// DrawString draws s at p and returns p advanced by the text extent. The text // is placed so that the left edge of the em square of the first character of s // and the baseline intersect at p. The majority of the affected pixels will be // above and to the right of the point, but some may be below or to the left. // For example, drawing a string that starts with a 'J' in an italic font may // affect pixels below and left of the point. // p is a raster.Point and can therefore represent sub-pixel positions. func (c *Context) DrawString(s string, p raster.Point) (raster.Point, error) { if c.font == nil { return raster.Point{}, errors.New("freetype: DrawText called with a nil font") } prev, hasPrev := truetype.Index(0), false for _, rune := range s { index := c.font.Index(rune) if hasPrev { p.X += raster.Fix32(c.font.Kerning(c.scale, prev, index)) << 2 } mask, offset, err := c.glyph(index, p) if err != nil { return raster.Point{}, err } p.X += raster.Fix32(c.font.HMetric(c.scale, index).AdvanceWidth) << 2 glyphRect := mask.Bounds().Add(offset) dr := c.clip.Intersect(glyphRect) if !dr.Empty() { mp := image.Point{0, dr.Min.Y - glyphRect.Min.Y} draw.DrawMask(c.dst, dr, c.src, image.ZP, mask, mp, draw.Over) } prev, hasPrev = index, true } return p, nil }