// Draw a line with an angle with specified line cap and join func Draw(gc draw2d.GraphicContext, cap draw2d.LineCap, join draw2d.LineJoin, x0, y0, x1, y1, offset float64) { gc.SetLineCap(cap) gc.SetLineJoin(join) // Draw thick line gc.SetStrokeColor(color.NRGBA{0x33, 0x33, 0x33, 0xFF}) gc.SetLineWidth(30.0) gc.MoveTo(x0, y0) gc.LineTo((x0+x1)/2+offset, (y0+y1)/2) gc.LineTo(x1, y1) gc.Stroke() // Draw thin helping line gc.SetStrokeColor(color.NRGBA{0xFF, 0x33, 0x33, 0xFF}) gc.SetLineWidth(2.56) gc.MoveTo(x0, y0) gc.LineTo((x0+x1)/2+offset, (y0+y1)/2) gc.LineTo(x1, y1) gc.Stroke() }