More WIP emoji work

emoji.go

@@ -1,76 +1,138 @@
 package freetype
 
 import (
-	"errors"
 	"fmt"
+	"os"
+	"path/filepath"
+	"strconv"
 	"strings"
-	"unicode/utf8"
 )
 
-type Emoji struct {
-	Codepoints []rune
-	Bytes      int
+type emoji struct {
+	Codepoint []rune
+	IsEmoji   bool
+	Path      string
+	Sub       emojiTable
 }
 
-var (
-	errNotAnEmoji = errors.New("not an emoji")
-)
-
-func inrange(val, min, max rune) bool {
-	return val >= min && val < max
-}
-
-// https://stackoverflow.com/questions/30757193/find-out-if-character-in-string-is-emoji/39425959
-func isEmoji(chr rune) bool {
-	switch {
-	case inrange(chr, 0x1f600, 0x1f64f), // Emoticons
-		inrange(chr, 0x1f300, 0x1f5ff), // Misc Symbols and Pictographs
-		inrange(chr, 0x1f680, 0x1f6ff), // Transport and Map
-		inrange(chr, 0x1f1e6, 0x1f1ff), // Regional country flags
-		inrange(chr, 0x2600, 0x26ff),   // Misc symbols
-		inrange(chr, 0x2700, 0x27bf),   // Dingbats
-		inrange(chr, 0xfe00, 0xfe0f),   // Variation Selectors
-		inrange(chr, 0x1f900, 0x1f9ff), // Supplemental Symbols and Pictographs
-		inrange(chr, 127000, 127600),   // Various asian characters
-		inrange(chr, 65024, 65039),     // Variation selector
-		inrange(chr, 9100, 9300),       // Misc items
-		inrange(chr, 8400, 8447):       // Combining Diacritical Marks for Symbols
-		return true
+func (e emoji) String() (str string) {
+	str = "Emoji("
+	for _, cprune := range e.Codepoint {
+		str += fmt.Sprintf("%U ", cprune)
 	}
-	return false
-}
-
-func isZWJ(chr rune) bool {
-	return chr == 8205
-}
-
-func parseEmoji(str string) (Emoji, error) {
-	if len(str) < 1 {
-		return Emoji{}, errNotAnEmoji
+	str = strings.TrimRight(str, " ") + ")"
+	if e.Sub != nil {
+		str += "+"
 	}
+	if e.IsEmoji {
+		str += fmt.Sprintf("\n  └ Path: %s", e.Path)
+	}
+	return str + "\n"
+}
 
-	emoji := Emoji{}
+type emojiTable map[rune]emoji
 
-	for _, r := range str {
-		// Check if rune is emoji
-		if !isEmoji(r) && !isZWJ(r) {
-			if len(emoji.Codepoints) < 1 {
-				return emoji, errNotAnEmoji
-			}
+func (em emojiTable) Find(str string) (emj emoji, length int) {
+	length = 0
+	for i, r := range str {
+		e, ok := em[r]
+		if !ok {
 			break
 		}
-
-		emoji.Codepoints = append(emoji.Codepoints, r)
-		emoji.Bytes += utf8.RuneLen(r)
+		// Check if there are more bytes to check
+		if len(str) > i && e.Sub != nil {
+			newemj, len := e.Sub.Find(str[i:])
+			if len > 0 {
+				length += len
+				emj = newemj
+				return
+			}
+		}
+		if e.IsEmoji {
+			emj = e
+		}
+		length++
 	}
-
-	return emoji, nil
+	return
 }
 
-func (e Emoji) String() string {
-	codepoints := []string{}
-	for _, cp := range e.Codepoints {
-		codepoints = append(codepoints, fmt.Sprintf("%U", cp))
-	}
-	return "Emoji(" + strings.Join(codepoints, ", ") + ")"
+func (em emojiTable) IsEmoji(cp rune) bool {
+	_, ok := em[cp]
+	return ok
+}
+
+func (em emojiTable) tostring(indent string, nomarker bool) (str string) {
+	counter := len(em)
+	marker := "│ "
+	if nomarker {
+		marker = "  "
+	}
+	for r, emo := range em {
+		listr := "├"
+		if counter == 1 {
+			listr = "└"
+		}
+		str += fmt.Sprintf(indent+"%s%s %U", marker, listr, r)
+		if emo.IsEmoji {
+			str += fmt.Sprintf(": %s", emo.Path)
+		}
+		str += "\n"
+		if emo.Sub != nil {
+			str += emo.Sub.tostring(indent+marker, counter == 1)
+		}
+		counter--
+	}
+	return
+}
+
+func (em emojiTable) String() string {
+	return "Emoji table\n" + em.tostring("", true)
+}
+
+func scanEmojiDirectory(emojipath string) (tab emojiTable, err error) {
+	tab = make(emojiTable)
+	filepath.Walk(emojipath, func(path string, info os.FileInfo, err error) error {
+		// Ignore non-images
+		if !strings.HasSuffix(strings.ToLower(path), ".png") {
+			return nil
+		}
+
+		// Get icon filename
+		emojiname := filepath.Base(path)
+
+		// Strip prefix and suffix
+		extsep := strings.LastIndexByte(emojiname, '.')
+		basesep := strings.IndexByte(emojiname, '_')
+		codepointstr := emojiname[basesep+2 : extsep]
+
+		// Split codepoints by separator (_)
+		codepointlist := strings.Split(codepointstr, "_")
+
+		// Parse codepoints to runes
+		curtab := &tab
+		codepoints := []rune{}
+		for cpi, cpstr := range codepointlist {
+			num, err := strconv.ParseInt(cpstr, 16, 32)
+			if err != nil {
+				return fmt.Errorf("malformed icon filename: %s (codepoints are not valid int32)", emojiname)
+			}
+			cprune := rune(num)
+			newemo := (*curtab)[cprune]
+			codepoints = append(codepoints, cprune)
+			newemo.Codepoint = codepoints[:]
+			if len(codepointlist) < cpi+2 {
+				// Set as emoji
+				newemo.IsEmoji = true
+				newemo.Path = path
+			} else {
+				// Add sub-entry
+				newemo.Sub = make(emojiTable)
+			}
+			(*curtab)[cprune] = newemo
+			curtab = &newemo.Sub
+		}
+		fmt.Println(codepointstr)
+		return nil
+	})
+	return tab, err
 }

example/emojis/main.go

@@ -34,6 +34,7 @@ var (
 	size     = flag.Float64("size", 20, "font size in points")
 	spacing  = flag.Float64("spacing", 1.5, "line spacing (e.g. 2 means double spaced)")
 	wonb     = flag.Bool("whiteonblack", false, "white text on a black background")
+	emojidir = flag.String("emojidir", "../../noto_emojis", "Path to emojis")
 )
 
 var text = []string{
@@ -72,6 +73,7 @@ func main() {
 	rgba := image.NewRGBA(image.Rect(0, 0, 640, 480))
 	draw.Draw(rgba, rgba.Bounds(), bg, image.ZP, draw.Src)
 	c := freetype.NewContext()
+	c.ScanEmojis(*emojidir)
 	c.SetDPI(*dpi)
 	c.SetFont(f)
 	c.SetFontSize(*size)

freetype.go

@@ -74,6 +74,8 @@ type Context struct {
 	hinting       font.Hinting
 	// cache is the glyph cache.
 	cache [nGlyphs * nXFractions * nYFractions]cacheEntry
+	// emojis is the table of all parsable emojis
+	emojis emojiTable
 }
 
 // PointToFixed converts the given number of points (as in "a 12 point font")
@@ -240,12 +242,10 @@ func (c *Context) DrawString(s string, p fixed.Point26_6) (fixed.Point26_6, erro
 			continue
 		}
 		// Check if rune is an emoji
-		if isEmoji(r) {
-			emoji, err := parseEmoji(s[index:])
-			if err == nil {
-				fmt.Println("Found emoji:", emoji)
-				nextchar = index + emoji.Bytes
-			}
+		if c.emojis != nil && c.emojis.IsEmoji(r) {
+			icon, length := c.emojis.Find(s[index:])
+			fmt.Printf("Found emoji at position #%d: (len %d)\n  %s", index, length, icon.String())
+			nextchar = index + length
 		}
 		index := c.f.Index(r)
 		if hasPrev {
@@ -353,3 +353,9 @@ func NewContext() *Context {
 		scale:    12 << 6,
 	}
 }
+
+// ScanEmojis scans a directory for emojis and adds them to the context's emoji repertoire
+func (c *Context) ScanEmojis(path string) (err error) {
+	c.emojis, err = scanEmojiDirectory(path)
+	return
+}