text_wrap_first.go

func drawLine(gc *draw2dimg.GraphicContext, str string, x float64, y float64) {
	gc.FillStringAt(str, x, y)
}

func drawText(gc *draw2dimg.GraphicContext, str string, width float64, height float64, x float64, y float64) {
	str = strings.Trim(str, " \n\r\t")
	lines := strings.Split(str, "\n")
	fontSize := gc.Current.FontSize
	offsetY := y
	wrapLines := []string{}
	runePerLine := int(width / fontSize)

	for _, line := range lines {
		len := utf8.RuneCountInString(line)
		chunks := []string{}
		list := []rune(line)

		for i := 0; i < len; i += runePerLine {
			max := i + runePerLine

			if max > len {
				chunks = append(chunks, string(list[i:len]))
			} else {
				chunks = append(chunks, string(list[i:max]))
			}
		}

		wrapLines = append(wrapLines, chunks...)
	}

	for _, line := range wrapLines {
		_, top, _, bottom := gc.GetStringBounds(line)
		drawLine(gc, line, x, offsetY)
		offsetY += (bottom - top) * lineHeight

		if offsetY > y+height {
			break
		}
	}
}