reactos/dll/opengl/opengl32/wgl.c

/*
 * COPYRIGHT:            See COPYING in the top level directory
 * PROJECT:              ReactOS kernel
 * FILE:                 lib/opengl32/wgl.c
 * PURPOSE:              OpenGL32 lib, rosglXXX functions
 * PROGRAMMER:           Anich Gregor (blight)
 * UPDATE HISTORY:
 *                       Feb 2, 2004: Created
 */

#define OPENGL32_GL_FUNC_PROTOTYPES
#include "opengl32.h"

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

#if !defined(UNIMPLEMENTED)
# define UNIMPLEMENTED DBGPRINT( "UNIMPLEMENTED" )
#endif


typedef struct _OPENGL_INFO
{
    DWORD Version;          /*!< Driver interface version */
    DWORD DriverVersion;    /*!< Driver version */
    WCHAR DriverName[256];  /*!< Driver name */
} OPENGL_INFO, *POPENGL_INFO;

/*! \brief Append OpenGL Rendering Context (GLRC) to list
 *
 * \param glrc [IN] Pointer to GLRC to append to list
 */
static
void
ROSGL_AppendContext( GLRC *glrc )
{
    /* synchronize */
    if (WaitForSingleObject( OPENGL32_processdata.glrc_mutex, INFINITE ) ==
        WAIT_FAILED)
    {
        DBGPRINT( "Error: WaitForSingleObject() failed (%d)", GetLastError() );
        return; /* FIXME: do we have to expect such an error and handle it? */
    }

    if (OPENGL32_processdata.glrc_list == NULL)
        OPENGL32_processdata.glrc_list = glrc;
    else
    {
        GLRC *p = OPENGL32_processdata.glrc_list;
        while (p->next != NULL)
            p = p->next;
        p->next = glrc;
    }

    /* release mutex */
    if (!ReleaseMutex( OPENGL32_processdata.glrc_mutex ))
        DBGPRINT( "Error: ReleaseMutex() failed (%d)", GetLastError() );
}


/*! \brief Remove OpenGL Rendering Context (GLRC) from list
 *
 * \param glrc [IN] Pointer to GLRC to remove from list
 */
static
void
ROSGL_RemoveContext( GLRC *glrc )
{
    /* synchronize */
    if (WaitForSingleObject( OPENGL32_processdata.glrc_mutex, INFINITE ) ==
        WAIT_FAILED)
    {
        DBGPRINT( "Error: WaitForSingleObject() failed (%d)", GetLastError() );
        return; /* FIXME: do we have to expect such an error and handle it? */
    }

    if (glrc == OPENGL32_processdata.glrc_list)
        OPENGL32_processdata.glrc_list = glrc->next;
    else
    {
        GLRC *p = OPENGL32_processdata.glrc_list;
        while (p != NULL)
        {
            if (p->next == glrc)
            {
                p->next = glrc->next;
                break;
            }
            p = p->next;
        }
        if (p == NULL)
            DBGPRINT( "Error: GLRC 0x%08x not found in list!", glrc );
    }

    /* release mutex */
    if (!ReleaseMutex( OPENGL32_processdata.glrc_mutex ))
        DBGPRINT( "Error: ReleaseMutex() failed (%d)", GetLastError() );
}


/*! \brief Create a new GL Context (GLRC) and append it to the list
 *
 * \return Pointer to new GLRC on success
 * \retval NULL Returned on failure (i.e. Out of memory)
 */
static
GLRC *
ROSGL_NewContext(void)
{
    GLRC *glrc;

    /* allocate GLRC */
    glrc = (GLRC*)HeapAlloc( GetProcessHeap(),
                  HEAP_ZERO_MEMORY | HEAP_GENERATE_EXCEPTIONS, sizeof (GLRC) );

    /* append to list */
    ROSGL_AppendContext( glrc );

    return glrc;
}

/*! \brief Delete all GLDCDATA with this IDC
 *
 * \param icd [IN] Pointer to a ICD
 */
static
VOID
ROSGL_DeleteDCDataForICD( GLDRIVERDATA *icd )
{
    GLDCDATA *p, **pptr;
    
    return;

    /* synchronize */
    if (WaitForSingleObject( OPENGL32_processdata.dcdata_mutex, INFINITE ) ==
        WAIT_FAILED)
    {
        DBGPRINT( "Error: WaitForSingleObject() failed (%d)", GetLastError() );
        return;
    }

    p = OPENGL32_processdata.dcdata_list;
    pptr = &OPENGL32_processdata.dcdata_list;
    while (p != NULL)
    {
        if (p->icd == icd)
        {
            *pptr = p->next;
            OPENGL32_UnloadICD( p->icd );

            if (!HeapFree( GetProcessHeap(), 0, p ))
                DBGPRINT( "Warning: HeapFree() on GLDCDATA failed (%d)",
                          GetLastError() );

            p = *pptr;
        }
        else
        {
            pptr = &p->next;
            p = p->next;
        }
    }

    /* release mutex */
    if (!ReleaseMutex( OPENGL32_processdata.dcdata_mutex ))
        DBGPRINT( "Error: ReleaseMutex() failed (%d)", GetLastError() );
}


/*! \brief Delete a GL Context (GLRC) and remove it from the list
 *
 * \param glrc [IN] Pointer to GLRC to delete
 *
 * \retval TRUE  Success
 * \retval FALSE Failure
 */
static
BOOL
ROSGL_DeleteContext( GLRC *glrc )
{
    /* unload icd */
    if ((glrc->icd != NULL) && (!InterlockedDecrement((LONG*)&glrc->icd->refcount)))
    {
        /* This is the last context, remove the ICD*/
        ROSGL_DeleteDCDataForICD( glrc->icd );
    }

    /* remove from list */
    ROSGL_RemoveContext( glrc );

    /* free memory */
    HeapFree( GetProcessHeap(), 0, glrc );

    return TRUE;
}


/*! \brief Check wether a GLRC is in the list
 *
 * \param glrc [IN] Pointer to GLRC to look for in the list
 *
 * \retval TRUE  GLRC was found
 * \retval FALSE GLRC was not found
 */
static
BOOL
ROSGL_ContainsContext( GLRC *glrc )
{
    GLRC *p;
    BOOL found = FALSE;

    /* synchronize */
    if (WaitForSingleObject( OPENGL32_processdata.glrc_mutex, INFINITE ) ==
        WAIT_FAILED)
    {
        DBGPRINT( "Error: WaitForSingleObject() failed (%d)", GetLastError() );
        return FALSE; /* FIXME: do we have to expect such an error and handle it? */
    }

    p = OPENGL32_processdata.glrc_list;
    while (p != NULL)
    {
        if (p == glrc)
        {
            found = TRUE;
            break;
        }
        p = p->next;
    }

    /* release mutex */
    if (!ReleaseMutex( OPENGL32_processdata.glrc_mutex ))
        DBGPRINT( "Error: ReleaseMutex() failed (%d)", GetLastError() );

    return found;
}


/*! \brief Get GL private DC data.
 *
 * This function adds an empty GLDCDATA to the list if there is no data for the
 * given DC yet.
 *
 * \param hdc [IN] Handle to a Device Context for which to get the data
 *
 * \return Pointer to GLDCDATA on success
 * \retval NULL on failure
 */
static
GLDCDATA *
ROSGL_GetPrivateDCData( HDC hdc )
{
    GLDCDATA *data;
    HANDLE handle;

    /* check hdc */
    if (GetObjectType( hdc ) != OBJ_DC && GetObjectType( hdc ) != OBJ_MEMDC)
    {
        DBGPRINT( "Error: hdc is not a DC handle!" );
        SetLastError( ERROR_INVALID_HANDLE );
        return FALSE;
    }

    /* synchronize */
    if (WaitForSingleObject( OPENGL32_processdata.dcdata_mutex, INFINITE ) ==
        WAIT_FAILED)
    {
        DBGPRINT( "Error: WaitForSingleObject() failed (%d)", GetLastError() );
        return NULL; /* FIXME: do we have to expect such an error and handle it? */
    }

    /* We must use the window to identify our data, as pixel format is
     * specific to a window for device context */
    handle = WindowFromDC(hdc);
    if(!handle)
        handle = hdc;

    /* look for data in list */
    data = OPENGL32_processdata.dcdata_list;
    while (data != NULL)
    {
        if (data->handle == handle) /* found */
            break;
        data = data->next;
    }

    /* allocate new data if not found in list */
    if (data == NULL)
    {
        data = HeapAlloc( GetProcessHeap(),
                          HEAP_ZERO_MEMORY | HEAP_GENERATE_EXCEPTIONS,
                          sizeof (GLDCDATA) );
        if (data == NULL)
        {
            DBGPRINT( "Error: HeapAlloc() failed (%d)", GetLastError() );
        }
        else
        {
            data->handle = handle;

            /* append data to list */
            if (OPENGL32_processdata.dcdata_list == NULL)
                OPENGL32_processdata.dcdata_list = data;
            else
            {
                GLDCDATA *p = OPENGL32_processdata.dcdata_list;
                while (p->next != NULL)
                    p = p->next;
                p->next = data;
            }
        }
    }

    /* release mutex */
    if (!ReleaseMutex( OPENGL32_processdata.dcdata_mutex ))
        DBGPRINT( "Error: ReleaseMutex() failed (%d)", GetLastError() );

    return data;
}


/*! \brief Get ICD from HDC.
 *
 * This function asks the display driver which OpenGL ICD to load for the given
 * HDC, loads it and returns a pointer to a GLDRIVERDATA struct on success.
 *
 * \param hdc [IN] Handle for DC for which to load/get the ICD
 *
 * \return Pointer to GLDRIVERDATA
 * \retval NULL Failure.
 */
static
GLDRIVERDATA *
ROSGL_ICDForHDC( HDC hdc )
{
    GLDCDATA *dcdata;
    GLDRIVERDATA *drvdata;

    dcdata = ROSGL_GetPrivateDCData( hdc );
    if (dcdata == NULL)
        return NULL;

    if (dcdata->icd == NULL)
    {
        LPCWSTR driverName;
        OPENGL_INFO info;

        /* NOTE: This might be done by multiple threads simultaneously, but only the fastest
                 actually gets to set the ICD! */

        driverName = _wgetenv( L"OPENGL32_DRIVER" );
        if (driverName == NULL)
        {
            DWORD dwInput;
            LONG ret;

            /* get driver name */
            dwInput = OPENGL_GETINFO;
            ret = ExtEscape( hdc, QUERYESCSUPPORT, sizeof (dwInput), (LPCSTR)&dwInput, 0, NULL );
            if (ret > 0)
            {
                dwInput = 0;
                ret = ExtEscape( hdc, OPENGL_GETINFO, sizeof (dwInput),
                                 (LPCSTR)&dwInput, sizeof (OPENGL_INFO),
                                 (LPSTR)&info );
            }
            if (ret <= 0)
            {
                HKEY hKey;
                DWORD type, size;

                if (ret < 0)
                {
                    DBGPRINT( "Warning: ExtEscape to get the drivername failed! (%d)", GetLastError() );
                    if (MessageBox( WindowFromDC( hdc ), L"Couldn't get installable client driver name!\nUsing default driver.",
                                    L"OPENGL32.dll: Warning", MB_OKCANCEL | MB_ICONWARNING ) == IDCANCEL)
                    {
                        return NULL;
                    }
                }

                /* open registry key */
                ret = RegOpenKeyExW( HKEY_LOCAL_MACHINE, OPENGL_DRIVERS_SUBKEY, 0, KEY_QUERY_VALUE, &hKey );
                if (ret != ERROR_SUCCESS)
                {
                    DBGPRINT( "Error: Couldn't open registry key '%ws'", OPENGL_DRIVERS_SUBKEY );
                    SetLastError( ret );
                    return NULL;
                }

                /* query value */
                size = sizeof (info.DriverName);
                ret = RegQueryValueExW( hKey, L"DefaultDriver", 0, &type, (LPBYTE)info.DriverName, &size );
                RegCloseKey( hKey );
                if (ret != ERROR_SUCCESS || type != REG_SZ)
                {
                    DBGPRINT( "Error: Couldn't query DefaultDriver value or not a string" );
                    SetLastError( ret );
                    return NULL;
                }
            }
        }
        else
        {
            wcsncpy( info.DriverName, driverName, sizeof (info.DriverName) / sizeof (info.DriverName[0]) );
        }
        /* load driver (or get a reference) */
        drvdata = OPENGL32_LoadICD( info.DriverName );
        if (drvdata == NULL)
        {
            WCHAR Buffer[256];
            snwprintf(Buffer, sizeof(Buffer)/sizeof(WCHAR),
                      L"Couldn't load driver \"%s\".", info.DriverName);
            MessageBox(WindowFromDC( hdc ), Buffer,
                       L"OPENGL32.dll: Warning",
                       MB_OK | MB_ICONWARNING);
        }
        else
        {
            /* Atomically set the ICD!!! */
            if (InterlockedCompareExchangePointer((PVOID*)&dcdata->icd,
                                                  (PVOID)drvdata,
                                                  NULL) != NULL)
            {
                /* Too bad, somebody else was faster... */
                DBGTRACE("ICD is already set!\n");
            }
        }
    }

    return dcdata->icd;
}


/*! \brief SetContextCallBack passed to DrvSetContext.
 *
 * This function gets called by the OpenGL driver whenever the current GL
 * context (dispatch table) is to be changed.
 *
 * \param table [IN] Function pointer table (first DWORD is number of functions)
 *
 * \return unkown (maybe void? ERROR_SUCCESS at the moment)
 */
DWORD
CALLBACK
ROSGL_SetContextCallBack( const ICDTable *table )
{
    TEB *teb;
    PROC *tebTable, *tebDispatchTable;
    INT size;

    teb = NtCurrentTeb();
    tebTable = (PROC *)teb->glTable;
    tebDispatchTable = (PROC *)teb->glDispatchTable;

    DBGTRACE( "Called!" );

    if (table != NULL)
    {
        DBGPRINT( "Function count: %d\n", table->num_funcs );

        /* save table */
        size = sizeof (PROC) * table->num_funcs;
        memcpy( tebTable, table->dispatch_table, size );
        memset( tebTable + table->num_funcs, 0, DISPATCH_TABLE_SIZE - size );
    }
    else
    {
        DBGPRINT( "Unsetting current context" );
        memset( tebTable, 0, DISPATCH_TABLE_SIZE );
    }

    /* put in empty functions as long as we dont have a fallback */
    #define X(func, ret, typeargs, args, icdidx, tebidx, stack) \
        if (tebTable[icdidx] == NULL) \
        { \
            if (table != NULL) \
                DBGPRINT( "Warning: GL proc '%s' is NULL", #func ); \
            tebTable[icdidx] = (PROC)glEmptyFunc##stack; \
        }
    GLFUNCS_MACRO
#undef X

    /* fill teb->glDispatchTable for fast calls */
#define X(func, ret, typeargs, args, icdidx, tebidx, stack) \
        if (tebidx >= 0) \
            tebDispatchTable[tebidx] = tebTable[icdidx];
    GLFUNCS_MACRO
#undef X

    DBGPRINT( "Done." );

    return ERROR_SUCCESS;
}


/*! \brief Returns the current pixelformat.
 *
 * \param hdc [IN] Handle to DC to get the pixelformat from
 *
 * \return Pixelformat index
 * \retval 0 Failure
 */
int
WINAPI
rosglGetPixelFormat( HDC hdc )
{
    GLDCDATA *dcdata;

    DBGTRACE( "Called!" );

    dcdata = ROSGL_GetPrivateDCData( hdc );
    if (dcdata == NULL)
    {
        DBGPRINT( "Error: ROSGL_GetPrivateDCData failed!" );
        return 0;
    }

    return dcdata->pixel_format;
}


/*! \brief Attempts to find the best matching pixel format for HDC
 *
 * This function is comparing each available format with the preferred one
 * and returns the one which is closest to it.
 * If PFD_DOUBLEBUFFER, PFD_STEREO or one of PFD_DRAW_TO_WINDOW,
 * PFD_DRAW_TO_BITMAP, PFD_SUPPORT_GDI and PDF_SUPPORT_OPENGL is given then
 * only formats which also support those will be enumerated (unless
 * PFD_DOUBLEBUFFER_DONTCARE or PFD_STEREO_DONTCARE is also set)
 *
 * \param hdc [IN] Handle to DC for which to get a pixel format index
 * \param pfd [IN] PFD describing what kind of format you want
 *
 * \return Pixel format index
 * \retval 0 Failed to find a suitable format
 */
#define BUFFERDEPTH_SCORE(want, have) \
    ((want == 0) ? (0) : ((want < have) ? (1) : ((want > have) ? (3) : (0))))

/* Score if we want and not have it */
#define FLAG_SCORE(want, have, flag) \
    (((want & ~have) & flag) ? (1) : (0))

/* Score if what we want is different than what we have, except when
   _DONTCARE was set */
#define FLAG_SCORE_DONTCARE(want, have, flag) \
    ((!(have & flag ## _DONTCARE)) && ((want & flag) != (have & flag)) ? (1) : (0))

int
APIENTRY
rosglChoosePixelFormat( HDC hdc, CONST PIXELFORMATDESCRIPTOR *pfd )
{
    GLDRIVERDATA *icd;
    PIXELFORMATDESCRIPTOR icdPfd;
    int i;
    int best = 0;
    int score, bestScore = 0x7fff; /* used to choose a pfd if no exact match */
    int icdNumFormats;

    DBGTRACE( "Called!" );

    /* load ICD */
    icd = ROSGL_ICDForHDC( hdc );
    if (icd == NULL)
        return 0;

    /* check input */
    if (pfd->nSize != sizeof (PIXELFORMATDESCRIPTOR) || pfd->nVersion != 1)
    {
        SetLastError( ERROR_INVALID_PARAMETER );
        return 0;
    }

    /* get number of formats */
    icdNumFormats = icd->DrvDescribePixelFormat( hdc, 1,
                    sizeof (PIXELFORMATDESCRIPTOR), &icdPfd );
    if (icdNumFormats == 0)
    {
        DBGPRINT( "Error: DrvDescribePixelFormat failed (%d)", GetLastError() );
        return 0;
    }
    DBGPRINT( "Info: Enumerating %d pixelformats", icdNumFormats );

    /* try to find best format */
    for (i = 0; i < icdNumFormats; i++)
    {
        if (icd->DrvDescribePixelFormat( hdc, i + 1,
            sizeof (PIXELFORMATDESCRIPTOR), &icdPfd ) == 0)
        {
            DBGPRINT( "Warning: DrvDescribePixelFormat failed (%d)",
                	  GetLastError() );
            break;
        }

        if ((pfd->dwFlags & PFD_GENERIC_ACCELERATED) != 0) /* we do not support such kind of drivers */
        {
            continue;
        }

        score = 0; /* higher is worse */

        /* compare flags */
        score += FLAG_SCORE(pfd->dwFlags, icdPfd.dwFlags, PFD_DRAW_TO_WINDOW);
        score += FLAG_SCORE(pfd->dwFlags, icdPfd.dwFlags, PFD_DRAW_TO_BITMAP);
        score += FLAG_SCORE(pfd->dwFlags, icdPfd.dwFlags, PFD_SUPPORT_GDI);
        score += FLAG_SCORE(pfd->dwFlags, icdPfd.dwFlags, PFD_SUPPORT_OPENGL);
        score += FLAG_SCORE_DONTCARE(pfd->dwFlags, icdPfd.dwFlags, PFD_DOUBLEBUFFER);
        score += FLAG_SCORE_DONTCARE(pfd->dwFlags, icdPfd.dwFlags, PFD_STEREO);

        /* check other attribs */
        if (pfd->iPixelType != icdPfd.iPixelType)
            score += 5; /* this is really bad i think */
        if (pfd->iLayerType != icdPfd.iLayerType)
            score += 15; /* this is very very bad ;) */

        score += BUFFERDEPTH_SCORE(pfd->cAlphaBits, icdPfd.cAlphaBits);
        score += BUFFERDEPTH_SCORE(pfd->cAccumBits, icdPfd.cAccumBits);
        score += BUFFERDEPTH_SCORE(pfd->cDepthBits, icdPfd.cDepthBits);
        score += BUFFERDEPTH_SCORE(pfd->cStencilBits, icdPfd.cStencilBits);
        score += BUFFERDEPTH_SCORE(pfd->cAuxBuffers, icdPfd.cAuxBuffers);

        /* check score */
        if (score < bestScore)
        {
            bestScore = score;
            best = i + 1;
            if (bestScore == 0)
                break;
        }
    }

    if (best == 0)
        SetLastError( 0 ); /* FIXME: set appropriate error */

    DBGPRINT( "Info: Suggesting pixelformat %d", best );
    return best;
}


/*! \brief Copy data specified by mask from one GLRC to another.
 *
 * \param src  [IN] Source GLRC
 * \param src  [OUT] Destination GLRC
 * \param mask [IN] Bitfield like given to glPushAttrib()
 *
 * \retval TRUE  Success
 * \retval FALSE Failure
 */
BOOL
APIENTRY
rosglCopyContext( HGLRC hsrc, HGLRC hdst, UINT mask )
{
    GLRC *src = (GLRC *)hsrc;
    GLRC *dst = (GLRC *)hdst;

    /* check glrcs */
    if (!ROSGL_ContainsContext( src ))
    {
        DBGPRINT( "Error: src GLRC not found!" );
        SetLastError( ERROR_INVALID_HANDLE );
        return FALSE;
    }
    if (!ROSGL_ContainsContext( dst ))
    {
        DBGPRINT( "Error: dst GLRC not found!" );
        SetLastError( ERROR_INVALID_HANDLE );
        return FALSE;
    }

    /* I think this is only possible within one ICD */
    if (src->icd != dst->icd)
    {
        DBGPRINT( "Error: src and dst GLRC use different ICDs!" );
        SetLastError( ERROR_INVALID_HANDLE );
        return FALSE;
    }

    /* copy data (call ICD) */
    return src->icd->DrvCopyContext( src->hglrc, dst->hglrc, mask );
}


/*! \brief Create a new GL Rendering Context.
 *
 * This function can create over- or underlay surfaces.
 *
 * \param hdc [IN] Handle for DC for which to create context
 * \param layer [IN] Layer number to bind (draw?) to
 *
 * \return Handle for the created GLRC
 * \retval NULL Failure
 */
HGLRC
APIENTRY
rosglCreateLayerContext( HDC hdc, int layer )
{
    GLDRIVERDATA *icd = NULL;
    GLRC *glrc;
    HGLRC drvHglrc = NULL;

    DBGTRACE( "Called!" );

/*	if (GetObjectType( hdc ) != OBJ_DC)
    {
        DBGPRINT( "Error: hdc is not a DC handle!" );
        return NULL;
    }
*/

    /* load ICD */
    icd = ROSGL_ICDForHDC( hdc );
    if (icd == NULL)
    {
        DBGPRINT( "Couldn't get ICD by HDC :-(" );
        /* FIXME: fallback? */
        return NULL;
    }

    /* create new GLRC */
    glrc = ROSGL_NewContext();
    if (glrc == NULL)
        return NULL;

    /* Don't forget to refcount it, icd will be released when last context is deleted */
    InterlockedIncrement((LONG*)&icd->refcount);

    /* You can't create a context without first setting a valid pixel format */
    if(rosglGetPixelFormat(hdc) == 0)
    {
        ROSGL_DeleteContext( glrc );
        SetLastError(ERROR_INVALID_PIXEL_FORMAT);
        return NULL;
    }


    /* create context */
    if (icd->DrvCreateLayerContext != NULL)
        drvHglrc = icd->DrvCreateLayerContext( hdc, layer );
    if (drvHglrc == NULL)
    {
        if (layer == 0 && icd->DrvCreateContext != NULL)
            drvHglrc = icd->DrvCreateContext( hdc );
        else
            DBGPRINT( "Warning: CreateLayerContext not supported by ICD!" );
    }

    if (drvHglrc == NULL)
    {
        /* FIXME: fallback to mesa? */
        DBGPRINT( "Error: DrvCreate[Layer]Context failed! (%d)", GetLastError() );
        ROSGL_DeleteContext( glrc );
        return NULL;
    }

    /* we have our GLRC in glrc and the ICD's GLRC in drvHglrc */
    glrc->hglrc = drvHglrc;
    glrc->icd = icd;

    return (HGLRC)glrc;
}


/*! \brief Create a new GL Rendering Context.
 *
 * \param hdc [IN] Handle for DC for which to create context
 *
 * \return Handle for the created GLRC
 * \retval NULL Failure
 */
HGLRC
APIENTRY
rosglCreateContext( HDC hdc )
{
    return rosglCreateLayerContext( hdc, 0 );
}


/*! \brief Delete an OpenGL context
 *
 * \param hglrc [IN] Handle to GLRC to delete;
 *
 * \retval TRUE  Success
 * \retval FALSE Failure (i.e. GLRC is current for a thread)
 */
BOOL
APIENTRY
rosglDeleteContext( HGLRC hglrc )
{
    GLRC *glrc = (GLRC *)hglrc;

    /* check if we know about this context */
    if (!ROSGL_ContainsContext( glrc ))
    {
        DBGPRINT( "Error: hglrc not found!" );
        SetLastError( ERROR_INVALID_HANDLE );
        return FALSE;
    }

    /* On windows, this is allowed to delete a context which is current */
    if (glrc->is_current)
    {
        /* But only for its own thread */
        if(glrc->thread_id != GetCurrentThreadId())
        {
            DBGPRINT( "Error: GLRC is current for DC 0x%08x", glrc->hdc );
            SetLastError( ERROR_INVALID_FUNCTION );
            return FALSE;
        }
        /* Unset it before going further */
        rosglMakeCurrent(NULL, NULL);
    }

    /* release ICD's context */
    if (glrc->hglrc != NULL)
    {
        if (!glrc->icd->DrvDeleteContext( glrc->hglrc ))
        {
            DBGPRINT( "Warning: DrvDeleteContext() failed (%d)", GetLastError() );
            return FALSE;
        }
    }

    /* free resources */
    return ROSGL_DeleteContext( glrc );
}


BOOL
APIENTRY
rosglDescribeLayerPlane( HDC hdc, int iPixelFormat, int iLayerPlane,
                         UINT nBytes, LPLAYERPLANEDESCRIPTOR plpd )
{
    UNIMPLEMENTED;
    SetLastError( ERROR_CALL_NOT_IMPLEMENTED );
    return FALSE;
}


/*! \brief Gets information about a pixelformat.
 *
 * \param hdc     [IN]  Handle to DC
 * \param iFormat [IN]  Pixelformat index
 * \param nBytes  [IN]  sizeof (pfd) - at most nBytes are copied into pfd
 * \param pfd     [OUT] Pointer to a PIXELFORMATDESCRIPTOR
 *
 * \return Maximum pixelformat index/number of formats
 * \retval 0 Failure
 */
int
APIENTRY
rosglDescribePixelFormat( HDC hdc, int iFormat, UINT nBytes,
                          LPPIXELFORMATDESCRIPTOR pfd )
{
    int ret = 0;
    GLDRIVERDATA *icd = ROSGL_ICDForHDC( hdc );

    if (icd != NULL)
    {
        ret = icd->DrvDescribePixelFormat( hdc, iFormat, nBytes, pfd );
        if (ret == 0)
            DBGPRINT( "Error: DrvDescribePixelFormat(format=%d) failed (%d)", iFormat, GetLastError() );
    }
    else
    {
        SetLastError( ERROR_INVALID_FUNCTION );
    }

    return ret;
}


/*! \brief Return the thread's current GLRC
 *
 * \return Handle for thread's current GLRC
 * \retval NULL No current GLRC set
 */
HGLRC
APIENTRY
rosglGetCurrentContext()
{
    return NtCurrentTeb()->glCurrentRC;
}


/*! \brief Return the thread's current DC
 *
 * \return Handle for thread's current DC
 * \retval NULL No current DC/GLRC set
 */
HDC
APIENTRY
rosglGetCurrentDC()
{
    GLRC* glrc = (GLRC*)NtCurrentTeb()->glCurrentRC;
    if(glrc) return glrc->hdc;
    return NULL;
}


int
APIENTRY
rosglGetLayerPaletteEntries( HDC hdc, int iLayerPlane, int iStart,
                             int cEntries, COLORREF *pcr )
{
    UNIMPLEMENTED;
    SetLastError( ERROR_CALL_NOT_IMPLEMENTED );
    return 0;
}


/*! \brief Get the address for an OpenGL extension function.
 *
 * The addresses this function returns are only valid within the same thread
 * which it was called from.
 *
 * \param proc [IN] Name of the function to look for
 *
 * \return The address of the proc
 * \retval NULL Failure
 */
PROC
APIENTRY
rosglGetProcAddress( LPCSTR proc )
{
    PROC func;
    GLRC* glrc = (GLRC*)NtCurrentTeb()->glCurrentRC;

    /* FIXME we should Flush the gl here */

    if (glrc == NULL)
    {
        DBGPRINT( "Error: No current GLRC!" );
        SetLastError( ERROR_INVALID_FUNCTION );
        return NULL;
    }

    func = glrc->icd->DrvGetProcAddress( proc );
    if (func != NULL)
    {
        DBGPRINT( "Info: Proc \"%s\" loaded from ICD.", proc );
        return func;
    }

    /* FIXME: Should we return wgl/gl 1.1 functions? */
    SetLastError( ERROR_PROC_NOT_FOUND );
    return NULL;
}

PROC
APIENTRY
rosglGetDefaultProcAddress( LPCSTR proc )
{
    PROC func;
    GLRC* glrc = (GLRC*)NtCurrentTeb()->glCurrentRC;

    /*  wglGetDefaultProcAddress does not flush the gl */

    if (glrc == NULL)
    {
        DBGPRINT( "Error: No current GLRC!" );
        SetLastError( ERROR_INVALID_FUNCTION );
        return NULL;
    }

    func = glrc->icd->DrvGetProcAddress( proc );
    if (func != NULL)
    {
        DBGPRINT( "Info: Proc \"%s\" loaded from ICD.", proc );
        return func;
    }

    /* FIXME: Should we return wgl/gl 1.1 functions? */
    SetLastError( ERROR_PROC_NOT_FOUND );
    return NULL;
}


/*! \brief Make the given GLRC the threads current GLRC for hdc
 *
 * \param hdc   [IN] Handle for a DC to be drawn on
 * \param hglrc [IN] Handle for a GLRC to make current
 *
 * \retval TRUE  Success
 * \retval FALSE Failure
 */
BOOL
APIENTRY
rosglMakeCurrent( HDC hdc, HGLRC hglrc )
{
    GLRC *glrc = (GLRC *)hglrc;
    ICDTable *icdTable = NULL;

    DBGTRACE( "Called!" );

    /* Is t a new context ? */
    if (glrc != NULL)
    {
        /* check hdc */
        if (GetObjectType( hdc ) != OBJ_DC && GetObjectType( hdc ) != OBJ_MEMDC)
        {
            DBGPRINT( "Error: hdc is not a DC handle!" );
            SetLastError( ERROR_INVALID_HANDLE );
            return FALSE;
        }

        /* check if we know about this glrc */
        if (!ROSGL_ContainsContext( glrc ))
        {
            DBGPRINT( "Error: hglrc not found!" );
            SetLastError( ERROR_INVALID_HANDLE );
            return FALSE;
        }

        /* check if it is available */
        if (glrc->is_current && glrc->thread_id != GetCurrentThreadId()) /* used by another thread */
        {
            DBGPRINT( "Error: hglrc is current for thread 0x%08x", glrc->thread_id );
            SetLastError( ERROR_INVALID_HANDLE );
            return FALSE;
        }

        /* Unset previous one */
        if (NtCurrentTeb()->glCurrentRC != NULL)
        {
            GLRC *oldglrc = (GLRC*)NtCurrentTeb()->glCurrentRC;
            oldglrc->is_current = FALSE;
            oldglrc->thread_id = 0;
            oldglrc->hdc = NULL;
            oldglrc->icd->DrvReleaseContext(oldglrc->hglrc);
        }

        /* call the ICD */
        if (glrc->hglrc != NULL)
        {
            DBGPRINT( "Info: Calling DrvSetContext!" );
            SetLastError( ERROR_SUCCESS );
            icdTable = glrc->icd->DrvSetContext( hdc, glrc->hglrc,
                                                 (void *)ROSGL_SetContextCallBack );
            if (icdTable == NULL)
            {
                DBGPRINT( "Error: DrvSetContext failed (%d)\n", GetLastError() );
                NtCurrentTeb()->glCurrentRC = NULL;
                return FALSE;
            }
            DBGPRINT( "Info: DrvSetContext succeeded!" );
        }

        /* make it current */
        glrc->is_current = TRUE;
        glrc->thread_id = GetCurrentThreadId();
        glrc->hdc = hdc;
        NtCurrentTeb()->glCurrentRC = (HGLRC)glrc;
    }
    else if(NtCurrentTeb()->glCurrentRC)
    {
        /* This is a call to unset the context */
        GLRC *oldglrc = (GLRC*)NtCurrentTeb()->glCurrentRC;
        oldglrc->is_current = FALSE;
        oldglrc->thread_id = 0;
        oldglrc->hdc = NULL;
        oldglrc->icd->DrvReleaseContext(oldglrc->hglrc);
        NtCurrentTeb()->glCurrentRC = NULL;
    }
    else
    {
        /*
         * To make wine tests happy.
         * Now, who cares if MakeCurrentContext(NULL, NULL) fails when current context is already NULL
         */
        if (GetObjectType( hdc ) != OBJ_DC && GetObjectType( hdc ) != OBJ_MEMDC)
        {
            DBGPRINT( "Error: hdc is not a DC handle!" );
            SetLastError( ERROR_INVALID_HANDLE );
            return FALSE;
        }
    }

    if (ROSGL_SetContextCallBack( icdTable ) != ERROR_SUCCESS && icdTable == NULL)
    {
        DBGPRINT( "Warning: ROSGL_SetContextCallBack failed!" );
    }

    return TRUE;
}


BOOL
APIENTRY
rosglRealizeLayerPalette( HDC hdc, int iLayerPlane, BOOL bRealize )
{
    UNIMPLEMENTED;
    SetLastError( ERROR_CALL_NOT_IMPLEMENTED );
    return FALSE;
}


int
APIENTRY
rosglSetLayerPaletteEntries( HDC hdc, int iLayerPlane, int iStart,
                             int cEntries, CONST COLORREF *pcr )
{
    UNIMPLEMENTED;
    SetLastError( ERROR_CALL_NOT_IMPLEMENTED );
    return 0;
}


/*! \brief Set a DCs pixelformat
 *
 * \param hdc     [IN] Handle to DC for which to set the format
 * \param iFormat [IN] Index of the pixelformat to set
 * \param pfd     [IN] Not sure what this is for
 *
 * \retval TRUE  Success
 * \retval FALSE Failure
 */
BOOL
WINAPI
rosglSetPixelFormat( HDC hdc, int iFormat, CONST PIXELFORMATDESCRIPTOR *pfd )
{
    GLDCDATA *dcdata;
    GLDRIVERDATA* icd;

    DBGTRACE( "Called!" );

    /* Get private DC data */
    dcdata = ROSGL_GetPrivateDCData( hdc );
    if (dcdata == NULL)
    {
        DBGPRINT( "Error: ROSGL_GetPrivateDCData() failed!" );
        return FALSE;
    }
    /* you can set the same pixel format twice, but you can't modify it */
    if(dcdata->pixel_format) return dcdata->pixel_format == iFormat;

    icd = ROSGL_ICDForHDC(hdc);
    if(icd == NULL)
        return 0;

    /* Call ICD function */
    if (!icd->DrvSetPixelFormat( hdc, iFormat, pfd ))
    {
        DBGPRINT( "Warning: DrvSetPixelFormat(format=%d) failed (%d)",
                  iFormat, GetLastError() );
        return FALSE;
    }
    dcdata->pixel_format = iFormat;

    return TRUE;
}


/*! \brief Enable display-list sharing between multiple GLRCs
 *
 * This will only work if both GLRCs are from the same driver.
 *
 * \param hglrc1 [IN] GLRC number 1
 * \param hglrc2 [IN] GLRC number 2
 *
 * \retval TRUE  Success
 * \retval FALSE Failure
 */
BOOL
APIENTRY
rosglShareLists( HGLRC hglrc1, HGLRC hglrc2 )
{
    GLRC *glrc1 = (GLRC *)hglrc1;
    GLRC *glrc2 = (GLRC *)hglrc2;

    /* check glrcs */
    if (!ROSGL_ContainsContext( glrc1 ))
    {
        DBGPRINT( "Error: hglrc1 not found!" );
        SetLastError( ERROR_INVALID_HANDLE );
        return FALSE;
    }
    if (!ROSGL_ContainsContext( glrc2 ))
    {
        DBGPRINT( "Error: hglrc2 not found!" );
        SetLastError( ERROR_INVALID_HANDLE );
        return FALSE;
    }

    /* I think this is only possible within one ICD */
    if (glrc1->icd != glrc2->icd)
    {
        DBGPRINT( "Error: hglrc1 and hglrc2 use different ICDs!" );
        SetLastError( ERROR_INVALID_HANDLE );
        return FALSE;
    }

    /* share lists (call ICD) */
    return glrc1->icd->DrvShareLists( glrc1->hglrc, glrc2->hglrc );
}


/*! \brief Flushes GL and swaps front/back buffer if appropriate
 *
 * \param hdc [IN] Handle to device context to swap buffers for
 *
 * \retval TRUE  Success
 * \retval FALSE Failure
 */
BOOL
APIENTRY
rosglSwapBuffers( HDC hdc )
{
    GLDRIVERDATA *icd = ROSGL_ICDForHDC( hdc );
    DBGTRACE( "Called!" );
    if (icd != NULL)
    {
        DBGPRINT( "Swapping buffers!" );
        if (!icd->DrvSwapBuffers( hdc ))
        {
            DBGPRINT( "Error: DrvSwapBuffers failed (%d)", GetLastError() );
            return FALSE;
        }
        return TRUE;
    }

    /* FIXME: implement own functionality? */
    SetLastError( ERROR_INVALID_FUNCTION );
    return FALSE;
}


BOOL
APIENTRY
rosglSwapLayerBuffers( HDC hdc, UINT fuPlanes )
{
    BOOL ret = FALSE;

    if(fuPlanes & WGL_SWAP_MAIN_PLANE)
        ret = rosglSwapBuffers(hdc);

    if(fuPlanes &~WGL_SWAP_MAIN_PLANE)
        DBGTRACE("wglSwapLayerBuffers is not fully implemented\n");

    return ret;
}

#ifdef __cplusplus
}; /* extern "C" */
#endif /* __cplusplus */

/* EOF */