GDI: SetPixelV Function

[José Roca]

 
The following example reads data from a file and creates a map on screen using SetPixelV. If the ASCII value of a byte is 0, it will show as black. At the other end of the spectrum, ASCII 255 will show as white.

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' ========================================================================================
' The following example uses the PaintDesktop function to fill the clipping region in the
' specified device context with the desktop pattern or wallpaper.
' ========================================================================================

' CSED_PBWIN - Use the PBWIN compiler
#COMPILE EXE
#DIM ALL
%UNICODE = 1

' // Include files for external files
#INCLUDE ONCE "CWindow.inc"   ' // CWindow class

' ========================================================================================
' Main
' ========================================================================================
FUNCTION WinMain (BYVAL hInstance AS DWORD, BYVAL hPrevInstance AS DWORD, BYVAL lpszCmdLine AS WSTRINGZ PTR, BYVAL nCmdShow AS LONG) AS LONG

   ' // Create an instance of the class
   LOCAL pWindow AS IWindow
   pWindow = CLASS "CWindow"
   IF ISNOTHING(pWindow) THEN EXIT FUNCTION

   ' // Create the main window
   ' // Note: CW_USEDEFAULT is used as the default value When passing 0's as the width and height
   pWindow.CreateWindow(%NULL, "PaintDesktop Demo", 0, 0, 0, 0, 0, 0, CODEPTR(WindowProc))
   ' // Change the background color
   pWindow.Brush = %COLOR_WINDOW + 1
   ' // Set the client size
   pWindow.SetClientSize 500, 320
   ' // Center the window
   pWindow.CenterWindow

   ' // Default message pump (you can replace it with your own)
   pWindow.DoEvents(nCmdShow)

END FUNCTION
' ========================================================================================

' ========================================================================================
' Main window procedure
' ========================================================================================
FUNCTION WindowProc (BYVAL hwnd AS DWORD, BYVAL wMsg AS DWORD, BYVAL wParam AS DWORD, BYVAL lParam AS LONG) AS LONG

   LOCAL hdc AS DWORD         ' // Window device context
   LOCAL ps  AS PAINTSTRUCT   ' // PAINTSTRUCT structure

   SELECT CASE wMsg

      CASE %WM_COMMAND
         SELECT CASE LO(WORD, wParam)
            CASE %IDCANCEL
               IF HI(WORD, wParam) = %BN_CLICKED THEN
                  SendMessage hwnd, %WM_CLOSE, 0, 0
                  EXIT FUNCTION
               END IF
         END SELECT

      CASE %WM_PAINT
         hdc = BeginPaint(hwnd, ps)
         PaintDEsktop hdc
         EndPaint hwnd, ps
         EXIT FUNCTION

      CASE %WM_ERASEBKGND
         hdc = wParam
         PaintDesktop hdc
         FUNCTION = %TRUE
         EXIT FUNCTION

      CASE %WM_DESTROY
         PostQuitMessage 0
         EXIT FUNCTION

   END SELECT

   FUNCTION = DefWindowProc(hwnd, wMsg, wParam, lParam)

END FUNCTION
' ========================================================================================