Additional metadata, Text Slot Rotation and Support for OTF fonts

go.mod

@@ -3,13 +3,14 @@ module github.com/mattermost/mattermost-plugin-memes
 go 1.12
 
 require (
-	github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0
+	github.com/fogleman/gg v1.3.0
 	github.com/gorilla/mux v1.7.4
 	github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51
 	github.com/mattermost/mattermost-server/v5 v5.24.0-rc1
 	github.com/mholt/archiver/v3 v3.3.0
 	github.com/pkg/errors v0.9.1
 	github.com/stretchr/testify v1.6.1
-	golang.org/x/image v0.0.0-20200430140353-33d19683fad8
+	golang.org/x/image v0.0.0-20220302094943-723b81ca9867
+	golang.org/x/text v0.3.7 // indirect
 	gopkg.in/yaml.v2 v2.3.0
 )

go.sum

@@ -113,6 +113,8 @@ github.com/fatih/color v1.7.0/go.mod h1:Zm6kSWBoL9eyXnKyktHP6abPY2pDugNf5Kwzbycv
 github.com/fatih/color v1.9.0 h1:8xPHl4/q1VyqGIPif1F+1V3Y3lSmrq01EabUW3CoW5s=
 github.com/fatih/color v1.9.0/go.mod h1:eQcE1qtQxscV5RaZvpXrrb8Drkc3/DdQ+uUYCNjL+zU=
 github.com/flynn/go-shlex v0.0.0-20150515145356-3f9db97f8568/go.mod h1:xEzjJPgXI435gkrCt3MPfRiAkVrwSbHsst4LCFVfpJc=
+github.com/fogleman/gg v1.3.0 h1:/7zJX8F6AaYQc57WQCyN9cAIz+4bCJGO9B+dyW29am8=
+github.com/fogleman/gg v1.3.0/go.mod h1:R/bRT+9gY/C5z7JzPU0zXsXHKM4/ayA+zqcVNZzPa1k=
 github.com/fortytw2/leaktest v1.3.0/go.mod h1:jDsjWgpAGjm2CA7WthBh/CdZYEPF31XHquHwclZch5g=
 github.com/francoispqt/gojay v1.2.13 h1:d2m3sFjloqoIUQU3TsHBgj6qg/BVGlTBeHDUmyJnXKk=
 github.com/francoispqt/gojay v1.2.13/go.mod h1:ehT5mTG4ua4581f1++1WLG0vPdaA9HaiDsoyrBGkyDY=
@@ -534,8 +536,8 @@ golang.org/x/image v0.0.0-20180708004352-c73c2afc3b81/go.mod h1:ux5Hcp/YLpHSI86h
 golang.org/x/image v0.0.0-20190321063152-3fc05d484e9f/go.mod h1:kZ7UVZpmo3dzQBMxlp+ypCbDeSB+sBbTgSJuh5dn5js=
 golang.org/x/image v0.0.0-20191009234506-e7c1f5e7dbb8/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/image v0.0.0-20200119044424-58c23975cae1/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
-golang.org/x/image v0.0.0-20200430140353-33d19683fad8 h1:6WW6V3x1P/jokJBpRQYUJnMHRP6isStQwCozxnU7XQw=
-golang.org/x/image v0.0.0-20200430140353-33d19683fad8/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
+golang.org/x/image v0.0.0-20220302094943-723b81ca9867 h1:TcHcE0vrmgzNH1v3ppjcMGbhG5+9fMuvOmUYwNEF4q4=
+golang.org/x/image v0.0.0-20220302094943-723b81ca9867/go.mod h1:023OzeP/+EPmXeapQh35lcL3II3LrY8Ic+EFFKVhULM=
 golang.org/x/lint v0.0.0-20180702182130-06c8688daad7/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
 golang.org/x/lint v0.0.0-20181217174547-8f45f776aaf1/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
@@ -615,8 +617,10 @@ golang.org/x/sys v0.0.0-20200515095857-1151b9dac4a9 h1:YTzHMGlqJu67/uEo1lBv0n3wB
 golang.org/x/sys v0.0.0-20200515095857-1151b9dac4a9/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.1-0.20180807135948-17ff2d5776d2/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
-golang.org/x/text v0.3.2 h1:tW2bmiBqwgJj/UpqtC8EpXEZVYOwU0yG4iWbprSVAcs=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
+golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/text v0.3.7 h1:olpwvP2KacW1ZWvsR7uQhoyTYvKAupfQrRGBFM352Gk=
+golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
 golang.org/x/time v0.0.0-20180412165947-fbb02b2291d2/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/time v0.0.0-20181108054448-85acf8d2951c/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/time v0.0.0-20190308202827-9d24e82272b4/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=

server/meme/template.go

@@ -2,7 +2,8 @@ package meme
 
 import (
 	"image"
-	"image/draw"
+
+	"github.com/fogleman/gg"
 )
 
 type Template struct {
@@ -12,16 +13,14 @@ type Template struct {
 }
 
 func (t *Template) Render(text []string) (image.Image, error) {
-	b := t.Image.Bounds()
-	img := image.NewRGBA(image.Rect(0, 0, b.Dx(), b.Dy()))
-	draw.Draw(img, img.Bounds(), t.Image, b.Min, draw.Src)
+	dc := gg.NewContextForImage(t.Image)
 
 	for i, slot := range t.TextSlots {
 		if i >= len(text) {
 			break
 		}
-		slot.Render(img, text[i])
+		slot.Render(dc, text[i], DEBUG)
 	}
 
-	return img, nil
+	return dc.Image(), nil
 }

server/meme/text_slot.go

@@ -1,198 +1,154 @@
 package meme
 
 import (
+	"fmt"
 	"image"
 	"image/color"
-	"image/draw"
 	"strings"
-	"unicode"
 
-	"github.com/golang/freetype/truetype"
+	"github.com/fogleman/gg"
 	"golang.org/x/image/font"
+	"golang.org/x/image/font/opentype"
 	"golang.org/x/image/math/fixed"
 )
 
 type HorizontalAlignment int
 
 const (
-	Left   HorizontalAlignment = -1
-	Center HorizontalAlignment = 0
-	Right  HorizontalAlignment = 1
+	Left HorizontalAlignment = iota
+	Center
+	Right
 )
 
 type VerticalAlignment int
 
 const (
-	Top    VerticalAlignment = -1
-	Middle VerticalAlignment = 0
-	Bottom VerticalAlignment = 1
+	Top VerticalAlignment = iota
+	Middle
+	Bottom
 )
 
+const DEBUG = false
+const lineSpacing = 0.8
+
 type TextSlot struct {
-	Bounds              image.Rectangle
-	Font                *truetype.Font
-	MaxFontSize         float64
-	HorizontalAlignment HorizontalAlignment
-	VerticalAlignment   VerticalAlignment
+	Font                *opentype.Font
 	TextColor           color.Color
 	OutlineColor        color.Color
+	HorizontalAlignment HorizontalAlignment
+	VerticalAlignment   VerticalAlignment
+	OutlineWidth        int
 	AllUppercase        bool
+	Bounds              image.Rectangle
+	MaxFontSize         float64
+	Rotation            float64
 }
 
-func (s *TextSlot) Render(img draw.Image, text string) {
+func (s *TextSlot) Render(dc *gg.Context, text string, debug bool) {
 	if s.AllUppercase {
 		text = strings.ToUpper(text)
 	}
+	dc.Push()
+	// Compute font size by taking measurement of a text
+	face, _, textHeight := faceForSlot(text, s.Font, s.MaxFontSize, s.Bounds.Dx(), s.Bounds.Dy())
+	dc.SetFontFace(face)
+
+	rotCenterX := float64((s.Bounds.Min.X + s.Bounds.Dx()) / 2)
+	rotCenterY := float64((s.Bounds.Min.Y + s.Bounds.Dy()) / 2)
+
+	dc.RotateAbout(gg.Radians(s.Rotation),
+		rotCenterX, rotCenterY)
+	dc.SetColor(s.OutlineColor)
 
-	layout := s.TextLayout(text)
-	if layout == nil {
-		return
+	outlineWidth := s.OutlineWidth // "stroke" size
+	if outlineWidth == 0 {
+		outlineWidth = 8
 	}
 
 	textColor := s.TextColor
 	if textColor == nil {
 		textColor = color.Black
 	}
 
-	for i, line := range layout.Lines {
-		if s.OutlineColor != nil {
-			// it's okay, memes aren't supposed to look good
-			offset := layout.Face.Metrics().Height / 16
-			for _, delta := range []fixed.Point26_6{
-				{X: offset, Y: offset},
-				{X: -offset, Y: offset},
-				{X: -offset, Y: -offset},
-				{X: offset, Y: -offset},
-			} {
-				drawer := font.Drawer{
-					Dst:  img,
-					Src:  image.NewUniform(s.OutlineColor),
-					Face: layout.Face,
-					Dot:  layout.LinePositions[i].Add(delta),
-				}
-				drawer.DrawString(line)
-			}
-		}
+	xStart := float64(s.Bounds.Min.X)
+	xAlign := gg.Align(s.HorizontalAlignment)
+
+	// Bottom padding for the text, because the string measurements account for top-padding but not bottom
+	yAlign := 0.1
+
+	yStart := float64(s.Bounds.Min.Y)
+	switch s.VerticalAlignment {
+	case Top:
+		yStart = float64(s.Bounds.Min.Y)
+	case Middle:
+		yStart = (float64(s.Bounds.Dy())-textHeight)/2.0 +
+			float64(s.Bounds.Min.Y)
+	case Bottom:
+		yStart = float64(s.Bounds.Max.Y) - textHeight
+	default:
+		break
+	}
 
-		drawer := font.Drawer{
-			Dst:  img,
-			Src:  image.NewUniform(textColor),
-			Face: layout.Face,
-			Dot:  layout.LinePositions[i],
+	if s.OutlineColor != nil {
+		offset := face.Metrics().Height / 256 * fixed.Int26_6(outlineWidth)
+		for _, delta := range []fixed.Point26_6{
+			{X: offset, Y: offset},
+			{X: -offset, Y: offset},
+			{X: -offset, Y: -offset},
+			{X: offset, Y: -offset},
+		} {
+			x := xStart + float64(delta.X)/64
+			y := yStart + float64(delta.Y)/64
+			dc.DrawStringWrapped(text, x, y, 0, yAlign, float64(s.Bounds.Dx()), lineSpacing, xAlign)
 		}
-		drawer.DrawString(line)
 	}
-}
 
-type TextLayout struct {
-	Face          font.Face
-	Lines         []string
-	LinePositions []fixed.Point26_6
+	dc.SetColor(textColor)
+	dc.DrawStringWrapped(text,
+		xStart,
+		yStart,
+		0, yAlign, float64(s.Bounds.Dx()), lineSpacing, xAlign)
+
+	if debug {
+		fmt.Printf("X %v Y %v W %v H %v\n", float64(s.Bounds.Min.X), float64(s.Bounds.Min.Y),
+			float64(s.Bounds.Dx()), float64(s.Bounds.Dy()))
+		dc.SetRGB(1, 0, 0)
+		dc.DrawRectangle(float64(s.Bounds.Min.X), float64(s.Bounds.Min.Y),
+			float64(s.Bounds.Dx()), float64(s.Bounds.Dy()))
+		dc.Stroke()
+	}
+
+	dc.Pop()
 }
 
-func (s *TextSlot) TextLayout(text string) *TextLayout {
-	fontSize := s.MaxFontSize
+func faceForSlot(text string, fontt *opentype.Font, maxFontSize float64, width int, height int) (font.Face, float64, float64) {
+	fontSize := maxFontSize
 	if fontSize == 0.0 {
-		fontSize = 80.0
+		fontSize = 80
 	}
-
-	hlimit := fixed.Int26_6(s.Bounds.Dx() * 64)
-	vlimit := fixed.Int26_6(s.Bounds.Dy() * 64)
-
+	w := 0.0
+	h := 0.0
+	dc := gg.NewContext(10, 10)
+	face, _ := opentype.NewFace(fontt, &opentype.FaceOptions{
+		Size:    fontSize,
+		DPI:     72,
+		Hinting: font.HintingNone,
+	})
 	for fontSize >= 6.0 {
-		face := truetype.NewFace(s.Font, &truetype.Options{
-			Size: fontSize,
+		face, _ = opentype.NewFace(fontt, &opentype.FaceOptions{
+			Size:    fontSize,
+			DPI:     72,
+			Hinting: font.HintingNone,
 		})
-		lineLimit := s.Bounds.Dy() / int(face.Metrics().Height/64)
-		lines, widths := lines(face, text, hlimit)
-		if len(lines) > lineLimit {
+		dc.SetFontFace(face)
+		lines := dc.WordWrap(text, float64(width))
+		w, h = dc.MeasureMultilineString(strings.Join(lines, "\n"), lineSpacing)
+		if w > float64(width) || h > float64(height)*lineSpacing {
 			fontSize -= (fontSize + 9) / 10
 			continue
 		}
-
-		layout := &TextLayout{
-			Face:          face,
-			Lines:         lines,
-			LinePositions: make([]fixed.Point26_6, len(lines)),
-		}
-
-		y := fixed.Int26_6(s.Bounds.Min.Y * 64)
-		totalHeight := face.Metrics().Height.Mul(fixed.Int26_6(len(lines) * 64))
-		switch s.VerticalAlignment {
-		case Middle:
-			y += (vlimit - totalHeight) / 2
-		case Bottom:
-			y += (vlimit - totalHeight)
-		}
-
-		for i, width := range widths {
-			x := fixed.Int26_6(s.Bounds.Min.X * 64)
-			switch s.HorizontalAlignment {
-			case Center:
-				x += (hlimit - width) / 2
-			case Right:
-				x += (hlimit - width)
-			}
-			y += face.Metrics().Height
-			layout.LinePositions[i] = fixed.Point26_6{
-				X: x,
-				Y: y,
-			}
-		}
-		return layout
-	}
-
-	return nil
-}
-
-func lines(face font.Face, text string, limit fixed.Int26_6) (lines []string, widths []fixed.Int26_6) {
-	for text != "" {
-		line, width, remaining := firstLine(face, text, limit)
-		if line == "" {
-			return nil, nil
-		}
-		lines = append(lines, line)
-		widths = append(widths, width)
-		text = remaining
-	}
-	return
-}
-
-func firstLine(face font.Face, text string, limit fixed.Int26_6) (string, fixed.Int26_6, string) {
-	text = strings.TrimSpace(text)
-
-	pos := 0
-	lastBreak := 0
-
-	var width fixed.Int26_6
-	var lastBreakWidth fixed.Int26_6
-
-	var prev rune = -1
-	for _, r := range text {
-		advance, ok := face.GlyphAdvance(r)
-		if !ok {
-			continue
-		}
-		if prev >= 0 {
-			advance += face.Kern(prev, r)
-		}
-
-		if unicode.IsSpace(r) && !unicode.IsSpace(prev) {
-			lastBreak = pos
-			lastBreakWidth = width
-		}
-
-		if width+advance > limit {
-			if lastBreak == 0 {
-				return string([]rune(text)[:pos]), width, string([]rune(text)[pos:])
-			}
-			return string([]rune(text)[:lastBreak]), lastBreakWidth, string([]rune(text)[lastBreak:])
-		}
-
-		pos++
-		width += advance
-		prev = r
+		break
 	}
 
-	return text, width, ""
+	return face, w, h
 }