How to modify a Visual Basic Picturebox with Powerbasic?

[Roberto Pérez Villalobos]

I'm trying to modify an image stored in a Visual Basic Pictute control using a PowerBasic Dll.

The function below works fine changing the back color, but I can not draw an elipse in the same image.

Someone know how to do it?


'________________________________________________________

#COMPILE DLL
#DIM ALL

%USEMACROS = 1
#INCLUDE "Win32API.inc"

GLOBAL ghInstance AS DWORD

'-------------------------------------------------------------------------------
' Main DLL entry point called by Windows...
'
FUNCTION LIBMAIN (BYVAL hInstance AS LONG, _
BYVAL fwdReason AS LONG, _
BYVAL lpvReserved AS LONG) AS LONG

SELECT CASE fwdReason

CASE %DLL_PROCESS_ATTACH
'Indicates that the DLL is being loaded by another process (a DLL
'or EXE is loading the DLL). DLLs can use this opportunity to
'initialize any instance or global data, such as arrays.

ghInstance = hInstance

FUNCTION = 1 'success!

'FUNCTION = 0 'failure! This will prevent the EXE from running.

CASE %DLL_PROCESS_DETACH
'Indicates that the DLL is being unloaded or detached from the
'calling application. DLLs can take this opportunity to clean
'up all resources for all threads attached and known to the DLL.

FUNCTION = 1 'success!

'FUNCTION = 0 'failure!

CASE %DLL_THREAD_ATTACH
'Indicates that the DLL is being loaded by a new thread in the
'calling application. DLLs can use this opportunity to
'initialize any thread local storage (TLS).

FUNCTION = 1 'success!

'FUNCTION = 0 'failure!

CASE %DLL_THREAD_DETACH
'Indicates that the thread is exiting cleanly. If the DLL has
'allocated any thread local storage, it should be released.

FUNCTION = 1 'success!

'FUNCTION = 0 'failure!

END SELECT

END FUNCTION

SUB ReplaceColor_and_elipse ALIAS "ReplaceColor_and_elipse" (BYVAL hDC_ORIGINAL AS LONG, _
BYVAL xOffset AS LONG, _
BYVAL yOffset AS LONG, _
BYVAL nWidth AS LONG, _
BYVAL nHeight AS LONG, _
BYVAL UseWidth AS LONG, _
BYVAL UseHeight AS LONG, _
BYVAL WasColor AS LONG, _
BYVAL NewColor AS LONG) EXPORT

REGISTER x AS LONG, y AS LONG

DIM BITMAP1 AS BITMAP
DIM BITMAP1_informacion AS BITMAPINFO
DIM pDW AS DWORD PTR

IF UseWidth = 0 THEN UseWidth = nWidth
IF UseHeight = 0 THEN UseHeight = nHeight


WasColor = RGB(GetBValue(WasColor), GetGValue(WasColor), GetRValue(WasColor))
NewColor = RGB(GetBValue(NewColor), GetGValue(NewColor), GetRValue(NewColor))

BITMAP1_informacion.bmiHeader.biSize = SIZEOF(BITMAP1_informacion.bmiHeader)
BITMAP1_informacion.bmiHeader.biWidth = nWidth
BITMAP1_informacion.bmiHeader.biHeight = nHeight
BITMAP1_informacion.bmiHeader.biPlanes = 1
BITMAP1_informacion.bmiHeader.biBitCount = 32
BITMAP1_informacion.bmiHeader.biCompression = %BI_RGB

DIM hDC_TEMPORAL AS LONG
DIM hTmpBmp AS LONG

hDC_TEMPORAL = CreateCompatibleDC (hDC_ORIGINAL)
hTmpBmp = CreateDIBSection(hDC_TEMPORAL, BITMAP1_informacion, %DIB_RGB_COLORS, 0, 0, 0)

CALL GlobalLock(hTmpBmp)

CALL SelectObject(hDC_TEMPORAL, hTmpBmp)
CALL BitBlt( hDC_TEMPORAL, 0, 0, nWidth, nHeight, hDC_ORIGINAL, 0, 0, %SRCCOPY)
CALL GetObject( hTmpBmp, SIZEOF(BITMAP1), BITMAP1)

FOR pDW = BITMAP1.bmBits TO BITMAP1.bmBits + (BITMAP1.bmWidth * BITMAP1.bmHeight * 4) STEP 4
IF @pDW = WasColor THEN @pDW = NewColor
NEXT

'**** ON THIS PART, I'M TRYING TO DRAW AN ELIPSE
GRAPHIC ATTACH hDC_TEMPORAL, hTmpBmp
GRAPHIC ELLIPSE (0, 0) - (nWidth, nHeight) , RGB(0,0,0),RGB(0,255,0),1
'************************************************************************************

CALL BitBlt(hDC_ORIGINAL, xOffset, yOffset, UseWidth, UseHeight, hDC_TEMPORAL, xOffset, yOffset, %SRCCOPY)

' Deallocate system resources.
CALL GlobalUnLock( hTmpBmp )
CALL DeleteDC( hDC_TEMPORAL )
CALL DeleteObject( hTmpBmp )

END SUB
'________________________________________________________

There is atached a winzip file with the source code in Powerbasic and Visual Basic.

[Michael Mattias]

**** ON THIS PART, I'M TRYING TO DRAW AN ELIPSE
GRAPHIC ATTACH hDC_TEMPORAL, hTmpBmp
GRAPHIC ELLIPSE (0, 0) - (nWidth, nHeight) , RGB(0,0,0),RGB(0,255,0),1

AFAIK you may not use the GRAPHIC XXX commands except against windows created with either GRAPHIC WINDOW or CONTROL ADD GRAPHIC.

But you can use the WinAPI Ellipse() function... ASSUMING Visual BASIC does not mind you screwing with its picture box control.

PS: Please use CODE TAGS when posting code. http://www.powerbasic.com/support/pb....php?do=bbcode

MCM

[John R. Heathcote]

Roberto,

IIRC you will have to use COM to draw your ellipse on a VB PictureBox control from PB.