text_wrap_second.go

func drawLine(gc *draw2dimg.GraphicContext, str string, maxX float64, maxY float64, x float64, y float64) (bool, float64) {
	// Handle empty line
	if len(strings.TrimSpace(str)) == 0 {
		return false, y + gc.Current.FontSize*lineHeight
	}

	list := []rune(str)
	length := len(list)
	offsetX := x
	offsetY := y
	fontSize := gc.Current.FontSize
	lineSize := fontSize * lineHeight

	for i := 0; i < length; i++ {
		chunk := string(list[i])
		textWidth := gc.FillStringAt(chunk, offsetX, offsetY)
		offsetX += textWidth

		if offsetX >= maxX {
			newY := offsetY + lineSize

			if newY >= maxY {
				return true, offsetY
			}

			offsetX = x
			offsetY = newY
		}
	}

	offsetY += lineSize

	return false, offsetY
}

func drawText(gc *draw2dimg.GraphicContext, str string, width float64, height float64, x float64, y float64) {
	// Trim newlines
	str = strings.Trim(str, "\r\n")

	// Split by lines
	lines := strings.Split(str, "\n")

	// Initial offset
	offsetY := y

	maxX := width + x
	maxY := height + y

	for _, line := range lines {
		end, newY := drawLine(gc, line, maxX, maxY, x, offsetY)

		if end || newY >= maxY {
			break
		}

		offsetY = newY
	}
}