drawRectOutline

fun GuiGraphics.drawRectOutline(
    x: Int, 
    y: Int, 
    width: Int, 
    height: Int, 
    color: Int, 
    thickness: Int = 1
)

Draws an unfilled rectangle outline of thickness pixels using the default GUI RenderType.

fun GuiGraphics.drawRectOutline(
    type: RenderType, 
    x: Int, 
    y: Int, 
    width: Int, 
    height: Int, 
    color: Int, 
    thickness: Int = 1
)

Draws an unfilled rectangle outline of thickness pixels as four filled edge strips.