X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/7ecf5ac7cd334ba3f447625dd7d970d62c302fcc..491b5be8305968871bc289453ed088a70c3de044:/src/msw/dc.cpp

diff --git a/src/msw/dc.cpp b/src/msw/dc.cpp
index 0bbb739078..0f31dee21b 100644
--- a/src/msw/dc.cpp
+++ b/src/msw/dc.cpp
@@ -40,8 +40,9 @@
     #include "wx/icon.h"
 #endif
 
-#include "wx/settings.h"
+#include "wx/sysopt.h"
 #include "wx/dcprint.h"
+#include "wx/module.h"
 
 #include <string.h>
 #include <math.h>
@@ -266,6 +267,10 @@ void wxDC::SelectOldObjects(WXHDC dc)
 
 void wxDC::UpdateClipBox()
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     RECT rect;
     GetClipBox(GetHdc(), &rect);
 
@@ -277,6 +282,10 @@ void wxDC::UpdateClipBox()
 
 void wxDC::DoSetClippingRegion(wxCoord x, wxCoord y, wxCoord w, wxCoord h)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     m_clipping = TRUE;
 
     // the region coords are always the device ones, so do the translation
@@ -305,6 +314,10 @@ void wxDC::DoSetClippingRegion(wxCoord x, wxCoord y, wxCoord w, wxCoord h)
 
 void wxDC::DoSetClippingRegionAsRegion(const wxRegion& region)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     wxCHECK_RET( GetHrgnOf(region), wxT("invalid clipping region") );
 
     m_clipping = TRUE;
@@ -320,6 +333,10 @@ void wxDC::DoSetClippingRegionAsRegion(const wxRegion& region)
 
 void wxDC::DestroyClippingRegion()
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     if (m_clipping && m_hDC)
     {
         // TODO: this should restore the previous clipping region,
@@ -357,6 +374,10 @@ bool wxDC::CanGetTextExtent() const
 
 int wxDC::GetDepth() const
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return 16;
+#endif
+    
     return (int)::GetDeviceCaps(GetHdc(), BITSPIXEL);
 }
 
@@ -366,6 +387,10 @@ int wxDC::GetDepth() const
 
 void wxDC::Clear()
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     RECT rect;
     if ( m_canvas )
     {
@@ -400,6 +425,10 @@ void wxDC::Clear()
 
 void wxDC::DoFloodFill(wxCoord x, wxCoord y, const wxColour& col, int style)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     if ( !::ExtFloodFill(GetHdc(), XLOG2DEV(x), YLOG2DEV(y),
                          col.GetPixel(),
                          style == wxFLOOD_SURFACE ? FLOODFILLSURFACE
@@ -425,6 +454,10 @@ void wxDC::DoFloodFill(wxCoord x, wxCoord y, const wxColour& col, int style)
 
 bool wxDC::DoGetPixel(wxCoord x, wxCoord y, wxColour *col) const
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return FALSE;
+#endif
+    
     wxCHECK_MSG( col, FALSE, _T("NULL colour parameter in wxDC::GetPixel") );
 
     // get the color of the pixel
@@ -437,6 +470,10 @@ bool wxDC::DoGetPixel(wxCoord x, wxCoord y, wxColour *col) const
 
 void wxDC::DoCrossHair(wxCoord x, wxCoord y)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     wxCoord x1 = x-VIEWPORT_EXTENT;
     wxCoord y1 = y-VIEWPORT_EXTENT;
     wxCoord x2 = x+VIEWPORT_EXTENT;
@@ -454,6 +491,10 @@ void wxDC::DoCrossHair(wxCoord x, wxCoord y)
 
 void wxDC::DoDrawLine(wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     (void)MoveToEx(GetHdc(), XLOG2DEV(x1), YLOG2DEV(y1), NULL);
     (void)LineTo(GetHdc(), XLOG2DEV(x2), YLOG2DEV(y2));
 
@@ -471,6 +512,10 @@ void wxDC::DoDrawArc(wxCoord x1, wxCoord y1,
                      wxCoord x2, wxCoord y2,
                      wxCoord xc, wxCoord yc)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     wxColourChanger cc(*this); // needed for wxSTIPPLE_MASK_OPAQUE handling
 
     double dx = xc - x1;
@@ -519,6 +564,10 @@ void wxDC::DoDrawArc(wxCoord x1, wxCoord y1,
 void wxDC::DoDrawCheckMark(wxCoord x1, wxCoord y1,
                            wxCoord width, wxCoord height)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     wxCoord x2 = x1 + width,
             y2 = y1 + height;
 
@@ -553,6 +602,10 @@ void wxDC::DoDrawCheckMark(wxCoord x1, wxCoord y1,
 
 void wxDC::DoDrawPoint(wxCoord x, wxCoord y)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     COLORREF color = 0x00ffffff;
     if (m_pen.Ok())
     {
@@ -566,6 +619,10 @@ void wxDC::DoDrawPoint(wxCoord x, wxCoord y)
 
 void wxDC::DoDrawPolygon(int n, wxPoint points[], wxCoord xoffset, wxCoord yoffset,int fillStyle)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     wxColourChanger cc(*this); // needed for wxSTIPPLE_MASK_OPAQUE handling
 
     // Do things less efficiently if we have offsets
@@ -599,6 +656,10 @@ void wxDC::DoDrawPolygon(int n, wxPoint points[], wxCoord xoffset, wxCoord yoffs
 
 void wxDC::DoDrawLines(int n, wxPoint points[], wxCoord xoffset, wxCoord yoffset)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     // Do things less efficiently if we have offsets
     if (xoffset != 0 || yoffset != 0)
     {
@@ -626,6 +687,10 @@ void wxDC::DoDrawLines(int n, wxPoint points[], wxCoord xoffset, wxCoord yoffset
 
 void wxDC::DoDrawRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     wxColourChanger cc(*this); // needed for wxSTIPPLE_MASK_OPAQUE handling
 
     wxCoord x2 = x + width;
@@ -663,6 +728,10 @@ void wxDC::DoDrawRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 
 void wxDC::DoDrawRoundedRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height, double radius)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     wxColourChanger cc(*this); // needed for wxSTIPPLE_MASK_OPAQUE handling
 
     // Now, a negative radius value is interpreted to mean
@@ -699,6 +768,10 @@ void wxDC::DoDrawRoundedRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord h
 
 void wxDC::DoDrawEllipse(wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     wxColourChanger cc(*this); // needed for wxSTIPPLE_MASK_OPAQUE handling
 
     wxCoord x2 = (x+width);
@@ -713,6 +786,10 @@ void wxDC::DoDrawEllipse(wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 // 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 __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     wxColourChanger cc(*this); // needed for wxSTIPPLE_MASK_OPAQUE handling
 
     wxCoord x2 = x + w;
@@ -756,6 +833,10 @@ void wxDC::DoDrawEllipticArc(wxCoord x,wxCoord y,wxCoord w,wxCoord h,double sa,d
 
 void wxDC::DoDrawIcon(const wxIcon& icon, wxCoord x, wxCoord y)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     wxCHECK_RET( icon.Ok(), wxT("invalid icon in DrawIcon") );
 
 #ifdef __WIN32__
@@ -770,6 +851,10 @@ void wxDC::DoDrawIcon(const wxIcon& icon, wxCoord x, wxCoord y)
 
 void wxDC::DoDrawBitmap( const wxBitmap &bmp, wxCoord x, wxCoord y, bool useMask )
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     wxCHECK_RET( bmp.Ok(), _T("invalid bitmap in wxDC::DrawBitmap") );
 
     int width = bmp.GetWidth(),
@@ -800,7 +885,9 @@ void wxDC::DoDrawBitmap( const wxBitmap &bmp, wxCoord x, wxCoord y, bool useMask
         // than the wxWindows fall-back implementation. So we need
         // to be able to switch this on and off at runtime.
         bool ok = FALSE;
-        if (wxSystemSettings::GetOptionInt(wxT("no-maskblt")) == 0)
+#if wxUSE_SYSTEM_OPTIONS
+        if (wxSystemOptions::GetOptionInt(wxT("no-maskblt")) == 0)
+#endif
         {
             HDC hdcMem = ::CreateCompatibleDC(GetHdc());
             ::SelectObject(hdcMem, GetHbitmapOf(bmp));
@@ -855,6 +942,10 @@ void wxDC::DoDrawBitmap( const wxBitmap &bmp, wxCoord x, wxCoord y, bool useMask
 
 void wxDC::DoDrawText(const wxString& text, wxCoord x, wxCoord y)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     DrawAnyText(text, x, y);
 
     // update the bounding box
@@ -867,6 +958,10 @@ void wxDC::DoDrawText(const wxString& text, wxCoord x, wxCoord y)
 
 void wxDC::DrawAnyText(const wxString& text, wxCoord x, wxCoord y)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     // prepare for drawing the text
     if ( m_textForegroundColour.Ok() )
         SetTextColor(GetHdc(), m_textForegroundColour.GetPixel());
@@ -899,6 +994,10 @@ void wxDC::DoDrawRotatedText(const wxString& text,
                              wxCoord x, wxCoord y,
                              double angle)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     // 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
@@ -967,6 +1066,10 @@ void wxDC::DoDrawRotatedText(const wxString& text,
 
 void wxDC::SetPalette(const wxPalette& palette)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     // Set the old object temporarily, in case the assignment deletes an object
     // that's not yet selected out.
     if (m_oldPalette)
@@ -1002,6 +1105,10 @@ void wxDC::SetPalette(const wxPalette& palette)
 
 void wxDC::SetFont(const wxFont& the_font)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     // Set the old object temporarily, in case the assignment deletes an object
     // that's not yet selected out.
     if (m_oldFont)
@@ -1033,6 +1140,10 @@ void wxDC::SetFont(const wxFont& the_font)
 
 void wxDC::SetPen(const wxPen& pen)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     // Set the old object temporarily, in case the assignment deletes an object
     // that's not yet selected out.
     if (m_oldPen)
@@ -1063,6 +1174,10 @@ void wxDC::SetPen(const wxPen& pen)
 
 void wxDC::SetBrush(const wxBrush& brush)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     // Set the old object temporarily, in case the assignment deletes an object
     // that's not yet selected out.
     if (m_oldBrush)
@@ -1110,6 +1225,10 @@ void wxDC::SetBrush(const wxBrush& brush)
 
 void wxDC::SetBackground(const wxBrush& brush)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     m_backgroundBrush = brush;
 
     if (!m_backgroundBrush.Ok())
@@ -1151,6 +1270,10 @@ void wxDC::SetBackground(const wxBrush& brush)
 
 void wxDC::SetBackgroundMode(int mode)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     m_backgroundMode = mode;
 
     // SetBackgroundColour now only refers to text background
@@ -1167,6 +1290,10 @@ void wxDC::SetBackgroundMode(int mode)
 
 void wxDC::SetLogicalFunction(int function)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     m_logicalFunction = function;
 
     SetRop(m_hDC);
@@ -1230,6 +1357,10 @@ void wxDC::EndPage()
 
 wxCoord wxDC::GetCharHeight() const
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return 0;
+#endif
+    
     TEXTMETRIC lpTextMetric;
 
     GetTextMetrics(GetHdc(), &lpTextMetric);
@@ -1239,6 +1370,10 @@ wxCoord wxDC::GetCharHeight() const
 
 wxCoord wxDC::GetCharWidth() const
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return 0;
+#endif
+    
     TEXTMETRIC lpTextMetric;
 
     GetTextMetrics(GetHdc(), &lpTextMetric);
@@ -1250,6 +1385,17 @@ 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
+    
     HFONT hfontOld;
     if ( font )
     {
@@ -1281,6 +1427,10 @@ void wxDC::DoGetTextExtent(const wxString& string, wxCoord *x, wxCoord *y,
 
 void wxDC::SetMapMode(int mode)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     m_mappingMode = mode;
 
     int pixel_width = 0;
@@ -1349,6 +1499,10 @@ void wxDC::SetMapMode(int mode)
 
 void wxDC::SetUserScale(double x, double y)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     m_userScaleX = x;
     m_userScaleY = y;
 
@@ -1357,6 +1511,10 @@ void wxDC::SetUserScale(double x, double y)
 
 void wxDC::SetAxisOrientation(bool xLeftRight, bool yBottomUp)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     m_signX = xLeftRight ? 1 : -1;
     m_signY = yBottomUp ? -1 : 1;
 
@@ -1365,6 +1523,10 @@ void wxDC::SetAxisOrientation(bool xLeftRight, bool yBottomUp)
 
 void wxDC::SetSystemScale(double x, double y)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     m_scaleX = x;
     m_scaleY = y;
 
@@ -1373,6 +1535,10 @@ void wxDC::SetSystemScale(double x, double y)
 
 void wxDC::SetLogicalOrigin(wxCoord x, wxCoord y)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     m_logicalOriginX = x;
     m_logicalOriginY = y;
 
@@ -1381,6 +1547,10 @@ void wxDC::SetLogicalOrigin(wxCoord x, wxCoord y)
 
 void wxDC::SetDeviceOrigin(wxCoord x, wxCoord y)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     m_deviceOriginX = x;
     m_deviceOriginY = y;
 
@@ -1442,8 +1612,13 @@ wxCoord wxDCBase::LogicalToDeviceYRel(wxCoord y) const
 bool wxDC::DoBlit(wxCoord xdest, wxCoord ydest,
                   wxCoord width, wxCoord height,
                   wxDC *source, wxCoord xsrc, wxCoord ysrc,
-                  int rop, bool useMask)
+                  int rop, bool useMask,
+                  wxCoord xsrcMask, wxCoord ysrcMask)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return FALSE;
+#endif
+    
     wxMask *mask = NULL;
     if ( useMask )
     {
@@ -1458,6 +1633,11 @@ bool wxDC::DoBlit(wxCoord xdest, wxCoord ydest,
         }
     }
 
+    if (xsrcMask == -1 && ysrcMask == -1)
+    {
+        xsrcMask = xsrc; ysrcMask = ysrc;
+    }
+
     COLORREF old_textground = ::GetTextColor(GetHdc());
     COLORREF old_background = ::GetBkColor(GetHdc());
     if (m_textForegroundColour.Ok())
@@ -1506,11 +1686,13 @@ bool wxDC::DoBlit(wxCoord xdest, wxCoord ydest,
         // On some systems, MaskBlt succeeds yet is much much slower
         // than the wxWindows fall-back implementation. So we need
         // to be able to switch this on and off at runtime.
-        if (wxSystemSettings::GetOptionInt(wxT("no-maskblt")) == 0)
+#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(), xsrc, ysrc,
+                            (HBITMAP)mask->GetMaskBitmap(), xsrcMask, ysrcMask,
                             MAKEROP4(dwRop, DSTCOPY)) != 0;
         }
 
@@ -1518,13 +1700,35 @@ bool wxDC::DoBlit(wxCoord xdest, wxCoord ydest,
 #endif // Win32
         {
             // Blit bitmap with mask
+            HDC dc_mask ;
+            HDC  dc_buffer ;
+            HBITMAP buffer_bmap ;
 
-            // create a temp buffer bitmap and DCs to access it and the mask
-            HDC dc_mask = ::CreateCompatibleDC(GetHdcOf(*source));
-            HDC dc_buffer = ::CreateCompatibleDC(GetHdc());
-            HBITMAP buffer_bmap = ::CreateCompatibleBitmap(GetHdc(), width, height);
-            ::SelectObject(dc_mask, (HBITMAP) mask->GetMaskBitmap());
-            ::SelectObject(dc_buffer, buffer_bmap);
+#if wxUSE_DC_CACHEING
+            if (TRUE)
+            {
+                // 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
+#endif
+            {
+                // 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);
+                ::SelectObject(dc_mask, (HBITMAP) mask->GetMaskBitmap());
+                ::SelectObject(dc_buffer, buffer_bmap);
+            }
 
             // copy dest to buffer
             if ( !::BitBlt(dc_buffer, 0, 0, (int)width, (int)height,
@@ -1544,7 +1748,7 @@ bool wxDC::DoBlit(wxCoord xdest, wxCoord ydest,
             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, xsrc, ysrc, SRCAND) )
+                           dc_mask, xsrcMask, ysrcMask, SRCAND) )
             {
                 wxLogLastError(wxT("BitBlt"));
             }
@@ -1553,7 +1757,7 @@ bool wxDC::DoBlit(wxCoord xdest, wxCoord ydest,
             ::SetBkColor(GetHdc(), RGB(0, 0, 0));
             ::SetTextColor(GetHdc(), RGB(255, 255, 255));
             if ( !::BitBlt(GetHdc(), xdest, ydest, (int)width, (int)height,
-                           dc_mask, xsrc, ysrc, SRCAND) )
+                           dc_mask, xsrcMask, ysrcMask, SRCAND) )
             {
                 wxLogLastError(wxT("BitBlt"));
             }
@@ -1571,10 +1775,15 @@ bool wxDC::DoBlit(wxCoord xdest, wxCoord ydest,
 
             // tidy up temporary DCs and bitmap
             ::SelectObject(dc_mask, 0);
-            ::DeleteDC(dc_mask);
             ::SelectObject(dc_buffer, 0);
-            ::DeleteDC(dc_buffer);
-            ::DeleteObject(buffer_bmap);
+
+#if !wxUSE_DC_CACHEING
+            {
+                ::DeleteDC(dc_mask);
+                ::DeleteDC(dc_buffer);
+                ::DeleteObject(buffer_bmap);
+            }
+#endif
         }
     }
     else // no mask, just BitBlt() it
@@ -1595,18 +1804,30 @@ bool wxDC::DoBlit(wxCoord xdest, wxCoord ydest,
 
 void wxDC::DoGetSize(int *w, int *h) const
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     if ( w ) *w = ::GetDeviceCaps(GetHdc(), HORZRES);
     if ( h ) *h = ::GetDeviceCaps(GetHdc(), VERTRES);
 }
 
 void wxDC::DoGetSizeMM(int *w, int *h) const
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     if ( w ) *w = ::GetDeviceCaps(GetHdc(), HORZSIZE);
     if ( h ) *h = ::GetDeviceCaps(GetHdc(), VERTSIZE);
 }
 
 wxSize wxDC::GetPPI() const
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return wxSize();
+#endif
+    
     int x = ::GetDeviceCaps(GetHdc(), LOGPIXELSX);
     int y = ::GetDeviceCaps(GetHdc(), LOGPIXELSY);
 
@@ -1616,6 +1837,10 @@ wxSize wxDC::GetPPI() const
 // For use by wxWindows only, unless custom units are required.
 void wxDC::SetLogicalScale(double x, double y)
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     m_logicalScaleX = x;
     m_logicalScaleY = y;
 }
@@ -1625,6 +1850,10 @@ void wxDC::DoGetTextExtent(const wxString& string, float *x, float *y,
                          float *descent, float *externalLeading,
                          wxFont *theFont, bool use16bit) const
 {
+#ifdef __WXMICROWIN__
+    if (!GetHDC()) return;
+#endif
+    
     wxCoord x1, y1, descent1, externalLeading1;
     GetTextExtent(string, & x1, & y1, & descent1, & externalLeading1, theFont, use16bit);
     *x = x1; *y = y1;
@@ -1635,4 +1864,141 @@ void wxDC::DoGetTextExtent(const wxString& string, float *x, float *y,
 }
 #endif
 
+#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);
+    wxNode* node = sm_bitmapCache.First();
+    while (node)
+    {
+        wxDCCacheEntry* entry = (wxDCCacheEntry*) node->Data();
+
+        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->Next();
+    }
+    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);
+    wxNode* node = sm_dcCache.First();
+    while (node)
+    {
+        wxDCCacheEntry* entry = (wxDCCacheEntry*) node->Data();
+
+        // Don't return the same one as we already have
+        if (!notThis || (notThis != entry))
+        {
+            if (entry->m_depth == depth)
+            {
+                return entry;
+            }
+        }
+
+        node = node->Next();
+    }
+    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()
+{
+    sm_bitmapCache.DeleteContents(TRUE);
+    sm_bitmapCache.Clear();
+    sm_bitmapCache.DeleteContents(FALSE);
+    sm_dcCache.DeleteContents(TRUE);
+    sm_dcCache.Clear();
+    sm_dcCache.DeleteContents(FALSE);
+}
+
+// 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