Как создать линию по диагонали?

#include <GDIPlus.au3>

$hGUI = GUICreate("GDI+", 210, 210)
GUISetState()

_Draw_Line(10, 10, 200, 200, 2, 0xFF0000)
_Draw_Line(200, 10, 10, 200, 4,0x0000FF)
_Draw_Line(10, 105, 200, 105, 3,0x00FF00)
_Draw_Line(105, 10, 105, 200, 5,0xFFFF00)

Do
Until GUIGetMsg() = -3

;$X1 - X1 координата
;$Y1 - Y1 координата
;$X2 - X2 координата
;$Y2 - Y2 координата
;$Bold - толщина линии
;$Color - цвет линии
Func _Draw_Line($X1, $Y1, $X2, $Y2, $bold=1, $Color=0x000000)
	_GDIPlus_Startup()
	Local $lastcolor = 0xFF000000 + $Color
	Local $hGraphic = _GDIPlus_GraphicsCreateFromHWND($hGUI)
	Local $hPen = _GDIPlus_PenCreate()
	_GDIPlus_PenSetColor($hPen, $lastcolor)
	_GDIPlus_PenSetWidth($hPen, $bold)
	_GDIPlus_GraphicsDrawLine($hGraphic, $X1, $Y1, $X2, $Y2, $hPen)
	_GDIPlus_PenDispose($hPen)
	_GDIPlus_GraphicsDispose($hGraphic)
	_GDIPlus_Shutdown()
EndFunc