X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/2b254edf9cb508b48bfd3f9cf76d46f7cf1e1f5b..43c42c18d36c703a88b1b7b697bac27fe5608eca:/src/msw/dib.cpp diff --git a/src/msw/dib.cpp b/src/msw/dib.cpp index fe4136e2a3..b12baf0f83 100644 --- a/src/msw/dib.cpp +++ b/src/msw/dib.cpp @@ -6,14 +6,13 @@ // Created: 03.03.03 (replaces the old file with the same name) // RCS-ID: $Id$ // Copyright: (c) 2003 Vadim Zeitlin -// License: wxWindows licence +// Licence: 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 and we shouldn't use - GetBitmapBits() at all because we can't do it with it) + caling GetDIBits() in the DC we use with it. */ // ============================================================================ @@ -31,40 +30,51 @@ #pragma hdrstop #endif +#if wxUSE_WXDIB + #ifndef WX_PRECOMP #include "wx/string.h" #include "wx/log.h" + #include "wx/intl.h" + #include "wx/bitmap.h" + #include "wx/image.h" #endif //WX_PRECOMP -#include "wx/bitmap.h" -#include "wx/intl.h" #include "wx/file.h" #include #include -#if !defined(__MWERKS__) && !defined(__SALFORDC__) #include -#endif - -#ifdef __GNUWIN32_OLD__ - #include "wx/msw/gnuwin32/extra.h" -#endif -#include "wx/image.h" #include "wx/msw/dib.h" +#ifdef __WXWINCE__ + #include // for SHLoadDIBitmap() +#endif + // ---------------------------------------------------------------------------- // private functions // ---------------------------------------------------------------------------- // calculate the number of palette entries needed for the bitmap with this // number of bits per pixel -static WORD wxGetNumOfBitmapColors(WORD bitsPerPixel) +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 bitsPerPixel <= 8 ? 1 << bitsPerPixel : 0; + 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; } // ============================================================================ @@ -77,43 +87,40 @@ static WORD wxGetNumOfBitmapColors(WORD bitsPerPixel) 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()") ); - - static const int infosize = sizeof(BITMAPINFOHEADER); - - BITMAPINFO *info = (BITMAPINFO *)malloc(infosize); - wxCHECK_MSG( info, NULL, _T("malloc(BITMAPINFO) failed") ); + // we don't support formats using palettes right now so we only create + // either 24bpp (RGB) or 32bpp (RGBA) bitmaps + wxASSERT_MSG( depth, wxT("invalid image depth in wxDIB::Create()") ); + if ( depth < 24 ) + depth = 24; - memset(info, 0, infosize); + // allocate memory for bitmap structures + BITMAPINFO info; + wxZeroMemory(info); - info->bmiHeader.biSize = infosize; - info->bmiHeader.biWidth = width; + info.bmiHeader.biSize = sizeof(BITMAPINFOHEADER); + 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.biHeight = height; - info->bmiHeader.biPlanes = 1; - info->bmiHeader.biBitCount = depth; - info->bmiHeader.biSizeImage = GetLineSize(width, depth)*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 + &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")); @@ -128,52 +135,149 @@ bool wxDIB::Create(int width, int height, int depth) return true; } -bool wxDIB::Create(const wxBitmap& bmp) +bool wxDIB::Create(HBITMAP hbmp) { - wxCHECK_MSG( bmp.Ok(), false, _T("wxDIB::Create(): invalid bitmap") ); + wxCHECK_MSG( hbmp, false, wxT("wxDIB::Create(): invalid bitmap") ); + + // 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)")); - const int w = bmp.GetWidth(); - const int h = bmp.GetHeight(); - int d = bmp.GetDepth(); - if ( d == -1 ) - d = wxDisplayDepth(); + return false; + } + + int d = bm.bmBitsPixel; + if ( d <= 0 ) + d = wxDisplayDepth(); + + if ( !Create(bm.bmWidth, bm.bmHeight, d) || !CopyFromDDB(hbmp) ) + return false; + } + + return true; +} - if ( !Create(w, h, d) ) +// 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) +{ + 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; - // we could have used GetDIBits() too but GetBitmapBits() is simpler - if ( !::GetBitmapBits + + if ( !::BitBlt( + hdcDst, + 0, 0, m_width, m_height, + hdcSrc, + 0, 0, + SRCCOPY + ) ) + { + wxLogLastError(wxT("BitBlt(DDB -> DIB)")); + + return false; + } + + return true; +} + +#else // !__WXWINCE__ + +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( wxT("GetObject(DIBSECTION) unexpectedly failed") ); + + return false; + } + + if ( !::GetDIBits ( - GetHbitmapOf(bmp), // the source DDB - GetLineSize(w, d)*h, // the number of bytes to copy - m_data // the pixels will be copied here + 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 0; + return false; } return true; } +#endif // __WXWINCE__/!__WXWINCE__ + // ---------------------------------------------------------------------------- // Loading/saving the DIBs // ---------------------------------------------------------------------------- bool wxDIB::Load(const wxString& filename) { +#ifdef __WXWINCE__ + m_handle = SHLoadDIBitmap(filename); +#else // !__WXWINCE__ m_handle = (HBITMAP)::LoadImage ( wxGetInstance(), - filename, + filename.t_str(), IMAGE_BITMAP, 0, 0, // don't specify the size LR_CREATEDIBSECTION | LR_LOADFROMFILE ); +#endif // __WXWINCE__ + if ( !m_handle ) { - wxLogLastError(_T("LoadImage(LR_CREATEDIBSECTION | LR_LOADFROMFILE)")); + wxLogLastError(wxT("Loading DIB from file")); return false; } @@ -183,16 +287,17 @@ bool wxDIB::Load(const wxString& filename) bool wxDIB::Save(const wxString& filename) { - wxCHECK_MSG( m_handle, false, _T("wxDIB::Save(): invalid object") ); + wxCHECK_MSG( m_handle, false, wxT("wxDIB::Save(): invalid object") ); +#if wxUSE_FILE wxFile file(filename, wxFile::write); bool ok = file.IsOpened(); if ( ok ) { DIBSECTION ds; - if ( !::GetObject(m_handle, sizeof(ds), &ds) ) + if ( !GetDIBSection(m_handle, &ds) ) { - wxLogLastError(_T("GetObject(hDIB)")); + wxLogLastError(wxT("GetObject(hDIB)")); } else { @@ -213,6 +318,9 @@ bool wxDIB::Save(const wxString& filename) file.Write(ds.dsBm.bmBits, sizeImage) == sizeImage; } } +#else // !wxUSE_FILE + bool ok = false; +#endif // wxUSE_FILE/!wxUSE_FILE if ( !ok ) { @@ -239,9 +347,9 @@ void wxDIB::DoGetObject() const // 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) ) + if ( !GetDIBSection(m_handle, &ds) ) { - wxLogLastError(_T("GetObject(hDIB)")); + wxLogLastError(wxT("GetObject(hDIB)")); return; } @@ -258,25 +366,51 @@ void wxDIB::DoGetObject() const // DDB <-> DIB conversions // ---------------------------------------------------------------------------- +#ifndef __WXWINCE__ + HBITMAP wxDIB::CreateDDB(HDC hdc) const { - wxCHECK_MSG( m_handle, 0, _T("wxDIB::CreateDDB(): invalid object") ); + wxCHECK_MSG( m_handle, 0, wxT("wxDIB::CreateDDB(): invalid object") ); DIBSECTION ds; - if ( !::GetObject(m_handle, sizeof(ds), &ds) ) + if ( !GetDIBSection(m_handle, &ds) ) { - wxLogLastError(_T("GetObject(hDIB)")); + wxLogLastError(wxT("GetObject(hDIB)")); return 0; } - return ConvertToBitmap((BITMAPINFO *)&ds.dsBmih, hdc, ds.dsBm.bmBits); + // 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); + } + + if ( !biClrUsed ) + { + return ConvertToBitmap((BITMAPINFO *)&ds.dsBmih, hdc, ds.dsBm.bmBits); + } + else + { + // 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); + } } /* static */ HBITMAP wxDIB::ConvertToBitmap(const BITMAPINFO *pbmi, HDC hdc, void *bits) { - wxCHECK_MSG( pbmi, 0, _T("invalid DIB in ConvertToBitmap") ); + wxCHECK_MSG( pbmi, 0, wxT("invalid DIB in ConvertToBitmap") ); // here we get BITMAPINFO struct followed by the actual bitmap bits and // BITMAPINFO starts with BITMAPINFOHEADER followed by colour info @@ -288,13 +422,31 @@ HBITMAP wxDIB::ConvertToBitmap(const BITMAPINFO *pbmi, HDC hdc, void *bits) if ( !bits ) { // we must skip over the colour table to get to the image data - - // biClrUsed has the number of colors but it may be not initialized at - // all - int numColors = pbmih->biClrUsed; - if ( !numColors ) + // + // 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 ) { - numColors = wxGetNumOfBitmapColors(pbmih->biBitCount); + 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); @@ -303,7 +455,7 @@ HBITMAP wxDIB::ConvertToBitmap(const BITMAPINFO *pbmi, HDC hdc, void *bits) HBITMAP hbmp = ::CreateDIBitmap ( hdc ? hdc // create bitmap compatible - : ScreenHDC(), // with this DC + : (HDC) ScreenHDC(), // with this DC pbmih, // used to get size &c CBM_INIT, // initialize bitmap bits too bits, // ... using this data @@ -354,7 +506,7 @@ size_t wxDIB::ConvertFromBitmap(BITMAPINFO *pbi, HBITMAP hbmp) bi.biBitCount = bm.bmBitsPixel; // memory we need for BITMAPINFO only - DWORD dwLen = bi.biSize + wxGetNumOfBitmapColors(bm.bmBitsPixel) * sizeof(RGBQUAD); + DWORD dwLen = bi.biSize + GetNumberOfColours(bm.bmBitsPixel) * sizeof(RGBQUAD); // get either just the image size or the image bits if ( !::GetDIBits @@ -394,17 +546,17 @@ HGLOBAL wxDIB::ConvertFromBitmap(HBITMAP hbmp) { // 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."), + wxLogError(_("Failed to allocate %luKb of memory for bitmap data."), (unsigned long)(size / 1024)); return NULL; } - if ( !ConvertFromBitmap((BITMAPINFO *)GlobalHandle(hDIB), hbmp) ) + 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") ); + wxFAIL_MSG( wxT("wxDIB::ConvertFromBitmap() unexpectedly failed") ); return NULL; } @@ -412,6 +564,8 @@ HGLOBAL wxDIB::ConvertFromBitmap(HBITMAP hbmp) return hDIB; } +#endif // __WXWINCE__ + // ---------------------------------------------------------------------------- // palette support // ---------------------------------------------------------------------------- @@ -420,12 +574,16 @@ HGLOBAL wxDIB::ConvertFromBitmap(HBITMAP hbmp) wxPalette *wxDIB::CreatePalette() const { - wxCHECK_MSG( m_handle, NULL, _T("wxDIB::CreatePalette(): invalid object") ); + // GetDIBColorTable not available in eVC3 +#if !defined(__WXMSW__) || defined(_WIN32_WCE) && _WIN32_WCE < 400 + return NULL; +#else + wxCHECK_MSG( m_handle, NULL, wxT("wxDIB::CreatePalette(): invalid object") ); DIBSECTION ds; - if ( !::GetObject(m_handle, sizeof(ds), &ds) ) + if ( !GetDIBSection(m_handle, &ds) ) { - wxLogLastError(_T("GetObject(hDIB)")); + wxLogLastError(wxT("GetObject(hDIB)")); return 0; } @@ -435,7 +593,7 @@ wxPalette *wxDIB::CreatePalette() const if ( !biClrUsed ) { // biClrUsed field might not be set - biClrUsed = wxGetNumOfBitmapColors(ds.dsBmih.biBitCount); + biClrUsed = GetNumberOfColours(ds.dsBmih.biBitCount); } if ( !biClrUsed ) @@ -447,18 +605,23 @@ wxPalette *wxDIB::CreatePalette() const return NULL; } + MemoryHDC hDC; + // 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") ); + wxCHECK_MSG( pPalette, NULL, wxT("out of memory") ); // initialize the palette header pPalette->palVersion = 0x300; // magic number, not in docs but works - pPalette->palNumEntries = biClrUsed; + 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); + // 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; @@ -473,7 +636,7 @@ wxPalette *wxDIB::CreatePalette() const if ( !hPalette ) { - wxLogLastError(_T("CreatePalette")); + wxLogLastError(wxT("CreatePalette")); return NULL; } @@ -482,6 +645,7 @@ wxPalette *wxDIB::CreatePalette() const palette->SetHPALETTE((WXHPALETTE)hPalette); return palette; +#endif } #endif // wxUSE_PALETTE @@ -492,9 +656,9 @@ wxPalette *wxDIB::CreatePalette() const #if wxUSE_IMAGE -bool wxDIB::Create(const wxImage& image) +bool wxDIB::Create(const wxImage& image, PixelFormat pf) { - wxCHECK_MSG( image.Ok(), false, _T("invalid wxImage in wxDIB ctor") ); + wxCHECK_MSG( image.IsOk(), false, wxT("invalid wxImage in wxDIB ctor") ); const int h = image.GetHeight(); const int w = image.GetWidth(); @@ -512,23 +676,58 @@ bool wxDIB::Create(const wxImage& image) 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; + 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 + // Copy one DIB line. Note that RGB components order is reversed in + // Windows bitmaps compared to wxImage and is actually BGR. unsigned char *dst = dstLineStart; - for ( int x = 0; x < w; x++ ) + if ( alpha ) { - // also, the order of RGB is inversed for DIBs - *dst++ = src[2]; - *dst++ = src[1]; - *dst++ = src[0]; + int x; + + switch ( pf ) + { + case PixelFormat_PreMultiplied: + // Pre-multiply pixel values so that the DIB could be used + // with ::AlphaBlend(). + for ( x = 0; x < w; x++ ) + { + 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; + } + break; + + case PixelFormat_NotPreMultiplied: + // Just copy pixel data without changing it. + for ( x = 0; x < w; x++ ) + { + *dst++ = src[2]; + *dst++ = src[1]; + *dst++ = src[0]; + + *dst++ = *alpha++; + src += 3; + } + break; + } - src += 3; - - if ( alpha ) - *dst++ = *alpha++; + } + else // no alpha channel + { + for ( int x = 0; x < w; x++ ) + { + *dst++ = src[2]; + *dst++ = src[1]; + *dst++ = src[0]; + src += 3; + } } // pass to the previous line in the image @@ -543,5 +742,112 @@ bool wxDIB::Create(const wxImage& image) return true; } +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.IsOk() ) + { + wxFAIL_MSG( wxT("could not allocate data for image") ); + return wxNullImage; + } + + const int bpp = GetDepth(); + + // Remember if we have any "real" transparency, i.e. either any partially + // transparent pixels or not all pixels are fully opaque or fully + // transparent. + bool hasAlpha = false; + bool hasOpaque = false; + bool hasTransparent = false; + + if ( bpp == 32 ) + { + // 32 bit bitmaps may be either 0RGB or ARGB and we don't know in + // advance which one do we have so suppose we have alpha of them and + // get rid of it later if it turns out we didn't. + image.SetAlpha(); + } + + // this is the same loop as in Create() just above but with copy direction + // reversed + 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 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++; + + if ( bpp == 32 ) + { + // wxImage uses non premultiplied alpha so undo + // premultiplication done in Create() above + const unsigned char a = *src; + *alpha++ = a; + + // Check what kind of alpha do we have. + switch ( a ) + { + case 0: + hasTransparent = true; + break; + + default: + // Anything in between means we have real transparency + // and must use alpha channel. + hasAlpha = true; + break; + + case 255: + hasOpaque = true; + break; + } + + if ( a > 0 ) + { + dst[0] = (dst[0] * 255) / a; + dst[1] = (dst[1] * 255) / a; + dst[2] = (dst[2] * 255) / a; + } + + src++; + } + + dst += 3; + } + + // 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; + } + + if ( hasOpaque && hasTransparent ) + hasAlpha = true; + + if ( !hasAlpha && image.HasAlpha() ) + image.ClearAlpha(); + + return image; +} + #endif // wxUSE_IMAGE +#endif // wxUSE_WXDIB