Draw a point with GDI+

[Andreik]

How can I draw only one point with GDI+? I tried to draw with _GDIPlus_GraphicsDrawLine() but 2 points.

[jvanegmond]

Try _GDIPlus_GraphicsFillRect with width 1 and heigth 1.

Edit: I think the proper technique is to create a pen and use the pen to draw a pixel.

Edited February 24, 2009 by Manadar

[Authenticity]

SetPixel?

[Andreik]

Try _GDIPlus_GraphicsFillRect with width 1 and heigth 1.

Edit: I think the proper technique is to create a pen and use the pen to draw a pixel.

Ok, I could create a pen but what function to choose to draw? _GDIPlus_GraphicsFillRect() work only for 2 pixels.

[Malkey]

How can I draw only one point with GDI+? I tried to draw with _GDIPlus_GraphicsDrawLine() but 2 points.

This example works and repaints very fast.

expandcollapse popup

#include <gdiplus.au3>
 #include <WindowsConstants.au3>
 
; Example modified from
; http://www.autoitscript.com/forum/index.php?s=&showtopic=89879&view=findpost&p=647719
 
 Opt("GUIOnEventMode", 1)
 
 Global Const $Width = 500
 Global Const $Height = 500
 Global Const $PI = 3.14159265
 
 $hWnd = GUICreate("Double buffering with GDI(+)", $Width, $Height)
 
 GUISetOnEvent(-3, "close")
 GUISetOnEvent(0xF, "MY_PAINT")
 _GDIPlus_Startup()
 
 $hGraphics = _GDIPlus_GraphicsCreateFromHWND($hWnd)
 $hBitmap = _GDIPlus_BitmapCreateFromGraphics($Width, $Height, $hGraphics)
 $hBackbuffer = _GDIPlus_ImageGetGraphicsContext($hBitmap)
 $ScreenDc = _WinAPI_GetDC($hWnd)
 
 GUISetState()
 _GDIPlus_GraphicsClear($hBackbuffer, 0xFFFFFFFF)
 _AntiAlias($hBackbuffer)
 
 For $nun = 3 To 444 Step 3
     _GDIPlus_BitmapSetPixel($hBitmap, $nun, $nun, 0xFF000000)
 Next
 
 $gdibitmap = _GDIPlus_BitmapCreateHBITMAPFromBitmap($hBitmap)
 $dc = _WinAPI_CreateCompatibleDC($ScreenDc)
 _WinAPI_SelectObject($dc, $gdibitmap)
 _WinAPI_BitBlt($ScreenDc, 0, 0, $Width, $Height, $dc, 0, 0, $SRCCOPY)
 
 GUIRegisterMsg(0xF, "MY_PAINT")
 
 Do
 Until Not Sleep(250)
 
 Func close()
     _WinAPI_DeleteDC($dc)
     _WinAPI_DeleteObject($gdibitmap)
     _WinAPI_ReleaseDC($hWnd, $ScreenDc)
     _GDIPlus_GraphicsDispose($hBackbuffer)
     _GDIPlus_BitmapDispose($hBitmap)
     _GDIPlus_GraphicsDispose($hGraphics)
     _GDIPlus_Shutdown()
 
     Exit
 EndFunc  ;==>close
 
 Func MY_PAINT($hWnd1, $MSG, $wParam, $lParam)
    ; Check, if the GUI with the Graphic should be repainted
     If $hWnd1 = $hWnd Then
         $Timer = TimerInit()
 
        ;_GDIPlus_GraphicsClear($hBackbuffer, 0xFFFFFFFF)
         DllCall($ghGDIPDll, "int", "GdipGraphicsClear", "hwnd", $hBackbuffer, "int", 0xFFFFFFFF)
 
        ;_WinAPI_BitBlt($ScreenDc, 0, 0, $Width, $Height, $dc, 0, 0, $SRCCOPY)
         DllCall("GDI32.dll", "int", "BitBlt", "hwnd", $ScreenDc, "int", 0, "int", 0, "int", $Width, "int", $Height, _
                 "hwnd", $dc, "int", 0, "int", 0, "int", $SRCCOPY)
         ConsoleWrite(TimerDiff($Timer) & @CRLF)
     EndIf
 EndFunc  ;==>MY_PAINT
 
 Func _GDIPlus_BitmapSetPixel($hBitmap, $iX, $iY, $iARGB)
     Local $aRet
     $aRet = DllCall($ghGDIPDll, "int", "GdipBitmapSetPixel", "hwnd", $hBitmap, "int", $iX, "int", $iY, "dword", $iARGB)
     Return
 EndFunc  ;==>_GDIPlus_BitmapSetPixel
 
 Func _GDIPlus_BitmapGetPixel($hBitmap, $iX, $iY)
     Local $tArgb, $pArgb, $aRet
     $tArgb = DllStructCreate("dword Argb")
     $pArgb = DllStructGetPtr($tArgb)
     $aRet = DllCall($ghGDIPDll, "int", "GdipBitmapGetPixel", "hwnd", $hBitmap, "int", $iX, "int", $iY, "ptr", $pArgb)
     Return "0x" & Hex(DllStructGetData($tArgb, "Argb"))
 EndFunc  ;==>_GDIPlus_BitmapGetPixel
 
 Func _AntiAlias($hGraphics)
     Local $aResult
     $aResult = DllCall($ghGDIPDll, "int", "GdipSetSmoothingMode", "hwnd", $hGraphics, "int", 2)
     If @error Then Return SetError(@error, @extended, False)
     Return SetError($aResult[0], 0, $aResult[0] = 0)
 EndFunc  ;==>_AntiAlias