.Segment, subpixelOffset fixed.Point26_6, glyphBo
 
 	dst := image.NewRGBA(image.Rect(0, 0, w, h))
 	rast.Draw(dst, dst.Bounds(), image.Opaque, image.Point{})
-	return ebiten.NewImageFromImage(dst)
+	img := a.NewImage(w, h)
+	img.Image().WritePixels(dst.Pix)
+
+	return img
 }
 
 func appendVectorPathFromSegments(path *vector.Path, segs []api.Segment, x, y float32) {
diff --git a/text/v2/gox.go b/text/v2/gox.go
index 625215d82..19d7160a6 100644
--- a/text/v2/gox.go
+++ b/text/v2/gox.go
@@ -21,7 +21,7 @@ import (
 	"golang.org/x/image/font"
 	"golang.org/x/image/math/fixed"
 
-	"github.com/hajimehoshi/ebiten/v2"
+	"github.com/Zyko0/Ebiary/atlas"
 	"github.com/hajimehoshi/ebiten/v2/vector"
 )
 
@@ -119,9 +119,10 @@ func (s *GoXFace) appendGlyphsForLine(glyphs []Glyph, line string, indexOffset i
 		// Append a glyph even if img is nil.
 		// This is necessary to return index information for control characters.
 		glyphs = append(glyphs, Glyph{
+			img:               img,
 			StartIndexInBytes: indexOffset + i,
 			EndIndexInBytes:   indexOffset + i + size,
-			Image:             img,
+			Image:             img.Image(),
 			X:                 float64(imgX),
 			Y:                 float64(imgY),
 		})
@@ -132,7 +133,7 @@ func (s *GoXFace) appendGlyphsForLine(glyphs []Glyph, line string, indexOffset i
 	return glyphs
 }
 
-func (s *GoXFace) glyphImage(r rune, origin fixed.Point26_6) (*ebiten.Image, int, int, fixed.Int26_6) {
+func (s *GoXFace) glyphImage(r rune, origin fixed.Point26_6) (*atlas.Image, int, int, fixed.Int26_6) {
 	// Assume that GoXFace's direction is always horizontal.
 	origin.X = adjustGranularity(origin.X, s)
 	origin.Y &^= ((1 << 6) - 1)
@@ -146,15 +147,15 @@ func (s *GoXFace) glyphImage(r rune, origin fixed.Point26_6) (*ebiten.Image, int
 		rune:    r,
 		xoffset: subpixelOffset.X,
 	}
-	img := s.glyphImageCache.getOrCreate(s, key, func() *ebiten.Image {
-		return s.glyphImageImpl(r, subpixelOffset, b)
+	img := s.glyphImageCache.getOrCreate(s, key, func(a *glyphAtlas) *atlas.Image {
+		return s.glyphImageImpl(a, r, subpixelOffset, b)
 	})
 	imgX := (origin.X + b.Min.X).Floor()
 	imgY := (origin.Y + b.Min.Y).Floor()
 	return img, imgX, imgY, a
 }
 
-func (s *GoXFace) glyphImageImpl(r rune, subpixelOffset fixed.Point26_6, glyphBounds fixed.Rectangle26_6) *ebiten.Image {
+func (s *GoXFace) glyphImageImpl(a *glyphAtlas, r rune, subpixelOffset fixed.Point26_6, glyphBounds fixed.Rectangle26_6) *atlas.Image {
 	w, h := (glyphBounds.Max.X - glyphBounds.Min.X).Ceil(), (glyphBounds.Max.Y - glyphBounds.Min.Y).Ceil()
 	if w == 0 || h == 0 {
 		return nil
@@ -178,7 +179,10 @@ func (s *GoXFace) glyphImageImpl(r rune, subpixelOffset fixed.Point26_6, glyphBo
 	}
 	d.DrawString(string(r))
 
-	return ebiten.NewImageFromImage(rgba)
+	img := a.NewImage(w, h)
+	img.Image().WritePixels(rgba.Pix)
+
+	return img
 }
 
 // direction implements Face.
diff --git a/text/v2/layout.go b/text/v2/layout.go
index fe874e01a..0dcad471a 100644
--- a/text/v2/layout.go
+++ b/text/v2/layout.go
@@ -17,6 +17,7 @@ package text
 import (
 	"strings"
 
+	"github.com/Zyko0/Ebiary/atlas"
 	"github.com/hajimehoshi/ebiten/v2"
 	"github.com/hajimehoshi/ebiten/v2/vector"
 )
@@ -111,15 +112,23 @@ func Draw(dst *ebiten.Image, text string, face Face, options *DrawOptions) {
 
 	geoM := drawOp.GeoM
 
+	dl := &atlas.DrawList{}
+	dc := &atlas.DrawCommand{}
 	for _, g := range AppendGlyphs(nil, text, face, &layoutOp) {
 		if g.Image == nil {
 			continue
 		}
-		drawOp.GeoM.Reset()
-		drawOp.GeoM.Translate(g.X, g.Y)
-		drawOp.GeoM.Concat(geoM)
-		dst.DrawImage(g.Image, &drawOp)
+		dc.GeoM.Reset()
+		dc.GeoM.Translate(g.X, g.Y)
+		dc.GeoM.Concat(geoM)
+		dc.ColorScale = drawOp.ColorScale
+		dc.Image = g.img
+		dl.Add(dc)
 	}
+	dl.Flush(dst, &atlas.DrawOptions{
+		Blend:  drawOp.Blend,
+		Filter: drawOp.Filter,
+	})
 }
 
 // AppendGlyphs appends glyphs to the given slice and returns a slice.
diff --git a/text/v2/text.go b/text/v2/text.go
index 32d750b71..5c17cae69 100644
--- a/text/v2/text.go
+++ b/text/v2/text.go
@@ -22,6 +22,7 @@ import (
 
 	"golang.org/x/image/math/fixed"
 
+	"github.com/Zyko0/Ebiary/atlas"
 	"github.com/hajimehoshi/ebiten/v2"
 	"github.com/hajimehoshi/ebiten/v2/vector"
 )
@@ -115,6 +116,11 @@ func adjustGranularity(x fixed.Int26_6, face Face) fixed.Int26_6 {
 
 // Glyph represents one glyph to render.
 type Glyph struct {
+	// Image is a rasterized glyph image.
+	// Image is a grayscale image i.e. RGBA values are the same.
+	// Image should be used as a render source and should not be modified.
+	img *atlas.Image
+
 	// StartIndexInBytes is the start index in bytes for the given string at AppendGlyphs.
 	StartIndexInBytes int
 

From 4601cffabafa7bfadfd0330122fdef87a7dd675c Mon Sep 17 00:00:00 2001
From: Zyko <13394516+Zyko0@users.noreply.github.com>
Date: Sat, 27 Jul 2024 18:01:06 +0200
Subject: [PATCH 2/2] Cleanup

---
 text/v2/atlas.go     | 4 ++++
 text/v2/glyph.go     | 2 +-
 text/v2/gotextseg.go | 9 ---------
 3 files changed, 5 insertions(+), 10 deletions(-)

diff --git a/text/v2/atlas.go b/text/v2/atlas.go
index ad7c47fac..733c99d4a 100644
--- a/text/v2/atlas.go
+++ b/text/v2/atlas.go
@@ -30,3 +30,7 @@ func (g *glyphAtlas) NewImage(w, h int) *atlas.Image {
 
 	return g.NewImage(w, h)
 }
+
+func (g *glyphAtlas) Free(img *atlas.Image) {
+	g.atlas.Free(img)
+}
diff --git a/text/v2/glyph.go b/text/v2/glyph.go
index 9af846af6..9b08c345b 100644
--- a/text/v2/glyph.go
+++ b/text/v2/glyph.go
@@ -93,7 +93,7 @@ func (g *glyphImageCache[Key]) getOrCreate(face Face, key Key, create func(a *gl
 					continue
 				}
 				delete(g.cache, key)
-				g.atlas.atlas.Free(e.image)
+				g.atlas.Free(e.image)
 			}
 		}
 	}
diff --git a/text/v2/gotextseg.go b/text/v2/gotextseg.go
index 3d7fa9e9d..7579e9bc0 100644
--- a/text/v2/gotextseg.go
+++ b/text/v2/gotextseg.go
@@ -16,7 +16,6 @@ package text
 
 import (
 	"image"
-	"image/color"
 	"image/draw"
 	"math"
 
@@ -26,7 +25,6 @@ import (
 	"github.com/go-text/typesetting/opentype/api"
 	"golang.org/x/image/math/fixed"
 
-	"github.com/hajimehoshi/ebiten/v2"
 	"github.com/hajimehoshi/ebiten/v2/vector"
 )
 
@@ -78,13 +76,6 @@ func segmentsToBounds(segs []api.Segment) fixed.Rectangle26_6 {
 	}
 }
 
-var whiteImage = ebiten.NewImage(3, 3)
-
-func init() {
-	whiteImage.Fill(color.White)
-	//whiteImage.Set(1, 1, color.White)
-}
-
 func segmentsToImage(a *glyphAtlas, segs []api.Segment, subpixelOffset fixed.Point26_6, glyphBounds fixed.Rectangle26_6) *atlas.Image {
 	if len(segs) == 0 {
 		return nil