u used both the same size
SetWindowSize( 1024, 768, 0 )
SetVirtualResolution( 1024, 768 )
if your window get 16:9 it will show 4:3 inside.
but i remember if the windows changed maximized and get back to normal it get a different size.
if you set full screen here it ignore the size x,y and used the desktop size
SetWindowSize
rem
rem AGK Application 2017.02.28, Player 27 Feb 2017
rem MR
SetWindowAllowResize( 1 )
SetWindowSize( 1024, 768, 0 )
SetVirtualResolution( 1024, 768 )
SetScissor( 0,0,0,0 )
SetClearColor(255,0,0)
Do
x1#=GetScreenBoundsLeft()
x2#=GetScreenBoundsRight()
y1#=GetScreenBoundsTop()
y2#=GetScreenBoundsBottom()
DrawBox(x1#,y1#,x2#,y2#,MakeColor(255,255,0),MakeColor(255,255,0),MakeColor(255,255,0),MakeColor(255,255,0),1)
DrawBox(x1#,y1#,x2#,y2#,MakeColor(0,255,0),MakeColor(0,255,0),MakeColor(0,255,0),MakeColor(0,255,0),0)
if GetPointerPressed() then exit
sync()
Loop
end
AGK (Steam) V2017.02.28 : Windows 10 Pro 64 Bit : AMD (17.2.1) Radeon R7 265 : Mac mini OS Sierra (10.12.2)