Fix CJK render problem partially (#222)

* Fixed CJK render problem
* Add partial support of loading CJK fonts

d2core/engine.go

@@ -40,19 +40,19 @@ import (
 // Engine is the core OpenDiablo2 engine
 type Engine struct {
 	Settings        *d2corecommon.Configuration // Engine configuration settings from json file
-	Files           map[string]string       // Map that defines which files are in which MPQs
+	Files           map[string]string           // Map that defines which files are in which MPQs
-	CheckedPatch    map[string]bool         // First time we check a file, we'll check if it's in the patch. This notes that we've already checked that.
+	CheckedPatch    map[string]bool             // First time we check a file, we'll check if it's in the patch. This notes that we've already checked that.
-	LoadingSprite   d2render.Sprite         // The sprite shown when loading stuff
+	LoadingSprite   d2render.Sprite             // The sprite shown when loading stuff
-	loadingProgress float64                 // LoadingProcess is a range between 0.0 and 1.0. If set, loading screen displays.
+	loadingProgress float64                     // LoadingProcess is a range between 0.0 and 1.0. If set, loading screen displays.
-	loadingIndex    int                     // Determines which load function is currently being called
+	loadingIndex    int                         // Determines which load function is currently being called
-	thingsToLoad    []func()                // The load functions for the next scene
+	thingsToLoad    []func()                    // The load functions for the next scene
-	stepLoadingSize float64                 // The size for each loading step
+	stepLoadingSize float64                     // The size for each loading step
 	CurrentScene    d2coreinterface.Scene       // The current scene being rendered
-	UIManager       *d2ui.Manager           // The UI manager
+	UIManager       *d2ui.Manager               // The UI manager
-	SoundManager    *d2audio.Manager        // The sound manager
+	SoundManager    *d2audio.Manager            // The sound manager
 	nextScene       d2coreinterface.Scene       // The next scene to be loaded at the end of the game loop
-	fullscreenKey   bool                    // When true, the fullscreen toggle is still being pressed
+	fullscreenKey   bool                        // When true, the fullscreen toggle is still being pressed
-	lastTime        float64                 // Last time we updated the scene
+	lastTime        float64                     // Last time we updated the scene
 	showFPS         bool
 }
 
@@ -104,11 +104,18 @@ var mutex sync.Mutex
 
 func (v *Engine) LoadFile(fileName string) []byte {
 	fileName = strings.ReplaceAll(fileName, "{LANG}", d2resource.LanguageCode)
+	// todo: separate CJK and latin characters from LanguageCode
+	if "CHI" == strings.ToUpper(d2resource.LanguageCode) {
+		fileName = strings.ReplaceAll(fileName, "{LANG_FONT}", d2resource.LanguageCode)
+	} else {
+		fileName = strings.ReplaceAll(fileName, "{LANG_FONT}", "latin")
+	}
 	fileName = strings.ToLower(fileName)
 	fileName = strings.ReplaceAll(fileName, `/`, "\\")
 	if fileName[0] == '\\' {
 		fileName = fileName[1:]
 	}
+
 	mutex.Lock()
 	defer mutex.Unlock()
 	// TODO: May want to cache some things if performance becomes an issue

d2render/d2ui/font.go

@@ -15,6 +15,10 @@ import (
 	"github.com/OpenDiablo2/OpenDiablo2/d2render"
 
 	"github.com/hajimehoshi/ebiten"
+
+	"encoding/binary"
+
+	"unicode"
 )
 
 var fontCache = map[string]*Font{}
@@ -28,7 +32,8 @@ type FontSize struct {
 // Font represents a font
 type Font struct {
 	fontSprite d2render.Sprite
-	metrics    map[uint8]FontSize
+	fontTable  map[uint16]uint16
+	metrics    map[uint16]FontSize
 }
 
 // GetFont creates or loads an existing font
@@ -45,21 +50,39 @@ func GetFont(font string, palette d2enum.PaletteType, fileProvider d2interface.F
 // CreateFont creates an instance of a MPQ Font
 func CreateFont(font string, palette d2enum.PaletteType, fileProvider d2interface.FileProvider) *Font {
 	result := &Font{
-		metrics: make(map[uint8]FontSize),
+		fontTable: make(map[uint16]uint16),
+		metrics:   make(map[uint16]FontSize),
 	}
+	// bug: performance issue when using CJK fonts, because ten thousand frames will be rendered PER font
 	result.fontSprite = d2render.CreateSprite(fileProvider.LoadFile(font+".dc6"), d2datadict.Palettes[palette])
 	woo := "Woo!\x01"
 	fontData := fileProvider.LoadFile(font + ".tbl")
 	if string(fontData[0:5]) != woo {
 		panic("No woo :(")
 	}
+
+	containsCjk := false
 	for i := 12; i < len(fontData); i += 14 {
-		fontSize := FontSize{
+		// font mappings, map unicode code points to array indics
-			Width:  fontData[i+3],
+		unicodeCode := binary.LittleEndian.Uint16(fontData[i : i+2])
-			Height: fontData[i+4],
+		fontIndex := binary.LittleEndian.Uint16(fontData[i+8 : i+10])
+		result.fontTable[unicodeCode] = fontIndex
+
+		if unicodeCode < unicode.MaxLatin1 {
+			result.metrics[unicodeCode] = FontSize{
+				Width:  fontData[i+3],
+				Height: fontData[i+4],
+			}
+		} else if !containsCjk {
+			// CJK characters are all in the same size
+			result.metrics[unicode.MaxLatin1] = FontSize{
+				Width:  fontData[i+3],
+				Height: fontData[i+4],
+			}
+			containsCjk = true
 		}
-		result.metrics[fontData[i+8]] = fontSize
 	}
+
 	return result
 }
 
@@ -69,19 +92,19 @@ func (v *Font) GetTextMetrics(text string) (width, height uint32) {
 	curWidth := uint32(0)
 	height = uint32(0)
 	maxCharHeight := uint32(0)
+	// todo: it can be saved as a struct member, since it only depends on `.Frames`
 	for _, m := range v.fontSprite.Frames {
 		maxCharHeight = d2helper.Max(maxCharHeight, uint32(m.Height))
 	}
-	for i := 0; i < len(text); i++ {
+	for _, ch := range text {
-		ch := text[i]
 		if ch == '\n' {
 			width = d2helper.Max(width, curWidth)
 			curWidth = 0
 			height += maxCharHeight + 6
 			continue
 		}
-		metric := v.metrics[uint8(ch)]
+
-		curWidth += uint32(metric.Width)
+		curWidth += v.getCharWidth(ch)
 	}
 	width = d2helper.Max(width, curWidth)
 	height += maxCharHeight
@@ -105,12 +128,12 @@ func (v *Font) Draw(x, y int, text string, color color.Color, target *ebiten.Ima
 		xPos := x + ((targetWidth / 2) - int(lineWidth/2))
 
 		for _, ch := range line {
-			char := uint8(ch)
+			width := v.getCharWidth(ch)
-			metric := v.metrics[char]
+			index := v.fontTable[uint16(ch)]
-			v.fontSprite.Frame = int16(char)
+			v.fontSprite.Frame = int16(index)
-			v.fontSprite.MoveTo(xPos, y+int(v.fontSprite.Frames[char].Height))
+			v.fontSprite.MoveTo(xPos, y+int(v.fontSprite.Frames[index].Height))
 			v.fontSprite.Draw(target)
-			xPos += int(metric.Width)
+			xPos += int(width)
 		}
 
 		if lineIdx >= len(lines)-1 {
@@ -121,3 +144,10 @@ func (v *Font) Draw(x, y int, text string, color color.Color, target *ebiten.Ima
 		y += int(maxCharHeight + 6)
 	}
 }
+
+func (v *Font) getCharWidth(char rune) (width uint32) {
+	if char < unicode.MaxLatin1 {
+		return uint32(v.metrics[uint16(char)].Width)
+	}
+	return uint32(v.metrics[unicode.MaxLatin1].Width)
+}