/*
 * DC clipping functions
 *
 * Copyright 1993 Alexandre Julliard
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <stdlib.h>
#include "windef.h"
#include "wingdi.h"
#include "wine/winuser16.h"
#include "gdi.h"
#include "wine/debug.h"

WINE_DEFAULT_DEBUG_CHANNEL(clipping);


/***********************************************************************
 *           CLIPPING_UpdateGCRegion
 *
 * Update the GC clip region when the ClipRgn or VisRgn have changed.
 */
void CLIPPING_UpdateGCRegion( DC * dc )
{
    if (!dc->hGCClipRgn) dc->hGCClipRgn = CreateRectRgn( 0, 0, 0, 0 );

    if (!dc->hVisRgn)
    {
        ERR("hVisRgn is zero. Please report this.\n" );
        exit(1);
    }

    if (dc->flags & DC_DIRTY) ERR( "DC is dirty. Please report this.\n" );

    if (!dc->hClipRgn)
        CombineRgn( dc->hGCClipRgn, dc->hVisRgn, 0, RGN_COPY );
    else
        CombineRgn(dc->hGCClipRgn, dc->hClipRgn, dc->hVisRgn, RGN_AND);
    if (dc->funcs->pSetDeviceClipping)
        dc->funcs->pSetDeviceClipping( dc->physDev, dc->hGCClipRgn );
}


/***********************************************************************
 *           SelectClipRgn    (GDI32.@)
 */
INT WINAPI SelectClipRgn( HDC hdc, HRGN hrgn )
{
    return ExtSelectClipRgn( hdc, hrgn, RGN_COPY );
}


/******************************************************************************
 *		ExtSelectClipRgn	[GDI32.@]
 */
INT WINAPI ExtSelectClipRgn( HDC hdc, HRGN hrgn, INT fnMode )
{
    INT retval;
    DC * dc = DC_GetDCUpdate( hdc );
    if (!dc) return ERROR;

    TRACE("%04x %04x %d\n", hdc, hrgn, fnMode );

    if (dc->funcs->pExtSelectClipRgn)
    {
        retval = dc->funcs->pExtSelectClipRgn( dc->physDev, hrgn, fnMode );
        GDI_ReleaseObj( hdc );
        return retval;
    }

    if (!hrgn)
    {
        if (fnMode == RGN_COPY)
        {
            if (dc->hClipRgn) DeleteObject( dc->hClipRgn );
            dc->hClipRgn = 0;
            retval = SIMPLEREGION; /* Clip region == whole DC */
        }
        else
        {
            FIXME("Unimplemented: hrgn NULL in mode: %d\n", fnMode);
            GDI_ReleaseObj( hdc );
            return ERROR;
        }
    }
    else
    {
        if (!dc->hClipRgn)
        {
            RECT rect;
            GetRgnBox( dc->hVisRgn, &rect );
            dc->hClipRgn = CreateRectRgnIndirect( &rect );
        }

        if(fnMode == RGN_COPY)
            retval = CombineRgn( dc->hClipRgn, hrgn, 0, fnMode );
        else
            retval = CombineRgn( dc->hClipRgn, dc->hClipRgn, hrgn, fnMode);
    }

    CLIPPING_UpdateGCRegion( dc );
    GDI_ReleaseObj( hdc );
    return retval;
}

/***********************************************************************
 *           SelectVisRgn   (GDI.105)
 *           SelectVisRgn16 (GDI32.@)
 */
INT16 WINAPI SelectVisRgn16( HDC16 hdc, HRGN16 hrgn )
{
    int retval;
    DC * dc;

    if (!hrgn) return ERROR;
    if (!(dc = DC_GetDCPtr( hdc ))) return ERROR;

    TRACE("%04x %04x\n", hdc, hrgn );

    dc->flags &= ~DC_DIRTY;

    retval = CombineRgn16( dc->hVisRgn, hrgn, 0, RGN_COPY );
    CLIPPING_UpdateGCRegion( dc );
    GDI_ReleaseObj( hdc );
    return retval;
}


/***********************************************************************
 *           OffsetClipRgn    (GDI32.@)
 */
INT WINAPI OffsetClipRgn( HDC hdc, INT x, INT y )
{
    INT ret = SIMPLEREGION;
    DC *dc = DC_GetDCUpdate( hdc );
    if (!dc) return ERROR;

    TRACE("%04x %d,%d\n", hdc, x, y );

    if(dc->funcs->pOffsetClipRgn)
        ret = dc->funcs->pOffsetClipRgn( dc->physDev, x, y );
    else if (dc->hClipRgn) {
        ret = OffsetRgn( dc->hClipRgn, XLSTODS(dc,x), YLSTODS(dc,y));
	CLIPPING_UpdateGCRegion( dc );
    }
    GDI_ReleaseObj( hdc );
    return ret;
}


/***********************************************************************
 *           OffsetVisRgn    (GDI.102)
 */
INT16 WINAPI OffsetVisRgn16( HDC16 hdc, INT16 x, INT16 y )
{
    INT16 retval;
    DC * dc = DC_GetDCUpdate( hdc );
    if (!dc) return ERROR;
    TRACE("%04x %d,%d\n", hdc, x, y );
    retval = OffsetRgn( dc->hVisRgn, x, y );
    CLIPPING_UpdateGCRegion( dc );
    GDI_ReleaseObj( hdc );
    return retval;
}


/***********************************************************************
 *           ExcludeClipRect    (GDI32.@)
 */
INT WINAPI ExcludeClipRect( HDC hdc, INT left, INT top,
                                INT right, INT bottom )
{
    HRGN newRgn;
    INT ret;
    DC *dc = DC_GetDCUpdate( hdc );
    if (!dc) return ERROR;

    TRACE("%04x %dx%d,%dx%d\n", hdc, left, top, right, bottom );

    if(dc->funcs->pExcludeClipRect)
        ret = dc->funcs->pExcludeClipRect( dc->physDev, left, top, right, bottom );
    else
    {
        RECT rect;
        rect.left = left;
        rect.top = top;
        rect.right = right;
        rect.bottom = bottom;
        LPtoDP( hdc, (POINT*)&rect, 2 );

        if (!(newRgn = CreateRectRgn( rect.left, rect.top, rect.right, rect.bottom ))) ret = ERROR;
        else
        {
            if (!dc->hClipRgn)
            {
                dc->hClipRgn = CreateRectRgn( 0, 0, 0, 0 );
                CombineRgn( dc->hClipRgn, dc->hVisRgn, 0, RGN_COPY );
            }
            ret = CombineRgn( dc->hClipRgn, dc->hClipRgn, newRgn, RGN_DIFF );
            DeleteObject( newRgn );
        }
        if (ret != ERROR) CLIPPING_UpdateGCRegion( dc );
    }
    GDI_ReleaseObj( hdc );
    return ret;
}


/***********************************************************************
 *           IntersectClipRect    (GDI32.@)
 */
INT WINAPI IntersectClipRect( HDC hdc, INT left, INT top, INT right, INT bottom )
{
    INT ret;
    DC *dc = DC_GetDCUpdate( hdc );
    if (!dc) return ERROR;

    TRACE("%04x %d,%d - %d,%d\n", hdc, left, top, right, bottom );

    if(dc->funcs->pIntersectClipRect)
        ret = dc->funcs->pIntersectClipRect( dc->physDev, left, top, right, bottom );
    else
    {
        RECT rect;

        rect.left   = left;
        rect.top    = top;
        rect.right  = right;
        rect.bottom = bottom;
        LPtoDP( hdc, (POINT*)&rect, 2 );

        if (!dc->hClipRgn)
        {
            dc->hClipRgn = CreateRectRgn( rect.left, rect.top, rect.right, rect.bottom );
            ret = SIMPLEREGION;
        }
        else
        {
            HRGN newRgn;

            if (!(newRgn = CreateRectRgn( rect.left, rect.top, rect.right, rect.bottom))) ret = ERROR;
            else
            {
                ret = CombineRgn( dc->hClipRgn, dc->hClipRgn, newRgn, RGN_AND );
                DeleteObject( newRgn );
            }
        }
        if (ret != ERROR) CLIPPING_UpdateGCRegion( dc );
    }
    GDI_ReleaseObj( hdc );
    return ret;
}


/***********************************************************************
 *           ExcludeVisRect   (GDI.73)
 *           ExcludeVisRect16 (GDI32.@)
 */
INT16 WINAPI ExcludeVisRect16( HDC16 hdc, INT16 left, INT16 top,
                             INT16 right, INT16 bottom )
{
    HRGN tempRgn;
    INT16 ret;
    RECT rect;
    DC * dc = DC_GetDCUpdate( hdc );
    if (!dc) return ERROR;

    rect.left   = left;
    rect.top    = top;
    rect.right  = right;
    rect.bottom = bottom;
    LPtoDP( hdc, (POINT*)&rect, 2 );

    TRACE("%04x %d,%d - %d,%d\n", hdc, rect.left, rect.top, rect.right, rect.bottom );

    if (!(tempRgn = CreateRectRgn( rect.left, rect.top, rect.right, rect.bottom ))) ret = ERROR;
    else
    {
        ret = CombineRgn( dc->hVisRgn, dc->hVisRgn, tempRgn, RGN_DIFF );
        DeleteObject( tempRgn );
    }
    if (ret != ERROR) CLIPPING_UpdateGCRegion( dc );
    GDI_ReleaseObj( hdc );
    return ret;
}


/***********************************************************************
 *           IntersectVisRect   (GDI.98)
 *           IntersectVisRect16 (GDI32.@)
 */
INT16 WINAPI IntersectVisRect16( HDC16 hdc, INT16 left, INT16 top,
                               INT16 right, INT16 bottom )
{
    HRGN tempRgn;
    INT16 ret;
    RECT rect;
    DC * dc = DC_GetDCUpdate( hdc );
    if (!dc) return ERROR;

    rect.left   = left;
    rect.top    = top;
    rect.right  = right;
    rect.bottom = bottom;
    LPtoDP( hdc, (POINT*)&rect, 2 );

    TRACE("%04x %d,%d - %d,%d\n", hdc, rect.left, rect.top, rect.right, rect.bottom );

    if (!(tempRgn = CreateRectRgn( rect.left, rect.top, rect.right, rect.bottom ))) ret = ERROR;
    else
    {
        ret = CombineRgn( dc->hVisRgn, dc->hVisRgn, tempRgn, RGN_AND );
        DeleteObject( tempRgn );
    }
    if (ret != ERROR) CLIPPING_UpdateGCRegion( dc );
    GDI_ReleaseObj( hdc );
    return ret;
}


/***********************************************************************
 *           PtVisible    (GDI32.@)
 */
BOOL WINAPI PtVisible( HDC hdc, INT x, INT y )
{
    BOOL ret = FALSE;
    DC *dc = DC_GetDCUpdate( hdc );

    TRACE("%04x %d,%d\n", hdc, x, y );
    if (!dc) return FALSE;
    if (dc->hGCClipRgn)
    {
        POINT pt;

        pt.x = x;
        pt.y = y;
        LPtoDP( hdc, &pt, 1 );
        ret = PtInRegion( dc->hGCClipRgn, pt.x, pt.y );
    }
    GDI_ReleaseObj( hdc );
    return ret;
}


/***********************************************************************
 *           RectVisible    (GDI32.@)
 */
BOOL WINAPI RectVisible( HDC hdc, const RECT* rect )
{
    BOOL ret = FALSE;
    RECT tmpRect;
    DC *dc = DC_GetDCUpdate( hdc );
    if (!dc) return FALSE;
    TRACE("%04x %d,%dx%d,%d\n",
          hdc, rect->left, rect->top, rect->right, rect->bottom );
    if (dc->hGCClipRgn)
    {
        /* copy rectangle to avoid overwriting by LPtoDP */
        tmpRect = *rect;
        LPtoDP( hdc, (LPPOINT)&tmpRect, 2 );
        ret = RectInRegion( dc->hGCClipRgn, &tmpRect );
    }
    GDI_ReleaseObj( hdc );
    return ret;
}


/***********************************************************************
 *           GetClipBox    (GDI32.@)
 */
INT WINAPI GetClipBox( HDC hdc, LPRECT rect )
{
    INT ret;
    DC *dc = DC_GetDCUpdate( hdc );
    if (!dc) return ERROR;
    ret = GetRgnBox( dc->hGCClipRgn, rect );
    DPtoLP( hdc, (LPPOINT)rect, 2 );
    GDI_ReleaseObj( hdc );
    return ret;
}


/***********************************************************************
 *           GetClipRgn  (GDI32.@)
 */
INT WINAPI GetClipRgn( HDC hdc, HRGN hRgn )
{
    INT ret = -1;
    DC * dc;
    if (hRgn && (dc = DC_GetDCPtr( hdc )))
    {
      if( dc->hClipRgn )
      {
          if( CombineRgn(hRgn, dc->hClipRgn, 0, RGN_COPY) != ERROR ) ret = 1;
      }
      else ret = 0;
      GDI_ReleaseObj( hdc );
    }
    return ret;
}

/***********************************************************************
 *           SaveVisRgn   (GDI.129)
 *           SaveVisRgn16 (GDI32.@)
 */
HRGN16 WINAPI SaveVisRgn16( HDC16 hdc )
{
    HRGN copy;
    GDIOBJHDR *obj, *copyObj;
    DC *dc = DC_GetDCUpdate( hdc );

    if (!dc) return 0;
    TRACE("%04x\n", hdc );

    if (!(obj = GDI_GetObjPtr( dc->hVisRgn, REGION_MAGIC )))
    {
        GDI_ReleaseObj( hdc );
	return 0;
    }
    if (!(copy = CreateRectRgn( 0, 0, 0, 0 )))
    {
        GDI_ReleaseObj( dc->hVisRgn );
        GDI_ReleaseObj( hdc );
        return 0;
    }
    CombineRgn( copy, dc->hVisRgn, 0, RGN_COPY );
    if (!(copyObj = GDI_GetObjPtr( copy, REGION_MAGIC )))
    {
        DeleteObject( copy );
        GDI_ReleaseObj( dc->hVisRgn );
        GDI_ReleaseObj( hdc );
	return 0;
    }
    copyObj->hNext = obj->hNext;
    obj->hNext = copy;
    GDI_ReleaseObj( copy );
    GDI_ReleaseObj( dc->hVisRgn );
    GDI_ReleaseObj( hdc );
    return copy;
}


/***********************************************************************
 *           RestoreVisRgn   (GDI.130)
 *           RestoreVisRgn16 (GDI32.@)
 */
INT16 WINAPI RestoreVisRgn16( HDC16 hdc )
{
    HRGN saved;
    GDIOBJHDR *obj, *savedObj;
    DC *dc = DC_GetDCPtr( hdc );
    INT16 ret = ERROR;

    if (!dc) return ERROR;

    TRACE("%04x\n", hdc );

    if (!(obj = GDI_GetObjPtr( dc->hVisRgn, REGION_MAGIC ))) goto done;
    saved = obj->hNext;

    if ((savedObj = GDI_GetObjPtr( saved, REGION_MAGIC )))
    {
        ret = CombineRgn( dc->hVisRgn, saved, 0, RGN_COPY );
        obj->hNext = savedObj->hNext;
        GDI_ReleaseObj( saved );
        DeleteObject( saved );
        dc->flags &= ~DC_DIRTY;
        CLIPPING_UpdateGCRegion( dc );
    }
    GDI_ReleaseObj( dc->hVisRgn );
 done:
    GDI_ReleaseObj( hdc );
    return ret;
}