Ejemplo n.º 1
0
Archivo: font.go Proyecto: Lealen/engi
func (f *Font) TextDimensions(text string) (int, int, int) {
	fnt := f.ttf
	size := f.Size
	var (
		totalWidth  = fixed.Int26_6(0)
		totalHeight = fixed.Int26_6(size)
		maxYBearing = fixed.Int26_6(0)
	)
	fupe := fixed.Int26_6(fnt.FUnitsPerEm())
	for _, char := range text {
		idx := fnt.Index(char)
		hm := fnt.HMetric(fupe, idx)
		vm := fnt.VMetric(fupe, idx)
		g := truetype.GlyphBuf{}
		err := g.Load(fnt, fupe, idx, font.HintingNone)
		if err != nil {
			log.Println(err)
			return 0, 0, 0
		}
		totalWidth += hm.AdvanceWidth
		yB := (vm.TopSideBearing * fixed.Int26_6(size)) / fupe
		if yB > maxYBearing {
			maxYBearing = yB
		}
	}

	// Scale to actual pixel size
	totalWidth *= fixed.Int26_6(size)
	totalWidth /= fupe

	return int(totalWidth), int(totalHeight), int(maxYBearing)
}
Ejemplo n.º 2
0
// our avatar image is square
func (g *drawer) Draw(s string, size int, bg *color.RGBA) image.Image {
	// draw the background
	dst := image.NewRGBA(image.Rect(0, 0, size, size))
	draw.Draw(dst, dst.Bounds(), &image.Uniform{bg}, image.ZP, draw.Src)

	// draw the text
	drawer := &font.Drawer{
		Dst:  dst,
		Src:  image.White,
		Face: g.face,
	}

	// font index
	fi := g.font.Index([]rune(s)[0])

	// glyph example: http://www.freetype.org/freetype2/docs/tutorial/metrics.png
	var gbuf truetype.GlyphBuf
	var err error
	var _fsize fixed.Int26_6 = fixed.Int26_6(g.fontSize * g.dpi * (64.0 / 72.0))
	err = gbuf.Load(g.font, _fsize, fi, font.HintingFull)
	if err != nil {
		// fixme
		drawer.DrawString("")
		return dst
	}

	// center
	dY := int((size - int(gbuf.Bounds.Max.Y-gbuf.Bounds.Min.Y)>>6) / 2)
	dX := int((size - int(gbuf.Bounds.Max.X-gbuf.Bounds.Min.X)>>6) / 2)
	y := int(gbuf.Bounds.Max.Y>>6) + dY
	x := 0 - int(gbuf.Bounds.Min.X>>6) + dX

	//y := 10 + int(math.Ceil(g.fontSize*g.dpi/72)) //FIXME: what does it mean?
	drawer.Dot = fixed.Point26_6{
		X: fixed.I(x), //(fixed.I(size) - drawer.MeasureString(s)) / 2,
		Y: fixed.I(y),
	}
	drawer.DrawString(s)

	return dst
}