* http://www.ml-consult.co.uk/foxst-29.htm
* http://www.foxite.com/archives/avicap32-camera-0000241185.htm
*** Eztwain.PRG - Start
* XDefs translation of \EZTwain\VC\eztwain.h
*-----------------------------------------------------------------
* EZTWAIN.H - interface to Easy TWAIN library
* (DLL=eztw32.dll)
*
* 1.15 2006.05.09 Fix: If user closed the scan dialog during an Acquire,
* the last DIB handle, if any, was returned!
* Added VB\Eztwain.bas to package.
* 1.14 2004.08.06 Set XFERMECH=NATIVE as soon as DS is opened.
* trying to deal with scanners that default to memory xfer.
* 1.13 1999.09.08 Documented correct return codes of AcquireToFilename.
* - No code changes -
* 1.12 1998.09.14 Added Fix32ToFloat, allow MSG_OPENDS triplet.
* Added SetXferMech, XferMech.
* 1.11 1998.08.17 Added ToFix32, SetContrast, SetBrightness.
* Modified TWAIN_ToFix32 to round away-from-zero.
* 1.09beta 1998.07.27 Reverted from 1.08 to 1.06 and worked forward again.
* 1.06 1997.08.21 correction to message hook, fixed 32-bit exports
* 1.05 1996.11.06 32-bit conversion
* 1.04 1995.05.03 added: WriteNativeToFile, WriteNativeToFilename,
* FreeNative, SetHideUI, GetHideUI, SetCurrentUnits,
* GetCurrentUnits, SetCurrentResolution, SetBitDepth,
* SetCurrentPixelType, SetCapOneValue.
* 1.0a 1994.06.23 first alpha version
* 0.0 1994.05.11 created
*
* EZTWAIN 1.x is not a product, and is not the work of any company involved
* in promoting or using the TWAIN standard. This code is sample code,
* provided without charge, and you use it entirely at your own risk.
* No rights or ownership is claimed by the author, or by any company
* or organization. There are no restrictions on use or (re)distribution.
*
* Download from: www.dosadi.com
*
* Support contact: support@dosadi.com
*
*--------- Basic calls
DECLARE LONG TWAIN_AcquireNative IN eztw32.dll ;
LONG hwndApp, ;
LONG wPixTypes
* The minimal use of EZTWAIN.DLL is to just call this routine, with 0 for
* both params. EZTWAIN creates a window if hwndApp is 0.
*
* Acquires a single image, from the currently selected Data Source, using
* Native-mode transfer. It waits until the source closes (if it's modal) or
* forces the source closed if not. The return value is a handle to the
* acquired image. Only one image can be acquired per call.
*
* Under Windows, the return value is a global memory handle - applying
* GlobalLock to it will return a (huge) pointer to the DIB, which
* starts with a BITMAPINFOHEADER.
* NOTE: You are responsible for disposing of the returned DIB - these things
* can eat up your Windows memory fast! See TWAIN_FreeNative below.
*
* The image type can be restricted using the following masks. A mask of 0
* means 'any pixel type is welcome'.
* Caution: You should not assume that the source will honor a pixel type
* restriction! If you care, check the parameters of the DIB.
#DEFINE TWAIN_BW 1
#DEFINE TWAIN_GRAY 2
#DEFINE TWAIN_RGB 4
#DEFINE TWAIN_PALETTE 8
#DEFINE TWAIN_ANYTYPE 0
DECLARE TWAIN_FreeNative IN eztw32.dll ;
LONG hdib
* Release the memory allocated to a native format image, as returned by
* TWAIN_AcquireNative. (If you are coding in C or C++, this is just a call
* to GlobalFree.)
* If you use TWAIN_AcquireNative and don't free the returned image handle,
* it stays around taking up Windows (virtual) memory until your application
* terminates. Memory required per square inch:
* 1 bit B&W 8-bit grayscale 24-bit color
* 100 dpi 1.25KB 10KB 30KB
* 200 dpi 5KB 40KB 120KB
* 300 dpi 11.25KB 90KB 270KB
* 400 dpi 20KB 160KB 480KB
*
DECLARE LONG TWAIN_AcquireToClipboard IN eztw32.dll ;
LONG hwndApp, ;
LONG wPixTypes
* Like AcquireNative, but puts the resulting image, if any, into the system
* clipboard. Under Windows, this will put a CF_DIB item in the clipboard
* if successful. If this call fails, the clipboard is either empty or
* contains the old contents.
* A return value of 1 indicates success, 0 indicates failure.
*
* Useful for environments like Visual Basic where it is hard to make direct
* use of a DIB handle. In fact, TWAIN_AcquireToClipboard uses
* TWAIN_AcquireNative for all the hard work.
DECLARE LONG TWAIN_AcquireToFilename IN eztw32.dll ;
LONG hwndApp, ;
STRING sFile
* Acquire an image and write it to a .BMP (Windows Bitmap) file.
* The file name and path in pszFile are used. If pszFile is NULL or
* points to an empty string, the user is prompted with a Save File dialog.
* Return values:
* 0 success
* -1 Acquire failed OR user cancelled File Save dialog
* -2 file open error (invalid path or name, or access denied)
* -3 (weird) unable to lock DIB - probably an invalid handle.
* -4 writing BMP data failed, possibly output device is full
DECLARE LONG TWAIN_SelectImageSource IN eztw32.dll ;
LONG hwnd
* This is the routine to call when the user chooses the "Select Source..."
* menu command from your application's File menu. Your app has one of
* these, right? The TWAIN spec calls for this feature to be available in
* your user interface, preferably as described.
* Note: If only one TWAIN device is installed on a system, it is selected
* automatically, so there is no need for the user to do Select Source.
* You should not require your users to do Select Source before Acquire.
*
* This function posts the Source Manager's Select Source dialog box.
* It returns after the user either OK's or CANCEL's that dialog.
* A return of 1 indicates OK, 0 indicates one of the following:
* a) The user cancelled the dialog
* b) The Source Manager found no data sources installed
* c) There was a failure before the Select Source dialog could be posted
* -- details --
* Only sources that can return images (that are in the DG_IMAGE group) are
* displayed. The current default source will be highlighted initially.
* In the standard implementation of "Select Source...", your application
* doesn't need to do anything except make this one call.
*
* If you want to be meticulous, disable your "Acquire" and "Select Source"
* menu items or buttons if TWAIN_IsAvailable() returns 0 - see below.
*--------- Basic TWAIN Inquiries
DECLARE LONG TWAIN_IsAvailable IN eztw32.dll
* Call this function any time to find out if TWAIN is installed on the
* system. It takes a little time on the first call, after that it's fast,
* just testing a flag. It returns 1 if the TWAIN Source Manager is
* installed & can be loaded, 0 otherwise.
DECLARE LONG TWAIN_EasyVersion IN eztw32.dll
* Returns the version number of EZTWAIN.DLL, multiplied by 100.
* So e.g. version 2.01 will return 201 from this call.
DECLARE LONG TWAIN_State IN eztw32.dll
* Returns the TWAIN Protocol State per the spec.
#DEFINE TWAIN_PRESESSION 1
#DEFINE TWAIN_SM_LOADED 2
#DEFINE TWAIN_SM_OPEN 3
#DEFINE TWAIN_SOURCE_OPEN 4
#DEFINE TWAIN_SOURCE_ENABLED 5
#DEFINE TWAIN_TRANSFER_READY 6
#DEFINE TWAIN_TRANSFERRING 7
*--------- DIB handling utilities ---------
DECLARE LONG TWAIN_DibDepth IN eztw32.dll ;
LONG hdib
* Depth of DIB, in bits i.e. bits per pixel.
DECLARE LONG TWAIN_DibWidth IN eztw32.dll ;
LONG hdib
* Width of DIB, in pixels (columns)
DECLARE LONG TWAIN_DibHeight IN eztw32.dll ;
LONG hdib
* Height of DIB, in lines (rows)
DECLARE LONG TWAIN_DibNumColors IN eztw32.dll ;
LONG hdib
* Number of colors in color table of DIB
DECLARE LONG TWAIN_RowSize IN eztw32.dll ;
LONG hdib
DECLARE TWAIN_ReadRow IN eztw32.dll ;
LONG hdib, ;
LONG nRow, ;
STRING @prow
* Read row n of the given DIB into buffer at prow.
* Caller is responsible for ensuring buffer is large enough.
* Row 0 is the *top* row of the image, as it would be displayed.
DECLARE LONG TWAIN_CreateDibPalette IN eztw32.dll ;
LONG hdib
* Create and return a logical palette to be used for drawing the DIB.
* For 1, 4, and 8-bit DIBs the palette contains the DIB color table.
* For 24-bit DIBs, a default halftone palette is returned.
DECLARE TWAIN_DrawDibToDC IN eztw32.dll ;
LONG hDC, ;
LONG dx, ;
LONG dy, ;
LONG w, ;
LONG h, ;
LONG hdib, ;
LONG sx, ;
LONG sy
* Draws a DIB on a device context.
* You should call CreateDibPalette, select that palette
* into the DC, and do a RealizePalette(hDC) first.
*--------- BMP file utilities
DECLARE LONG TWAIN_WriteNativeToFilename IN eztw32.dll ;
LONG hdib, ;
STRING sFile
* Writes a DIB handle to a .BMP file
*
* hdib = DIB handle, as returned by TWAIN_AcquireNative
* pszFile = far pointer to NUL-terminated filename
* If pszFile is NULL or points to a null string, prompts the user
* for the filename with a standard file-save dialog.
*
* Return values:
* 0 success
* -1 user cancelled File Save dialog
* -2 file open error (invalid path or name, or access denied)
* -3 (weird) unable to lock DIB - probably an invalid handle.
* -4 writing BMP data failed, possibly output device is full
DECLARE LONG TWAIN_WriteNativeToFile IN eztw32.dll ;
LONG hdib, ;
LONG fh
* Writes a DIB to a file in .BMP format.
*
* hdib = DIB handle, as returned by TWAIN_AcquireNative
* fh = file handle, as returned by _open, _lopen or OpenFile
*
* Return value as for TWAIN_WriteNativeToFilename
DECLARE LONG TWAIN_LoadNativeFromFilename IN eztw32.dll ;
STRING sFile
* Load a .BMP file and return a DIB handle (as from AcquireNative.)
* Accepts a filename (including path & extension).
* If pszFile is NULL or points to a null string, the user is prompted.
* Returns a DIB handle if successful, otherwise NULL.
DECLARE LONG TWAIN_LoadNativeFromFile IN eztw32.dll ;
LONG fh
* Like LoadNativeFromFilename, but takes an already open file handle.
DECLARE TWAIN_SetHideUI IN eztw32.dll ;
LONG fHide
DECLARE LONG TWAIN_GetHideUI IN eztw32.dll
* These functions control the 'hide source user interface' flag.
* This flag is cleared initially, but if you set it non-zero, then when
* a source is enabled it will be asked to hide its user interface.
* Note that this is only a request - some sources will ignore it!
* This affects AcquireNative, AcquireToClipboard, and EnableSource.
* If the user interface is hidden, you will probably want to set at least
* some of the basic acquisition parameters yourself - see
* SetCurrentUnits, SetBitDepth, SetCurrentPixelType and
* SetCurrentResolution below.
*--------- Application Registration
DECLARE TWAIN_RegisterApp IN eztw32.dll ;
LONG nMajorNum, ;
LONG nMinorNum, ;
LONG nLanguage, ;
LONG nCountry, ;
STRING @lpszVersion, ;
STRING @lpszMfg, ;
STRING @lpszFamily, ;
STRING @lpszProduct
*
* TWAIN_RegisterApp can be called *AS THE FIRST CALL*, to register the
* application. If this function is not called, the application is given a
* 'generic' registration by EZTWAIN.
* Registration only provides this information to the Source Manager and any
* sources you may open - it is used for debugging, and (frankly) by some
* sources to give special treatment to certain applications.
*--------- Error Analysis and Reporting ------------------------------------
DECLARE LONG TWAIN_GetResultCode IN eztw32.dll
* Return the result code (TWRC_xxx) from the last triplet sent to TWAIN
DECLARE LONG TWAIN_GetConditionCode IN eztw32.dll
* Return the condition code from the last triplet sent to TWAIN.
* (To be precise, from the last call to TWAIN_DS below)
* If a source is NOT open, return the condition code of the source manager.
DECLARE TWAIN_ErrorBox IN eztw32.dll ;
STRING sMsg
* Post an error message dialog with an exclamation mark, OK button,
* and the title 'TWAIN Error'.
* pszMsg points to a null-terminated message string.
DECLARE TWAIN_ReportLastError IN eztw32.dll ;
STRING sMsg
* Like TWAIN_ErrorBox, but if some details are available from
* TWAIN about the last failure, they are included in the message box.
*--------- TWAIN State Control ------------------------------------
DECLARE LONG TWAIN_LoadSourceManager IN eztw32.dll
* Finds and loads the Data Source Manager, TWAIN.DLL.
* If Source Manager is already loaded, does nothing and returns TRUE.
* This can fail if TWAIN.DLL is not installed (in the right place), or
* if the library cannot load for some reason (insufficient memory?) or
* if TWAIN.DLL has been corrupted.
DECLARE LONG TWAIN_OpenSourceManager IN eztw32.dll ;
LONG hwnd
* Opens the Data Source Manager, if not already open.
* If the Source Manager is already open, does nothing and returns TRUE.
* This call will fail if the Source Manager is not loaded.
DECLARE LONG TWAIN_OpenDefaultSource IN eztw32.dll
* This opens the source selected in the Select Source dialog.
* If a source is already open, does nothing and returns TRUE.
* Fails if the source manager is not loaded and open.
DECLARE LONG TWAIN_EnableSource IN eztw32.dll ;
LONG hwnd
* Enables the open Data Source. This posts the source's user interface
* and allows image acquisition to begin. If the source is already enabled,
* this call does nothing and returns TRUE.
DECLARE LONG TWAIN_DisableSource IN eztw32.dll
* Disables the open Data Source, if any.
* This closes the source's user interface.
* If there is not an enabled source, does nothing and returns TRUE.
DECLARE LONG TWAIN_CloseSource IN eztw32.dll
* Closes the open Data Source, if any.
* If the source is enabled, disables it first.
* If there is not an open source, does nothing and returns TRUE.
DECLARE LONG TWAIN_CloseSourceManager IN eztw32.dll ;
LONG hwnd
* Closes the Data Source Manager, if it is open.
* If a source is open, disables and closes it as needed.
* If the Source Manager is not open, does nothing and returns TRUE.
DECLARE LONG TWAIN_UnloadSourceManager IN eztw32.dll
* Unloads the Data Source Manager i.e. TWAIN.DLL - releasing
* any associated memory or resources.
* This call will fail if the Source Manager is open, otherwise
* it always succeeds and returns TRUE.
DECLARE LONG TWAIN_WaitForNativeXfer IN eztw32.dll ;
LONG hwnd
DECLARE TWAIN_ModalEventLoop IN eztw32.dll
* Process messages until termination, source disable, or image transfer.
DECLARE LONG TWAIN_EndXfer IN eztw32.dll
DECLARE LONG TWAIN_AbortAllPendingXfers IN eztw32.dll
*--------- High-level Capability Negotiation Functions --------
DECLARE LONG TWAIN_NegotiateXferCount IN eztw32.dll ;
LONG nXfers
* Negotiate with open Source the number of images application will accept.
* This is only allowed in State 4 (TWAIN_SOURCE_OPEN)
* nXfers = -1 means any number
DECLARE LONG TWAIN_NegotiatePixelTypes IN eztw32.dll ;
LONG wPixTypes
* Negotiate with the source to restrict pixel types that can be acquired.
* This tries to restrict the source to a *set* of pixel types,
* See TWAIN_AcquireNative above for some mask constants.
* --> This is only allowed in State 4 (TWAIN_SOURCE_OPEN)
* A parameter of 0 (TWAIN_ANYTYPE) causes no negotiation & no restriction.
* You should not assume that the source will honor your restrictions, even
* if this call succeeds!
DECLARE LONG TWAIN_GetCurrentUnits IN eztw32.dll
* Ask the source what its current unit of measure is.
* If anything goes wrong, this function just returns TWUN_INCHES (0).
DECLARE LONG TWAIN_SetCurrentUnits IN eztw32.dll ;
LONG nUnits
* Set the current unit of measure for the source.
* Unit of measure codes are in TWAIN.H, but TWUN_INCHES is 0.
DECLARE LONG TWAIN_GetBitDepth IN eztw32.dll
* Get the current bitdepth, which can depend on the current PixelType.
* Bit depth is per color channel e.g. 24-bit RGB has bit depth 8.
* If anything goes wrong, this function returns 0.
DECLARE LONG TWAIN_SetBitDepth IN eztw32.dll ;
LONG nBits
* (Try to) set the current bitdepth (for the current pixel type).
DECLARE LONG TWAIN_GetPixelType IN eztw32.dll
* Ask the source for the current pixel type.
* If anything goes wrong (it shouldn't), this function returns 0 (TWPT_BW).
DECLARE LONG TWAIN_SetCurrentPixelType IN eztw32.dll ;
LONG nPixType
* (Try to) set the current pixel type for acquisition.
* This is only allowed in State 4 (TWAIN_SOURCE_OPEN)
* The source may select this pixel type, but don't assume it will.
DECLARE DOUBLE TWAIN_GetCurrentResolution IN eztw32.dll
* Ask the source for the current (horizontal) resolution.
* Resolution is in dots per current unit! (See TWAIN_GetCurrentUnits above)
* If anything goes wrong (it shouldn't) this function returns 0.0
DECLARE DOUBLE TWAIN_GetYResolution IN eztw32.dll
* Returns the current vertical resolution, in dots per *current unit*.
* In the event of failure, returns 0.0.
DECLARE LONG TWAIN_SetCurrentResolution IN eztw32.dll ;
DOUBLE dRes
* (Try to) set the current resolution for acquisition.
* Resolution is in dots per current unit! (See TWAIN_GetCurrentUnits above)
* This is only allowed in State 4 (TWAIN_SOURCE_OPEN)
* Note: The source may select this resolution, but don't assume it will.
DECLARE LONG TWAIN_SetContrast IN eztw32.dll ;
DOUBLE dCon
* (Try to) set the current contrast for acquisition.
* The TWAIN standard says that the range for this cap is -1000 ... +1000
DECLARE LONG TWAIN_SetBrightness IN eztw32.dll ;
DOUBLE dBri
* (Try to) set the current brightness for acquisition.
* The TWAIN standard says that the range for this cap is -1000 ... +1000
DECLARE LONG TWAIN_SetXferMech IN eztw32.dll ;
LONG mech
DECLARE LONG TWAIN_XferMech IN eztw32.dll
* (Try to) set or get the transfer mode - one of the following:
#DEFINE XFERMECH_NATIVE 0
#DEFINE XFERMECH_FILE 1
#DEFINE XFERMECH_MEMORY 2
*--------- Low-level Capability Negotiation Functions --------
* Setting a capability is valid only in State 4 (TWAIN_SOURCE_OPEN)
* Getting a capability is valid in State 4 or any higher state.
DECLARE LONG TWAIN_SetCapOneValue IN eztw32.dll ;
LONG Cap, ;
LONG ItemType, ;
LONG ItemVal
* Do a DAT_CAPABILITY/MSG_SET, on capability 'Cap' (e.g. ICAP_PIXELTYPE,
* CAP_AUTOFEED, etc.) using a TW_ONEVALUE container with the given item type
* and value. The item value must fit into 32 bits.
* Returns TRUE (1) if successful, FALSE (0) otherwise.
DECLARE LONG TWAIN_GetCapCurrent IN eztw32.dll ;
LONG Cap, ;
LONG ItemType, ;
STRING @pVal
* Do a DAT_CAPABILITY/MSG_GETCURRENT on capability 'Cap'.
* Copy the current value out of the returned container into *pVal.
* If the operation fails (the source refuses the request), or if the
* container is not a ONEVALUE or ENUMERATION, or if the item type of the
* returned container is incompatible with the expected TWTY_ type in nType,
* returns FALSE. If this function returns FALSE, *pVal is not touched.
DECLARE LONG TWAIN_ToFix32 IN eztw32.dll ;
DOUBLE d
* Convert a floating-point value to a 32-bit TW_FIX32 value that can be passed
* to e.g. TWAIN_SetCapOneValue
DECLARE DOUBLE TWAIN_Fix32ToFloat IN eztw32.dll ;
LONG nfix
* Convert a TW_FIX32 value (as returned from some capability inquiries)
* to a double (floating point) value.
*--------- Lowest-level functions for TWAIN protocol --------
DECLARE LONG TWAIN_DS IN eztw32.dll ;
LONG DG, ;
LONG DAT, ;
LONG MSG, ;
STRING @pData
* Passes the triplet (DG, DAT, MSG, pData) to the open data source if any.
* Returns 1 (TRUE) if the result code is TWRC_SUCCESS, 0 (FALSE) otherwise.
* The last result code can be retrieved with TWAIN_GetResultCode(), and the corresponding
* condition code can be retrieved with TWAIN_GetConditionCode().
* If no source is open this call will fail, result code TWRC_FAILURE, condition code TWCC_NODS.
DECLARE LONG TWAIN_Mgr IN eztw32.dll ;
LONG DG, ;
LONG DAT, ;
LONG MSG, ;
STRING @pData
* Passes a triplet to the Data Source Manager (DSM).
* Returns 1 (TRUE) if the result code is TWRC_SUCCESS, 0 (FALSE) otherwise.
* The last result code can be retrieved with TWAIN_GetResultCode(), and the corresponding
* condition code can be retrieved with TWAIN_GetConditionCode().
* If the Source Manager is not open, this call will fail, and set the result code to TWRC_FAILURE,
* with a condition code of TWCC_SEQERROR (triplet out of sequence).
*** Eztwain.PRG - End
*** Sample.Prg - Start
Local oForm
oForm = Createobject("Tform")
oForm.Show(1)
* end of main
Define Class Tform As Form
#Define WM_CAP_START 0x0400
#Define WM_CAP_DRIVER_CONNECT (WM_CAP_START+10)
#Define WM_CAP_DRIVER_DISCONNECT (WM_CAP_START+11)
#Define WM_CAP_DRIVER_GET_CAPS (WM_CAP_START+14)
#Define WM_CAP_SET_PREVIEW (WM_CAP_START+50)
#Define WM_CAP_SET_OVERLAY (WM_CAP_START+51)
#Define WM_CAP_SET_PREVIEWRATE (WM_CAP_START+52)
#Define WM_CAP_GET_STATUS (WM_CAP_START+54)
#Define WM_CAP_GRAB_FRAME (WM_CAP_START+60)
Width=1054
Height=798
AutoCenter=.T.
Caption="Using Video Capture"
MinButton=.F.
MaxButton=.F.
hWindow=0
hCapture=0
capWidth=0
capHeight=0
capOverlay=0
Add Object cmdGetFrame As CommandButton With Default=.T.,;
Left=15, Top=5, Height=27, Width=90, Caption="Get Frame",;
Enabled=.F.
Add Object cmdPreview As CommandButton With Default=.T.,;
Left=106, Top=5, Height=27, Width=100, Caption="Preview Video",;
Enabled=.F.
Add Object cmdClose As CommandButton With Cancel=.T.,;
Left=207, Top=5, Height=27, Width=70, Caption="Close"
Procedure Activate
If This.hWindow = 0
Declare Integer GetFocus In user32
This.hWindow = GetFocus()
This.CreateCaptureWindow
This.DriverConnect
This.cmdPreview.Click
Endif
Procedure Destroy
This.ReleaseCaptureWindow
Procedure cmdClose.Click
Thisform.Release
Procedure cmdGetFrame.Click
Thisform.GetFrame
Procedure cmdPreview.Click
Thisform.StartPreview
Procedure GetFrame
This.msg(WM_CAP_GRAB_FRAME, 0,0)
#Define WM_CAP_FILE_SAVEDIB (WM_CAP_START + 25)
Local lcFile
lcFile = "" && File name to create
lcFile = "D:\Yedek\SampleX.BMP"
This.msg(WM_CAP_GRAB_FRAME, 0,0)
This.msg(WM_CAP_FILE_SAVEDIB, 0, lcFile,1)
Procedure CreateCaptureWindow
#Define WS_CHILD 0x40000000
#Define WS_VISIBLE 0x10000000
Declare Integer capCreateCaptureWindow In avicap32;
STRING lpszWindowName, Long dwStyle,;
INTEGER x, Integer Y,;
INTEGER nWidth, Integer nHeight,;
INTEGER hParent, Integer nID
This.hCapture = capCreateCaptureWindow("",;
WS_CHILD+WS_VISIBLE,;
10,40,1024,768, This.hWindow, 1)
Procedure DriverConnect
This.msg(WM_CAP_DRIVER_CONNECT, 0,0)
If This.IsCaptureConnected()
This.GetCaptureDimensions
Store .T. To This.cmdGetFrame.Enabled,;
THIS.cmdPreview.Enabled
This.Caption = This.Caption + ": connected, " +;
LTRIM(Str(This.capWidth)) + "x" +;
LTRIM(Str(This.capHeight))
Else
This.Caption = This.Caption + ": failed to connect"
Endif
Procedure DriverDisconnect
This.msg(WM_CAP_DRIVER_DISCONNECT, 0,0)
Procedure ReleaseCaptureWindow
If This.hCapture <> 0
This.DriverDisconnect
Declare Integer DestroyWindow In user32 Integer HWnd
= DestroyWindow(This.hCapture)
This.hCapture = 0
Endif
Procedure msg(msg, wParam, Lparam, nMode)
If This.hCapture = 0
Return
Endif
If Vartype(nMode) <> "N" Or nMode=0
Declare Integer SendMessage In user32;
INTEGER HWnd, Integer Msg,;
INTEGER wParam, Integer Lparam
= SendMessage(This.hCapture, msg, wParam, Lparam)
Else
Declare Integer SendMessage In user32;
INTEGER HWnd, Integer Msg,;
INTEGER wParam, String @Lparam
= SendMessage(This.hCapture, msg, wParam, @Lparam)
Endif
Function IsCaptureConnected
* analyzing fCaptureInitialized member of the CAPDRIVERCAPS structure
#Define CAPDRIVERCAPS_SIZE 44
Local cBuffer, nResult
cBuffer = Repli(Chr(0),CAPDRIVERCAPS_SIZE)
This.msg(WM_CAP_DRIVER_GET_CAPS, Len(cBuffer), @cBuffer, 1)
This.capOverlay = buf2dword(Substr(cBuffer,5,4))
nResult = Asc(Substr(cBuffer, 21,1))
Return (nResult<>0)
Procedure GetCaptureDimensions
* reading uiImageWidth and uiImageHeight members
* of the CAPSTATUS structure
* #Define CAPSTATUS_SIZE 76
#Define CAPSTATUS_SIZE 76
Local cBuffer
cBuffer = Repli(Chr(0), CAPSTATUS_SIZE)
This.msg(WM_CAP_GET_STATUS, Len(cBuffer), @cBuffer, 1)
This.capWidth = buf2dword(Substr(cBuffer,1,4)) && 1,4
This.capHeight = buf2dword(Substr(cBuffer,5,4)) && 5,4
Procedure StartPreview
This.msg(WM_CAP_SET_PREVIEWRATE, 30,0)
This.msg(WM_CAP_SET_PREVIEW, 1,0)
If This.capOverlay <> 0
This.msg(WM_CAP_SET_OVERLAY, 1,0)
Endif
Procedure StopPreview
This.msg(WM_CAP_SET_PREVIEW, 0,0)
Enddefine
Function buf2dword(lcBuffer)
Return Asc(Substr(lcBuffer, 1,1)) + ;
BitLShift(Asc(Substr(lcBuffer, 2,1)), 8) +;
BitLShift(Asc(Substr(lcBuffer, 3,1)), 16) +;
BitLShift(Asc(Substr(lcBuffer, 4,1)), 24)
*** Sample.Prg - End
