Wrapping DLL

BlitzMax Forums/BlitzMax Programming/Wrapping DLL

Jake L.

(Posted 2007) [#1]

Hi there,

I got some money left and bought me a Logitech G15 (can't resist the LCD-Display). I got the SDK that unluckily just came with a .lib :( But others wrote a DLL-wrapper (both .NET and oldschool), so I tried to wrap the DLL into Bmax. I managed to compile the stuff, but it failed to work. My C/C++ skills are very bad, so maybe some of you (blessed with C-Knowledge) could have a look at my code and point me to some erros.

First there is a general question:
Could this DLL be wrapped to be used from within BMax? (ignoring the callback stuff - Callbacks are only used for buttons so could be ignored for now)

If the answer to the above is yes, the next question is where did I made an error? It failed on G15_LcdConnect (I get no error but no connection-handle as well).

Ok, here's the deal: if some folks from the C-department could help me out, I will contribute a well documented and easy to use G15-Module with support for ingame-usage as well as output for debugging/profiling purposes.

Here's the original sdk-headerfile:

/*

  lglcd.h

  library definition for lglcd.a
  part of lglcd for Microsoft(R) Windows(R)

  The Logitech LCD SDK, including all acompanying documentation,
  is protected by intellectual property laws.  All use of the Logitech
  LCD SDK is subject to the License Agreement found in the
  "ReadMe License Agreement" file and in the Reference Manual.  All rights
  not expressly granted by Logitech are reserved.


  01/14/2005    1.00    initial draft
  02/23/2005    1.01    added callbacks, implemented changes as discussed

*/

#ifndef _LGLCD_H_INCLUDED_
#define _LGLCD_H_INCLUDED_

#ifdef __cplusplus
extern "C" {
#endif

#pragma pack(push, 8)

//// Definitions

// Invalid handle definitions
#define LGLCD_INVALID_CONNECTION            (-1)
#define LGLCD_INVALID_DEVICE                (-1)

// Soft-Button masks
#define LGLCDBUTTON_BUTTON0                 (0x00000001)
#define LGLCDBUTTON_BUTTON1                 (0x00000002)
#define LGLCDBUTTON_BUTTON2                 (0x00000004)
#define LGLCDBUTTON_BUTTON3                 (0x00000008)


//************************************************************************
// lgLcdDeviceDesc
//************************************************************************

typedef struct
{
    DWORD Width;
    DWORD Height;
    DWORD Bpp;
    DWORD NumSoftButtons;
} lgLcdDeviceDesc;


//************************************************************************
// lgLcdBitmap
//************************************************************************

#define LGLCD_BMP_FORMAT_160x43x1           (0x00000001)
#define LGLCD_BMP_WIDTH                     (160)
#define LGLCD_BMP_HEIGHT                    (43)

typedef struct
{
    DWORD Format;
} lgLcdBitmapHeader;

typedef struct
{
    lgLcdBitmapHeader hdr;
    BYTE pixels[LGLCD_BMP_WIDTH*LGLCD_BMP_HEIGHT];
} lgLcdBitmap160x43x1;

// Priorities
#define LGLCD_PRIORITY_IDLE_NO_SHOW         (0)
#define LGLCD_PRIORITY_BACKGROUND           (64)	
#define LGLCD_PRIORITY_NORMAL               (128)
#define LGLCD_PRIORITY_ALERT                (255)
#define LGLCD_SYNC_UPDATE(priority)         (0x80000000 | (priority))
#define LGLCD_ASYNC_UPDATE(priority)        (priority)


//************************************************************************
// Callbacks
//************************************************************************

// Callback used to notify client of soft button change
typedef DWORD (WINAPI *lgLcdOnSoftButtonsCB)(IN int device,
                                             IN DWORD dwButtons,
                                             IN const PVOID pContext);

// Callback used to allow client to pop up a "configuration panel"
typedef DWORD (WINAPI *lgLcdOnConfigureCB)(IN int connection,
                                           IN const PVOID pContext);


//************************************************************************
// lgLcdConnectContext
//************************************************************************
typedef struct
{
    // Set to NULL if not configurable
    lgLcdOnConfigureCB configCallback;
    PVOID configContext;
} lgLcdConfigureContext;

typedef struct
{
    // "Friendly name" display in the listing
    LPCWSTR appFriendlyName;
    // isPersistent determines whether this connection persists in the list
    BOOL isPersistent;
    // isAutostartable determines whether the client can be started by
    // LCDMon
    BOOL isAutostartable;
    lgLcdConfigureContext onConfigure;
    // --> Connection handle
    int connection;
} lgLcdConnectContextW;

typedef struct
{
    // "Friendly name" display in the listing
    LPCSTR appFriendlyName;
    // isPersistent determines whether this connection persists in the list
    BOOL isPersistent;
    // isAutostartable determines whether the client can be started by
    // LCDMon
    BOOL isAutostartable;
    lgLcdConfigureContext onConfigure;
    // --> Connection handle
    int connection;
} lgLcdConnectContextA;

#ifdef UNICODE
typedef lgLcdConnectContextW lgLcdConnectContext;
#else
typedef lgLcdConnectContextA lgLcdConnectContext;
#endif

//************************************************************************
// lgLcdOpenContext
//************************************************************************

typedef struct
{
    // Set to NULL if no softbutton notifications are needed
    lgLcdOnSoftButtonsCB softbuttonsChangedCallback;
    PVOID softbuttonsChangedContext;
} lgLcdSoftbuttonsChangedContext;

typedef struct
{
    int connection;
    // Device index to open
    int index;
    lgLcdSoftbuttonsChangedContext onSoftbuttonsChanged;
    // --> Device handle
    int device;
} lgLcdOpenContext;



//************************************************************************
// Prototypes
//************************************************************************

// Initialize the library by calling this function.
DWORD WINAPI lgLcdInit(void);

// Must be called to release the library and free all allocated structures.
DWORD WINAPI lgLcdDeInit(void);

// Connect as a client to the LCD subsystem. Provide name to be
// displayed for user when viewing the user interface of the LCD module,
// as well as a configuration callback and context, and a flag that states
// whether this client is startable by LCDMon
DWORD WINAPI lgLcdConnectW(IN OUT lgLcdConnectContextW *ctx);
DWORD WINAPI lgLcdConnectA(IN OUT lgLcdConnectContextA *ctx);
#ifdef UNICODE
#define lgLcdConnect lgLcdConnectW
#else
#define lgLcdConnect lgLcdConnectA
#endif // !UNICODE

// Must be called to release the connection and free all allocated resources
DWORD WINAPI lgLcdDisconnect(int connection);

// To determine all connected LCD devices supported by this library, and
// their capabilities. Start with index 0, and increment by one, until
// the library returns an error (WHICH?).
DWORD WINAPI lgLcdEnumerate(IN int connection, IN int index,
                            OUT lgLcdDeviceDesc *description);

// Opens the LCD at position=index. Library sets the device parameter to
// its internal reference to the device. Calling application provides the
// device handle in all calls that access the LCD.
DWORD WINAPI lgLcdOpen(IN OUT lgLcdOpenContext *ctx);

// Closes the LCD. Must be paired with lgLcdOpen.
DWORD WINAPI lgLcdClose(IN int device);

// Reads the state of the soft buttons for the device.
DWORD WINAPI lgLcdReadSoftButtons(IN int device, OUT DWORD *buttons);

// Provides a bitmap to be displayed on the LCD. The priority field
// further describes the way in which the bitmap is to be applied.
DWORD WINAPI lgLcdUpdateBitmap(IN int device,
                               IN const lgLcdBitmapHeader *bitmap,
                               IN DWORD priority);


#pragma pack(pop)

#ifdef __cplusplus
}
#endif

#endif // _LGLCD_H_INCLUDED_

//** end of lglcd.h ***************************************************

and here comes my noobish trial to convert this:

SuperStrict 

Import pub.win32

'Invalid Handle definitions
Const LGLCD_INVALID_CONNECTION%	=	-1
Const LGLCD_INVALID_DEVICE%		=	-1

'Soft-Button masks
Const LGLCDBUTTON_BUTTON0%		=	$00000001
Const LGLCDBUTTON_BUTTON1%		=   $00000002
Const LGLCDBUTTON_BUTTON2%		=   $00000004
Const LGLCDBUTTON_BUTTON3%		=   $00000008

Type lgLcdDeviceDesc
	Field Width:Int
	Field Height:Int
	Field Bpp:Int
	Field NumSoftButtons:Int
End Type

'Bitmap stuff
Const LGLCD_BMP_FORMAT_160x42x1%=	$00000001
Const LGLCD_BMP_WIDTH%			=	160
Const LGLCD_BMP_HEIGHT%			=	43

Type lgLcdBitmapHeader
	Field Format:Int
End Type

Type lgLcdBitmap160x43x1
	Field hdr:lgLcdBitmapHeader
	Field pixels:Byte[LGLCD_BMP_WIDTH*LGLCD_BMP_HEIGHT]
End Type


'Priorities
Const LGLCD_PRIORITY_IDLE_NO_SHOW%	=	0
Const LGLCD_PRIORITY_BACKGROUND%	=	64
Const LGLCD_PRIORITY_NORMAL%		=	128
Const LGLCD_PRIORITY_ALERT%			=	255

'#define LGLCD_SYNC_UPDATE(priority)         (0x80000000 | (priority))
'#define LGLCD_ASYNC_UPDATE(priority)        (priority)

'// Callback used To allow client To pop up a "configuration panel"
'typedef DWORD (WINAPI *lgLcdOnConfigureCB)(IN Int connection,  IN Const PVOID pContext);
Type lgLcdConfigureContext
	Field configCallback:Byte Ptr
	Field configContext:Byte Ptr
End Type
    

Type lgLcdConnectContext
	Field appFriendlyName:Short Ptr
	Field isPersistent:Int
	Field isAutoStartable:Int
	Field onConfigure:lgLcdConfigureContext
	Field connection:Int=-1
End Type

'// Callback used To Notify client of soft button change
'typedef DWORD (WINAPI *lgLcdOnSoftButtonsCB)(IN Int device,  IN DWORD dwButtons,  IN Const PVOID pContext);
Type lgLcdSoftbuttonsChangedContext
	Field softbuttonsChangedCallback(connection:Int, pContext:Byte Ptr)
	Field softbuttonsChangedContext:Int
End Type

Type lgLcdOpenContext
	Field connection:Int
	Field index:Int
	Field onSoftbuttonsChanged(connection:Int,pContext:Byte Ptr)
	Field device:Int
End Type


Const  DllName:String = "lgLcd.dll"
Local DllHandle% = LoadLibraryA(DllName)

Global G15_LCDInit:Int()"Win32" = GetProcAddress(DllHandle,"lgLcdInit")
Global G15_LCDDeInit:Int()"Win32" = GetProcAddress(DllHandle,"lgLcdDeInit")
Global G15_LCDConnect:Int(ctx:lgLcdConnectContext)=GetProcAddress(DllHandle,"lgLcdConnectW")
Global G15_LCDDisconnect:Int(connection:Int)=GetProcAddress(Dllhandle,"lgLcdDisconnect")
Global G15_LCDEnumerate:Int(connection:Int,index:Int,description:lgLcdDeviceDesc)=GetProcAddress(Dllhandle,"lgLcdEnumerate")
Global G15_LCDOpen:Int(ctx:lgLcdOpenContext)=GetProcAddress(Dllhandle,"lgLcdOpen")
Global G15_LCDClose:Int(device:Int)=GetProcAddress(Dllhandle,"lgLcdClose")
Global G15_LCDReadSoftButtons:Int(device:Int,buttons:Int Ptr)=GetProcAddress(DllHandle,"lgLcdReadSoftButtons")
Global G15_LCDUpdateBitmap:Int(device:Int,bitmap:lgLCDBitmapheader,priority:Int)=GetProcAddress(DllHandle,"lgLcdUpdateBitmap")

Hopefully someone can help me out. Would be really nice (and way cool) to get BMax-support for this.

Thanks
Jake

Dreamora

(Posted 2007) [#2]

Naming of the functions is wrong.
As you mention lib I assume you use Visual Studio compiler in which case the naming will get mangled ...

I think it was like _FunctionName@InputBufferSize, but you could use a PE explorer or wordpad to find that one out :)

for example for lgLcdConnectW( ContextW *ctx) this would mean:
_lgLcdConnectW@4

Jake L.

(Posted 2007) [#3]

But this won't apply to DLLs, does it? I'd like to use an (existing) wrapper-DLL from this lib. The lib itself isn't compatible to MinGW.

Update: After some websearching I found [a http://sourceforge.net/projects/mylcd/ /] would be very useful. It's fully crossplattform, comes with sources and is able to work together with a whole bunch of LCD-Displays. It should be "relative" easy to create a bmx-module from this...well, if I only knew C++.

Anyone interested?

Jake

PS: I think the plain "draw bitmap to display"-functionality is all bmax-users would want. The other stuff (font rendering etc.) is already existing in bmax.

BORNtobeNAMELESS

(Posted 2007) [#4]

This myLCD sounds very interesting.
I'll try to create a Bmax Module if it.

Punksmurf

(Posted 2007) [#5]

How are you faring with creating a module?

Just bought the same keyboard and wondered :)

LAB[au]

(Posted 2007) [#6]

There is lying the last version of it ... I believe

http://btbn.de/ModServer/

Punksmurf

(Posted 2007) [#7]

Ah, thanks, but it's linux only so I don't think it'll work trough the windows drivers ;)