DeleteFunction argument should be non-const since it

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

diff --git a/src/msw/dib.cpp b/src/msw/dib.cpp
index d86337576a86a2206a20122aece28253af39d405..9b1c1a6160f7c51b3417989432a05b6dab866e5b 100644 (file)
--- a/src/msw/dib.cpp
+++ b/src/msw/dib.cpp
@@ -1,934 +1,803 @@
-/*******************************************************************************
- *                                                                            *
- * MODULE      : DIB.CC                                                       *
- *                                                                            *
- *  DESCRIPTION : Routines for dealing with Device Independent Bitmaps.        *
- *                                                                            *
- *  FUNCTIONS  :                                                              *
- *                                                                            *
- *                ReadDIB()           - Reads a DIB                            *
- *                                                                            *
- *               WriteDIB()          - Writes a global handle in CF_DIB format*
- *                                     to a file.                             *
- *                                                                            *
- *               PaletteSize()       - Calculates the palette size in bytes   *
- *                                     of given DIB                           *
- *                                                                            *
- *               DibNumColors()      - Determines the number of colors in DIB *
- *                                                                            *
- *               DibFromBitmap()     - Creates a DIB repr. the DDB passed in. *
- *                                                                            *
- *                                                                            *
- *               lread()             - Private routine to read more than 64k  *
- *                                                                            *
- *               lwrite()            - Private routine to write more than 64k *
- *                                                                            *
- *******************************************************************************/
+///////////////////////////////////////////////////////////////////////////////
+// Name:        src/msw/dib.cpp
+// Purpose:     implements wxDIB class
+// Author:      Vadim Zeitlin
+// Modified by:
+// Created:     03.03.03 (replaces the old file with the same name)
+// RCS-ID:      $Id$
+// Copyright:   (c) 2003 Vadim Zeitlin <vadim@wxwindows.org>
+// 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
+// ============================================================================
+
+// ----------------------------------------------------------------------------
+// headers
+// ----------------------------------------------------------------------------

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

-#define IN_WX_MAIN_CPP

 #include "wx/wxprec.h"
 
 #include "wx/wxprec.h"
 

-#if defined(__BORLANDC__)
-#pragma hdrstop
+#ifdef __BORLANDC__
+    #pragma hdrstop

 #endif
 
 #ifndef WX_PRECOMP
 #endif
 
 #ifndef WX_PRECOMP

-#include "wx/setup.h"
-#include "wx/defs.h"
-#endif
+    #include "wx/string.h"
+    #include "wx/log.h"
+#endif //WX_PRECOMP
+
+#if wxUSE_WXDIB
+
+#include "wx/bitmap.h"
+#include "wx/intl.h"
+#include "wx/file.h"

 
 

-#include <windows.h>

 #include <stdio.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <stdlib.h>

-#include <memory.h>

 
 

+#if !defined(__MWERKS__) && !defined(__SALFORDC__)
+    #include <memory.h>
+#endif
+
+#include "wx/image.h"

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

-#ifdef __GNUWIN32__
-#include "wx/msw/gnuwin32/extra.h"
+#ifdef __WXWINCE__
+    #include <shellapi.h>       // for SHLoadDIBitmap()

 #endif
 
 #endif
 

-#ifndef SEEK_CUR
-/* flags for _lseek */
-#define        SEEK_CUR 1
-#define        SEEK_END 2
-#define        SEEK_SET 0
-#endif
+// ----------------------------------------------------------------------------
+// private functions
+// ----------------------------------------------------------------------------

 
 

-#define MAXREAD  32768                          /* Number of bytes to be read during */
-                                                /* each read operation.                         */
-
-/* Header signatutes for various resources */
-#define BFT_ICON        0x4349  /* 'IC' */
-#define BFT_BITMAP 0x4d42       /* 'BM' */
-#define BFT_CURSOR 0x5450       /* 'PT' */
-
-/* macro to determine if resource is a DIB */
-#define ISDIB(bft) ((bft) == BFT_BITMAP)
-
-/* Macro to align given value to the closest DWORD (unsigned long ) */
-#define ALIGNULONG(i)  ((i+3)/4*4)
-
-/* Macro to determine to round off the given value to the closest byte */
-#define WIDTHBYTES(i)  ((i+31)/32*4)
-
-#define PALVERSION             0x300
-#define MAXPALETTE     256       /* max. # supported palette entries */
-
-DWORD PASCAL lread(int fh, VOID FAR *pv, DWORD ul);
-DWORD PASCAL lwrite(int fh, VOID FAR *pv, DWORD ul);
-
-BOOL            WriteDIB (LPSTR szFile,HANDLE hdib);
-WORD            PaletteSize (VOID FAR * pv);
-WORD            DibNumColors (VOID FAR * pv);
-// HANDLE               DibFromBitmap (HBITMAP hbm, DWORD biStyle, WORD biBits, HPALETTE hpal);
-BOOL             PASCAL MakeBitmapAndPalette(HDC,HANDLE,HPALETTE *,HBITMAP *);
-HPALETTE MakeDIBPalette(LPBITMAPINFOHEADER);
-BOOL             ReadDIB(LPSTR lpFileName, HBITMAP *bitmap, HPALETTE *palette);
-
-/****************************************************************************
- *                                                                         *
- *  FUNCTION   : WriteDIB(LPSTR szFile,HANDLE hdib)                        *
- *                                                                         *
- *  PURPOSE    : Write a global handle in CF_DIB format to a file.         *
- *                                                                         *
- *  RETURNS    : TRUE  - if successful.                                    *
- *              FALSE - otherwise                                          *
- *                                                                         *
- ****************************************************************************/
-
-BOOL WriteDIB(LPSTR szFile, HANDLE hdib)
+// calculate the number of palette entries needed for the bitmap with this
+// number of bits per pixel
+static inline WORD GetNumberOfColours(WORD bitsPerPixel)

 {
 {

-       BITMAPFILEHEADER        hdr;
-       LPBITMAPINFOHEADER  lpbi;
-       int                 fh;
-       OFSTRUCT            of;
+    // 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);
+}

 
 

-       if (!hdib)
-               return FALSE;
+// 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;
+}

 
 

-       fh = OpenFile(szFile, &of, OF_CREATE | OF_READWRITE);
-       if (fh == -1)
-               return FALSE;
+// ============================================================================
+// implementation
+// ============================================================================

 
 

-#ifdef __WINDOWS_386__
-        lpbi = (LPBITMAPINFOHEADER) MK_FP32(GlobalLock(hdib));
-#else
-        lpbi = (LPBITMAPINFOHEADER) GlobalLock(hdib);
-#endif
-    /* 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 + 
-                PaletteSize(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;
-}
+// ----------------------------------------------------------------------------
+// wxDIB creation
+// ----------------------------------------------------------------------------

 
 

-/****************************************************************************
- *                                                                         *
- *  FUNCTION   :  PaletteSize(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.                         *
- *                                                                         *
- ****************************************************************************/
-
-WORD PaletteSize(VOID FAR * pv)
+bool wxDIB::Create(int width, int height, int depth)

 {
 {

-       LPBITMAPINFOHEADER lpbi;
-       WORD           NumColors;
+    // 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;
+
+    // allocate memory for bitmap structures
+    static const int sizeHeader = sizeof(BITMAPINFOHEADER);
+
+    BITMAPINFO *info = (BITMAPINFO *)malloc(sizeHeader);
+    wxCHECK_MSG( info, false, _T("malloc(BITMAPINFO) failed") );
+
+    memset(info, 0, sizeHeader);
+
+    info->bmiHeader.biSize = sizeHeader;
+    info->bmiHeader.biWidth = width;
+
+    // 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.biBitCount = (WORD)depth;
+    info->bmiHeader.biSizeImage = GetLineSize(width, depth)*height;
+
+    m_handle = ::CreateDIBSection
+                 (
+                    0,              // hdc (unused with DIB_RGB_COLORS)
+                    info,           // bitmap description
+                    DIB_RGB_COLORS, // use RGB, not palette
+                    &m_data,        // [out] DIB bits
+                    NULL,           // don't use file mapping
+                    0               // file mapping offset (not used here)
+                 );
+
+    free(info);
+
+    if ( !m_handle )
+    {
+        wxLogLastError(wxT("CreateDIBSection"));
+
+        return false;
+    }

 
 

-       lpbi = (LPBITMAPINFOHEADER) pv;
-       NumColors = DibNumColors(lpbi);
+    m_width = width;
+    m_height = height;
+    m_depth = depth;

 
 

-       if (lpbi->biSize == sizeof(BITMAPCOREHEADER))
-               return NumColors * sizeof(RGBTRIPLE);
-       else 
-               return NumColors * sizeof(RGBQUAD);
+    return true;

 }
 
 }
 

-/****************************************************************************
- *                                                                         *
- *  FUNCTION   : DibNumColors(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.                          *
- *                                                                         *
- ****************************************************************************/
-
-WORD DibNumColors(VOID FAR *pv)
+bool wxDIB::Create(const wxBitmap& bmp)

 {
 {

-       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;
-               }
-       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;
-               }
-}
+    wxCHECK_MSG( bmp.Ok(), false, _T("wxDIB::Create(): invalid bitmap") );

 
 

-/****************************************************************************
- *                                                                         *
- *  FUNCTION   : DibFromBitmap()                                           *
- *                                                                         *
- *  PURPOSE    : Will create a global memory block in DIB format that      *
- *              represents the Device-dependent bitmap (DDB) passed in.    *
- *                                                                         *
- *  RETURNS    : A handle to the DIB                                       *
- *                                                                         *
- ****************************************************************************/
-
-#if NOTHING
-HANDLE DibFromBitmap(HBITMAP hbm, DWORD biStyle, WORD biBits, HPALETTE hpal)
-{
-       BITMAP               bm;
-       BITMAPINFOHEADER     bi;
-       BITMAPINFOHEADER FAR *lpbi;
-       DWORD                dwLen;
-       HANDLE               hdib;
-       HANDLE               h;
-       HDC                  hdc;
-
-       if (!hbm)
-               return NULL;
-
-       if (hpal == NULL)
-               hpal = GetStockObject(DEFAULT_PALETTE);
-
-       GetObject(hbm, sizeof (bm), (LPSTR) &bm);
-
-       if (biBits == 0)
-               biBits = bm.bmPlanes * bm.bmBitsPixel;
-
-       bi.biSize = sizeof(BITMAPINFOHEADER);
-       bi.biWidth = bm.bmWidth;
-       bi.biHeight = bm.bmHeight;
-       bi.biPlanes = 1;
-       bi.biBitCount = biBits;
-       bi.biCompression = biStyle;
-       bi.biSizeImage = 0;
-       bi.biXPelsPerMeter = 0;
-       bi.biYPelsPerMeter = 0;
-       bi.biClrUsed = 0;
-       bi.biClrImportant = 0;
-
-       dwLen = bi.biSize + PaletteSize(&bi);
-
-       hdc = GetDC(NULL);
-       hpal = SelectPalette(hdc, hpal, FALSE);
-       RealizePalette(hdc);
-
-       hdib = GlobalAlloc(GHND, dwLen);
-
-       if (!hdib) {
-               SelectPalette(hdc, hpal, FALSE);
-               ReleaseDC(NULL, hdc);
-               return NULL;
-               }
-
-#ifdef __WINDOWS_386__
-       lpbi = (BITMAPINFOHEADER FAR *) MK_FP32(GlobalLock(hdib));
-#else
-       lpbi = (BITMAPINFOHEADER FAR *) GlobalLock(hdib);
-#endif
+    if ( !Create(GetHbitmapOf(bmp)) )
+        return false;

 
 

-       *lpbi = bi;
-
-    /* call GetDIBits with a NULL lpBits param, so it will calculate the
-     *  biSizeImage field for us
-     */
-       GetDIBits(hdc, hbm, 0, (WORD) bi.biHeight,
-                NULL, (LPBITMAPINFO) lpbi, DIB_RGB_COLORS);
-
-       bi = *lpbi;
-       GlobalUnlock(hdib);
-
-    /* If the driver did not fill in the biSizeImage field, make one up */
-       if (bi.biSizeImage == 0) {
-               bi.biSizeImage = WIDTHBYTES((DWORD)bm.bmWidth * biBits) * bm.bmHeight;
-
-               if (biStyle != BI_RGB)
-                       bi.biSizeImage = (bi.biSizeImage * 3) / 2;
-               }
-
-    /* realloc the buffer big enough to hold all the bits */
-       dwLen = bi.biSize + PaletteSize(&bi) + bi.biSizeImage;
-       if (h = GlobalReAlloc(hdib, dwLen, 0))
-               hdib = h;
-       else {
-               GlobalFree(hdib);
-               hdib = NULL;
-
-               SelectPalette(hdc, hpal, FALSE);
-               ReleaseDC(NULL, hdc);
-               return hdib;
-               }
-
-    /* call GetDIBits with a NON-NULL lpBits param, and actualy get the
-     *  bits this time
-     */
-#ifdef __WINDOWS_386__
-       lpbi = (BITMAPINFOHEADER FAR *) MK_FP32(GlobalLock(hdib));
-#else
-       lpbi = (BITMAPINFOHEADER FAR *) GlobalLock(hdib);
-#endif
+    m_hasAlpha = bmp.HasAlpha();

 
 

-       if (GetDIBits(hdc,
-                hbm,
-                0,
-                (WORD) bi.biHeight,
-                (LPSTR) lpbi + (WORD) lpbi->biSize + PaletteSize(lpbi),
-                (LPBITMAPINFO) lpbi, DIB_RGB_COLORS) == 0) {
-               GlobalUnlock(hdib);
-               hdib = NULL;
-               SelectPalette(hdc, hpal, FALSE);
-               ReleaseDC(NULL, hdc);
-               return NULL;
-               }
-
-       bi = *lpbi;
-       GlobalUnlock(hdib);
-
-       SelectPalette(hdc, hpal, FALSE);
-       ReleaseDC(NULL, hdc);
-       return hdib;
+    return true;

 }
 }

-#endif

 
 

- /************* PRIVATE ROUTINES TO READ/WRITE MORE THAN 64K ***************/
-/****************************************************************************
- *                                                                         *
- *  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.                            *
- *                                                                         *
- ****************************************************************************/
-
-DWORD PASCAL lread(int fh, void far *pv, DWORD ul)
+bool wxDIB::Create(HBITMAP hbmp)

 {
 {

-       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;
-               }
-       if (_lread(fh, (LPSTR) hp, (WORD) ul) != (WORD) ul)
-               return 0;
-       return ulT;
+    // 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) )
+    {
+        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(wxT("GetObject(bitmap)"));
+
+            return false;
+        }
+
+        int d = bm.bmBitsPixel;
+        if ( d <= 0 )
+            d = wxDisplayDepth();
+
+        if ( !Create(bm.bmWidth, bm.bmHeight, d) || !CopyFromDDB(hbmp) )
+            return false;
+    }
+
+    return true;

 }
 
 }
 

-/****************************************************************************
- *                                                                         *
- *  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.                         *
- *                                                                         *
- ****************************************************************************/
-
-DWORD PASCAL lwrite(int fh, VOID FAR *pv, DWORD ul)
+// 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::CopyFromDDB(HBITMAP hbmp)

 {
 {

-       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, (WORD) ul) != (WORD) ul)
-               return 0;
-       return ulT;
+    MemoryHDC hdcSrc;
+    if ( !hdcSrc )
+        return false;
+
+    SelectInHDC selectSrc(hdcSrc, hbmp);
+    if ( !selectSrc )
+        return false;
+
+    MemoryHDC hdcDst;
+    if ( !hdcDst )
+        return false;
+
+    SelectInHDC selectDst(hdcDst, m_handle);
+    if ( !selectDst )
+        return false;
+
+
+    if ( !::BitBlt(
+                    hdcDst,
+                    0, 0, m_width, m_height,
+                    hdcSrc,
+                    0, 0,
+                    SRCCOPY
+                  ) )
+    {
+        wxLogLastError(_T("BitBlt(DDB -> DIB)"));
+
+        return false;
+    }
+
+    return true;

 }
 
 }
 

-/****************************************************************************
- *
- *  FUNCTION   : ReadDIB(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 ReadDIB(LPSTR lpFileName, HBITMAP *bitmap, HPALETTE *palette)
+#else // !__WXWINCE__
+
+bool wxDIB::CopyFromDDB(HBITMAP hbmp)

 {
 {

-    int fh;
-    LPBITMAPINFOHEADER lpbi;
-    OFSTRUCT          of;
-    BITMAPFILEHEADER   bf;
-    WORD               nNumColors;
-    BOOL result = FALSE;
-    char str[128];
-    WORD offBits;
-    HDC hDC;
-    BOOL bCoreHead = FALSE;
-    HANDLE hDIB = 0;
-
-    /* Open the file and get a handle to it's BITMAPINFO */
-
-    fh = OpenFile (lpFileName, &of, OF_READ);
-    if (fh == -1) {
-       wsprintf(str,"Can't open file '%ls'", (LPSTR)lpFileName);
-       MessageBox(NULL, str, "Error", MB_ICONSTOP | MB_OK);
-       return (0);
+    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") );
+
+        return false;

     }
     }

-    
-    hDIB = GlobalAlloc(GHND, (DWORD)(sizeof(BITMAPINFOHEADER) + 
-                                       256 * sizeof(RGBQUAD)));
-    if (!hDIB)
-       return(0);
-
-#ifdef __WINDOWS_386__
-    lpbi = (LPBITMAPINFOHEADER)MK_FP32(GlobalLock(hDIB));
-#else
-    lpbi = (LPBITMAPINFOHEADER)GlobalLock(hDIB);
-#endif

 
 

-    /* read the BITMAPFILEHEADER */
-    if (sizeof (bf) != _lread (fh, (LPSTR)&bf, sizeof (bf)))
-       goto ErrExit;
+    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()"));
+
+        return false;
+    }
+
+    return true;
+}

 
 

-    if (bf.bfType != 0x4d42)   /* 'BM' */
-       goto ErrExit;
+#endif // __WXWINCE__/!__WXWINCE__

 
 

-    if (sizeof(BITMAPCOREHEADER) != _lread (fh, (LPSTR)lpbi, sizeof(BITMAPCOREHEADER)))
-       goto ErrExit;
+// ----------------------------------------------------------------------------
+// Loading/saving the DIBs
+// ----------------------------------------------------------------------------

 
 

-    if (lpbi->biSize == sizeof(BITMAPCOREHEADER))
+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__
+
+    if ( !m_handle )

     {
     {

-       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;
+        wxLogLastError(_T("Loading DIB from file"));
+
+        return false;

     }
     }

-    else
+
+    return true;
+}
+
+bool wxDIB::Save(const wxString& filename)
+{
+    wxCHECK_MSG( m_handle, false, _T("wxDIB::Save(): invalid object") );
+
+    wxFile file(filename, wxFile::write);
+    bool ok = file.IsOpened();
+    if ( ok )

     {
     {

-       // 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;
+        DIBSECTION ds;
+        if ( !GetDIBSection(m_handle, &ds) )
+        {
+            wxLogLastError(_T("GetObject(hDIB)"));
+        }
+        else
+        {
+            BITMAPFILEHEADER bmpHdr;
+            wxZeroMemory(bmpHdr);
+
+            const size_t sizeHdr = ds.dsBmih.biSize;
+            const size_t sizeImage = ds.dsBmih.biSizeImage;
+
+            bmpHdr.bfType = 0x4d42;    // 'BM' in little endian
+            bmpHdr.bfOffBits = sizeof(BITMAPFILEHEADER) + ds.dsBmih.biSize;
+            bmpHdr.bfSize = bmpHdr.bfOffBits + sizeImage;
+
+            // 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;
+        }

     }
 
     }
 

-    if (!(nNumColors = (WORD)lpbi->biClrUsed))
+    if ( !ok )

     {
     {

-       /* no color table for 24-bit, default size otherwise */
-       if (lpbi->biBitCount != 24)
-           nNumColors = 1 << lpbi->biBitCount; /* standard size table */
+        wxLogError(_("Failed to save the bitmap image to file \"%s\"."),
+                   filename.c_str());

     }
 
     }
 

-    /* fill in some default values if they are zero */
-    if (lpbi->biClrUsed == 0)
-       lpbi->biClrUsed = nNumColors;
+    return ok;
+}

 
 

-    if (lpbi->biSizeImage == 0)
+// ----------------------------------------------------------------------------
+// wxDIB accessors
+// ----------------------------------------------------------------------------
+
+void wxDIB::DoGetObject() const
+{
+    // only do something if we have a valid DIB but we don't [yet] have valid
+    // data
+    if ( m_handle && !m_data )

     {
     {

-       lpbi->biSizeImage = ((((lpbi->biWidth * (DWORD)lpbi->biBitCount) + 31) & ~31) >> 3)
-                        * lpbi->biHeight;
+        // 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;

     }
     }

+}

 
 

-    /* 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;
+// ----------------------------------------------------------------------------
+// DDB <-> DIB conversions
+// ----------------------------------------------------------------------------

 
 

-#ifdef __WINDOWS_386__
-    lpbi = (LPBITMAPINFOHEADER)MK_FP32(GlobalLock(hDIB));
-#else
-    lpbi = (LPBITMAPINFOHEADER)GlobalLock(hDIB);
-#endif
+#ifndef __WXWINCE__

 
 

-    /* read the color table */
-    if (!bCoreHead)
-       _lread(fh, (LPSTR)(lpbi) + lpbi->biSize, nNumColors * sizeof(RGBQUAD));
-    else
+HBITMAP wxDIB::CreateDDB(HDC hdc) const
+{
+    wxCHECK_MSG( m_handle, 0, _T("wxDIB::CreateDDB(): invalid object") );
+
+    DIBSECTION ds;
+    if ( !GetDIBSection(m_handle, &ds) )

     {
     {

-       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--)
-       {
-           pQuad[i].rgbRed = pTriple[i].rgbtRed;
-           pQuad[i].rgbBlue = pTriple[i].rgbtBlue;
-           pQuad[i].rgbGreen = pTriple[i].rgbtGreen;
-           pQuad[i].rgbReserved = 0;
-       }
-    }
+        wxLogLastError(_T("GetObject(hDIB)"));

 
 

-    /* offset to the bits from start of DIB header */
-    offBits = (WORD)lpbi->biSize + nNumColors * sizeof(RGBQUAD);
+        return 0;
+    }

 
 

-    if (bf.bfOffBits != 0L)
+    // how many colours are we going to have in the palette?
+    DWORD biClrUsed = ds.dsBmih.biClrUsed;
+    if ( !biClrUsed )

     {
     {

-        _llseek(fh,bf.bfOffBits,SEEK_SET);
+        // biClrUsed field might not be set
+        biClrUsed = GetNumberOfColours(ds.dsBmih.biBitCount);

     }
 
     }
 

-    if (lpbi->biSizeImage == lread(fh, (LPSTR)lpbi + offBits, lpbi->biSizeImage))
+    if ( !biClrUsed )

     {
     {

-       GlobalUnlock(hDIB);
-
-       hDC = GetDC(NULL);
-       if (!MakeBitmapAndPalette(hDC, hDIB, palette,
-                                       bitmap))
-       {
-           ReleaseDC(NULL,hDC);
-           goto ErrExit2;
-       }
-       else
-       {
-           ReleaseDC(NULL,hDC);
-            GlobalFree(hDIB);
-           result = TRUE;
-       }
+        return ConvertToBitmap((BITMAPINFO *)&ds.dsBmih, hdc, ds.dsBm.bmBits);

     }
     else
     {
     }
     else
     {

-ErrExit:
-       GlobalUnlock(hDIB);
-ErrExit2:
-       GlobalFree(hDIB);
+        // fake a BITMAPINFO w/o bits, just the palette info
+        wxCharBuffer bmi(sizeof(BITMAPINFO) + (biClrUsed - 1)*sizeof(RGBQUAD));
+        BITMAPINFO *pBmi = (BITMAPINFO *)bmi.data();
+        MemoryHDC hDC;
+        // get the colour table
+        SelectInHDC sDC(hDC, m_handle);
+        ::GetDIBColorTable(hDC, 0, biClrUsed, pBmi->bmiColors);
+        memcpy(&pBmi->bmiHeader, &ds.dsBmih, ds.dsBmih.biSize);
+
+        return ConvertToBitmap(pBmi, hdc, ds.dsBm.bmBits);

     }
     }

-
-    _lclose(fh);
-    return(result);

 }
 
 }
 

-/****************************************************************************
- *
- *  FUNCTION   : MakeBitmapAndPalette
- *
- *  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
- *
- ****************************************************************************/
-BOOL PASCAL MakeBitmapAndPalette(HDC hDC, HANDLE hDIB,
-                       HPALETTE * phPal, HBITMAP * phBitmap)
+/* static */
+HBITMAP wxDIB::ConvertToBitmap(const BITMAPINFO *pbmi, HDC hdc, void *bits)

 {
 {

-    LPBITMAPINFOHEADER lpInfo;
-    BOOL result = FALSE;
-    HBITMAP hBitmap;
-    HPALETTE hPalette, hOldPal;
-    LPSTR lpBits;
-
-#ifdef __WINDOWS_386__
-    lpInfo = (LPBITMAPINFOHEADER) MK_FP32(GlobalLock(hDIB));
-#else
-    lpInfo = (LPBITMAPINFOHEADER) GlobalLock(hDIB);
-#endif
+    wxCHECK_MSG( pbmi, 0, _T("invalid DIB in ConvertToBitmap") );

 
 

-    if ((hPalette = MakeDIBPalette(lpInfo)))
+    // 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 )

     {
     {

-       // 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;
-       }
+        // 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 )
+        {
+            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);

     }
     }

-    return(result);
-}

 
 

-/****************************************************************************
- *                                                                         *
- *  FUNCTION   : MakeDIBPalette(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 MakeDIBPalette(LPBITMAPINFOHEADER lpInfo)
-{
-    NPLOGPALETTE 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)
+    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 )

     {
     {

-/*
-       npPal = (NPLOGPALETTE)LocalAlloc(LMEM_FIXED, sizeof(LOGPALETTE) + 
-                               (WORD)lpInfo->biClrUsed * sizeof(PALETTEENTRY));
-*/
-       npPal = (NPLOGPALETTE)malloc(sizeof(LOGPALETTE) + 
-                               (WORD)lpInfo->biClrUsed * sizeof(PALETTEENTRY));
-
-        if (!npPal)
-           return(FALSE);
-
-       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; 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);
-//     LocalFree((HANDLE)npPal);
-        free(npPal);
-        
-       return(hLogPal);
+        wxLogLastError(wxT("CreateDIBitmap"));

     }
 
     }
 

-    /* 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 hbmp;

 }
 
 }
 

-bool wxLoadIntoBitmap(char *filename, wxBitmap *bitmap, wxColourMap **pal)
+/* static */
+size_t wxDIB::ConvertFromBitmap(BITMAPINFO *pbi, HBITMAP hbmp)

 {
 {

-  HBITMAP hBitmap;
-  HPALETTE hPalette;
+    wxASSERT_MSG( hbmp, wxT("invalid bmp can't be converted to DIB") );

 
 

-  bool success = (ReadDIB(filename, &hBitmap, &hPalette) != 0);
+    // prepare all the info we need
+    BITMAP bm;
+    if ( !::GetObject(hbmp, sizeof(bm), &bm) )
+    {
+        wxLogLastError(wxT("GetObject(bitmap)"));

 
 

-  if (!success)
-  {
-    DeleteObject(hPalette);
-    return FALSE;
-  }
+        return 0;
+    }

 
 

-  if (hPalette)
-  {
-    if (pal)
+    // 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
+            ) )

     {
     {

-      *pal = new wxColourMap;
-      (*pal)->SetHPALETTE((WXHPALETTE) hPalette);
+        wxLogLastError(wxT("GetDIBits()"));
+
+        return 0;

     }
     }

-    else
-      DeleteObject(hPalette);
-  }
-  else if (pal)
-    *pal = NULL;

 
 

-  if (hBitmap)
-  {
-    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);
-    bitmap->SetOk(TRUE);
-    return TRUE;
-  }
-  else return FALSE;
+    // return the total size
+    return dwLen + bi.biSizeImage;

 }
 
 }
 

-wxBitmap *wxLoadBitmap(char *filename, wxColourMap **pal)
+/* static */
+HGLOBAL wxDIB::ConvertFromBitmap(HBITMAP hbmp)

 {
 {

-  wxBitmap *bitmap = new wxBitmap;
-  if (wxLoadIntoBitmap(filename, bitmap, pal))
-    return bitmap;
-  else
-  {
-    delete bitmap;
-    return NULL;
-  }
-}
+    // first calculate the size needed
+    const size_t size = ConvertFromBitmap(NULL, hbmp);
+    if ( !size )
+    {
+        // conversion to DDB failed?
+        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.
-//
-// History:   Date      Reason
-//            11/07/91  Created
-//             
-//---------------------------------------------------------------------
-
-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;
-}
+    HGLOBAL hDIB = ::GlobalAlloc(GMEM_MOVEABLE, size);
+    if ( !hDIB )
+    {
+        // 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 *)GlobalPtrLock(hDIB), hbmp) )
+    {
+        // this really shouldn't happen... it worked the first time, why not
+        // now?
+        wxFAIL_MSG( _T("wxDIB::ConvertFromBitmap() unexpectedly failed") );

 
 

+        return NULL;
+    }

 
 

-LPSTR FindDIBBits (LPSTR lpbi)
-{
-   return (lpbi + *(LPDWORD)lpbi + PaletteSize (lpbi));
+    return hDIB;

 }
 
 }
 

-//---------------------------------------------------------------------
-//
-// 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.
-//
-//             Stolen almost verbatim from ShowDIB.
-//
-// 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.
-//
-// History:   Date      Reason
-//             6/01/91  Created
-//             
-//---------------------------------------------------------------------
+#endif // __WXWINCE__
+
+// ----------------------------------------------------------------------------
+// palette support
+// ----------------------------------------------------------------------------

 
 

-HANDLE BitmapToDIB (HBITMAP hBitmap, HPALETTE hPal)
+#if wxUSE_PALETTE
+
+wxPalette *wxDIB::CreatePalette() const

 {
 {

-   BITMAP             Bitmap;
-   BITMAPINFOHEADER   bmInfoHdr;
-   LPBITMAPINFOHEADER lpbmInfoHdr;
-   LPSTR              lpBits;
-   HDC                hMemDC;
-   HANDLE             hDIB;
-   HPALETTE           hOldPal = NULL;
+    // GetDIBColorTable not available in eVC3
+#if defined(_WIN32_WCE) && _WIN32_WCE < 400
+    return NULL;
+#else
+    wxCHECK_MSG( m_handle, NULL, _T("wxDIB::CreatePalette(): invalid object") );

 
 

-      // 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.
+    DIBSECTION ds;
+    if ( !GetDIBSection(m_handle, &ds) )
+    {
+        wxLogLastError(_T("GetObject(hDIB)"));

 
 

-   if (!hBitmap)
-      return NULL;
+        return 0;
+    }

 
 

-   if (!GetObject (hBitmap, sizeof (Bitmap), (LPSTR) &Bitmap))
-      return NULL;
+    // how many colours are we going to have in the palette?
+    DWORD biClrUsed = ds.dsBmih.biClrUsed;
+    if ( !biClrUsed )
+    {
+        // biClrUsed field might not be set
+        biClrUsed = GetNumberOfColours(ds.dsBmih.biBitCount);
+    }

 
 

-   InitBitmapInfoHeader (&bmInfoHdr, 
-                         Bitmap.bmWidth, 
-                         Bitmap.bmHeight, 
-                         Bitmap.bmPlanes * Bitmap.bmBitsPixel);
+    if ( !biClrUsed )
+    {
+        // 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;
+    }

 
 

+    MemoryHDC hDC;

 
 

-      // Now allocate memory for the DIB.  Then, set the BITMAPINFOHEADER
-      //  into this memory, and find out where the bitmap bits go.
+    // 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") );

 
 

-   hDIB = GlobalAlloc (GHND, sizeof (BITMAPINFOHEADER) + 
-             PaletteSize ((LPSTR) &bmInfoHdr) + bmInfoHdr.biSizeImage);
+    // initialize the palette header
+    pPalette->palVersion = 0x300;  // magic number, not in docs but works
+    pPalette->palNumEntries = (WORD)biClrUsed;

 
 

-   if (!hDIB)
-      return NULL;
+    // and the colour table
+    wxCharBuffer rgb(sizeof(RGBQUAD) * biClrUsed);
+    RGBQUAD *pRGB = (RGBQUAD*)rgb.data();
+    SelectInHDC selectHandle(hDC, m_handle);
+    ::GetDIBColorTable(hDC, 0, biClrUsed, pRGB);
+    for ( DWORD i = 0; i < biClrUsed; i++, pRGB++ )
+    {
+        pPalette->palPalEntry[i].peRed = pRGB->rgbRed;
+        pPalette->palPalEntry[i].peGreen = pRGB->rgbGreen;
+        pPalette->palPalEntry[i].peBlue = pRGB->rgbBlue;
+        pPalette->palPalEntry[i].peFlags = 0;
+    }

 
 

-#ifdef __WINDOWS_386__
-   lpbmInfoHdr  = (LPBITMAPINFOHEADER) MK_FP32(GlobalLock (hDIB));
-#else
-   lpbmInfoHdr  = (LPBITMAPINFOHEADER) GlobalLock (hDIB);
-#endif
+    HPALETTE hPalette = ::CreatePalette(pPalette);

 
 

-   *lpbmInfoHdr = bmInfoHdr;
-   lpBits       = FindDIBBits ((LPSTR) lpbmInfoHdr);
+    free(pPalette);

 
 

+    if ( !hPalette )
+    {
+        wxLogLastError(_T("CreatePalette"));

 
 

-      // Now, we need a DC to hold our bitmap.  If the app passed us
-      //  a palette, it should be selected into the DC.
+        return NULL;
+    }

 
 

-   hMemDC       = GetDC (NULL);
+    wxPalette *palette = new wxPalette;
+    palette->SetHPALETTE((WXHPALETTE)hPalette);

 
 

-   if (hPal)
-      {
-      hOldPal = SelectPalette (hMemDC, hPal, FALSE);
-      RealizePalette (hMemDC);
-      }
+    return palette;
+#endif
+}

 
 

+#endif // wxUSE_PALETTE

 
 

+// ----------------------------------------------------------------------------
+// wxImage support
+// ----------------------------------------------------------------------------

 
 

-      // 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 wxUSE_IMAGE

 
 

-   if (!GetDIBits (hMemDC, 
-                   hBitmap, 
-                   0, 
-                   Bitmap.bmHeight, 
-                   lpBits, 
-                   (LPBITMAPINFO) lpbmInfoHdr, 
-                   DIB_RGB_COLORS))
-      {
-      GlobalUnlock (hDIB);
-      GlobalFree (hDIB);
-      hDIB = NULL;
-      }
-   else
-      GlobalUnlock (hDIB);
+bool wxDIB::Create(const wxImage& image)
+{
+    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
+    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;
+}

 
 

-      // Finally, clean up and return.
+wxImage wxDIB::ConvertToImage() const
+{
+    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() )
+    {
+        wxFAIL_MSG( wxT("could not allocate data for image") );
+        return wxNullImage;
+    }

 
 

-   if (hOldPal)
-      SelectPalette (hMemDC, hOldPal, FALSE);
+    if ( m_hasAlpha )
+    {
+        image.SetAlpha();
+    }

 
 

-   ReleaseDC (NULL, hMemDC);
+    // 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++ )
+    {
+        // 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;
+    }

 
 

-   return hDIB;
+    return image;

 }
 
 }
 

-bool wxSaveBitmap(char *filename, wxBitmap *bitmap, wxColourMap *colourmap)
-{
-  HPALETTE hPalette = 0;
-  if (colourmap)
-    hPalette = (HPALETTE) colourmap->GetHPALETTE();
-
-  HANDLE dibHandle = BitmapToDIB((HBITMAP) bitmap->GetHBITMAP(), hPalette);
-  if (dibHandle)
-  {
-    bool success = (WriteDIB(filename, dibHandle) != 0);
-    GlobalFree(dibHandle);
-    return success;
-  }
-  else return FALSE;
-}
+#endif // wxUSE_IMAGE

 
 

+#endif // wxUSE_WXDIB