Draw a rectangle in Golang?

Question

I want to draw a mailing label with some rectangles, barcodes, and then finally generate a PNG/PDF file.

Is there is a better way to draw a shape in Go other than to

Answer 1

My noob shot at drawing a rectangle of given line thickness. Still primitive

func Rect(x1, y1, x2, y2, thickness int, img *image.RGBA) {
    col := color.RGBA{0, 0, 0, 255}

    for t:=0; t