/////////////////////////////////////////////////////////////////////////////// // 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) // Copyright: (c) 2003 Vadim Zeitlin // 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. */ // ============================================================================ // declarations // ============================================================================ // ---------------------------------------------------------------------------- // headers // ---------------------------------------------------------------------------- // For compilers that support precompilation, includes "wx.h". #include "wx/wxprec.h" #ifdef __BORLANDC__ #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/file.h" #include #include #include #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 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 // ============================================================================ // ---------------------------------------------------------------------------- // wxDIB creation // ---------------------------------------------------------------------------- bool wxDIB::Create(int width, int height, int depth) { // 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; // allocate memory for bitmap structures BITMAPINFO info; wxZeroMemory(info); 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.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) ); if ( !m_handle ) { wxLogLastError(wxT("CreateDIBSection")); return false; } m_width = width; m_height = height; m_depth = depth; return true; } bool wxDIB::Create(HBITMAP hbmp) { 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)")); return false; } int d = bm.bmBitsPixel; if ( d <= 0 ) d = wxDisplayDepth(); if ( !Create(bm.bmWidth, bm.bmHeight, d) || !CopyFromDDB(hbmp) ) return false; } return true; } // 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; 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 ( 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; } #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.t_str(), IMAGE_BITMAP, 0, 0, // don't specify the size LR_CREATEDIBSECTION | LR_LOADFROMFILE ); #endif // __WXWINCE__ if ( !m_handle ) { wxLogLastError(wxT("Loading DIB from file")); return false; } return true; } bool wxDIB::Save(const wxString& filename) { 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 ( !GetDIBSection(m_handle, &ds) ) { wxLogLastError(wxT("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; } } #else // !wxUSE_FILE bool ok = false; #endif // wxUSE_FILE/!wxUSE_FILE if ( !ok ) { wxLogError(_("Failed to save the bitmap image to file \"%s\"."), filename.c_str()); } return ok; } // ---------------------------------------------------------------------------- // 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 ) { // 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(wxT("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; } } // ---------------------------------------------------------------------------- // DDB <-> DIB conversions // ---------------------------------------------------------------------------- #ifndef __WXWINCE__ HBITMAP wxDIB::CreateDDB(HDC hdc) const { wxCHECK_MSG( m_handle, 0, wxT("wxDIB::CreateDDB(): invalid object") ); DIBSECTION ds; if ( !GetDIBSection(m_handle, &ds) ) { wxLogLastError(wxT("GetObject(hDIB)")); return 0; } // 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, 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 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 ) { // 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); } 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 ) { wxLogLastError(wxT("CreateDIBitmap")); } 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) ) { wxLogLastError(wxT("GetObject(bitmap)")); return 0; } // 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 ) ) { wxLogLastError(wxT("GetDIBits()")); return 0; } // return the total size return dwLen + bi.biSizeImage; } /* static */ HGLOBAL wxDIB::ConvertFromBitmap(HBITMAP hbmp) { // first calculate the size needed const size_t size = ConvertFromBitmap(NULL, hbmp); if ( !size ) { // conversion to DDB failed? return NULL; } 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 allocate %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( wxT("wxDIB::ConvertFromBitmap() unexpectedly failed") ); return NULL; } return hDIB; } #endif // __WXWINCE__ // ---------------------------------------------------------------------------- // palette support // ---------------------------------------------------------------------------- #if wxUSE_PALETTE wxPalette *wxDIB::CreatePalette() const { // 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 ( !GetDIBSection(m_handle, &ds) ) { wxLogLastError(wxT("GetObject(hDIB)")); return 0; } // 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 ) { // 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; // 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, wxT("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 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; } HPALETTE hPalette = ::CreatePalette(pPalette); free(pPalette); if ( !hPalette ) { wxLogLastError(wxT("CreatePalette")); return NULL; } wxPalette *palette = new wxPalette; palette->SetHPALETTE((WXHPALETTE)hPalette); return palette; #endif } #endif // wxUSE_PALETTE // ---------------------------------------------------------------------------- // wxImage support // ---------------------------------------------------------------------------- #if wxUSE_IMAGE bool wxDIB::Create(const wxImage& image, PixelFormat pf) { wxCHECK_MSG( image.IsOk(), false, wxT("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; 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 = 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. Note that RGB components order is reversed in // Windows bitmaps compared to wxImage and is actually BGR. unsigned char *dst = dstLineStart; if ( alpha ) { 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; } } 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 src -= 2*srcBytesPerLine; if ( alpha ) alpha -= 2*w; // and to the next one in the DIB dstLineStart += dstBytesPerLine; } 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