- // sizeLimit is the MS upper limit for the DIB size
- int sizeLimit = 1024*768*3;
-
- // width and height of the device-dependent bitmap
- int width = GetWidth();
- int bmpHeight = GetHeight();
-
- // calc the number of bytes per scanline and padding
- int bytePerLine = width*3;
- int sizeDWORD = sizeof( DWORD );
- div_t lineBoundary = div( bytePerLine, sizeDWORD );
- int padding = 0;
- if( lineBoundary.rem > 0 )
- {
- padding = sizeDWORD - lineBoundary.rem;
- bytePerLine += padding;
- }
- // calc the number of DIBs and heights of DIBs
- int numDIB = 1;
- int hRemain = 0;
- int height = sizeLimit/bytePerLine;
- if( height >= bmpHeight )
- height = bmpHeight;
- else
- {
- div_t result = div( bmpHeight, height );
- numDIB = result.quot;
- hRemain = result.rem;
- if( hRemain >0 ) numDIB++;
- }
-
- // set bitmap parameters
- wxBitmap bitmap;
- wxCHECK_MSG( Ok(), bitmap, _T("invalid image") );
- bitmap.SetWidth( width );
- bitmap.SetHeight( bmpHeight );
- bitmap.SetDepth( wxDisplayDepth() );
-
- // create a DIB header
- int headersize = sizeof(BITMAPINFOHEADER);
- LPBITMAPINFO lpDIBh = (BITMAPINFO *) malloc( headersize );
- wxCHECK_MSG( lpDIBh, bitmap, _T("could not allocate memory for DIB header") );
- // Fill in the DIB header
- lpDIBh->bmiHeader.biSize = headersize;
- lpDIBh->bmiHeader.biWidth = (DWORD)width;
- lpDIBh->bmiHeader.biHeight = (DWORD)(-height);
- lpDIBh->bmiHeader.biSizeImage = bytePerLine*height;
- // the general formula for biSizeImage:
- // ( ( ( ((DWORD)width*24) +31 ) & ~31 ) >> 3 ) * height;
- lpDIBh->bmiHeader.biPlanes = 1;
- lpDIBh->bmiHeader.biBitCount = 24;
- lpDIBh->bmiHeader.biCompression = BI_RGB;
- lpDIBh->bmiHeader.biClrUsed = 0;
- // These seem not really needed for our purpose here.
- lpDIBh->bmiHeader.biClrImportant = 0;
- lpDIBh->bmiHeader.biXPelsPerMeter = 0;
- lpDIBh->bmiHeader.biYPelsPerMeter = 0;
- // memory for DIB data
- unsigned char *lpBits;
- lpBits = (unsigned char *)malloc( lpDIBh->bmiHeader.biSizeImage );
- if( !lpBits )
- {
- wxFAIL_MSG( _T("could not allocate memory for DIB") );
- free( lpDIBh );
- return bitmap;
- }
-
- // create and set the device-dependent bitmap
- HDC hdc = ::GetDC(NULL);
- HDC memdc = ::CreateCompatibleDC( hdc );
- HBITMAP hbitmap;
- hbitmap = ::CreateCompatibleBitmap( hdc, width, bmpHeight );
- ::SelectObject( memdc, hbitmap);
-
- // copy image data into DIB data and then into DDB (in a loop)
- unsigned char *data = GetData();
- int i, j, n;
- int origin = 0;
- unsigned char *ptdata = data;
- unsigned char *ptbits;
-
- for( n=0; n<numDIB; n++ )
- {
- if( numDIB > 1 && n == numDIB-1 && hRemain > 0 )
- {
- // redefine height and size of the (possibly) last smaller DIB
- // memory is not reallocated
- height = hRemain;
- lpDIBh->bmiHeader.biHeight = (DWORD)(-height);
- lpDIBh->bmiHeader.biSizeImage = bytePerLine*height;
- }
- ptbits = lpBits;
-
- for( j=0; j<height; j++ )
- {
- for( i=0; i<width; i++ )
- {
- *(ptbits++) = *(ptdata+2);
- *(ptbits++) = *(ptdata+1);
- *(ptbits++) = *(ptdata );
- ptdata += 3;
- }
- for( i=0; i< padding; i++ ) *(ptbits++) = 0;
- }
- ::StretchDIBits( memdc, 0, origin, width, height,\
- 0, 0, width, height, lpBits, lpDIBh, DIB_RGB_COLORS, SRCCOPY);
- origin += height;
- // if numDIB = 1, lines below can also be used
- // hbitmap = CreateDIBitmap( hdc, &(lpDIBh->bmiHeader), CBM_INIT, lpBits, lpDIBh, DIB_RGB_COLORS );
- // The above line is equivalent to the following two lines.
- // hbitmap = ::CreateCompatibleBitmap( hdc, width, height );
- // ::SetDIBits( hdc, hbitmap, 0, height, lpBits, lpDIBh, DIB_RGB_COLORS);
- // or the following lines
- // hbitmap = ::CreateCompatibleBitmap( hdc, width, height );
- // HDC memdc = ::CreateCompatibleDC( hdc );
- // ::SelectObject( memdc, hbitmap);
- // ::SetDIBitsToDevice( memdc, 0, 0, width, height,
- // 0, 0, 0, height, (void *)lpBits, lpDIBh, DIB_RGB_COLORS);
- // ::SelectObject( memdc, 0 );
- // ::DeleteDC( memdc );
- }
- bitmap.SetHBITMAP( (WXHBITMAP) hbitmap );
-
- // similarly, created an mono-bitmap for the possible mask
- if( HasMask() )
- {
- hbitmap = ::CreateBitmap( (WORD)width, (WORD)bmpHeight, 1, 1, NULL );
- ::SelectObject( memdc, hbitmap);
- if( numDIB == 1 ) height = bmpHeight;
- else height = sizeLimit/bytePerLine;
- lpDIBh->bmiHeader.biHeight = (DWORD)(-height);
- lpDIBh->bmiHeader.biSizeImage = bytePerLine*height;
- origin = 0;
- unsigned char r = GetMaskRed();
- unsigned char g = GetMaskGreen();
- unsigned char b = GetMaskBlue();
- unsigned char zero = 0, one = 255;
- ptdata = data;
- for( n=0; n<numDIB; n++ )
- {
- if( numDIB > 1 && n == numDIB - 1 && hRemain > 0 )
- {
- // redefine height and size of the (possibly) last smaller DIB
- // memory is not reallocated
- height = hRemain;
- lpDIBh->bmiHeader.biHeight = (DWORD)(-height);
- lpDIBh->bmiHeader.biSizeImage = bytePerLine*height;
- }
- ptbits = lpBits;
- for( int j=0; j<height; j++ )
- {
- for(i=0; i<width; i++ )
- {
- if( (*(ptdata++)!=r) | (*(ptdata++)!=g) | (*(ptdata++)!=b) )
- {
- *(ptbits++) = one;
- *(ptbits++) = one;
- *(ptbits++) = one;
- }
- else
- {
- *(ptbits++) = zero;
- *(ptbits++) = zero;
- *(ptbits++) = zero;
- }
- }
- for( i=0; i< padding; i++ ) *(ptbits++) = zero;
- }
- ::StretchDIBits( memdc, 0, origin, width, height,\
- 0, 0, width, height, lpBits, lpDIBh, DIB_RGB_COLORS, SRCCOPY);
- origin += height;
- }
- // create a wxMask object
- wxMask *mask = new wxMask();
- mask->SetMaskBitmap( (WXHBITMAP) hbitmap );
- bitmap.SetMask( mask );
- // It will be deleted when the wxBitmap object is deleted (as of 01/1999)
- /* The following can also be used but is slow to run
- wxColour colour( GetMaskRed(), GetMaskGreen(), GetMaskBlue());
- wxMask *mask = new wxMask( bitmap, colour );
- bitmap.SetMask( mask );
- */
- }
-
- // free allocated resources
- ::SelectObject( memdc, 0 );
- ::DeleteDC( memdc );
- ::ReleaseDC(NULL, hdc);
- free(lpDIBh);
- free(lpBits);
-
- // check the wxBitmap object
- if( bitmap.GetHBITMAP() )
- bitmap.SetOk( TRUE );
- else
- bitmap.SetOk( FALSE );
-
- return bitmap;
projects / wxWidgets.git / blobdiff