X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/526954c5968baa29218c994ec48e476ae2bd4b9f..655e246b86923bf721f1725191140451a189ca0c:/src/msw/dib.cpp?ds=inline diff --git a/src/msw/dib.cpp b/src/msw/dib.cpp index 9ea25315bf..14a44e2339 100644 --- a/src/msw/dib.cpp +++ b/src/msw/dib.cpp @@ -137,20 +137,10 @@ bool wxDIB::Create(int width, int height, int depth) return true; } -bool wxDIB::Create(const wxBitmap& bmp) -{ - wxCHECK_MSG( bmp.Ok(), false, wxT("wxDIB::Create(): invalid bitmap") ); - - if ( !Create(GetHbitmapOf(bmp)) ) - return false; - - m_hasAlpha = bmp.HasAlpha(); - - 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; @@ -280,7 +270,7 @@ bool wxDIB::Load(const wxString& filename) m_handle = (HBITMAP)::LoadImage ( wxGetInstance(), - filename.fn_str(), + filename.t_str(), IMAGE_BITMAP, 0, 0, // don't specify the size LR_CREATEDIBSECTION | LR_LOADFROMFILE @@ -668,7 +658,7 @@ 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, wxT("invalid wxImage in wxDIB ctor") ); @@ -677,8 +667,8 @@ bool wxDIB::Create(const wxImage& image) // 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; + const bool hasAlpha = image.HasAlpha(); + const int bpp = hasAlpha ? 32 : 24; if ( !Create(w, h, bpp) ) return false; @@ -688,32 +678,53 @@ 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 = m_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; if ( alpha ) { - for ( int x = 0; x < w; x++ ) + int x; + + switch ( pf ) { - // 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; + 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++ ) { - // RGB order is reversed. *dst++ = src[2]; *dst++ = src[1]; *dst++ = src[0]; @@ -748,20 +759,30 @@ wxImage wxDIB::ConvertToImage() const return wxNullImage; } - if ( m_hasAlpha ) + 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 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++ ) { @@ -773,20 +794,36 @@ wxImage wxDIB::ConvertToImage() const dst[1] = *src++; dst[0] = *src++; - if ( is32bit ) + if ( bpp == 32 ) { - if ( alpha ) + // 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 ) { - // wxImage uses non premultiplied alpha so undo - // premultiplication done in Create() above - const unsigned char a = *src; - *alpha++ = a; - if ( a > 0 ) - { - dst[0] = (dst[0] * 255) / a; - dst[1] = (dst[1] * 255) / a; - dst[2] = (dst[2] * 255) / 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++; @@ -804,6 +841,12 @@ wxImage wxDIB::ConvertToImage() const srcLineStart += srcBytesPerLine; } + if ( hasOpaque && hasTransparent ) + hasAlpha = true; + + if ( !hasAlpha && image.HasAlpha() ) + image.ClearAlpha(); + return image; }