WinCE fixes

[wxWidgets.git] / src / msw / dib.cpp

diff --git a/src/msw/dib.cpp b/src/msw/dib.cpp
index f5abc79777a3741d2fc067c97711fd6ede8697ce..1a57decc31716919a0a84471a63faaa121c1a3a9 100644 (file)
--- a/src/msw/dib.cpp
+++ b/src/msw/dib.cpp
@@ -9,6 +9,12 @@
 // License:     wxWindows licence
 ///////////////////////////////////////////////////////////////////////////////
 
 // License:     wxWindows licence
 ///////////////////////////////////////////////////////////////////////////////
 

+/*
+    TODO: support for palettes is very incomplete, several functions simply
+          ignore them (we should select and realize the palette, if any, before
+          caling GetDIBits() in the DC we use with it.
+ */
+

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


@@ -29,23 +35,50 @@
     #include "wx/log.h"
 #endif //WX_PRECOMP
 
     #include "wx/log.h"
 #endif //WX_PRECOMP
 

+#if wxUSE_WXDIB
+

 #include "wx/bitmap.h"
 #include "wx/intl.h"
 #include "wx/bitmap.h"
 #include "wx/intl.h"

+#include "wx/file.h"

 
 #include <stdio.h>
 #include <stdlib.h>
 
 #if !defined(__MWERKS__) && !defined(__SALFORDC__)
 
 #include <stdio.h>
 #include <stdlib.h>
 
 #if !defined(__MWERKS__) && !defined(__SALFORDC__)

-#include <memory.h>
-#endif
-
-#ifdef __GNUWIN32_OLD__
-    #include "wx/msw/gnuwin32/extra.h"
+    #include <memory.h>

 #endif
 
 #include "wx/image.h"
 #include "wx/msw/dib.h"
 
 #endif
 
 #include "wx/image.h"
 #include "wx/msw/dib.h"
 

+#ifdef __WXWINCE__
+    #include <shellapi.h>       // for SHLoadDIBitmap()
+#endif
+
+// ----------------------------------------------------------------------------
+// private functions
+// ----------------------------------------------------------------------------
+
+// calculate the number of palette entries needed for the bitmap with this
+// number of bits per pixel
+static inline WORD GetNumberOfColours(WORD bitsPerPixel)
+{
+    // only 1, 4 and 8bpp bitmaps use palettes (well, they could be used with
+    // 24bpp ones too but we don't support this as I think it's quite uncommon)
+    return (WORD)(bitsPerPixel <= 8 ? 1 << bitsPerPixel : 0);
+}
+
+// wrapper around ::GetObject() for DIB sections
+static inline bool GetDIBSection(HBITMAP hbmp, DIBSECTION *ds)
+{
+    // note that at least under Win9x (this doesn't seem to happen under Win2K
+    // but this doesn't mean anything, of course), GetObject() may return
+    // sizeof(DIBSECTION) for a bitmap which is *not* a DIB section and the way
+    // to check for it is by looking at the bits pointer
+    return ::GetObject(hbmp, sizeof(DIBSECTION), ds) == sizeof(DIBSECTION) &&
+                ds->dsBm.bmBits;
+}
+

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


@@ -56,27 +89,34 @@
 
 bool wxDIB::Create(int width, int height, int depth)
 {
 
 bool wxDIB::Create(int width, int height, int depth)
 {

-    // we don't handle the palette yet
-    wxASSERT_MSG( depth == 24 || depth == 32,
-                    _T("unsupported image depth in wxDIB::Create()") );
+    // we don't support formats using palettes right now so we only create
+    // either 24bpp (RGB) or 32bpp (RGBA) bitmaps
+    wxASSERT_MSG( depth, _T("invalid image depth in wxDIB::Create()") );
+    if ( depth < 24 )
+        depth = 24;

 
 

-    static const int infosize = sizeof(BITMAPINFOHEADER);
+    // allocate memory for bitmap structures
+    static const int sizeHeader = sizeof(BITMAPINFOHEADER);

 
 

-    BITMAPINFO *info = (BITMAPINFO *)malloc(infosize);
-    wxCHECK_MSG( info, NULL, _T("malloc(BITMAPINFO) failed") );
+    BITMAPINFO *info = (BITMAPINFO *)malloc(sizeHeader);
+    wxCHECK_MSG( info, false, _T("malloc(BITMAPINFO) failed") );

 
 

-    memset(info, 0, infosize);
+    memset(info, 0, sizeHeader);

 
 

-    info->bmiHeader.biSize = infosize;
+    info->bmiHeader.biSize = sizeHeader;

     info->bmiHeader.biWidth = width;
     info->bmiHeader.biWidth = width;

-    info->bmiHeader.biHeight = -height;
+
+    // we use positive height here which corresponds to a DIB with normal, i.e.
+    // bottom to top, order -- normally using negative height (which means
+    // reversed for MS and hence natural for all the normal people top to
+    // bottom line scan order) could be used to avoid the need for the image
+    // reversal in Create(image) but this doesn't work under NT, only Win9x!
+    info->bmiHeader.biHeight = height;
+

     info->bmiHeader.biPlanes = 1;
     info->bmiHeader.biPlanes = 1;

-    info->bmiHeader.biBitCount = depth;
-    info->bmiHeader.biCompression = BI_RGB;
+    info->bmiHeader.biBitCount = (WORD)depth;

     info->bmiHeader.biSizeImage = GetLineSize(width, depth)*height;
 
     info->bmiHeader.biSizeImage = GetLineSize(width, depth)*height;
 

-    // No need to report an error here.  If it fails, we just won't use a
-    // file mapping and CreateDIBSection will just allocate memory for us.

     m_handle = ::CreateDIBSection
                  (
                     0,              // hdc (unused with DIB_RGB_COLORS)
     m_handle = ::CreateDIBSection
                  (
                     0,              // hdc (unused with DIB_RGB_COLORS)


@@ -103,795 +143,627 @@ bool wxDIB::Create(int width, int height, int depth)
     return true;
 }
 
     return true;
 }
 

-// ----------------------------------------------------------------------------
-// wxDIB accessors
-// ----------------------------------------------------------------------------
+bool wxDIB::Create(const wxBitmap& bmp)
+{
+    wxCHECK_MSG( bmp.Ok(), false, _T("wxDIB::Create(): invalid bitmap") );

 
 

-void wxDIB::DoGetObject() const
+    if ( !Create(GetHbitmapOf(bmp)) )
+        return false;
+
+    m_hasAlpha = bmp.HasAlpha();
+
+    return true;
+}
+
+bool wxDIB::Create(HBITMAP hbmp)

 {
 {

-    // only do something if we have a valid DIB but we don't [yet] have valid
-    // data
-    if ( m_handle && !m_data )
+    // this bitmap could already be a DIB section in which case we don't need
+    // to convert it to DIB
+    DIBSECTION ds;
+    if ( GetDIBSection(hbmp, &ds) )

     {
     {

-        // although all the info we need is in BITMAP and so we don't really
-        // need DIBSECTION we still ask for it as modifying the bit values only
-        // works for the real DIBs and not for the bitmaps and it's better to
-        // check for this now rather than trying to find out why it doesn't
-        // work later
-        DIBSECTION ds;
-        if ( !::GetObject(m_handle, sizeof(ds), &ds) )
+        m_handle = hbmp;
+
+        // wxBitmap will free it, not we
+        m_ownsHandle = false;
+
+        // copy all the bitmap parameters too as we have them now anyhow
+        m_width = ds.dsBm.bmWidth;
+        m_height = ds.dsBm.bmHeight;
+        m_depth = ds.dsBm.bmBitsPixel;
+
+        m_data = ds.dsBm.bmBits;
+    }
+    else // no, it's a DDB -- convert it to DIB
+    {
+        // prepare all the info we need
+        BITMAP bm;
+        if ( !::GetObject(hbmp, sizeof(bm), &bm) )

         {
         {

-            wxLogLastError(_T("GetObject(hDIB)"));
+            wxLogLastError(wxT("GetObject(bitmap)"));

 
 

-            return;
+            return false;

         }
 
         }
 

-        wxDIB *self = wxConstCast(this, wxDIB);
+        int d = bm.bmBitsPixel;
+        if ( d <= 0 )
+            d = wxDisplayDepth();

 
 

-        self->m_width = ds.dsBm.bmWidth;
-        self->m_height = ds.dsBm.bmHeight;
-        self->m_depth = ds.dsBm.bmBitsPixel;
-        self->m_data = ds.dsBm.bmBits;
+        if ( !Create(bm.bmWidth, bm.bmHeight, d) || !CopyFromDDB(hbmp) )
+            return false;

     }
     }

-}

 
 

-// ----------------------------------------------------------------------------
-// wxImage support
-// ----------------------------------------------------------------------------
+    return true;
+}

 
 

-#if wxUSE_IMAGE
+// Windows CE doesn't have GetDIBits() so use an alternative implementation
+// for it
+//
+// in fact I'm not sure if GetDIBits() is really much better than using
+// BitBlt() like this -- it should be faster but I didn't do any tests, if
+// anybody has time to do them and by chance finds that GetDIBits() is not
+// much faster than BitBlt(), we could always use the Win CE version here
+#ifdef __WXWINCE__

 
 

-bool wxDIB::Create(const wxImage& image)
+bool wxDIB::CopyFromDDB(HBITMAP hbmp)

 {
 {

-    wxCHECK_MSG( image.Ok(), false, _T("invalid wxImage in wxDIB ctor") );
-
-    const int h = image.GetHeight();
-    const int w = image.GetWidth();
-
-    // if we have alpha channel, we need to create a 32bpp RGBA DIB, otherwise
-    // a 24bpp RGB is sufficient
-    const bool hasAlpha = image.HasAlpha();
-    const int bpp = hasAlpha ? 32 : 24;
+    MemoryHDC hdcSrc;
+    if ( !hdcSrc )
+        return false;

 
 

-    if ( !Create(w, h, bpp) )
+    SelectInHDC selectSrc(hdcSrc, hbmp);
+    if ( !selectSrc )

         return false;
 
         return false;
 

-    // DIBs are stored in bottom to top order so we need to copy bits line by
-    // line and starting from the end
-    const int srcBytesPerLine = w * 3;
-    const int dstBytesPerLine = GetLineSize(w, bpp);
-    const unsigned char *src = image.GetData() + ((h - 1) * srcBytesPerLine);
-    const unsigned char *alpha = hasAlpha ? image.GetAlpha() + (h - 1)*w : NULL;
-    unsigned char *dstLineStart = (unsigned char *)m_data;
-    for ( int y = 0; y < h; y++ )
-    {
-        // copy one DIB line
-        unsigned char *dst = dstLineStart;
-        for ( int x = 0; x < w; x++ )
-        {
-            // also, the order of RGB is inversed for DIBs
-            *dst++ = src[2];
-            *dst++ = src[1];
-            *dst++ = src[0];
+    MemoryHDC hdcDst;
+    if ( !hdcDst )
+        return false;

 
 

-            src += 3;
+    SelectInHDC selectDst(hdcDst, m_handle);
+    if ( !selectDst )
+        return false;

 
 

-            if ( alpha )
-                *dst++ = *alpha++;
-        }

 
 

-        // pass to the previous line in the image
-        src -= 2*srcBytesPerLine;
-        if ( alpha )
-            alpha -= 2*w;
+    if ( !::BitBlt(
+                    hdcDst,
+                    0, 0, m_width, m_height,
+                    hdcSrc,
+                    0, 0,
+                    SRCCOPY
+                  ) )
+    {
+        wxLogLastError(_T("BitBlt(DDB -> DIB)"));

 
 

-        // and to the next one in the DIB
-        dstLineStart += dstBytesPerLine;
+        return false;

     }
 
     return true;
 }
 
     }
 
     return true;
 }
 

-#endif // wxUSE_IMAGE
+#else // !__WXWINCE__

 
 

-// ============================================================================
-// old DIB code, to be integrated in wxDIB class
-// ============================================================================
-
-/*
- *  Routines for dealing with Device Independent Bitmaps.
- *
- *                  wxReadDIB()           - Reads a DIB
- *                  wxWriteDIB()            - Writes a global handle in CF_DIB format
- *                                          to a file.
- *                  wxPaletteSize()       - Calculates the palette size in bytes
- *                                          of given DIB
- *                  wxDibNumColors()        - Determines the number of colors in DIB
- *                  wxDibFromBitmap()       - Creates a DIB repr. the DDB passed in.
- *                  lread()               - Private routine to read more than 64k
- *                  lwrite()              - Private routine to write more than 64k
- */
+bool wxDIB::CopyFromDDB(HBITMAP hbmp)
+{
+    DIBSECTION ds;
+    if ( !GetDIBSection(m_handle, &ds) )
+    {
+        // we're sure that our handle is a DIB section, so this should work
+        wxFAIL_MSG( _T("GetObject(DIBSECTION) unexpectedly failed") );

 
 

-#ifndef SEEK_CUR
-/* flags for _lseek */
-#define        SEEK_CUR 1
-#define        SEEK_END 2
-#define        SEEK_SET 0
-#endif
+        return false;
+    }

 
 

-#define MAXREAD  32768                                 /* Number of bytes to be read during */
-                                                 /* each read operation.                         */
+    if ( !::GetDIBits
+            (
+                ScreenHDC(),                // the DC to use
+                hbmp,                       // the source DDB
+                0,                          // first scan line
+                m_height,                   // number of lines to copy
+                ds.dsBm.bmBits,             // pointer to the buffer
+                (BITMAPINFO *)&ds.dsBmih,   // bitmap header
+                DIB_RGB_COLORS              // and not DIB_PAL_COLORS
+            ) )
+    {
+        wxLogLastError(wxT("GetDIBits()"));

 
 

-/* Header signatutes for various resources */
-#define BFT_ICON         0x4349         /* 'IC' */
-#define BFT_BITMAP 0x4d42         /* 'BM' */
-#define BFT_CURSOR 0x5450         /* 'PT(' */
+        return false;
+    }

 
 

-/* macro to determine if resource is a DIB */
-#define ISDIB(bft) ((bft) == BFT_BITMAP)
+    return true;
+}

 
 

-/* Macro to align given value to the closest DWORD (unsigned long ) */
-#define ALIGNULONG(i)        ((i+3)/4*4)
+#endif // __WXWINCE__/!__WXWINCE__

 
 

-/* Macro to determine to round off the given value to the closest byte */
-#define WIDTHBYTES(i)        ((i+31)/32*4)
+// ----------------------------------------------------------------------------
+// Loading/saving the DIBs
+// ----------------------------------------------------------------------------

 
 

-#define PALVERSION                0x300
-#define MAXPALETTE        256          /* max. # supported palette entries */
+bool wxDIB::Load(const wxString& filename)
+{
+#ifdef __WXWINCE__
+    m_handle = SHLoadDIBitmap(filename);
+#else // !__WXWINCE__
+    m_handle = (HBITMAP)::LoadImage
+                         (
+                            wxGetInstance(),
+                            filename,
+                            IMAGE_BITMAP,
+                            0, 0, // don't specify the size
+                            LR_CREATEDIBSECTION | LR_LOADFROMFILE
+                         );
+#endif // __WXWINCE__

 
 

-static DWORD lread(int fh, VOID FAR *pv, DWORD ul);
-static DWORD lwrite(int fh, VOID FAR *pv, DWORD ul);
+    if ( !m_handle )
+    {
+        wxLogLastError(_T("Loading DIB from file"));

 
 

-static bool wxWriteDIB (LPTSTR szFile,HANDLE hdib);
-WORD        wxPaletteSize (VOID FAR * pv); // This is non-static as some apps use it externally
-static WORD wxDibNumColors (VOID FAR * pv);
-static bool wxMakeBitmapAndPalette(HDC,HANDLE,HPALETTE *,HBITMAP *);
+        return false;
+    }

 
 

-/*
- *  FUNCTION   : wxWriteDIB(LPSTR szFile,HANDLE hdib)
- *  PURPOSE    : Write a global handle in CF_DIB format to a file.
- *  RETURNS    : TRUE  - if successful.
- *               FALSE - otherwise
- */
+    return true;
+}

 
 

-static bool wxWriteDIB(LPTSTR szFile, HANDLE hdib)
+bool wxDIB::Save(const wxString& filename)

 {
 {

-    BITMAPFILEHEADER        hdr;
-    LPBITMAPINFOHEADER  lpbi;
-    int                 fh;
-    OFSTRUCT            of;
-    
-    if (!hdib)
-        return FALSE;
-    
-    fh = OpenFile(wxConvertWX2MB(szFile), &of, OF_CREATE | OF_READWRITE);
-    if (fh == -1)
-        return FALSE;
-    
-    lpbi = (LPBITMAPINFOHEADER) GlobalLock(hdib);
-
-    /* Fill in the fields of the file header */
-    hdr.bfType = BFT_BITMAP;
-    hdr.bfSize = GlobalSize(hdib) + sizeof(BITMAPFILEHEADER);
-    hdr.bfReserved1 = 0;
-    hdr.bfReserved2 = 0;
-    hdr.bfOffBits = (DWORD) sizeof(BITMAPFILEHEADER) + lpbi->biSize +
-        wxPaletteSize(lpbi);
-    
-    /* Write the file header */
-    _lwrite(fh, (LPSTR) &hdr, sizeof(BITMAPFILEHEADER));
-    
-    /* Write the DIB header and the bits */
-    lwrite(fh, (LPSTR) lpbi, GlobalSize(hdib));
-    
-    GlobalUnlock(hdib);
-    _lclose(fh);
-    return TRUE;
-}
+    wxCHECK_MSG( m_handle, false, _T("wxDIB::Save(): invalid object") );

 
 

-/*
- *  FUNCTION   :  wxPaletteSize(VOID FAR * pv)
- *  PURPOSE    :  Calculates the palette size in bytes. If the info. block
- *                is of the BITMAPCOREHEADER type, the number of colors is
- *                multiplied by 3 to give the palette size, otherwise the
- *                number of colors is multiplied by 4.
- *  RETURNS    :  Palette size in number of bytes.
- */
+    wxFile file(filename, wxFile::write);
+    bool ok = file.IsOpened();
+    if ( ok )
+    {
+        DIBSECTION ds;
+        if ( !GetDIBSection(m_handle, &ds) )
+        {
+            wxLogLastError(_T("GetObject(hDIB)"));
+        }
+        else
+        {
+            BITMAPFILEHEADER bmpHdr;
+            wxZeroMemory(bmpHdr);

 
 

-WORD wxPaletteSize(VOID FAR * pv)
-{
-    LPBITMAPINFOHEADER lpbi;
-    WORD               NumColors;
-    
-    lpbi = (LPBITMAPINFOHEADER) pv;
-    NumColors = wxDibNumColors(lpbi);
-    
-    if (lpbi->biSize == sizeof(BITMAPCOREHEADER))
-        return (WORD)(NumColors * sizeof(RGBTRIPLE));
-    else
-        return (WORD)(NumColors * sizeof(RGBQUAD));
-}
+            const size_t sizeHdr = ds.dsBmih.biSize;
+            const size_t sizeImage = ds.dsBmih.biSizeImage;

 
 

-/*
- *  FUNCTION   : wxDibNumColors(VOID FAR * pv)
- *  PURPOSE    : Determines the number of colors in the DIB by looking at
- *               the BitCount filed in the info block.
- *  RETURNS    : The number of colors in the DIB.                            *
- */
+            bmpHdr.bfType = 0x4d42;    // 'BM' in little endian
+            bmpHdr.bfOffBits = sizeof(BITMAPFILEHEADER) + ds.dsBmih.biSize;
+            bmpHdr.bfSize = bmpHdr.bfOffBits + sizeImage;

 
 

-static WORD wxDibNumColors(VOID FAR *pv)
-{
-    int                 bits;
-    BITMAPINFOHEADER        *lpbi;
-    BITMAPCOREHEADER        *lpbc;
-    
-    lpbi = ((BITMAPINFOHEADER*) pv);
-    lpbc = ((BITMAPCOREHEADER*) pv);
-    
-    /*        With the BITMAPINFO format headers, the size of the palette
-     *        is in biClrUsed, whereas in the BITMAPCORE - style headers, it
-     *        is dependent on the bits per pixel ( = 2 raised to the power of
-     *        bits/pixel).
-     */
-    if (lpbi->biSize != sizeof(BITMAPCOREHEADER)) {
-        if (lpbi->biClrUsed != 0)
-            return (WORD) lpbi->biClrUsed;
-        bits = lpbi->biBitCount;
+            // first write the file header, then the bitmap header and finally the
+            // bitmap data itself
+            ok = file.Write(&bmpHdr, sizeof(bmpHdr)) == sizeof(bmpHdr) &&
+                    file.Write(&ds.dsBmih, sizeHdr) == sizeHdr &&
+                        file.Write(ds.dsBm.bmBits, sizeImage) == sizeImage;
+        }

     }
     }

-    else
-        bits = lpbc->bcBitCount;
-    
-    switch (bits) {
-    case 1:
-        return 2;
-    case 4:
-        return 16;
-    case 8:
-        return 256;
-    default:
-        /* A 24 bitcount DIB has no color table */
-        return 0;
+
+    if ( !ok )
+    {
+        wxLogError(_("Failed to save the bitmap image to file \"%s\"."),
+                   filename.c_str());

     }
     }

+
+    return ok;

 }
 
 }
 

-/*
- *  FUNCTION   : lread(int fh, VOID FAR *pv, DWORD ul)
- *  PURPOSE    : Reads data in steps of 32k till all the data has been read.
- *  RETURNS    : 0 - If read did not proceed correctly.
- *               number of bytes read otherwise.
- */
+// ----------------------------------------------------------------------------
+// wxDIB accessors
+// ----------------------------------------------------------------------------

 
 

-static DWORD lread(int fh, void far *pv, DWORD ul)
+void wxDIB::DoGetObject() const

 {
 {

-    DWORD     ulT = ul;
-#if defined(WINNT) || defined(__WIN32__) || defined(__WIN32__)
-    BYTE *hp = (BYTE *) pv;
-#else
-    BYTE huge *hp = (BYTE huge *) pv;
-#endif
-    while (ul > (DWORD) MAXREAD) {
-        if (_lread(fh, (LPSTR) hp, (WORD) MAXREAD) != MAXREAD)
-            return 0;
-        ul -= MAXREAD;
-        hp += MAXREAD;
+    // only do something if we have a valid DIB but we don't [yet] have valid
+    // data
+    if ( m_handle && !m_data )
+    {
+        // although all the info we need is in BITMAP and so we don't really
+        // need DIBSECTION we still ask for it as modifying the bit values only
+        // works for the real DIBs and not for the bitmaps and it's better to
+        // check for this now rather than trying to find out why it doesn't
+        // work later
+        DIBSECTION ds;
+        if ( !GetDIBSection(m_handle, &ds) )
+        {
+            wxLogLastError(_T("GetObject(hDIB)"));
+            return;
+        }
+
+        wxDIB *self = wxConstCast(this, wxDIB);
+
+        self->m_width = ds.dsBm.bmWidth;
+        self->m_height = ds.dsBm.bmHeight;
+        self->m_depth = ds.dsBm.bmBitsPixel;
+        self->m_data = ds.dsBm.bmBits;

     }
     }

-    if (_lread(fh, (LPSTR) hp, (WXUINT) ul) != (WXUINT) ul)
-        return 0;
-    return ulT;

 }
 
 }
 

-/*
- *  FUNCTION   : lwrite(int fh, VOID FAR *pv, DWORD ul)
- *  PURPOSE    : Writes data in steps of 32k till all the data is written.
- *  RETURNS    : 0 - If write did not proceed correctly.
- *               number of bytes written otherwise.
- */
+// ----------------------------------------------------------------------------
+// DDB <-> DIB conversions
+// ----------------------------------------------------------------------------

 
 

-static DWORD lwrite(int fh, VOID FAR *pv, DWORD ul)
+#ifndef __WXWINCE__
+
+HBITMAP wxDIB::CreateDDB(HDC hdc) const

 {
 {

-    DWORD     ulT = ul;
-#if defined(WINNT) || defined(__WIN32__) || defined(__WIN32__)
-    BYTE *hp = (BYTE *) pv;
-#else
-    BYTE huge *hp = (BYTE huge *) pv;
-#endif
-    while (ul > MAXREAD) {
-        if (_lwrite(fh, (LPSTR) hp, (WORD) MAXREAD) != MAXREAD)
-            return 0;
-        ul -= MAXREAD;
-        hp += MAXREAD;
-    }
-    if (_lwrite(fh, (LPSTR) hp, (WXUINT) ul) != (WXUINT) ul)
+    wxCHECK_MSG( m_handle, 0, _T("wxDIB::CreateDDB(): invalid object") );
+
+    DIBSECTION ds;
+    if ( !GetDIBSection(m_handle, &ds) )
+    {
+        wxLogLastError(_T("GetObject(hDIB)"));
+

         return 0;
         return 0;

-    return ulT;
+    }
+
+    return ConvertToBitmap((BITMAPINFO *)&ds.dsBmih, hdc, ds.dsBm.bmBits);

 }
 
 }
 

-/*
- *  FUNCTION   : wxReadDIB(hWnd)
- *  PURPOSE    : Reads a DIB from a file, obtains a handle to its
- *               BITMAPINFO struct. and loads the DIB.  Once the DIB
- *               is loaded, the function also creates a bitmap and
- *               palette out of the DIB for a device-dependent form.
- *  RETURNS    : TRUE  - DIB loaded and bitmap/palette created
- *                       The DIBINIT structure pointed to by pInfo is
- *                       filled with the appropriate handles.
- *               FALSE - otherwise
- */
- 
-bool wxReadDIB(LPTSTR lpFileName, HBITMAP *bitmap, HPALETTE *palette)
+/* static */
+HBITMAP wxDIB::ConvertToBitmap(const BITMAPINFO *pbmi, HDC hdc, void *bits)

 {
 {

-    int fh;
-    LPBITMAPINFOHEADER lpbi;
-    OFSTRUCT               of;
-    BITMAPFILEHEADER   bf;
-    WORD                nNumColors;
-    bool result = FALSE;
-    WORD offBits;
-    HDC hDC;
-    bool bCoreHead = FALSE;
-    HANDLE hDIB = 0;
-    
-    /* Open the file and get a handle to it's BITMAPINFO */
-    
-    fh = OpenFile (wxConvertWX2MB(lpFileName), &of, OF_READ);
-    if (fh == -1) {
-        wxLogError(_("Can't open file '%s'"), lpFileName);
-        return (0);
-    }
-    
-    hDIB = GlobalAlloc(GHND, (DWORD)(sizeof(BITMAPINFOHEADER) +
-        256 * sizeof(RGBQUAD)));
-    if (!hDIB)
-        return(0);
-    
-    lpbi = (LPBITMAPINFOHEADER)GlobalLock(hDIB);
-    
-    /* read the BITMAPFILEHEADER */
-    if (sizeof (bf) != _lread (fh, (LPSTR)&bf, sizeof (bf)))
-        goto ErrExit;
-    
-    if (bf.bfType != 0x4d42)        /* 'BM' */
-        goto ErrExit;
-    
-    if (sizeof(BITMAPCOREHEADER) != _lread (fh, (LPSTR)lpbi, sizeof(BITMAPCOREHEADER)))
-        goto ErrExit;
-    
-    if (lpbi->biSize == sizeof(BITMAPCOREHEADER))
-    {
-        lpbi->biSize = sizeof(BITMAPINFOHEADER);
-        lpbi->biBitCount = ((LPBITMAPCOREHEADER)lpbi)->bcBitCount;
-        lpbi->biPlanes = ((LPBITMAPCOREHEADER)lpbi)->bcPlanes;
-        lpbi->biHeight = ((LPBITMAPCOREHEADER)lpbi)->bcHeight;
-        lpbi->biWidth = ((LPBITMAPCOREHEADER)lpbi)->bcWidth;
-        bCoreHead = TRUE;
-    }
-    else
-    {
-        // get to the start of the header and read INFOHEADER
-        _llseek(fh,sizeof(BITMAPFILEHEADER),SEEK_SET);
-        if (sizeof(BITMAPINFOHEADER) != _lread (fh, (LPSTR)lpbi, sizeof(BITMAPINFOHEADER)))
-            goto ErrExit;
-    }
-    
-    nNumColors = (WORD)lpbi->biClrUsed;
-    if ( nNumColors == 0 )
-    {
-        /* no color table for 24-bit, default size otherwise */
-        if (lpbi->biBitCount != 24)
-            nNumColors = 1 << lpbi->biBitCount;        /* standard size table */
-    }
-    
-    /* fill in some default values if they are zero */
-    if (lpbi->biClrUsed == 0)
-        lpbi->biClrUsed = nNumColors;
-    
-    if (lpbi->biSizeImage == 0)
-    {
-        lpbi->biSizeImage = ((((lpbi->biWidth * (DWORD)lpbi->biBitCount) + 31) & ~31) >> 3)
-            * lpbi->biHeight;
-    }
-    
-    /* get a proper-sized buffer for header, color table and bits */
-    GlobalUnlock(hDIB);
-    hDIB = GlobalReAlloc(hDIB, lpbi->biSize +
-        nNumColors * sizeof(RGBQUAD) +
-        lpbi->biSizeImage, 0);
-    if (!hDIB)        /* can't resize buffer for loading */
-        goto ErrExit2;
-    
-    lpbi = (LPBITMAPINFOHEADER)GlobalLock(hDIB);
-    
-    /* read the color table */
-    if (!bCoreHead)
-        _lread(fh, (LPSTR)(lpbi) + lpbi->biSize, nNumColors * sizeof(RGBQUAD));
-    else
+    wxCHECK_MSG( pbmi, 0, _T("invalid DIB in ConvertToBitmap") );
+
+    // here we get BITMAPINFO struct followed by the actual bitmap bits and
+    // BITMAPINFO starts with BITMAPINFOHEADER followed by colour info
+    const BITMAPINFOHEADER *pbmih = &pbmi->bmiHeader;
+
+    // get the pointer to the start of the real image data if we have a plain
+    // DIB and not a DIB section (in the latter case the pointer must be passed
+    // to us by the caller)
+    if ( !bits )

     {
     {

-        signed int i;
-        RGBQUAD FAR *pQuad;
-        RGBTRIPLE FAR *pTriple;
-        
-        _lread(fh, (LPSTR)(lpbi) + lpbi->biSize, nNumColors * sizeof(RGBTRIPLE));
-        
-        pQuad = (RGBQUAD FAR *)((LPSTR)lpbi + lpbi->biSize);
-        pTriple = (RGBTRIPLE FAR *) pQuad;
-        for (i = nNumColors - 1; i >= 0; i--)
+        // we must skip over the colour table to get to the image data
+        //
+        // colour table either has the real colour data in which case its
+        // number of entries is given by biClrUsed or is used for masks to be
+        // used for extracting colour information from true colour bitmaps in
+        // which case it always have exactly 3 DWORDs
+        int numColors;
+        switch ( pbmih->biCompression )

         {
         {

-            pQuad[i].rgbRed = pTriple[i].rgbtRed;
-            pQuad[i].rgbBlue = pTriple[i].rgbtBlue;
-            pQuad[i].rgbGreen = pTriple[i].rgbtGreen;
-            pQuad[i].rgbReserved = 0;
+            case BI_BITFIELDS:
+                numColors = 3;
+                break;
+
+            case BI_RGB:
+                // biClrUsed has the number of colors but it may be not initialized at
+                // all
+                numColors = pbmih->biClrUsed;
+                if ( !numColors )
+                {
+                    numColors = GetNumberOfColours(pbmih->biBitCount);
+                }
+                break;
+
+            default:
+                // no idea how it should be calculated for the other cases
+                numColors = 0;

         }
         }

+
+        bits = (char *)pbmih + sizeof(*pbmih) + numColors*sizeof(RGBQUAD);

     }
     }

-    
-    /* offset to the bits from start of DIB header */
-    offBits = (WORD)(lpbi->biSize + nNumColors * sizeof(RGBQUAD));
-    
-    if (bf.bfOffBits != 0L)
+
+    HBITMAP hbmp = ::CreateDIBitmap
+                     (
+                        hdc ? hdc           // create bitmap compatible
+                            : (HDC) ScreenHDC(),  //  with this DC
+                        pbmih,              // used to get size &c
+                        CBM_INIT,           // initialize bitmap bits too
+                        bits,               // ... using this data
+                        pbmi,               // this is used for palette only
+                        DIB_RGB_COLORS      // direct or indexed palette?
+                     );
+
+    if ( !hbmp )

     {
     {

-        _llseek(fh,bf.bfOffBits,SEEK_SET);
+        wxLogLastError(wxT("CreateDIBitmap"));

     }
     }

-    
-    if (lpbi->biSizeImage == lread(fh, (LPSTR)lpbi + offBits, lpbi->biSizeImage))
+
+    return hbmp;
+}
+
+/* static */
+size_t wxDIB::ConvertFromBitmap(BITMAPINFO *pbi, HBITMAP hbmp)
+{
+    wxASSERT_MSG( hbmp, wxT("invalid bmp can't be converted to DIB") );
+
+    // prepare all the info we need
+    BITMAP bm;
+    if ( !::GetObject(hbmp, sizeof(bm), &bm) )

     {
     {

-        GlobalUnlock(hDIB);
-        
-        hDC = GetDC(NULL);
-        if (!wxMakeBitmapAndPalette(hDC, hDIB, palette,
-            bitmap))
-        {
-            ReleaseDC(NULL,hDC);
-            goto ErrExit2;
-        }
-        else
-        {
-            ReleaseDC(NULL,hDC);
-            GlobalFree(hDIB);
-            result = TRUE;
-        }
+        wxLogLastError(wxT("GetObject(bitmap)"));
+
+        return 0;

     }
     }

-    else
+
+    // we need a BITMAPINFO anyhow and if we're not given a pointer to it we
+    // use this one
+    BITMAPINFO bi2;
+
+    const bool wantSizeOnly = pbi == NULL;
+    if ( wantSizeOnly )
+        pbi = &bi2;
+
+    // just for convenience
+    const int h = bm.bmHeight;
+
+    // init the header
+    BITMAPINFOHEADER& bi = pbi->bmiHeader;
+    wxZeroMemory(bi);
+    bi.biSize = sizeof(BITMAPINFOHEADER);
+    bi.biWidth = bm.bmWidth;
+    bi.biHeight = h;
+    bi.biPlanes = 1;
+    bi.biBitCount = bm.bmBitsPixel;
+
+    // memory we need for BITMAPINFO only
+    DWORD dwLen = bi.biSize + GetNumberOfColours(bm.bmBitsPixel) * sizeof(RGBQUAD);
+
+    // get either just the image size or the image bits
+    if ( !::GetDIBits
+            (
+                ScreenHDC(),                        // the DC to use
+                hbmp,                               // the source DDB
+                0,                                  // first scan line
+                h,                                  // number of lines to copy
+                wantSizeOnly ? NULL                 // pointer to the buffer or
+                             : (char *)pbi + dwLen, // NULL if we don't have it
+                pbi,                                // bitmap header
+                DIB_RGB_COLORS                      // or DIB_PAL_COLORS
+            ) )

     {
     {

-ErrExit:
-    GlobalUnlock(hDIB);
-ErrExit2:
-    GlobalFree(hDIB);
+        wxLogLastError(wxT("GetDIBits()"));
+
+        return 0;

     }
     }

-    
-    _lclose(fh);
-    return(result);
+
+    // return the total size
+    return dwLen + bi.biSizeImage;

 }
 
 }
 

-/*
- *  FUNCTION   : wxMakeBitmapAndPalette
- *  PURPOSE    : Given a DIB, creates a bitmap and corresponding palette
- *               to be used for a device-dependent representation of
- *               of the image.
- *  RETURNS    : TRUE  --> success. phPal and phBitmap are filled with
- *                         appropriate handles.  Caller is responsible
- *                         for freeing objects.
- *               FALSE --> unable to create objects.  both pointer are
- *                         not valid
- */
- 
-static bool wxMakeBitmapAndPalette(HDC hDC, HANDLE hDIB,
-                        HPALETTE * phPal, HBITMAP * phBitmap)
+/* static */
+HGLOBAL wxDIB::ConvertFromBitmap(HBITMAP hbmp)

 {
 {

-    LPBITMAPINFOHEADER lpInfo;
-    bool result = FALSE;
-    HBITMAP hBitmap;
-    HPALETTE hPalette, hOldPal;
-    LPSTR lpBits;
-    
-    lpInfo = (LPBITMAPINFOHEADER) GlobalLock(hDIB);
-    
-    hPalette = wxMakeDIBPalette(lpInfo);
-    if ( hPalette )
+    // first calculate the size needed
+    const size_t size = ConvertFromBitmap(NULL, hbmp);
+    if ( !size )

     {
     {

-        // Need to realize palette for converting DIB to bitmap.
-        hOldPal = SelectPalette(hDC, hPalette, TRUE);
-        RealizePalette(hDC);
-        
-        lpBits = (LPSTR)lpInfo + (WORD)lpInfo->biSize +
-            (WORD)lpInfo->biClrUsed * sizeof(RGBQUAD);
-        hBitmap = CreateDIBitmap(hDC, lpInfo, CBM_INIT, lpBits,
-            (LPBITMAPINFO)lpInfo, DIB_RGB_COLORS);
-        
-        SelectPalette(hDC, hOldPal, TRUE);
-        RealizePalette(hDC);
-        
-        if (!hBitmap)
-            DeleteObject(hPalette);
-        else
-        {
-            *phBitmap = hBitmap;
-            *phPal = hPalette;
-            result = TRUE;
-        }
+        // conversion to DDB failed?
+        return NULL;

     }
     }

-    
-    GlobalUnlock (hDIB);  // glt
-    
-    return(result);
-}

 
 

-/*
- *  FUNCTION   : wxMakeDIBPalette(lpInfo)
- *  PURPOSE    : Given a BITMAPINFOHEADER, create a palette based on
- *               the color table.
- *  RETURNS    : non-zero - handle of a corresponding palette
- *               zero - unable to create palette
- */
- 
-HPALETTE wxMakeDIBPalette(LPBITMAPINFOHEADER lpInfo)
-{
-    LPLOGPALETTE npPal;
-    RGBQUAD far *lpRGB;
-    HPALETTE hLogPal;
-    WORD i;
-    
-    /* since biClrUsed field was filled during the loading of the DIB,
-     * we know it contains the number of colors in the color table.
-     */
-    if (lpInfo->biClrUsed)
+    HGLOBAL hDIB = ::GlobalAlloc(GMEM_MOVEABLE, size);
+    if ( !hDIB )

     {
     {

-        npPal = (LPLOGPALETTE)malloc(sizeof(LOGPALETTE) +
-            (WORD)lpInfo->biClrUsed * sizeof(PALETTEENTRY));
-        if (!npPal)
-            return NULL;
-        
-        npPal->palVersion = 0x300;
-        npPal->palNumEntries = (WORD)lpInfo->biClrUsed;
-        
-        /* get pointer to the color table */
-        lpRGB = (RGBQUAD FAR *)((LPSTR)lpInfo + lpInfo->biSize);
-        
-        /* copy colors from the color table to the LogPalette structure */
-        for (i = 0; (DWORD)i < lpInfo->biClrUsed; i++, lpRGB++)
-        {
-            npPal->palPalEntry[i].peRed = lpRGB->rgbRed;
-            npPal->palPalEntry[i].peGreen = lpRGB->rgbGreen;
-            npPal->palPalEntry[i].peBlue = lpRGB->rgbBlue;
-            npPal->palPalEntry[i].peFlags = 0;
-        }
-        
-        hLogPal = CreatePalette((LPLOGPALETTE)npPal);
-        free(npPal);
-        
-        return(hLogPal);
+        // this is an error which does risk to happen especially under Win9x
+        // and which the user may understand so let him know about it
+        wxLogError(_("Failed to allocated %luKb of memory for bitmap data."),
+                   (unsigned long)(size / 1024));
+
+        return NULL;
+    }
+
+    if ( !ConvertFromBitmap((BITMAPINFO *)(void *)GlobalPtr(hDIB), hbmp) )
+    {
+        // this really shouldn't happen... it worked the first time, why not
+        // now?
+        wxFAIL_MSG( _T("wxDIB::ConvertFromBitmap() unexpectedly failed") );
+
+        return NULL;

     }
     }

-    
-    /* 24-bit DIB with no color table. Return default palette. Another
-     * option would be to create a 256 color "rainbow" palette to provide
-     * some good color choices.
-     */
-    else
-        return((HPALETTE) GetStockObject(DEFAULT_PALETTE));
+
+    return hDIB;

 }
 
 }
 

-bool wxLoadIntoBitmap(wxChar *filename, wxBitmap *bitmap, wxPalette **pal)
+#endif // __WXWINCE__
+
+// ----------------------------------------------------------------------------
+// palette support
+// ----------------------------------------------------------------------------
+
+#if wxUSE_PALETTE
+
+wxPalette *wxDIB::CreatePalette() const

 {
 {

-    HBITMAP hBitmap = NULL;
-    HPALETTE hPalette = NULL;
-    
-    bool success = (wxReadDIB(filename, &hBitmap, &hPalette) != 0);
-    
-    if (!success)
+    wxCHECK_MSG( m_handle, NULL, _T("wxDIB::CreatePalette(): invalid object") );
+
+    DIBSECTION ds;
+    if ( !GetDIBSection(m_handle, &ds) )

     {
     {

-        if (hPalette)
-            DeleteObject(hPalette);
-        return FALSE;
+        wxLogLastError(_T("GetObject(hDIB)"));
+
+        return 0;

     }
     }

-    
-    if (hPalette)
+
+    // how many colours are we going to have in the palette?
+    DWORD biClrUsed = ds.dsBmih.biClrUsed;
+    if ( !biClrUsed )

     {
     {

-#if wxUSE_PALETTE
-        if (pal)
-        {
-            *pal = new wxPalette;
-            (*pal)->SetHPALETTE((WXHPALETTE) hPalette);
-        }
-        else
-#endif // wxUSE_PALETTE
-            DeleteObject(hPalette);
+        // biClrUsed field might not be set
+        biClrUsed = GetNumberOfColours(ds.dsBmih.biBitCount);

     }
     }

-    else if (pal)
-        *pal = NULL;
-    
-    if (hBitmap)
+
+    if ( !biClrUsed )

     {
     {

-        BITMAP bm;
-        GetObject(hBitmap, sizeof(bm), (LPSTR)&bm);
-        
-        bitmap->SetHBITMAP((WXHBITMAP) hBitmap);
-        bitmap->SetWidth(bm.bmWidth);
-        bitmap->SetHeight(bm.bmHeight);
-        bitmap->SetDepth(bm.bmPlanes * bm.bmBitsPixel);
-#if WXWIN_COMPATIBILITY_2
-        bitmap->SetOk(TRUE);
-#endif // WXWIN_COMPATIBILITY_2
-        return TRUE;
+        // bitmaps of this depth don't have palettes at all
+        //
+        // NB: another possibility would be to return
+        //     GetStockObject(DEFAULT_PALETTE) or even CreateHalftonePalette()?
+        return NULL;

     }
     }

-    else return FALSE;
-}

 
 

-wxBitmap *wxLoadBitmap(wxChar *filename, wxPalette **pal)
-{
-    wxBitmap *bitmap = new wxBitmap;
-    if (wxLoadIntoBitmap(filename, bitmap, pal))
-        return bitmap;
-    else
+    // LOGPALETTE struct has only 1 element in palPalEntry array, we're
+    // going to have biClrUsed of them so add necessary space
+    LOGPALETTE *pPalette = (LOGPALETTE *)
+        malloc(sizeof(LOGPALETTE) + (biClrUsed - 1)*sizeof(PALETTEENTRY));
+    wxCHECK_MSG( pPalette, NULL, _T("out of memory") );
+
+    // initialize the palette header
+    pPalette->palVersion = 0x300;  // magic number, not in docs but works
+    pPalette->palNumEntries = (WORD)biClrUsed;
+
+    // and the colour table (it starts right after the end of the header)
+    const RGBQUAD *pRGB = (RGBQUAD *)((char *)&ds.dsBmih + ds.dsBmih.biSize);
+    for ( DWORD i = 0; i < biClrUsed; i++, pRGB++ )

     {
     {

-        delete bitmap;
+        pPalette->palPalEntry[i].peRed = pRGB->rgbRed;
+        pPalette->palPalEntry[i].peGreen = pRGB->rgbGreen;
+        pPalette->palPalEntry[i].peBlue = pRGB->rgbBlue;
+        pPalette->palPalEntry[i].peFlags = 0;
+    }
+
+    HPALETTE hPalette = ::CreatePalette(pPalette);
+
+    free(pPalette);
+
+    if ( !hPalette )
+    {
+        wxLogLastError(_T("CreatePalette"));
+

         return NULL;
     }
         return NULL;
     }

-}

 
 

-/*
- *
- * Function:   InitBitmapInfoHeader
- *
- * Purpose:    Does a "standard" initialization of a BITMAPINFOHEADER,
- *             given the Width, Height, and Bits per Pixel for the
- *             DIB.
- *
- *             By standard, I mean that all the relevant fields are set
- *             to the specified values.  biSizeImage is computed, the
- *             biCompression field is set to "no compression," and all
- *             other fields are 0.
- *
- *             Note that DIBs only allow BitsPixel values of 1, 4, 8, or
- *             24.  This routine makes sure that one of these values is
- *             used (whichever is most appropriate for the specified
- *             nBPP).
- *
- * Parms:      lpBmInfoHdr == Far pointer to a BITMAPINFOHEADER structure
- *                            to be filled in.
- *             dwWidth     == Width of DIB (not in Win 3.0 & 3.1, high
- *                            word MUST be 0).
- *             dwHeight    == Height of DIB (not in Win 3.0 & 3.1, high
- *                            word MUST be 0).
- *             nBPP        == Bits per Pixel for the DIB.
- *
- */
+    wxPalette *palette = new wxPalette;
+    palette->SetHPALETTE((WXHPALETTE)hPalette);

 
 

-static void InitBitmapInfoHeader (LPBITMAPINFOHEADER lpBmInfoHdr,
-                                        DWORD dwWidth,
-                                        DWORD dwHeight,
-                                          int nBPP)
-{
-    //   _fmemset (lpBmInfoHdr, 0, sizeof (BITMAPINFOHEADER));
-    memset (lpBmInfoHdr, 0, sizeof (BITMAPINFOHEADER));
-    
-    lpBmInfoHdr->biSize      = sizeof (BITMAPINFOHEADER);
-    lpBmInfoHdr->biWidth     = dwWidth;
-    lpBmInfoHdr->biHeight    = dwHeight;
-    lpBmInfoHdr->biPlanes    = 1;
-    
-    if (nBPP <= 1)
-        nBPP = 1;
-    else if (nBPP <= 4)
-        nBPP = 4;
-    else if (nBPP <= 8)
-        nBPP = 8;
-   /* Doesn't work
-        else if (nBPP <= 16)
-        nBPP = 16;
-    */
-    else
-        nBPP = 24;
-    
-    lpBmInfoHdr->biBitCount  = nBPP;
-    lpBmInfoHdr->biSizeImage = WIDTHBYTES (dwWidth * nBPP) * dwHeight;
+    return palette;

 }
 
 }
 

-LPSTR wxFindDIBBits (LPSTR lpbi)
+#endif // wxUSE_PALETTE
+
+// ----------------------------------------------------------------------------
+// wxImage support
+// ----------------------------------------------------------------------------
+
+#if wxUSE_IMAGE
+
+bool wxDIB::Create(const wxImage& image)

 {
 {

-    return (lpbi + *(LPDWORD)lpbi + wxPaletteSize (lpbi));
-}
+    wxCHECK_MSG( image.Ok(), false, _T("invalid wxImage in wxDIB ctor") );

 
 

-/*
- * Function:   BitmapToDIB
- *
- * Purpose:    Given a device dependent bitmap and a palette, returns
- *             a handle to global memory with a DIB spec in it.  The
- *             DIB is rendered using the colors of the palette passed in.
- *
- * Parms:      hBitmap == Handle to device dependent bitmap compatible
- *                        with default screen display device.
- *             hPal    == Palette to render the DDB with.  If it's NULL,
- *                        use the default palette.
- */
+    const int h = image.GetHeight();
+    const int w = image.GetWidth();

 
 

-HANDLE wxBitmapToDIB (HBITMAP hBitmap, HPALETTE hPal)
+    // if we have alpha channel, we need to create a 32bpp RGBA DIB, otherwise
+    // a 24bpp RGB is sufficient
+    m_hasAlpha = image.HasAlpha();
+    const int bpp = m_hasAlpha ? 32 : 24;
+
+    if ( !Create(w, h, bpp) )
+        return false;
+
+    // DIBs are stored in bottom to top order (see also the comment above in
+    // Create()) so we need to copy bits line by line and starting from the end
+    const int srcBytesPerLine = w * 3;
+    const int dstBytesPerLine = GetLineSize(w, bpp);
+    const unsigned char *src = image.GetData() + ((h - 1) * srcBytesPerLine);
+    const unsigned char *alpha = m_hasAlpha ? image.GetAlpha() + (h - 1)*w
+                                            : NULL;
+    unsigned char *dstLineStart = (unsigned char *)m_data;
+    for ( int y = 0; y < h; y++ )
+    {
+        // copy one DIB line
+        unsigned char *dst = dstLineStart;
+        if ( alpha )
+        {
+            for ( int x = 0; x < w; x++ )
+            {
+                // RGB order is reversed, and we need to premultiply
+                // all channels by alpha value for use with ::AlphaBlend.
+                const unsigned char a = *alpha++;
+                *dst++ = (unsigned char)((src[2] * a + 127) / 255);
+                *dst++ = (unsigned char)((src[1] * a + 127) / 255);
+                *dst++ = (unsigned char)((src[0] * a + 127) / 255);
+                *dst++ = a;
+                src += 3;
+            }
+        }
+        else // no alpha channel
+        {
+            for ( int x = 0; x < w; x++ )
+            {
+                // RGB order is reversed.
+                *dst++ = src[2];
+                *dst++ = src[1];
+                *dst++ = src[0];
+                src += 3;
+            }
+        }
+
+        // pass to the previous line in the image
+        src -= 2*srcBytesPerLine;
+        if ( alpha )
+            alpha -= 2*w;
+
+        // and to the next one in the DIB
+        dstLineStart += dstBytesPerLine;
+    }
+
+    return true;
+}
+
+wxImage wxDIB::ConvertToImage() const

 {
 {

-    BITMAP             Bitmap;
-    BITMAPINFOHEADER   bmInfoHdr;
-    LPBITMAPINFOHEADER lpbmInfoHdr;
-    LPSTR              lpBits;
-    HDC                hMemDC;
-    HANDLE             hDIB;
-    HPALETTE           hOldPal = NULL;
-    
-    // Do some setup -- make sure the Bitmap passed in is valid,
-    //  get info on the bitmap (like its height, width, etc.),
-    //  then setup a BITMAPINFOHEADER.
-    
-    if (!hBitmap)
-        return NULL;
-    
-    if (!GetObject (hBitmap, sizeof (Bitmap), (LPSTR) &Bitmap))
-        return NULL;
-    
-    InitBitmapInfoHeader (&bmInfoHdr,
-        Bitmap.bmWidth,
-        Bitmap.bmHeight,
-        Bitmap.bmPlanes * Bitmap.bmBitsPixel);    
-    
-    // Now allocate memory for the DIB.  Then, set the BITMAPINFOHEADER
-    //  into this memory, and find out where the bitmap bits go.
-    
-    hDIB = GlobalAlloc (GHND, sizeof (BITMAPINFOHEADER) +
-        wxPaletteSize ((LPSTR) &bmInfoHdr) + bmInfoHdr.biSizeImage);
-    
-    if (!hDIB)
-        return NULL;
-    
-    lpbmInfoHdr  = (LPBITMAPINFOHEADER) GlobalLock (hDIB);
-    
-    *lpbmInfoHdr = bmInfoHdr;
-    lpBits       = wxFindDIBBits ((LPSTR) lpbmInfoHdr);
-    
-    
-    // Now, we need a DC to hold our bitmap.  If the app passed us
-    //  a palette, it should be selected into the DC.
-    
-    hMemDC = GetDC (NULL);
-    
-    if (hPal)
+    wxCHECK_MSG( IsOk(), wxNullImage,
+                    wxT("can't convert invalid DIB to wxImage") );
+
+    // create the wxImage object
+    const int w = GetWidth();
+    const int h = GetHeight();
+    wxImage image(w, h, false /* don't bother clearing memory */);
+    if ( !image.Ok() )

     {
     {

-        hOldPal = SelectPalette (hMemDC, hPal, FALSE);
-        RealizePalette (hMemDC);
+        wxFAIL_MSG( wxT("could not allocate data for image") );
+        return wxNullImage;

     }
     }

-    
-    // We're finally ready to get the DIB.  Call the driver and let
-    // it party on our bitmap.  It will fill in the color table,
-    // and bitmap bits of our global memory block.
-    
-    if (!GetDIBits (hMemDC, hBitmap, 0, Bitmap.bmHeight, lpBits,
-            (LPBITMAPINFO) lpbmInfoHdr, DIB_RGB_COLORS))
+
+    if ( m_hasAlpha )

     {
     {

-        GlobalUnlock (hDIB);
-        GlobalFree (hDIB);
-        hDIB = NULL;
+        image.SetAlpha();

     }
     }

-    else
-        GlobalUnlock (hDIB);   
-    
-    // Finally, clean up and return.
-    
-    if (hOldPal)
-        SelectPalette (hMemDC, hOldPal, FALSE);
-    
-    ReleaseDC (NULL, hMemDC);
-    
-    return hDIB;
-}

 
 

-bool wxSaveBitmap(wxChar *filename, wxBitmap *bitmap, wxPalette *palette)
-{
-    HPALETTE hPalette = 0;
-#if wxUSE_PALETTE
-    if (palette)
-        hPalette = (HPALETTE) palette->GetHPALETTE();
-#endif // wxUSE_PALETTE
-    
-    HANDLE dibHandle = wxBitmapToDIB((HBITMAP) bitmap->GetHBITMAP(), hPalette);
-    if (dibHandle)
+    // this is the same loop as in Create() just above but with copy direction
+    // reversed
+    const int bpp = GetDepth();
+    const int dstBytesPerLine = w * 3;
+    const int srcBytesPerLine = GetLineSize(w, bpp);
+    unsigned char *dst = image.GetData() + ((h - 1) * dstBytesPerLine);
+    unsigned char *alpha = image.HasAlpha() ? image.GetAlpha() + (h - 1)*w
+                                            : NULL;
+    const bool is32bit = bpp == 32;
+    const unsigned char *srcLineStart = (unsigned char *)GetData();
+    for ( int y = 0; y < h; y++ )

     {
     {

-        bool success = (wxWriteDIB(filename, dibHandle) != 0);
-        GlobalFree(dibHandle);
-        return success;
+        // copy one DIB line
+        const unsigned char *src = srcLineStart;
+        for ( int x = 0; x < w; x++ )
+        {
+            dst[2] = *src++;
+            dst[1] = *src++;
+            dst[0] = *src++;
+
+            dst += 3;
+
+            if ( is32bit )
+            {
+                if ( alpha )
+                    *alpha++ = *src;
+                src++;
+            }
+        }
+
+        // pass to the previous line in the image
+        dst -= 2*dstBytesPerLine;
+        if ( alpha )
+            alpha -= 2*w;
+
+        // and to the next one in the DIB
+        srcLineStart += srcBytesPerLine;

     }
     }

-    else return FALSE;
+
+    return image;

 }
 
 }
 

+#endif // wxUSE_IMAGE
+
+#endif // wxUSE_WXDIB
+