Exemplo n.º 1
1
func drawText(font *truetype.Font, c *freetype.Context, color color.Color, rgba *image.RGBA, text string) (int, int) {
	fg := image.NewUniform(color)
	bg := image.Transparent
	draw.Draw(rgba, rgba.Bounds(), bg, image.ZP, draw.Src)
	c.SetFont(font)
	c.SetDst(rgba)
	c.SetSrc(fg)
	c.SetClip(rgba.Bounds())
	// height is the fraction of the font that is above the line, 1.0 would mean
	// that the font never falls below the line
	// TODO: wtf - this is all wrong!
	// fix fonts - we can't change the font size easily
	height := 1.3
	pt := freetype.Pt(0, int(float64(c.PointToFixed(*size)>>8)*height))
	adv, _ := c.DrawString(text, pt)
	pt.X += adv.X
	py := int(float64(pt.Y>>8)/height + 0.01)
	return int(pt.X >> 8), py
}
Exemplo n.º 2
0
// CenterX returns the Point at which string s will be centered within rect r
// along the X coordinate when passed to c.DrawString. The Y coordinate will be 0.
// Clip is set to r before returning.
func CenterX(c *freetype.Context, s string, r image.Rectangle) (fixed.Point26_6, error) {
	w, err := DrawWidth(c, s)
	c.SetClip(r)
	if err != nil {
		return fixed.Point26_6{}, err
	}
	half := Int26_6(0.5)
	xmin := freetype.Pt(r.Min.X, 0)
	return freetype.Pt(r.Dx(), 0).Mul(half).Sub(w.Mul(half)).Add(xmin), nil
}
Exemplo n.º 3
0
func NewFontFace(path string, size float64, fg, bg color.Color) (fontface *FontFace, err error) {
	var (
		font      *truetype.Font
		fontbytes []byte
		bounds    truetype.Bounds
		context   *freetype.Context
		scale     float32
	)
	if fontbytes, err = ioutil.ReadFile(path); err != nil {
		return
	}
	if font, err = freetype.ParseFont(fontbytes); err != nil {
		return
	}
	bounds = font.Bounds(1)
	fmt.Printf("bounds %v\n", bounds)
	context = freetype.NewContext()
	context.SetFont(font)
	context.SetFontSize(size)
	context.SetDPI(72)
	scale = float32(context.PointToFixed(size) / 64)
	fontface = &FontFace{
		font:    font,
		charw:   scale * float32(bounds.XMax-bounds.XMin),
		charh:   scale * float32(bounds.YMax-bounds.YMin),
		fg:      fg,
		bg:      bg,
		context: context,
	}
	return
}
Exemplo n.º 4
0
func NewFontFace(path string, pixels float32, fg, bg color.Color) (fontface *FontFace, err error) {
	var (
		font      *truetype.Font
		fontbytes []byte
		bounds    fixed.Rectangle26_6
		context   *freetype.Context
		points    float32
		dpi       float32 = 96
	)
	if fontbytes, err = ioutil.ReadFile(path); err != nil {
		return
	}
	if font, err = freetype.ParseFont(fontbytes); err != nil {
		return
	}
	points = pixels * 72 / dpi
	bounds = font.Bounds(fixed.I(int(pixels)))
	context = freetype.NewContext()
	context.SetFont(font)
	context.SetFontSize(float64(points))
	context.SetDPI(float64(dpi))
	fontface = &FontFace{
		font:    font,
		charw:   float32(bounds.Max.X-bounds.Min.X) / 64,
		charh:   float32(bounds.Max.Y-bounds.Min.Y) / 64,
		offy:    float32(bounds.Min.Y) / 64,
		fg:      fg,
		bg:      bg,
		context: context,
	}
	return
}
Exemplo n.º 5
0
// DrawWidth simulates drawing s using Context c and returns the raster.Point
// where X is the width of the drawn string. The context's src and dst are
// unused, but the font should already be set. Clip is set to an empty Rectangle
// and should be reset afterwards.
func DrawWidth(c *freetype.Context, s string) (fixed.Point26_6, error) {
	// nil rectangle is always empty so draw is never called
	c.SetClip(image.Rectangle{})
	p, err := c.DrawString(s, fixed.Point26_6{}) // 0,0
	return p, err
}