/////////////////////////////////////////////////////////////////////////////
// Name:        dc.cpp
// Purpose:     wxDC class
// Author:      Julian Smart
// Modified by:
// Created:     01/02/97
// RCS-ID:      $Id: dc.cpp,v 1.182 2004/10/06 20:18:41 ABX Exp $
// Copyright:   (c) Julian Smart
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

// ===========================================================================
// declarations
// ===========================================================================

// ---------------------------------------------------------------------------
// headers
// ---------------------------------------------------------------------------

#if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
    #pragma implementation "dc.h"
#endif

// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"

#ifdef __BORLANDC__
    #pragma hdrstop
#endif

#ifndef WX_PRECOMP
    #include "wx/image.h"
    #include "wx/window.h"
    #include "wx/dc.h"
    #include "wx/utils.h"
    #include "wx/dialog.h"
    #include "wx/app.h"
    #include "wx/bitmap.h"
    #include "wx/dcmemory.h"
    #include "wx/log.h"
    #include "wx/icon.h"
#endif

#include "wx/msw/private.h" // needs to be before #include <commdlg.h>
#include "wx/msw/missing.h" // needs to be before #include <commdlg.h>

#include "wx/sysopt.h"
#include "wx/dcprint.h"
#include "wx/module.h"
#include "wx/dynload.h"

#ifdef wxHAVE_RAW_BITMAP
#include "wx/rawbmp.h"
#endif

#include <string.h>
#include <math.h>

#if wxUSE_COMMON_DIALOGS && !defined(__WXMICROWIN__)
    #include <commdlg.h>
#endif

#ifndef __WIN32__
    #include <print.h>
#endif

#ifndef AC_SRC_ALPHA
#define AC_SRC_ALPHA 1
#endif

/* Quaternary raster codes */
#ifndef MAKEROP4
#define MAKEROP4(fore,back) (DWORD)((((back) << 8) & 0xFF000000) | (fore))
#endif

// apparently with MicroWindows it is possible that HDC is 0 so we have to
// check for this ourselves
#ifdef __WXMICROWIN__
    #define WXMICROWIN_CHECK_HDC if ( !GetHDC() ) return;
    #define WXMICROWIN_CHECK_HDC_RET(x) if ( !GetHDC() ) return x;
#else
    #define WXMICROWIN_CHECK_HDC
    #define WXMICROWIN_CHECK_HDC_RET(x)
#endif

IMPLEMENT_ABSTRACT_CLASS(wxDC, wxDCBase)

// ---------------------------------------------------------------------------
// constants
// ---------------------------------------------------------------------------

static const int VIEWPORT_EXTENT = 1000;

static const int MM_POINTS = 9;
static const int MM_METRIC = 10;

// usually this is defined in math.h
#ifndef M_PI
    static const double M_PI = 3.14159265358979323846;
#endif // M_PI

// ROPs which don't have standard names (see "Ternary Raster Operations" in the
// MSDN docs for how this and other numbers in wxDC::Blit() are obtained)
#define DSTCOPY 0x00AA0029      // a.k.a. NOP operation

// ----------------------------------------------------------------------------
// macros for logical <-> device coords conversion
// ----------------------------------------------------------------------------

/*
   We currently let Windows do all the translations itself so these macros are
   not really needed (any more) but keep them to enhance readability of the
   code by allowing to see where are the logical and where are the device
   coordinates used.
 */

#ifdef __WXWINCE__
    #define XLOG2DEV(x) ((x-m_logicalOriginX)*m_signX+m_deviceOriginX)
    #define YLOG2DEV(y) ((y-m_logicalOriginY)*m_signY+m_deviceOriginY)
    #define XDEV2LOG(x) ((x-m_deviceOriginX)*m_signX+m_logicalOriginX)
    #define YDEV2LOG(y) ((y-m_deviceOriginY)*m_signY+m_logicalOriginY)
#else
    #define XLOG2DEV(x) (x)
    #define YLOG2DEV(y) (y)
    #define XDEV2LOG(x) (x)
    #define YDEV2LOG(y) (y)
#endif

// ---------------------------------------------------------------------------
// private functions
// ---------------------------------------------------------------------------

// convert degrees to radians
static inline double DegToRad(double deg) { return (deg * M_PI) / 180.0; }

// call AlphaBlend() to blit contents of hdcSrc to hdcDst using alpha
//
// NB: bmpSrc is the bitmap selected in hdcSrc, it is not really needed
//     to pass it to this function but as we already have it at the point
//     of call anyhow we do
//
// return true if we could draw the bitmap in one way or the other, false
// otherwise
static bool AlphaBlt(HDC hdcDst,
                     int x, int y, int w, int h,
                     HDC hdcSrc,
                     const wxBitmap& bmpSrc);

#ifdef wxHAVE_RAW_BITMAP
// our (limited) AlphaBlend() replacement
static void
wxAlphaBlend(HDC hdcDst, int x, int y, int w, int h, const wxBitmap& bmp);
#endif

// ----------------------------------------------------------------------------
// private classes
// ----------------------------------------------------------------------------

// instead of duplicating the same code which sets and then restores text
// colours in each wxDC method working with wxSTIPPLE_MASK_OPAQUE brushes,
// encapsulate this in a small helper class

// wxColourChanger: changes the text colours in the ctor if required and
//                  restores them in the dtor
class wxColourChanger
{
public:
    wxColourChanger(wxDC& dc);
   ~wxColourChanger();

private:
    wxDC& m_dc;

    COLORREF m_colFgOld, m_colBgOld;

    bool m_changed;

    DECLARE_NO_COPY_CLASS(wxColourChanger)
};

// this class saves the old stretch blit mode during its life time
class StretchBltModeChanger
{
public:
    StretchBltModeChanger(HDC hdc, int mode)
        : m_hdc(hdc)
    {
#ifndef __WXWINCE__
        m_modeOld = ::SetStretchBltMode(m_hdc, mode);
        if ( !m_modeOld )
            wxLogLastError(_T("SetStretchBltMode"));
#else
        wxUnusedVar(mode);
#endif
    }

    ~StretchBltModeChanger()
    {
#ifndef __WXWINCE__
        if ( !::SetStretchBltMode(m_hdc, m_modeOld) )
            wxLogLastError(_T("SetStretchBltMode"));
#endif
    }

private:
    const HDC m_hdc;

    int m_modeOld;

    DECLARE_NO_COPY_CLASS(StretchBltModeChanger)
};

// ===========================================================================
// implementation
// ===========================================================================

// ----------------------------------------------------------------------------
// wxColourChanger
// ----------------------------------------------------------------------------

wxColourChanger::wxColourChanger(wxDC& dc) : m_dc(dc)
{
    const wxBrush& brush = dc.GetBrush();
    if ( brush.Ok() && brush.GetStyle() == wxSTIPPLE_MASK_OPAQUE )
    {
        HDC hdc = GetHdcOf(dc);
        m_colFgOld = ::GetTextColor(hdc);
        m_colBgOld = ::GetBkColor(hdc);

        // note that Windows convention is opposite to wxWidgets one, this is
        // why text colour becomes the background one and vice versa
        const wxColour& colFg = dc.GetTextForeground();
        if ( colFg.Ok() )
        {
            ::SetBkColor(hdc, colFg.GetPixel());
        }

        const wxColour& colBg = dc.GetTextBackground();
        if ( colBg.Ok() )
        {
            ::SetTextColor(hdc, colBg.GetPixel());
        }

        SetBkMode(hdc,
                  dc.GetBackgroundMode() == wxTRANSPARENT ? TRANSPARENT
                                                          : OPAQUE);

        // flag which telsl us to undo changes in the dtor
        m_changed = true;
    }
    else
    {
        // nothing done, nothing to undo
        m_changed = false;
    }
}

wxColourChanger::~wxColourChanger()
{
    if ( m_changed )
    {
        // restore the colours we changed
        HDC hdc = GetHdcOf(m_dc);

        ::SetBkMode(hdc, TRANSPARENT);
        ::SetTextColor(hdc, m_colFgOld);
        ::SetBkColor(hdc, m_colBgOld);
    }
}

// ---------------------------------------------------------------------------
// wxDC
// ---------------------------------------------------------------------------

// Default constructor
wxDC::wxDC()
{
    m_canvas = NULL;

    m_oldBitmap = 0;
    m_oldPen = 0;
    m_oldBrush = 0;
    m_oldFont = 0;
#if wxUSE_PALETTE
    m_oldPalette = 0;
#endif // wxUSE_PALETTE

    m_bOwnsDC = false;
    m_hDC = 0;
}

wxDC::~wxDC()
{
    if ( m_hDC != 0 )
    {
        SelectOldObjects(m_hDC);

        // if we own the HDC, we delete it, otherwise we just release it

        if ( m_bOwnsDC )
        {
            ::DeleteDC(GetHdc());
        }
        else // we don't own our HDC
        {
            if (m_canvas)
            {
                ::ReleaseDC(GetHwndOf(m_canvas), GetHdc());
            }
            else
            {
                // Must have been a wxScreenDC
                ::ReleaseDC((HWND) NULL, GetHdc());
            }
        }
    }
}

// This will select current objects out of the DC,
// which is what you have to do before deleting the
// DC.
void wxDC::SelectOldObjects(WXHDC dc)
{
    if (dc)
    {
        if (m_oldBitmap)
        {
            ::SelectObject((HDC) dc, (HBITMAP) m_oldBitmap);
#ifdef __WXDEBUG__
            if (m_selectedBitmap.Ok())
            {
                m_selectedBitmap.SetSelectedInto(NULL);
            }
#endif
        }
        m_oldBitmap = 0;
        if (m_oldPen)
        {
            ::SelectObject((HDC) dc, (HPEN) m_oldPen);
        }
        m_oldPen = 0;
        if (m_oldBrush)
        {
            ::SelectObject((HDC) dc, (HBRUSH) m_oldBrush);
        }
        m_oldBrush = 0;
        if (m_oldFont)
        {
            ::SelectObject((HDC) dc, (HFONT) m_oldFont);
        }
        m_oldFont = 0;

#if wxUSE_PALETTE
        if (m_oldPalette)
        {
            ::SelectPalette((HDC) dc, (HPALETTE) m_oldPalette, FALSE);
        }
        m_oldPalette = 0;
#endif // wxUSE_PALETTE
    }

    m_brush = wxNullBrush;
    m_pen = wxNullPen;
#if wxUSE_PALETTE
    m_palette = wxNullPalette;
#endif // wxUSE_PALETTE
    m_font = wxNullFont;
    m_backgroundBrush = wxNullBrush;
    m_selectedBitmap = wxNullBitmap;
}

// ---------------------------------------------------------------------------
// clipping
// ---------------------------------------------------------------------------

void wxDC::UpdateClipBox()
{
    WXMICROWIN_CHECK_HDC

    RECT rect;
    ::GetClipBox(GetHdc(), &rect);

    m_clipX1 = (wxCoord) XDEV2LOG(rect.left);
    m_clipY1 = (wxCoord) YDEV2LOG(rect.top);
    m_clipX2 = (wxCoord) XDEV2LOG(rect.right);
    m_clipY2 = (wxCoord) YDEV2LOG(rect.bottom);
}

void
wxDC::DoGetClippingBox(wxCoord *x, wxCoord *y, wxCoord *w, wxCoord *h) const
{
    // check if we should try to retrieve the clipping region possibly not set
    // by our SetClippingRegion() but preset by Windows:this can only happen
    // when we're associated with an existing HDC usign SetHDC(), see there
    if ( m_clipping && !m_clipX1 && !m_clipX2 )
    {
        wxDC *self = wxConstCast(this, wxDC);
        self->UpdateClipBox();

        if ( !m_clipX1 && !m_clipX2 )
            self->m_clipping = false;
    }

    wxDCBase::DoGetClippingBox(x, y, w, h);
}

// common part of DoSetClippingRegion() and DoSetClippingRegionAsRegion()
void wxDC::SetClippingHrgn(WXHRGN hrgn)
{
    wxCHECK_RET( hrgn, wxT("invalid clipping region") );

    WXMICROWIN_CHECK_HDC

    // note that we combine the new clipping region with the existing one: this
    // is compatible with what the other ports do and is the documented
    // behaviour now (starting with 2.3.3)
#if defined(__WXWINCE__)
    RECT rectClip;
    if ( !::GetClipBox(GetHdc(), &rectClip) )
        return;

    HRGN hrgnDest = ::CreateRectRgn(0, 0, 0, 0);
    HRGN hrgnClipOld = ::CreateRectRgn(rectClip.left, rectClip.top,
                                       rectClip.right, rectClip.bottom);

    if ( ::CombineRgn(hrgnDest, hrgnClipOld, (HRGN)hrgn, RGN_AND) != ERROR )
    {
        ::SelectClipRgn(GetHdc(), hrgnDest);
    }

    ::DeleteObject(hrgnClipOld);
    ::DeleteObject(hrgnDest);
#else // !WinCE
    if ( ::ExtSelectClipRgn(GetHdc(), (HRGN)hrgn, RGN_AND) == ERROR )
    {
        wxLogLastError(_T("ExtSelectClipRgn"));

        return;
    }
#endif // WinCE/!WinCE

    m_clipping = true;

    UpdateClipBox();
}

void wxDC::DoSetClippingRegion(wxCoord x, wxCoord y, wxCoord w, wxCoord h)
{
    // the region coords are always the device ones, so do the translation
    // manually
    //
    // FIXME: possible +/-1 error here, to check!
    HRGN hrgn = ::CreateRectRgn(LogicalToDeviceX(x),
                                LogicalToDeviceY(y),
                                LogicalToDeviceX(x + w),
                                LogicalToDeviceY(y + h));
    if ( !hrgn )
    {
        wxLogLastError(_T("CreateRectRgn"));
    }
    else
    {
        SetClippingHrgn((WXHRGN)hrgn);

        ::DeleteObject(hrgn);
    }
}

void wxDC::DoSetClippingRegionAsRegion(const wxRegion& region)
{
    SetClippingHrgn(region.GetHRGN());
}

void wxDC::DestroyClippingRegion()
{
    WXMICROWIN_CHECK_HDC

    if (m_clipping && m_hDC)
    {
        // TODO: this should restore the previous clipping region,
        //       so that OnPaint processing works correctly, and the update
        //       clipping region doesn't get destroyed after the first
        //       DestroyClippingRegion.
        HRGN rgn = CreateRectRgn(0, 0, 32000, 32000);
        ::SelectClipRgn(GetHdc(), rgn);
        ::DeleteObject(rgn);
    }

    wxDCBase::DestroyClippingRegion();
}

// ---------------------------------------------------------------------------
// query capabilities
// ---------------------------------------------------------------------------

bool wxDC::CanDrawBitmap() const
{
    return true;
}

bool wxDC::CanGetTextExtent() const
{
#ifdef __WXMICROWIN__
    // TODO Extend MicroWindows' GetDeviceCaps function
    return true;
#else
    // What sort of display is it?
    int technology = ::GetDeviceCaps(GetHdc(), TECHNOLOGY);

    return (technology == DT_RASDISPLAY) || (technology == DT_RASPRINTER);
#endif
}

int wxDC::GetDepth() const
{
    WXMICROWIN_CHECK_HDC_RET(16)

    return (int)::GetDeviceCaps(GetHdc(), BITSPIXEL);
}

// ---------------------------------------------------------------------------
// drawing
// ---------------------------------------------------------------------------

void wxDC::Clear()
{
    WXMICROWIN_CHECK_HDC

    RECT rect;
    if ( m_canvas )
    {
        GetClientRect((HWND) m_canvas->GetHWND(), &rect);
    }
    else
    {
        // No, I think we should simply ignore this if printing on e.g.
        // a printer DC.
        // wxCHECK_RET( m_selectedBitmap.Ok(), wxT("this DC can't be cleared") );
        if (!m_selectedBitmap.Ok())
            return;

        rect.left = 0; rect.top = 0;
        rect.right = m_selectedBitmap.GetWidth();
        rect.bottom = m_selectedBitmap.GetHeight();
    }

#ifndef __WXWINCE__
    (void) ::SetMapMode(GetHdc(), MM_TEXT);
#endif

    DWORD colour = ::GetBkColor(GetHdc());
    HBRUSH brush = ::CreateSolidBrush(colour);
    ::FillRect(GetHdc(), &rect, brush);
    ::DeleteObject(brush);

#ifndef __WXWINCE__
    int width = DeviceToLogicalXRel(VIEWPORT_EXTENT)*m_signX,
        height = DeviceToLogicalYRel(VIEWPORT_EXTENT)*m_signY;

    ::SetMapMode(GetHdc(), MM_ANISOTROPIC);

    ::SetViewportExtEx(GetHdc(), VIEWPORT_EXTENT, VIEWPORT_EXTENT, NULL);
    ::SetWindowExtEx(GetHdc(), width, height, NULL);
    ::SetViewportOrgEx(GetHdc(), (int)m_deviceOriginX, (int)m_deviceOriginY, NULL);
    ::SetWindowOrgEx(GetHdc(), (int)m_logicalOriginX, (int)m_logicalOriginY, NULL);
#endif
}

bool wxDC::DoFloodFill(wxCoord x, wxCoord y, const wxColour& col, int style)
{
#ifdef __WXWINCE__
    wxUnusedVar(x);
    wxUnusedVar(y);
    wxUnusedVar(col);
    wxUnusedVar(style);
    return false;
#else

    WXMICROWIN_CHECK_HDC_RET(false)

    bool success = (0 != ::ExtFloodFill(GetHdc(), XLOG2DEV(x), YLOG2DEV(y),
                         col.GetPixel(),
                         style == wxFLOOD_SURFACE ? FLOODFILLSURFACE
                                                  : FLOODFILLBORDER) ) ;
    if (!success)
    {
        // quoting from the MSDN docs:
        //
        //      Following are some of the reasons this function might fail:
        //
        //      * The filling could not be completed.
        //      * The specified point has the boundary color specified by the
        //        crColor parameter (if FLOODFILLBORDER was requested).
        //      * The specified point does not have the color specified by
        //        crColor (if FLOODFILLSURFACE was requested)
        //      * The point is outside the clipping region that is, it is not
        //        visible on the device.
        //
        wxLogLastError(wxT("ExtFloodFill"));
    }

    CalcBoundingBox(x, y);

    return success;
#endif
}

bool wxDC::DoGetPixel(wxCoord x, wxCoord y, wxColour *col) const
{
    WXMICROWIN_CHECK_HDC_RET(false)

    wxCHECK_MSG( col, false, _T("NULL colour parameter in wxDC::GetPixel") );

    // get the color of the pixel
    COLORREF pixelcolor = ::GetPixel(GetHdc(), XLOG2DEV(x), YLOG2DEV(y));

    wxRGBToColour(*col, pixelcolor);

    return true;
}

void wxDC::DoCrossHair(wxCoord x, wxCoord y)
{
    WXMICROWIN_CHECK_HDC

    wxCoord x1 = x-VIEWPORT_EXTENT;
    wxCoord y1 = y-VIEWPORT_EXTENT;
    wxCoord x2 = x+VIEWPORT_EXTENT;
    wxCoord y2 = y+VIEWPORT_EXTENT;

    wxDrawLine(GetHdc(), XLOG2DEV(x1), YLOG2DEV(y), XLOG2DEV(x2), YLOG2DEV(y));
    wxDrawLine(GetHdc(), XLOG2DEV(x), YLOG2DEV(y1), XLOG2DEV(x), YLOG2DEV(y2));

    CalcBoundingBox(x1, y1);
    CalcBoundingBox(x2, y2);
}

void wxDC::DoDrawLine(wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2)
{
    WXMICROWIN_CHECK_HDC

    wxDrawLine(GetHdc(), XLOG2DEV(x1), YLOG2DEV(y1), XLOG2DEV(x2), YLOG2DEV(y2));

    CalcBoundingBox(x1, y1);
    CalcBoundingBox(x2, y2);
}

// Draws an arc of a circle, centred on (xc, yc), with starting point (x1, y1)
// and ending at (x2, y2)
void wxDC::DoDrawArc(wxCoord x1, wxCoord y1,
                     wxCoord x2, wxCoord y2,
                     wxCoord xc, wxCoord yc)
{
#ifdef __WXWINCE__
    // Slower emulation since WinCE doesn't support Pie and Arc
    double r = sqrt( (x1-xc)*(x1-xc) + (y1-yc)*(y1-yc) );
    double sa = acos((x1-xc)/r)/M_PI*180; // between 0 and 180
    if( y1>yc ) sa = -sa; // below center
    double ea = atan2(yc-y2, x2-xc)/M_PI*180;
    DoDrawEllipticArcRot( xc-r, yc-r, 2*r, 2*r, sa, ea );
#else

    WXMICROWIN_CHECK_HDC

    wxColourChanger cc(*this); // needed for wxSTIPPLE_MASK_OPAQUE handling

    double dx = xc - x1;
    double dy = yc - y1;
    double radius = (double)sqrt(dx*dx+dy*dy);
    wxCoord r = (wxCoord)radius;

    // treat the special case of full circle separately
    if ( x1 == x2 && y1 == y2 )
    {
        DrawEllipse(xc - r, yc - r, 2*r, 2*r);
        return;
    }

    wxCoord xx1 = XLOG2DEV(x1);
    wxCoord yy1 = YLOG2DEV(y1);
    wxCoord xx2 = XLOG2DEV(x2);
    wxCoord yy2 = YLOG2DEV(y2);
    wxCoord xxc = XLOG2DEV(xc);
    wxCoord yyc = YLOG2DEV(yc);
    wxCoord ray = (wxCoord) sqrt(double((xxc-xx1)*(xxc-xx1)+(yyc-yy1)*(yyc-yy1)));

    wxCoord xxx1 = (wxCoord) (xxc-ray);
    wxCoord yyy1 = (wxCoord) (yyc-ray);
    wxCoord xxx2 = (wxCoord) (xxc+ray);
    wxCoord yyy2 = (wxCoord) (yyc+ray);

    if ( m_brush.Ok() && m_brush.GetStyle() != wxTRANSPARENT )
    {
        // Have to add 1 to bottom-right corner of rectangle
        // to make semi-circles look right (crooked line otherwise).
        // Unfortunately this is not a reliable method, depends
        // on the size of shape.
        // TODO: figure out why this happens!
        Pie(GetHdc(),xxx1,yyy1,xxx2+1,yyy2+1, xx1,yy1,xx2,yy2);
    }
    else
    {
        Arc(GetHdc(),xxx1,yyy1,xxx2,yyy2, xx1,yy1,xx2,yy2);
    }

    CalcBoundingBox(xc - r, yc - r);
    CalcBoundingBox(xc + r, yc + r);
#endif
}

void wxDC::DoDrawCheckMark(wxCoord x1, wxCoord y1,
                           wxCoord width, wxCoord height)
{
    WXMICROWIN_CHECK_HDC

    wxCoord x2 = x1 + width,
            y2 = y1 + height;

#if defined(__WIN32__) && !defined(__SYMANTEC__) && !defined(__WXMICROWIN__)
    RECT rect;
    rect.left   = x1;
    rect.top    = y1;
    rect.right  = x2;
    rect.bottom = y2;

#ifdef __WXWINCE__
    DrawFrameControl(GetHdc(), &rect, DFC_BUTTON, DFCS_BUTTONCHECK);
#else
    DrawFrameControl(GetHdc(), &rect, DFC_MENU, DFCS_MENUCHECK);
#endif
#else // Symantec-MicroWin
    // draw a cross
    HPEN blackPen = ::CreatePen(PS_SOLID, 1, RGB(0, 0, 0));
    HPEN whiteBrush = (HPEN)::GetStockObject(WHITE_BRUSH);
    HPEN hPenOld = (HPEN)::SelectObject(GetHdc(), blackPen);
    HPEN hBrushOld = (HPEN)::SelectObject(GetHdc(), whiteBrush);
    ::SetROP2(GetHdc(), R2_COPYPEN);
    Rectangle(GetHdc(), x1, y1, x2, y2);
    MoveToEx(GetHdc(), x1, y1, NULL);
    LineTo(GetHdc(), x2, y2);
    MoveToEx(GetHdc(), x2, y1, NULL);
    LineTo(GetHdc(), x1, y2);
    ::SelectObject(GetHdc(), hPenOld);
    ::SelectObject(GetHdc(), hBrushOld);
    ::DeleteObject(blackPen);
#endif // Win32/Symantec-MicroWin

    CalcBoundingBox(x1, y1);
    CalcBoundingBox(x2, y2);
}

void wxDC::DoDrawPoint(wxCoord x, wxCoord y)
{
    WXMICROWIN_CHECK_HDC

    COLORREF color = 0x00ffffff;
    if (m_pen.Ok())
    {
        color = m_pen.GetColour().GetPixel();
    }

    SetPixel(GetHdc(), XLOG2DEV(x), YLOG2DEV(y), color);

    CalcBoundingBox(x, y);
}

void wxDC::DoDrawPolygon(int n, wxPoint points[], wxCoord xoffset, wxCoord yoffset,int fillStyle)
{
    WXMICROWIN_CHECK_HDC

    wxColourChanger cc(*this); // needed for wxSTIPPLE_MASK_OPAQUE handling

    // Do things less efficiently if we have offsets
    if (xoffset != 0 || yoffset != 0)
    {
        POINT *cpoints = new POINT[n];
        int i;
        for (i = 0; i < n; i++)
        {
            cpoints[i].x = (int)(points[i].x + xoffset);
            cpoints[i].y = (int)(points[i].y + yoffset);

            CalcBoundingBox(cpoints[i].x, cpoints[i].y);
        }
#ifndef __WXWINCE__
        int prev = SetPolyFillMode(GetHdc(),fillStyle==wxODDEVEN_RULE?ALTERNATE:WINDING);
#else
        wxUnusedVar(fillStyle);
#endif
        (void)Polygon(GetHdc(), cpoints, n);
#ifndef __WXWINCE__
        SetPolyFillMode(GetHdc(),prev);
#endif
        delete[] cpoints;
    }
    else
    {
        int i;
        for (i = 0; i < n; i++)
            CalcBoundingBox(points[i].x, points[i].y);

#ifndef __WXWINCE__
        int prev = SetPolyFillMode(GetHdc(),fillStyle==wxODDEVEN_RULE?ALTERNATE:WINDING);
#endif
        (void)Polygon(GetHdc(), (POINT*) points, n);
#ifndef __WXWINCE__
        SetPolyFillMode(GetHdc(),prev);
#endif
    }
}

void
wxDC::DoDrawPolyPolygon(int n,
                        int count[],
                        wxPoint points[],
                        wxCoord xoffset,
                        wxCoord yoffset,
                        int fillStyle)
{
#ifdef __WXWINCE__
    wxDCBase::DoDrawPolyPolygon(n, count, points, xoffset, yoffset, fillStyle);
#else
    WXMICROWIN_CHECK_HDC

    wxColourChanger cc(*this); // needed for wxSTIPPLE_MASK_OPAQUE handling
    int i, cnt;
    for (i = cnt = 0; i < n; i++)
        cnt += count[i];

    // Do things less efficiently if we have offsets
    if (xoffset != 0 || yoffset != 0)
    {
        POINT *cpoints = new POINT[cnt];
        for (i = 0; i < cnt; i++)
        {
            cpoints[i].x = (int)(points[i].x + xoffset);
            cpoints[i].y = (int)(points[i].y + yoffset);

            CalcBoundingBox(cpoints[i].x, cpoints[i].y);
        }
#ifndef __WXWINCE__
        int prev = SetPolyFillMode(GetHdc(),fillStyle==wxODDEVEN_RULE?ALTERNATE:WINDING);
#endif
        (void)PolyPolygon(GetHdc(), cpoints, count, n);
#ifndef __WXWINCE__
        SetPolyFillMode(GetHdc(),prev);
#endif
        delete[] cpoints;
    }
    else
    {
        for (i = 0; i < cnt; i++)
            CalcBoundingBox(points[i].x, points[i].y);

#ifndef __WXWINCE__
        int prev = SetPolyFillMode(GetHdc(),fillStyle==wxODDEVEN_RULE?ALTERNATE:WINDING);
#endif
        (void)PolyPolygon(GetHdc(), (POINT*) points, count, n);
#ifndef __WXWINCE__
        SetPolyFillMode(GetHdc(),prev);
#endif
    }
#endif
  // __WXWINCE__
}

void wxDC::DoDrawLines(int n, wxPoint points[], wxCoord xoffset, wxCoord yoffset)
{
    WXMICROWIN_CHECK_HDC

    // Do things less efficiently if we have offsets
    if (xoffset != 0 || yoffset != 0)
    {
        POINT *cpoints = new POINT[n];
        int i;
        for (i = 0; i < n; i++)
        {
            cpoints[i].x = (int)(points[i].x + xoffset);
            cpoints[i].y = (int)(points[i].y + yoffset);

            CalcBoundingBox(cpoints[i].x, cpoints[i].y);
        }
        (void)Polyline(GetHdc(), cpoints, n);
        delete[] cpoints;
    }
    else
    {
        int i;
        for (i = 0; i < n; i++)
            CalcBoundingBox(points[i].x, points[i].y);

        (void)Polyline(GetHdc(), (POINT*) points, n);
    }
}

void wxDC::DoDrawRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height)
{
    WXMICROWIN_CHECK_HDC

    wxColourChanger cc(*this); // needed for wxSTIPPLE_MASK_OPAQUE handling

    wxCoord x2 = x + width;
    wxCoord y2 = y + height;

    if ((m_logicalFunction == wxCOPY) && (m_pen.GetStyle() == wxTRANSPARENT))
    {
        RECT rect;
        rect.left = XLOG2DEV(x);
        rect.top = YLOG2DEV(y);
        rect.right = XLOG2DEV(x2);
        rect.bottom = YLOG2DEV(y2);
        (void)FillRect(GetHdc(), &rect, (HBRUSH)m_brush.GetResourceHandle() );
    }
    else
    {
        // Windows draws the filled rectangles without outline (i.e. drawn with a
        // transparent pen) one pixel smaller in both directions and we want them
        // to have the same size regardless of which pen is used - adjust

        // I wonder if this shouldn´t be done after the LOG2DEV() conversions. RR.
        if ( m_pen.GetStyle() == wxTRANSPARENT )
        {
            x2++;
            y2++;
        }

        (void)Rectangle(GetHdc(), XLOG2DEV(x), YLOG2DEV(y), XLOG2DEV(x2), YLOG2DEV(y2));
    }


    CalcBoundingBox(x, y);
    CalcBoundingBox(x2, y2);
}

void wxDC::DoDrawRoundedRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height, double radius)
{
    WXMICROWIN_CHECK_HDC

    wxColourChanger cc(*this); // needed for wxSTIPPLE_MASK_OPAQUE handling

    // Now, a negative radius value is interpreted to mean
    // 'the proportion of the smallest X or Y dimension'

    if (radius < 0.0)
    {
        double smallest = (width < height) ? width : height;
        radius = (- radius * smallest);
    }

    wxCoord x2 = (x+width);
    wxCoord y2 = (y+height);

    // Windows draws the filled rectangles without outline (i.e. drawn with a
    // transparent pen) one pixel smaller in both directions and we want them
    // to have the same size regardless of which pen is used - adjust
    if ( m_pen.GetStyle() == wxTRANSPARENT )
    {
        x2++;
        y2++;
    }

    (void)RoundRect(GetHdc(), XLOG2DEV(x), YLOG2DEV(y), XLOG2DEV(x2),
        YLOG2DEV(y2), (int) (2*XLOG2DEV(radius)), (int)( 2*YLOG2DEV(radius)));

    CalcBoundingBox(x, y);
    CalcBoundingBox(x2, y2);
}

void wxDC::DoDrawEllipse(wxCoord x, wxCoord y, wxCoord width, wxCoord height)
{
    WXMICROWIN_CHECK_HDC

    wxColourChanger cc(*this); // needed for wxSTIPPLE_MASK_OPAQUE handling

    wxCoord x2 = (x+width);
    wxCoord y2 = (y+height);

    (void)Ellipse(GetHdc(), XLOG2DEV(x), YLOG2DEV(y), XLOG2DEV(x2), YLOG2DEV(y2));

    CalcBoundingBox(x, y);
    CalcBoundingBox(x2, y2);
}

// Chris Breeze 20/5/98: first implementation of DrawEllipticArc on Windows
void wxDC::DoDrawEllipticArc(wxCoord x,wxCoord y,wxCoord w,wxCoord h,double sa,double ea)
{
#ifdef __WXWINCE__
    DoDrawEllipticArcRot( x, y, w, h, sa, ea );
#else

    WXMICROWIN_CHECK_HDC

    wxColourChanger cc(*this); // needed for wxSTIPPLE_MASK_OPAQUE handling

    wxCoord x2 = x + w;
    wxCoord y2 = y + h;

    int rx1 = XLOG2DEV(x+w/2);
    int ry1 = YLOG2DEV(y+h/2);
    int rx2 = rx1;
    int ry2 = ry1;

    sa = DegToRad(sa);
    ea = DegToRad(ea);

    rx1 += (int)(100.0 * abs(w) * cos(sa));
    ry1 -= (int)(100.0 * abs(h) * m_signY * sin(sa));
    rx2 += (int)(100.0 * abs(w) * cos(ea));
    ry2 -= (int)(100.0 * abs(h) * m_signY * sin(ea));

    // draw pie with NULL_PEN first and then outline otherwise a line is
    // drawn from the start and end points to the centre
    HPEN hpenOld = (HPEN) ::SelectObject(GetHdc(), (HPEN) ::GetStockObject(NULL_PEN));
    if (m_signY > 0)
    {
        (void)Pie(GetHdc(), XLOG2DEV(x), YLOG2DEV(y), XLOG2DEV(x2)+1, YLOG2DEV(y2)+1,
                  rx1, ry1, rx2, ry2);
    }
    else
    {
        (void)Pie(GetHdc(), XLOG2DEV(x), YLOG2DEV(y)-1, XLOG2DEV(x2)+1, YLOG2DEV(y2),
                  rx1, ry1-1, rx2, ry2-1);
    }

    ::SelectObject(GetHdc(), hpenOld);

    (void)Arc(GetHdc(), XLOG2DEV(x), YLOG2DEV(y), XLOG2DEV(x2), YLOG2DEV(y2),
              rx1, ry1, rx2, ry2);

    CalcBoundingBox(x, y);
    CalcBoundingBox(x2, y2);
#endif
}

void wxDC::DoDrawIcon(const wxIcon& icon, wxCoord x, wxCoord y)
{
    WXMICROWIN_CHECK_HDC

    wxCHECK_RET( icon.Ok(), wxT("invalid icon in DrawIcon") );

#ifdef __WIN32__
    ::DrawIconEx(GetHdc(), XLOG2DEV(x), YLOG2DEV(y), GetHiconOf(icon), icon.GetWidth(), icon.GetHeight(), 0, NULL, DI_NORMAL);
#else
    ::DrawIcon(GetHdc(), XLOG2DEV(x), YLOG2DEV(y), GetHiconOf(icon));
#endif

    CalcBoundingBox(x, y);
    CalcBoundingBox(x + icon.GetWidth(), y + icon.GetHeight());
}

void wxDC::DoDrawBitmap( const wxBitmap &bmp, wxCoord x, wxCoord y, bool useMask )
{
    WXMICROWIN_CHECK_HDC

    wxCHECK_RET( bmp.Ok(), _T("invalid bitmap in wxDC::DrawBitmap") );

    int width = bmp.GetWidth(),
        height = bmp.GetHeight();

    HBITMAP hbmpMask = 0;

#if wxUSE_PALETTE
    HPALETTE oldPal = 0;
#endif // wxUSE_PALETTE

    if ( bmp.HasAlpha() )
    {
        MemoryHDC hdcMem;
        SelectInHDC select(hdcMem, GetHbitmapOf(bmp));

        if ( AlphaBlt(GetHdc(), x, y, width, height, hdcMem, bmp) )
            return;
    }

    if ( useMask )
    {
        wxMask *mask = bmp.GetMask();
        if ( mask )
            hbmpMask = (HBITMAP)mask->GetMaskBitmap();

        if ( !hbmpMask )
        {
            // don't give assert here because this would break existing
            // programs - just silently ignore useMask parameter
            useMask = false;
        }
    }
    if ( useMask )
    {
#ifdef __WIN32__
        // use MaskBlt() with ROP which doesn't do anything to dst in the mask
        // points
        // On some systems, MaskBlt succeeds yet is much much slower
        // than the wxWidgets fall-back implementation. So we need
        // to be able to switch this on and off at runtime.
        bool ok = false;
#if wxUSE_SYSTEM_OPTIONS
        if (wxSystemOptions::GetOptionInt(wxT("no-maskblt")) == 0)
#endif
        {
            HDC cdc = GetHdc();
            HDC hdcMem = ::CreateCompatibleDC(GetHdc());
            HGDIOBJ hOldBitmap = ::SelectObject(hdcMem, GetHbitmapOf(bmp));
#if wxUSE_PALETTE
            wxPalette *pal = bmp.GetPalette();
            if ( pal && ::GetDeviceCaps(cdc,BITSPIXEL) <= 8 )
            {
                oldPal = ::SelectPalette(hdcMem, GetHpaletteOf(*pal), FALSE);
                ::RealizePalette(hdcMem);
            }
#endif // wxUSE_PALETTE

            ok = ::MaskBlt(cdc, x, y, width, height,
                            hdcMem, 0, 0,
                            hbmpMask, 0, 0,
                            MAKEROP4(SRCCOPY, DSTCOPY)) != 0;

#if wxUSE_PALETTE
            if (oldPal)
                ::SelectPalette(hdcMem, oldPal, FALSE);
#endif // wxUSE_PALETTE

            ::SelectObject(hdcMem, hOldBitmap);
            ::DeleteDC(hdcMem);
        }

        if ( !ok )
#endif // Win32
        {
            // Rather than reproduce wxDC::Blit, let's do it at the wxWin API
            // level
            wxMemoryDC memDC;
            memDC.SelectObject(bmp);

            Blit(x, y, width, height, &memDC, 0, 0, wxCOPY, useMask);

            memDC.SelectObject(wxNullBitmap);
        }
    }
    else // no mask, just use BitBlt()
    {
        HDC cdc = GetHdc();
        HDC memdc = ::CreateCompatibleDC( cdc );
        HBITMAP hbitmap = (HBITMAP) bmp.GetHBITMAP( );

        wxASSERT_MSG( hbitmap, wxT("bitmap is ok but HBITMAP is NULL?") );

        COLORREF old_textground = ::GetTextColor(GetHdc());
        COLORREF old_background = ::GetBkColor(GetHdc());
        if (m_textForegroundColour.Ok())
        {
            ::SetTextColor(GetHdc(), m_textForegroundColour.GetPixel() );
        }
        if (m_textBackgroundColour.Ok())
        {
            ::SetBkColor(GetHdc(), m_textBackgroundColour.GetPixel() );
        }

#if wxUSE_PALETTE
        wxPalette *pal = bmp.GetPalette();
        if ( pal && ::GetDeviceCaps(cdc,BITSPIXEL) <= 8 )
        {
            oldPal = ::SelectPalette(memdc, GetHpaletteOf(*pal), FALSE);
            ::RealizePalette(memdc);
        }
#endif // wxUSE_PALETTE

        HGDIOBJ hOldBitmap = ::SelectObject( memdc, hbitmap );
        ::BitBlt( cdc, x, y, width, height, memdc, 0, 0, SRCCOPY);

#if wxUSE_PALETTE
        if (oldPal)
            ::SelectPalette(memdc, oldPal, FALSE);
#endif // wxUSE_PALETTE

        ::SelectObject( memdc, hOldBitmap );
        ::DeleteDC( memdc );

        ::SetTextColor(GetHdc(), old_textground);
        ::SetBkColor(GetHdc(), old_background);
    }
}

void wxDC::DoDrawText(const wxString& text, wxCoord x, wxCoord y)
{
    WXMICROWIN_CHECK_HDC

    DrawAnyText(text, x, y);

    // update the bounding box
    CalcBoundingBox(x, y);

    wxCoord w, h;
    GetTextExtent(text, &w, &h);
    CalcBoundingBox(x + w, y + h);
}

void wxDC::DrawAnyText(const wxString& text, wxCoord x, wxCoord y)
{
    WXMICROWIN_CHECK_HDC

    // prepare for drawing the text
    if ( m_textForegroundColour.Ok() )
        SetTextColor(GetHdc(), m_textForegroundColour.GetPixel());

    DWORD old_background = 0;
    if ( m_textBackgroundColour.Ok() )
    {
        old_background = SetBkColor(GetHdc(), m_textBackgroundColour.GetPixel() );
    }

    SetBkMode(GetHdc(), m_backgroundMode == wxTRANSPARENT ? TRANSPARENT
                                                          : OPAQUE);

#ifdef __WXWINCE__
    if ( ::ExtTextOut(GetHdc(), XLOG2DEV(x), YLOG2DEV(y), 0, NULL,
                   text.c_str(), text.length(), NULL) == 0 )
    {
        wxLogLastError(wxT("TextOut"));
    }
#else
    if ( ::TextOut(GetHdc(), XLOG2DEV(x), YLOG2DEV(y),
                   text.c_str(), text.length()) == 0 )
    {
        wxLogLastError(wxT("TextOut"));
    }
#endif

    // restore the old parameters (text foreground colour may be left because
    // it never is set to anything else, but background should remain
    // transparent even if we just drew an opaque string)
    if ( m_textBackgroundColour.Ok() )
        (void)SetBkColor(GetHdc(), old_background);

    SetBkMode(GetHdc(), TRANSPARENT);
}

void wxDC::DoDrawRotatedText(const wxString& text,
                             wxCoord x, wxCoord y,
                             double angle)
{
    WXMICROWIN_CHECK_HDC

    // we test that we have some font because otherwise we should still use the
    // "else" part below to avoid that DrawRotatedText(angle = 180) and
    // DrawRotatedText(angle = 0) use different fonts (we can't use the default
    // font for drawing rotated fonts unfortunately)
    if ( (angle == 0.0) && m_font.Ok() )
    {
        DoDrawText(text, x, y);
    }
#ifndef __WXMICROWIN__
    else
    {
        // NB: don't take DEFAULT_GUI_FONT (a.k.a. wxSYS_DEFAULT_GUI_FONT)
        //     because it's not TrueType and so can't have non zero
        //     orientation/escapement under Win9x
        wxFont font = m_font.Ok() ? m_font : *wxSWISS_FONT;
        HFONT hfont = (HFONT)font.GetResourceHandle();
        LOGFONT lf;
        if ( ::GetObject(hfont, sizeof(lf), &lf) == 0 )
        {
            wxLogLastError(wxT("GetObject(hfont)"));
        }

        // GDI wants the angle in tenth of degree
        long angle10 = (long)(angle * 10);
        lf.lfEscapement = angle10;
        lf. lfOrientation = angle10;

        hfont = ::CreateFontIndirect(&lf);
        if ( !hfont )
        {
            wxLogLastError(wxT("CreateFont"));
        }
        else
        {
            HFONT hfontOld = (HFONT)::SelectObject(GetHdc(), hfont);

            DrawAnyText(text, x, y);

            (void)::SelectObject(GetHdc(), hfontOld);
            (void)::DeleteObject(hfont);
        }

        // call the bounding box by adding all four vertices of the rectangle
        // containing the text to it (simpler and probably not slower than
        // determining which of them is really topmost/leftmost/...)
        wxCoord w, h;
        GetTextExtent(text, &w, &h);

        double rad = DegToRad(angle);

        // "upper left" and "upper right"
        CalcBoundingBox(x, y);
        CalcBoundingBox(x + wxCoord(w*cos(rad)), y - wxCoord(w*sin(rad)));

        // "bottom left" and "bottom right"
        x += (wxCoord)(h*sin(rad));
        y += (wxCoord)(h*cos(rad));
        CalcBoundingBox(x, y);
        CalcBoundingBox(x + wxCoord(w*cos(rad)), y - wxCoord(w*sin(rad)));
    }
#endif
}

// ---------------------------------------------------------------------------
// set GDI objects
// ---------------------------------------------------------------------------

#if wxUSE_PALETTE

void wxDC::DoSelectPalette(bool realize)
{
    WXMICROWIN_CHECK_HDC

    // Set the old object temporarily, in case the assignment deletes an object
    // that's not yet selected out.
    if (m_oldPalette)
    {
        ::SelectPalette(GetHdc(), (HPALETTE) m_oldPalette, FALSE);
        m_oldPalette = 0;
    }

    if ( m_palette.Ok() )
    {
        HPALETTE oldPal = ::SelectPalette(GetHdc(),
                                          GetHpaletteOf(m_palette),
                                          false);
        if (!m_oldPalette)
            m_oldPalette = (WXHPALETTE) oldPal;

        if (realize)
            ::RealizePalette(GetHdc());
    }
}

void wxDC::SetPalette(const wxPalette& palette)
{
    if ( palette.Ok() )
    {
        m_palette = palette;
        DoSelectPalette(true);
    }
}

void wxDC::InitializePalette()
{
    if ( wxDisplayDepth() <= 8 )
    {
        // look for any window or parent that has a custom palette. If any has
        // one then we need to use it in drawing operations
        wxWindow *win = m_canvas->GetAncestorWithCustomPalette();

        m_hasCustomPalette = win && win->HasCustomPalette();
        if ( m_hasCustomPalette )
        {
            m_palette = win->GetPalette();

            // turn on MSW translation for this palette
            DoSelectPalette();
        }
    }
}

#endif // wxUSE_PALETTE

// SetFont/Pen/Brush() really ask to be implemented as a single template
// function... but doing it is not worth breaking OpenWatcom build <sigh>

void wxDC::SetFont(const wxFont& font)
{
    WXMICROWIN_CHECK_HDC

    if ( font == m_font )
        return;

    if ( font.Ok() )
    {
        HGDIOBJ hfont = ::SelectObject(GetHdc(), GetHfontOf(font));
        if ( hfont == HGDI_ERROR )
        {
            wxLogLastError(_T("SelectObject(font)"));
        }
        else // selected ok
        {
            if ( !m_oldFont )
                m_oldFont = (WXHPEN)hfont;

            m_font = font;
        }
    }
    else // invalid font, reset the current font
    {
        if ( m_oldFont )
        {
            if ( ::SelectObject(GetHdc(), (HPEN) m_oldFont) == HGDI_ERROR )
            {
                wxLogLastError(_T("SelectObject(old font)"));
            }

            m_oldFont = 0;
        }

        m_font = wxNullFont;
    }
}

void wxDC::SetPen(const wxPen& pen)
{
    WXMICROWIN_CHECK_HDC

    if ( pen == m_pen )
        return;

    if ( pen.Ok() )
    {
        HGDIOBJ hpen = ::SelectObject(GetHdc(), GetHpenOf(pen));
        if ( hpen == HGDI_ERROR )
        {
            wxLogLastError(_T("SelectObject(pen)"));
        }
        else // selected ok
        {
            if ( !m_oldPen )
                m_oldPen = (WXHPEN)hpen;

            m_pen = pen;
        }
    }
    else // invalid pen, reset the current pen
    {
        if ( m_oldPen )
        {
            if ( ::SelectObject(GetHdc(), (HPEN) m_oldPen) == HGDI_ERROR )
            {
                wxLogLastError(_T("SelectObject(old pen)"));
            }

            m_oldPen = 0;
        }

        m_pen = wxNullPen;
    }
}

void wxDC::SetBrush(const wxBrush& brush)
{
    WXMICROWIN_CHECK_HDC

    if ( brush == m_brush )
        return;

    if ( brush.Ok() )
    {
        // we must make sure the brush is aligned with the logical coordinates
        // before selecting it
        wxBitmap *stipple = brush.GetStipple();
        if ( stipple && stipple->Ok() )
        {
            if ( !::SetBrushOrgEx
                    (
                        GetHdc(),
                        m_deviceOriginX % stipple->GetWidth(),
                        m_deviceOriginY % stipple->GetHeight(),
                        NULL                    // [out] previous brush origin
                    ) )
            {
                wxLogLastError(_T("SetBrushOrgEx()"));
            }
        }

        HGDIOBJ hbrush = ::SelectObject(GetHdc(), GetHbrushOf(brush));
        if ( hbrush == HGDI_ERROR )
        {
            wxLogLastError(_T("SelectObject(brush)"));
        }
        else // selected ok
        {
            if ( !m_oldBrush )
                m_oldBrush = (WXHPEN)hbrush;

            m_brush = brush;
        }
    }
    else // invalid brush, reset the current brush
    {
        if ( m_oldBrush )
        {
            if ( ::SelectObject(GetHdc(), (HPEN) m_oldBrush) == HGDI_ERROR )
            {
                wxLogLastError(_T("SelectObject(old brush)"));
            }

            m_oldBrush = 0;
        }

        m_brush = wxNullBrush;
    }
}

void wxDC::SetBackground(const wxBrush& brush)
{
    WXMICROWIN_CHECK_HDC

    m_backgroundBrush = brush;

    if ( m_backgroundBrush.Ok() )
    {
        (void)SetBkColor(GetHdc(), m_backgroundBrush.GetColour().GetPixel());
    }
}

void wxDC::SetBackgroundMode(int mode)
{
    WXMICROWIN_CHECK_HDC

    m_backgroundMode = mode;

    // SetBackgroundColour now only refers to text background
    // and m_backgroundMode is used there
}

void wxDC::SetLogicalFunction(int function)
{
    WXMICROWIN_CHECK_HDC

    m_logicalFunction = function;

    SetRop(m_hDC);
}

void wxDC::SetRop(WXHDC dc)
{
    if ( !dc || m_logicalFunction < 0 )
        return;

    int rop;

    switch (m_logicalFunction)
    {
        case wxCLEAR:        rop = R2_BLACK;         break;
        case wxXOR:          rop = R2_XORPEN;        break;
        case wxINVERT:       rop = R2_NOT;           break;
        case wxOR_REVERSE:   rop = R2_MERGEPENNOT;   break;
        case wxAND_REVERSE:  rop = R2_MASKPENNOT;    break;
        case wxCOPY:         rop = R2_COPYPEN;       break;
        case wxAND:          rop = R2_MASKPEN;       break;
        case wxAND_INVERT:   rop = R2_MASKNOTPEN;    break;
        case wxNO_OP:        rop = R2_NOP;           break;
        case wxNOR:          rop = R2_NOTMERGEPEN;   break;
        case wxEQUIV:        rop = R2_NOTXORPEN;     break;
        case wxSRC_INVERT:   rop = R2_NOTCOPYPEN;    break;
        case wxOR_INVERT:    rop = R2_MERGENOTPEN;   break;
        case wxNAND:         rop = R2_NOTMASKPEN;    break;
        case wxOR:           rop = R2_MERGEPEN;      break;
        case wxSET:          rop = R2_WHITE;         break;

        default:
           wxFAIL_MSG( wxT("unsupported logical function") );
           return;
    }

    SetROP2(GetHdc(), rop);
}

bool wxDC::StartDoc(const wxString& WXUNUSED(message))
{
    // We might be previewing, so return true to let it continue.
    return true;
}

void wxDC::EndDoc()
{
}

void wxDC::StartPage()
{
}

void wxDC::EndPage()
{
}

// ---------------------------------------------------------------------------
// text metrics
// ---------------------------------------------------------------------------

wxCoord wxDC::GetCharHeight() const
{
    WXMICROWIN_CHECK_HDC_RET(0)

    TEXTMETRIC lpTextMetric;

    GetTextMetrics(GetHdc(), &lpTextMetric);

    return lpTextMetric.tmHeight;
}

wxCoord wxDC::GetCharWidth() const
{
    WXMICROWIN_CHECK_HDC_RET(0)

    TEXTMETRIC lpTextMetric;

    GetTextMetrics(GetHdc(), &lpTextMetric);

    return lpTextMetric.tmAveCharWidth;
}

void wxDC::DoGetTextExtent(const wxString& string, wxCoord *x, wxCoord *y,
                           wxCoord *descent, wxCoord *externalLeading,
                           wxFont *font) const
{
#ifdef __WXMICROWIN__
    if (!GetHDC())
    {
        if (x) *x = 0;
        if (y) *y = 0;
        if (descent) *descent = 0;
        if (externalLeading) *externalLeading = 0;
        return;
    }
#endif // __WXMICROWIN__

    HFONT hfontOld;
    if ( font )
    {
        wxASSERT_MSG( font->Ok(), _T("invalid font in wxDC::GetTextExtent") );

        hfontOld = (HFONT)::SelectObject(GetHdc(), GetHfontOf(*font));
    }
    else // don't change the font
    {
        hfontOld = 0;
    }

    SIZE sizeRect;
    TEXTMETRIC tm;

    GetTextExtentPoint(GetHdc(), string, string.length(), &sizeRect);
    GetTextMetrics(GetHdc(), &tm);

    if (x)
        *x = sizeRect.cx;
    if (y)
        *y = sizeRect.cy;
    if (descent)
        *descent = tm.tmDescent;
    if (externalLeading)
        *externalLeading = tm.tmExternalLeading;

    if ( hfontOld )
    {
        ::SelectObject(GetHdc(), hfontOld);
    }
}


// Each element of the array will be the width of the string up to and
// including the coresoponding character in text.

bool wxDC::DoGetPartialTextExtents(const wxString& text, wxArrayInt& widths) const
{
    static int maxLenText = -1;
    static int maxWidth = -1;
    int fit = 0;
    SIZE sz = {0,0};
    int stlen = text.Length();

    if (maxLenText == -1)
    {
        // Win9x and WinNT+ have different limits
        int version = wxGetOsVersion();
        maxLenText = version == wxWINDOWS_NT ? 65535 : 8192;
        maxWidth =   version == wxWINDOWS_NT ? INT_MAX : 32767;
    }

    widths.Empty();
    widths.Add(0, stlen);  // fill the array with zeros

    if (!::GetTextExtentExPoint(GetHdc(),
                                text.c_str(),           // string to check
                                wxMin(stlen, maxLenText),
                                maxWidth,
                                &fit,                   // [out] count of chars
                                                        // that will fit
                                &widths[0],             // array to fill
                                &sz))
    {
        // API failed
        wxLogLastError(wxT("GetTextExtentExPoint"));
        return false;
    }

    return true;
}




void wxDC::SetMapMode(int mode)
{
    WXMICROWIN_CHECK_HDC

    m_mappingMode = mode;

    if ( mode == wxMM_TEXT )
    {
        m_logicalScaleX =
        m_logicalScaleY = 1.0;
    }
    else // need to do some calculations
    {
        int pixel_width = ::GetDeviceCaps(GetHdc(), HORZRES),
            pixel_height = ::GetDeviceCaps(GetHdc(), VERTRES),
            mm_width = ::GetDeviceCaps(GetHdc(), HORZSIZE),
            mm_height = ::GetDeviceCaps(GetHdc(), VERTSIZE);

        if ( (mm_width == 0) || (mm_height == 0) )
        {
            // we can't calculate mm2pixels[XY] then!
            return;
        }

        double mm2pixelsX = (double)pixel_width / mm_width,
               mm2pixelsY = (double)pixel_height / mm_height;

        switch (mode)
        {
            case wxMM_TWIPS:
                m_logicalScaleX = twips2mm * mm2pixelsX;
                m_logicalScaleY = twips2mm * mm2pixelsY;
                break;

            case wxMM_POINTS:
                m_logicalScaleX = pt2mm * mm2pixelsX;
                m_logicalScaleY = pt2mm * mm2pixelsY;
                break;

            case wxMM_METRIC:
                m_logicalScaleX = mm2pixelsX;
                m_logicalScaleY = mm2pixelsY;
                break;

            case wxMM_LOMETRIC:
                m_logicalScaleX = mm2pixelsX / 10.0;
                m_logicalScaleY = mm2pixelsY / 10.0;
                break;

            default:
                wxFAIL_MSG( _T("unknown mapping mode in SetMapMode") );
        }
    }

    // VZ: it seems very wasteful to always use MM_ANISOTROPIC when in 99% of
    //     cases we could do with MM_TEXT and in the remaining 0.9% with
    //     MM_ISOTROPIC (TODO!)
#ifndef __WXWINCE__
    ::SetMapMode(GetHdc(), MM_ANISOTROPIC);

    int width = DeviceToLogicalXRel(VIEWPORT_EXTENT)*m_signX,
        height = DeviceToLogicalYRel(VIEWPORT_EXTENT)*m_signY;

    ::SetViewportExtEx(GetHdc(), VIEWPORT_EXTENT, VIEWPORT_EXTENT, NULL);
    ::SetWindowExtEx(GetHdc(), width, height, NULL);

    ::SetViewportOrgEx(GetHdc(), m_deviceOriginX, m_deviceOriginY, NULL);
    ::SetWindowOrgEx(GetHdc(), m_logicalOriginX, m_logicalOriginY, NULL);
#endif
}

void wxDC::SetUserScale(double x, double y)
{
    WXMICROWIN_CHECK_HDC

    if ( x == m_userScaleX && y == m_userScaleY )
        return;

    m_userScaleX = x;
    m_userScaleY = y;

    this->SetMapMode(m_mappingMode);
}

void wxDC::SetAxisOrientation(bool xLeftRight, bool yBottomUp)
{
    WXMICROWIN_CHECK_HDC

#ifndef __WXWINCE__
    int signX = xLeftRight ? 1 : -1,
        signY = yBottomUp ? -1 : 1;

    if ( signX != m_signX || signY != m_signY )
    {
        m_signX = signX;
        m_signY = signY;

        SetMapMode(m_mappingMode);
    }
#else
    wxUnusedVar(xLeftRight);
    wxUnusedVar(yBottomUp);
#endif
}

void wxDC::SetSystemScale(double x, double y)
{
    WXMICROWIN_CHECK_HDC

    if ( x == m_scaleX && y == m_scaleY )
        return;

    m_scaleX = x;
    m_scaleY = y;

#ifndef __WXWINCE__
    SetMapMode(m_mappingMode);
#endif
}

void wxDC::SetLogicalOrigin(wxCoord x, wxCoord y)
{
    WXMICROWIN_CHECK_HDC

    if ( x == m_logicalOriginX && y == m_logicalOriginY )
        return;

    m_logicalOriginX = x;
    m_logicalOriginY = y;

#ifndef __WXWINCE__
    ::SetWindowOrgEx(GetHdc(), (int)m_logicalOriginX, (int)m_logicalOriginY, NULL);
#endif
}

void wxDC::SetDeviceOrigin(wxCoord x, wxCoord y)
{
    WXMICROWIN_CHECK_HDC

    if ( x == m_deviceOriginX && y == m_deviceOriginY )
        return;

    m_deviceOriginX = x;
    m_deviceOriginY = y;

#ifndef __WXWINCE__
    ::SetViewportOrgEx(GetHdc(), (int)m_deviceOriginX, (int)m_deviceOriginY, NULL);
#endif
}

// ---------------------------------------------------------------------------
// coordinates transformations
// ---------------------------------------------------------------------------

wxCoord wxDCBase::DeviceToLogicalX(wxCoord x) const
{
    return DeviceToLogicalXRel(x - m_deviceOriginX)*m_signX + m_logicalOriginX;
}

wxCoord wxDCBase::DeviceToLogicalXRel(wxCoord x) const
{
    // axis orientation is not taken into account for conversion of a distance
    return (wxCoord)(x / (m_logicalScaleX*m_userScaleX*m_scaleX));
}

wxCoord wxDCBase::DeviceToLogicalY(wxCoord y) const
{
    return DeviceToLogicalYRel(y - m_deviceOriginY)*m_signY + m_logicalOriginY;
}

wxCoord wxDCBase::DeviceToLogicalYRel(wxCoord y) const
{
    // axis orientation is not taken into account for conversion of a distance
    return (wxCoord)( y / (m_logicalScaleY*m_userScaleY*m_scaleY));
}

wxCoord wxDCBase::LogicalToDeviceX(wxCoord x) const
{
    return LogicalToDeviceXRel(x - m_logicalOriginX)*m_signX + m_deviceOriginX;
}

wxCoord wxDCBase::LogicalToDeviceXRel(wxCoord x) const
{
    // axis orientation is not taken into account for conversion of a distance
    return (wxCoord) (x*m_logicalScaleX*m_userScaleX*m_scaleX);
}

wxCoord wxDCBase::LogicalToDeviceY(wxCoord y) const
{
    return LogicalToDeviceYRel(y - m_logicalOriginY)*m_signY + m_deviceOriginY;
}

wxCoord wxDCBase::LogicalToDeviceYRel(wxCoord y) const
{
    // axis orientation is not taken into account for conversion of a distance
    return (wxCoord) (y*m_logicalScaleY*m_userScaleY*m_scaleY);
}

// ---------------------------------------------------------------------------
// bit blit
// ---------------------------------------------------------------------------

bool wxDC::DoBlit(wxCoord xdest, wxCoord ydest,
                  wxCoord width, wxCoord height,
                  wxDC *source, wxCoord xsrc, wxCoord ysrc,
                  int rop, bool useMask,
                  wxCoord xsrcMask, wxCoord ysrcMask)
{
    wxCHECK_MSG( source, false, _T("wxDC::Blit(): NULL wxDC pointer") );

    WXMICROWIN_CHECK_HDC_RET(false)

    // if either the source or destination has alpha channel, we must use
    // AlphaBlt() as other function don't handle it correctly
    const wxBitmap& bmpSrc = source->m_selectedBitmap;
    if ( bmpSrc.Ok() && (bmpSrc.HasAlpha() ||
            (m_selectedBitmap.Ok() && m_selectedBitmap.HasAlpha())) )
    {
        if ( AlphaBlt(GetHdc(), xdest, ydest, width, height,
                      GetHdcOf(*source), bmpSrc) )
            return true;
    }

    wxMask *mask = NULL;
    if ( useMask )
    {
        mask = bmpSrc.GetMask();

        if ( !(bmpSrc.Ok() && mask && mask->GetMaskBitmap()) )
        {
            // don't give assert here because this would break existing
            // programs - just silently ignore useMask parameter
            useMask = false;
        }
    }

    if (xsrcMask == -1 && ysrcMask == -1)
    {
        xsrcMask = xsrc; ysrcMask = ysrc;
    }

    COLORREF old_textground = ::GetTextColor(GetHdc());
    COLORREF old_background = ::GetBkColor(GetHdc());
    if (m_textForegroundColour.Ok())
    {
        ::SetTextColor(GetHdc(), m_textForegroundColour.GetPixel() );
    }
    if (m_textBackgroundColour.Ok())
    {
        ::SetBkColor(GetHdc(), m_textBackgroundColour.GetPixel() );
    }

    DWORD dwRop;
    switch (rop)
    {
        case wxXOR:          dwRop = SRCINVERT;        break;
        case wxINVERT:       dwRop = DSTINVERT;        break;
        case wxOR_REVERSE:   dwRop = 0x00DD0228;       break;
        case wxAND_REVERSE:  dwRop = SRCERASE;         break;
        case wxCLEAR:        dwRop = BLACKNESS;        break;
        case wxSET:          dwRop = WHITENESS;        break;
        case wxOR_INVERT:    dwRop = MERGEPAINT;       break;
        case wxAND:          dwRop = SRCAND;           break;
        case wxOR:           dwRop = SRCPAINT;         break;
        case wxEQUIV:        dwRop = 0x00990066;       break;
        case wxNAND:         dwRop = 0x007700E6;       break;
        case wxAND_INVERT:   dwRop = 0x00220326;       break;
        case wxCOPY:         dwRop = SRCCOPY;          break;
        case wxNO_OP:        dwRop = DSTCOPY;          break;
        case wxSRC_INVERT:   dwRop = NOTSRCCOPY;       break;
        case wxNOR:          dwRop = NOTSRCCOPY;       break;
        default:
           wxFAIL_MSG( wxT("unsupported logical function") );
           return false;
    }

    bool success = false;

    if (useMask)
    {
#ifdef __WIN32__
        // we want the part of the image corresponding to the mask to be
        // transparent, so use "DSTCOPY" ROP for the mask points (the usual
        // meaning of fg and bg is inverted which corresponds to wxWin notion
        // of the mask which is also contrary to the Windows one)

        // On some systems, MaskBlt succeeds yet is much much slower
        // than the wxWidgets fall-back implementation. So we need
        // to be able to switch this on and off at runtime.
#if wxUSE_SYSTEM_OPTIONS
        if (wxSystemOptions::GetOptionInt(wxT("no-maskblt")) == 0)
#endif
        {
           success = ::MaskBlt
                       (
                            GetHdc(),
                            xdest, ydest, width, height,
                            GetHdcOf(*source),
                            xsrc, ysrc,
                            (HBITMAP)mask->GetMaskBitmap(),
                            xsrcMask, ysrcMask,
                            MAKEROP4(dwRop, DSTCOPY)
                        ) != 0;
        }

        if ( !success )
#endif // Win32
        {
            // Blit bitmap with mask
            HDC dc_mask ;
            HDC  dc_buffer ;
            HBITMAP buffer_bmap ;

#if wxUSE_DC_CACHEING
            // create a temp buffer bitmap and DCs to access it and the mask
            wxDCCacheEntry* dcCacheEntry1 = FindDCInCache(NULL, source->GetHDC());
            dc_mask = (HDC) dcCacheEntry1->m_dc;

            wxDCCacheEntry* dcCacheEntry2 = FindDCInCache(dcCacheEntry1, GetHDC());
            dc_buffer = (HDC) dcCacheEntry2->m_dc;

            wxDCCacheEntry* bitmapCacheEntry = FindBitmapInCache(GetHDC(),
                width, height);

            buffer_bmap = (HBITMAP) bitmapCacheEntry->m_bitmap;
#else // !wxUSE_DC_CACHEING
            // create a temp buffer bitmap and DCs to access it and the mask
            dc_mask = ::CreateCompatibleDC(GetHdcOf(*source));
            dc_buffer = ::CreateCompatibleDC(GetHdc());
            buffer_bmap = ::CreateCompatibleBitmap(GetHdc(), width, height);
#endif // wxUSE_DC_CACHEING/!wxUSE_DC_CACHEING
            HGDIOBJ hOldMaskBitmap = ::SelectObject(dc_mask, (HBITMAP) mask->GetMaskBitmap());
            HGDIOBJ hOldBufferBitmap = ::SelectObject(dc_buffer, buffer_bmap);

            // copy dest to buffer
            if ( !::BitBlt(dc_buffer, 0, 0, (int)width, (int)height,
                           GetHdc(), xdest, ydest, SRCCOPY) )
            {
                wxLogLastError(wxT("BitBlt"));
            }

            // copy src to buffer using selected raster op
            if ( !::BitBlt(dc_buffer, 0, 0, (int)width, (int)height,
                           GetHdcOf(*source), xsrc, ysrc, dwRop) )
            {
                wxLogLastError(wxT("BitBlt"));
            }

            // set masked area in buffer to BLACK (pixel value 0)
            COLORREF prevBkCol = ::SetBkColor(GetHdc(), RGB(255, 255, 255));
            COLORREF prevCol = ::SetTextColor(GetHdc(), RGB(0, 0, 0));
            if ( !::BitBlt(dc_buffer, 0, 0, (int)width, (int)height,
                           dc_mask, xsrcMask, ysrcMask, SRCAND) )
            {
                wxLogLastError(wxT("BitBlt"));
            }

            // set unmasked area in dest to BLACK
            ::SetBkColor(GetHdc(), RGB(0, 0, 0));
            ::SetTextColor(GetHdc(), RGB(255, 255, 255));
            if ( !::BitBlt(GetHdc(), xdest, ydest, (int)width, (int)height,
                           dc_mask, xsrcMask, ysrcMask, SRCAND) )
            {
                wxLogLastError(wxT("BitBlt"));
            }
            ::SetBkColor(GetHdc(), prevBkCol);   // restore colours to original values
            ::SetTextColor(GetHdc(), prevCol);

            // OR buffer to dest
            success = ::BitBlt(GetHdc(), xdest, ydest,
                               (int)width, (int)height,
                               dc_buffer, 0, 0, SRCPAINT) != 0;
            if ( !success )
            {
                wxLogLastError(wxT("BitBlt"));
            }

            // tidy up temporary DCs and bitmap
            ::SelectObject(dc_mask, hOldMaskBitmap);
            ::SelectObject(dc_buffer, hOldBufferBitmap);

#if !wxUSE_DC_CACHEING
            {
                ::DeleteDC(dc_mask);
                ::DeleteDC(dc_buffer);
                ::DeleteObject(buffer_bmap);
            }
#endif
        }
    }
    else // no mask, just BitBlt() it
    {
        // if we already have a DIB, draw it using StretchDIBits(), otherwise
        // use StretchBlt() if available and finally fall back to BitBlt()

        // FIXME: use appropriate WinCE functions
#ifndef __WXWINCE__
        const int caps = ::GetDeviceCaps(GetHdc(), RASTERCAPS);
        if ( bmpSrc.Ok() && (caps & RC_STRETCHDIB) )
        {
            DIBSECTION ds;
            wxZeroMemory(ds);

            if ( ::GetObject(GetHbitmapOf(bmpSrc),
                             sizeof(ds),
                             &ds) == sizeof(ds) )
            {
                StretchBltModeChanger changeMode(GetHdc(), COLORONCOLOR);

                // Figure out what co-ordinate system we're supposed to specify
                // ysrc in.
                const LONG hDIB = ds.dsBmih.biHeight;
                if ( hDIB > 0 )
                {
                    // reflect ysrc
                    ysrc = hDIB - (ysrc + height);
                }

                if ( ::StretchDIBits(GetHdc(),
                                     xdest, ydest,
                                     width, height,
                                     xsrc, ysrc,
                                     width, height,
                                     ds.dsBm.bmBits,
                                     (LPBITMAPINFO)&ds.dsBmih,
                                     DIB_RGB_COLORS,
                                     SRCCOPY
                                     ) == (int)GDI_ERROR )
                {
                    // On Win9x this API fails most (all?) of the time, so
                    // logging it becomes quite distracting.  Since it falls
                    // back to the code below this is not really serious, so
                    // don't log it.
                    //wxLogLastError(wxT("StretchDIBits"));
                }
                else
                {
                    success = true;
                }
            }
        }

        if ( !success && (caps & RC_STRETCHBLT) )
#endif
        // __WXWINCE__
        {
#ifndef __WXWINCE__
            StretchBltModeChanger changeMode(GetHdc(), COLORONCOLOR);
#endif

            if ( !::StretchBlt
                    (
                        GetHdc(),
                        xdest, ydest, width, height,
                        GetHdcOf(*source),
                        xsrc, ysrc, width, height,
                        dwRop
                    ) )
            {
                wxLogLastError(_T("StretchBlt"));
            }
            else
            {
                success = true;
            }
        }

        if ( !success )
        {
            if ( !::BitBlt
                    (
                        GetHdc(),
                        xdest, ydest,
                        (int)width, (int)height,
                        GetHdcOf(*source),
                        xsrc, ysrc,
                        dwRop
                    ) )
            {
                wxLogLastError(_T("BitBlt"));
            }
            else
            {
                success = true;
            }
        }
    }

    ::SetTextColor(GetHdc(), old_textground);
    ::SetBkColor(GetHdc(), old_background);

    return success;
}

void wxDC::DoGetSize(int *w, int *h) const
{
    WXMICROWIN_CHECK_HDC

    if ( w ) *w = ::GetDeviceCaps(GetHdc(), HORZRES);
    if ( h ) *h = ::GetDeviceCaps(GetHdc(), VERTRES);
}

void wxDC::DoGetSizeMM(int *w, int *h) const
{
    WXMICROWIN_CHECK_HDC

    // if we implement it in terms of DoGetSize() instead of directly using the
    // results returned by GetDeviceCaps(HORZ/VERTSIZE) as was done before, it
    // will also work for wxWindowDC and wxClientDC even though their size is
    // not the same as the total size of the screen
    int wPixels, hPixels;
    DoGetSize(&wPixels, &hPixels);

    if ( w )
    {
        int wTotal = ::GetDeviceCaps(GetHdc(), HORZRES);

        wxCHECK_RET( wTotal, _T("0 width device?") );

        *w = (wPixels * ::GetDeviceCaps(GetHdc(), HORZSIZE)) / wTotal;
    }

    if ( h )
    {
        int hTotal = ::GetDeviceCaps(GetHdc(), VERTRES);

        wxCHECK_RET( hTotal, _T("0 height device?") );

        *h = (hPixels * ::GetDeviceCaps(GetHdc(), VERTSIZE)) / hTotal;
    }
}

wxSize wxDC::GetPPI() const
{
    WXMICROWIN_CHECK_HDC_RET(wxSize())

    int x = ::GetDeviceCaps(GetHdc(), LOGPIXELSX);
    int y = ::GetDeviceCaps(GetHdc(), LOGPIXELSY);

    return wxSize(x, y);
}

// For use by wxWidgets only, unless custom units are required.
void wxDC::SetLogicalScale(double x, double y)
{
    WXMICROWIN_CHECK_HDC

    m_logicalScaleX = x;
    m_logicalScaleY = y;
}

// ----------------------------------------------------------------------------
// DC caching
// ----------------------------------------------------------------------------

#if wxUSE_DC_CACHEING

/*
 * This implementation is a bit ugly and uses the old-fashioned wxList class, so I will
 * improve it in due course, either using arrays, or simply storing pointers to one
 * entry for the bitmap, and two for the DCs. -- JACS
 */

wxList wxDC::sm_bitmapCache;
wxList wxDC::sm_dcCache;

wxDCCacheEntry::wxDCCacheEntry(WXHBITMAP hBitmap, int w, int h, int depth)
{
    m_bitmap = hBitmap;
    m_dc = 0;
    m_width = w;
    m_height = h;
    m_depth = depth;
}

wxDCCacheEntry::wxDCCacheEntry(WXHDC hDC, int depth)
{
    m_bitmap = 0;
    m_dc = hDC;
    m_width = 0;
    m_height = 0;
    m_depth = depth;
}

wxDCCacheEntry::~wxDCCacheEntry()
{
    if (m_bitmap)
        ::DeleteObject((HBITMAP) m_bitmap);
    if (m_dc)
        ::DeleteDC((HDC) m_dc);
}

wxDCCacheEntry* wxDC::FindBitmapInCache(WXHDC dc, int w, int h)
{
    int depth = ::GetDeviceCaps((HDC) dc, PLANES) * ::GetDeviceCaps((HDC) dc, BITSPIXEL);
    wxList::compatibility_iterator node = sm_bitmapCache.GetFirst();
    while (node)
    {
        wxDCCacheEntry* entry = (wxDCCacheEntry*) node->GetData();

        if (entry->m_depth == depth)
        {
            if (entry->m_width < w || entry->m_height < h)
            {
                ::DeleteObject((HBITMAP) entry->m_bitmap);
                entry->m_bitmap = (WXHBITMAP) ::CreateCompatibleBitmap((HDC) dc, w, h);
                if ( !entry->m_bitmap)
                {
                    wxLogLastError(wxT("CreateCompatibleBitmap"));
                }
                entry->m_width = w; entry->m_height = h;
                return entry;
            }
            return entry;
        }

        node = node->GetNext();
    }
    WXHBITMAP hBitmap = (WXHBITMAP) ::CreateCompatibleBitmap((HDC) dc, w, h);
    if ( !hBitmap)
    {
        wxLogLastError(wxT("CreateCompatibleBitmap"));
    }
    wxDCCacheEntry* entry = new wxDCCacheEntry(hBitmap, w, h, depth);
    AddToBitmapCache(entry);
    return entry;
}

wxDCCacheEntry* wxDC::FindDCInCache(wxDCCacheEntry* notThis, WXHDC dc)
{
    int depth = ::GetDeviceCaps((HDC) dc, PLANES) * ::GetDeviceCaps((HDC) dc, BITSPIXEL);
    wxList::compatibility_iterator node = sm_dcCache.GetFirst();
    while (node)
    {
        wxDCCacheEntry* entry = (wxDCCacheEntry*) node->GetData();

        // Don't return the same one as we already have
        if (!notThis || (notThis != entry))
        {
            if (entry->m_depth == depth)
            {
                return entry;
            }
        }

        node = node->GetNext();
    }
    WXHDC hDC = (WXHDC) ::CreateCompatibleDC((HDC) dc);
    if ( !hDC)
    {
        wxLogLastError(wxT("CreateCompatibleDC"));
    }
    wxDCCacheEntry* entry = new wxDCCacheEntry(hDC, depth);
    AddToDCCache(entry);
    return entry;
}

void wxDC::AddToBitmapCache(wxDCCacheEntry* entry)
{
    sm_bitmapCache.Append(entry);
}

void wxDC::AddToDCCache(wxDCCacheEntry* entry)
{
    sm_dcCache.Append(entry);
}

void wxDC::ClearCache()
{
    WX_CLEAR_LIST(wxList, sm_dcCache);
    WX_CLEAR_LIST(wxList, sm_bitmapCache);
}

// Clean up cache at app exit
class wxDCModule : public wxModule
{
public:
    virtual bool OnInit() { return true; }
    virtual void OnExit() { wxDC::ClearCache(); }

private:
    DECLARE_DYNAMIC_CLASS(wxDCModule)
};

IMPLEMENT_DYNAMIC_CLASS(wxDCModule, wxModule)

#endif // wxUSE_DC_CACHEING

// ----------------------------------------------------------------------------
// alpha channel support
// ----------------------------------------------------------------------------

static bool AlphaBlt(HDC hdcDst,
                     int x, int y, int width, int height,
                     HDC hdcSrc,
                     const wxBitmap& bmp)
{
    wxASSERT_MSG( bmp.Ok() && bmp.HasAlpha(), _T("AlphaBlt(): invalid bitmap") );
    wxASSERT_MSG( hdcDst && hdcSrc, _T("AlphaBlt(): invalid HDC") );

    // do we have AlphaBlend() and company in the headers?
#if defined(AC_SRC_OVER) && wxUSE_DYNLIB_CLASS
    // yes, now try to see if we have it during run-time
    typedef BOOL (WINAPI *AlphaBlend_t)(HDC,int,int,int,int,
                                        HDC,int,int,int,int,
                                        BLENDFUNCTION);

    // bitmaps can be drawn only from GUI thread so there is no need to
    // protect this static variable from multiple threads
    static bool s_triedToLoad = false;
    static AlphaBlend_t pfnAlphaBlend = NULL;
    if ( !s_triedToLoad )
    {
        s_triedToLoad = true;

        // don't give errors about the DLL being unavailable, we're
        // prepared to handle this
        wxLogNull nolog;

        wxDynamicLibrary dll(_T("msimg32.dll"));
        if ( dll.IsLoaded() )
        {
            pfnAlphaBlend = (AlphaBlend_t)dll.GetSymbol(_T("AlphaBlend"));
            if ( pfnAlphaBlend )
            {
                // we must keep the DLL loaded if we want to be able to
                // call AlphaBlend() so just never unload it at all, not a
                // big deal
                dll.Detach();
            }
        }
    }

    if ( pfnAlphaBlend )
    {
        BLENDFUNCTION bf;
        bf.BlendOp = AC_SRC_OVER;
        bf.BlendFlags = 0;
        bf.SourceConstantAlpha = 0xff;
        bf.AlphaFormat = AC_SRC_ALPHA;

        if ( pfnAlphaBlend(hdcDst, x, y, width, height,
                           hdcSrc, 0, 0, width, height,
                           bf) )
        {
            // skip wxAlphaBlend() call below
            return true;
        }

        wxLogLastError(_T("AlphaBlend"));
    }
#endif // defined(AC_SRC_OVER)

    // AlphaBlend() unavailable of failed: use our own (probably much slower)
    // implementation
#ifdef wxHAVE_RAW_BITMAP
    wxAlphaBlend(hdcDst, x, y, width, height, bmp);

    return true;
#else // !wxHAVE_RAW_BITMAP
    // no wxAlphaBlend() neither, fall back to using simple BitBlt() (we lose
    // alpha but at least something will be shown like this)
    wxUnusedVar(bmp);
    return false;
#endif // wxHAVE_RAW_BITMAP
}


// wxAlphaBlend: our fallback if ::AlphaBlend() is unavailable
#ifdef wxHAVE_RAW_BITMAP

static void
wxAlphaBlend(HDC hdcDst, int xDst, int yDst, int w, int h, const wxBitmap& bmpSrc)
{
    // get the destination DC pixels
    wxBitmap bmpDst(w, h, 32 /* force creating RGBA DIB */);
    MemoryHDC hdcMem;
    SelectInHDC select(hdcMem, GetHbitmapOf(bmpDst));

    if ( !::BitBlt(hdcMem, 0, 0, w, h, hdcDst, 0, 0, SRCCOPY) )
    {
        wxLogLastError(_T("BitBlt"));
    }

    // combine them with the source bitmap using alpha
    wxAlphaPixelData dataDst(bmpDst),
                     dataSrc((wxBitmap &)bmpSrc);

    wxCHECK_RET( dataDst && dataSrc,
                    _T("failed to get raw data in wxAlphaBlend") );

    wxAlphaPixelData::Iterator pDst(dataDst),
                               pSrc(dataSrc);

    for ( int y = 0; y < h; y++ )
    {
        wxAlphaPixelData::Iterator pDstRowStart = pDst,
                                   pSrcRowStart = pSrc;

        for ( int x = 0; x < w; x++ )
        {
            // note that source bitmap uses premultiplied alpha (as required by
            // the real AlphaBlend)
            const unsigned beta = 255 - pSrc.Alpha();

            pDst.Red() = pSrc.Red() + (beta * pDst.Red() + 127) / 255;
            pDst.Blue() = pSrc.Blue() + (beta * pDst.Blue() + 127) / 255;
            pDst.Green() = pSrc.Green() + (beta * pDst.Green() + 127) / 255;

            ++pDst;
            ++pSrc;
        }

        pDst = pDstRowStart;
        pSrc = pSrcRowStart;
        pDst.OffsetY(dataDst, 1);
        pSrc.OffsetY(dataSrc, 1);
    }

    // and finally blit them back to the destination DC
    if ( !::BitBlt(hdcDst, xDst, yDst, w, h, hdcMem, 0, 0, SRCCOPY) )
    {
        wxLogLastError(_T("BitBlt"));
    }
}

#endif // #ifdef wxHAVE_RAW_BITMAP
