DrawGetDPI - ProGUI Reference Manual

Syntax

DpiX = DrawGetDPI(*DPI_Y.Integer=#Null)

Description

Retrieves the current horizontal and optionally vertical Dots Per Inch (DPI) values being used by the active drawing context for scaling calculations.

Parameters

*DPI_Y.Integer (optional)
A pointer to an integer variable that will receive the current vertical DPI value. If #Null, only the horizontal DPI is returned.

Return Value

Returns the current horizontal DPI value as an Integer. Returns 0 or #False if called outside a BeginDraw() / EndDraw() block.

Remarks

This function allows querying the DPI setting currently applied to the drawing context, which determines the scaling factor for DIP-based coordinates and sizes. This value might differ from the window's native DPI if DrawDPI() was used to override the default. The default DPI returned by this function when drawing begins is the native DPI of the output target (window or image).

Example

IncludeFile "ProGUI_PB.pbi"

StartProGUI()

Procedure DrawHandler(Window, EventType, *EventData.PG_EventDraw, *UserData)
  
    DrawClear(RGB(255, 255, 255), 1)

    CurrentDpiX = DrawGetDPI(@CurrentDpiY)
    Debug "Initial Draw DPI - X: " + Str(CurrentDpiX) + ", Y: " + Str(CurrentDpiY)

    ; Change DPI
    DrawDPI(192)

    CurrentDpiX = DrawGetDPI(@CurrentDpiY)
    Debug "Changed Draw DPI - X: " + Str(CurrentDpiX) + ", Y: " + Str(CurrentDpiY)

    ; Restore default
    DrawDPI(#PG_DrawDPI_Auto)
    CurrentDpiX = DrawGetDPI(@CurrentDpiY)
    Debug "Restored Draw DPI - X: " + Str(CurrentDpiX) + ", Y: " + Str(CurrentDpiY)

EndProcedure

MyWindow = CreateWindow(0, 0, 300, 150, "Get Draw DPI Example")

If MyWindow
  AddEventHandler(MyWindow, #PG_Event_Draw, @DrawHandler())
  WindowShow(MyWindow, #True, #PG_Window_ScreenCentered)

  Repeat
    Event = WaitWindowEvent()
  Until Event = #PB_Event_CloseWindow
EndIf

StopProGUI()

Supported OS

Windows, Linux