func NewSDFFont3(fontPath string, size float64, dpi int, readonly bool, firstRune, lastRune rune, sdfSize float64, scanRange int) (*Font, error) {
fontBytes, err := ioutil.ReadFile(fontPath)
if err != nil {
return nil, err
}
font, err := freetype.ParseFont(fontBytes)
if err != nil {
return nil, err
}
fontBytes = nil
c := freetype.NewContext()
c.SetDPI(dpi)
c.SetFont(font)
c.SetFontSize(sdfSize)
c.SetSrc(image.White)
ratio := sdfSize / size
text := ""
for i := firstRune; i < lastRune+1; i++ {
text += string(i)
}
rects := make([]image.Rectangle, 0)
LetterArray := make(map[rune]*LetterInfo)
for _, r := range text {
index := font.Index(r)
mask, offset, err := c.Glyph(index, freetype.Pt(0, 0))
if err != nil {
fmt.Println("Rune generation error:", err)
continue
}
bd := mask.Bounds()
AdvanceWidth := c.FUnitToFix32(int(font.HMetric(index).AdvanceWidth)).Float()
LeftSideBearing := c.FUnitToFix32(int(font.HMetric(index).LeftSideBearing)).Float()
AdvanceWidth = AdvanceWidth / float32(sdfSize)
LeftSideBearing = LeftSideBearing / float32(sdfSize)
YOffset := (float32(-offset.Y) - float32(mask.Bounds().Max.Y)) / float32(sdfSize)
relativeWidth := float32(bd.Dx()) / float32(sdfSize)
relativeHeight := float32(bd.Dy()) / float32(sdfSize)
sdfBounds := mask.Bounds()
sdfBounds.Max.X = int(float64(sdfBounds.Max.X)/ratio) + 2
sdfBounds.Max.Y = int(float64(sdfBounds.Max.Y)/ratio) + 2
rects = append(rects, sdfBounds)
LetterArray[r] = &LetterInfo{sdfBounds, YOffset, LeftSideBearing, AdvanceWidth, relativeWidth, relativeHeight}
}
ay, ax, e := FindOptimalSize(10, rects...)
if e != nil {
return nil, e
}
dst := image.NewRGBA(image.Rect(0, 0, int(ax), int(ay)))
node := NewBin(int(ax), int(ay), Padding)
rects, e = node.InsertArray(rects)
if e != nil {
return nil, e
}
rectIndex := 0
for _, r := range text {
index := font.Index(r)
mask, _, err := c.Glyph(index, freetype.Pt(0, 0))
if err != nil {
fmt.Println("Rune generation error:", err)
continue
}
rect := rects[rectIndex]
newMask := image.NewAlpha(rect)
//Note: this is slow we need to find better algorithm
for xx := 0; xx < newMask.Bounds().Dx(); xx++ {
for yy := 0; yy < newMask.Bounds().Dy(); yy++ {
alpha := FindSDFAlpha(mask, int(float64(xx)*ratio), int(float64(yy)*ratio), scanRange)
newMask.SetAlpha(xx, yy, color.Alpha{uint8(alpha)})
}
}
draw.Draw(dst, rect, newMask, image.ZP, draw.Src)
LetterArray[r].Rect = rect
rectIndex++
}
texture, err := NewTexture(dst, dst.Pix)
if err != nil {
return nil, err
}
if readonly {
texture.SetReadOnly()
}
texture.SetFiltering(Linear, Linear)
return &Font{texture, LetterArray, size, dpi, true}, nil
}
func NewFont2(fontPath string, size float64, dpi int, readonly bool, firstRune, lastRune rune) (*Font, error) {
fontBytes, err := ioutil.ReadFile(fontPath)
if err != nil {
return nil, err
}
font, err := freetype.ParseFont(fontBytes)
if err != nil {
return nil, err
}
fontBytes = nil
c := freetype.NewContext()
c.SetDPI(dpi)
c.SetFont(font)
c.SetFontSize(size)
c.SetSrc(image.White)
text := ""
for i := firstRune; i < lastRune+1; i++ {
text += string(i)
}
rects := make([]image.Rectangle, 0)
LetterArray := make(map[rune]*LetterInfo)
for _, r := range text {
index := font.Index(r)
mask, offset, err := c.Glyph(index, freetype.Pt(0, 0))
if err != nil {
fmt.Println("Rune generation error:", err)
continue
}
bd := mask.Bounds()
AdvanceWidth := c.FUnitToFix32(int(font.HMetric(index).AdvanceWidth)).Float()
LeftSideBearing := c.FUnitToFix32(int(font.HMetric(index).LeftSideBearing)).Float()
AdvanceWidth = AdvanceWidth / float32(size)
LeftSideBearing = LeftSideBearing / float32(size)
YOffset := (float32(-offset.Y) - float32(mask.Bounds().Max.Y)) / float32(size)
relativeWidth := float32(bd.Dx()) / float32(size)
relativeHeight := float32(bd.Dy()) / float32(size)
rects = append(rects, mask.Bounds())
LetterArray[r] = &LetterInfo{bd, YOffset, LeftSideBearing, AdvanceWidth, relativeWidth, relativeHeight}
}
ay, ax, e := FindOptimalSize(10, rects...)
if e != nil {
return nil, e
}
dst := image.NewRGBA(image.Rect(0, 0, int(ax), int(ay)))
node := NewBin(int(ax), int(ay), Padding)
rects, e = node.InsertArray(rects)
if e != nil {
return nil, e
}
rectIndex := 0
for _, r := range text {
index := font.Index(r)
mask, _, err := c.Glyph(index, freetype.Pt(0, 0))
if err != nil {
fmt.Println("Rune generation error:", err)
continue
}
rect := rects[rectIndex]
draw.Draw(dst, rect, mask, image.ZP, draw.Src)
LetterArray[r].Rect = rect
rectIndex++
}
texture, err := NewTexture(dst, dst.Pix)
if err != nil {
return nil, err
}
if readonly {
texture.SetReadOnly()
}
texture.SetFiltering(Linear, Linear)
return &Font{texture, LetterArray, size, dpi, false}, nil
}