allow specifying the mask colour in wxImage::ConvertAlphaToMask() (closes #10143)

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

diff --git a/src/msw/dib.cpp b/src/msw/dib.cpp
index 66ebda4954c55bc634f3b31f25d036aa8af2fdc9..35ddb6d72fe3b33bb76fd1c77b933ba3ba50b428 100644 (file)
--- a/src/msw/dib.cpp
+++ b/src/msw/dib.cpp
@@ -30,25 +30,25 @@
     #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
 
-#if wxUSE_WXDIB
-
-#include "wx/bitmap.h"
-#include "wx/intl.h"
 #include "wx/file.h"
 
 #include <stdio.h>
 #include <stdlib.h>
 
-#if !defined(__MWERKS__) && !defined(__SALFORDC__)
+#if !defined(__MWERKS__)
     #include <memory.h>
 #endif
 
-#include "wx/image.h"
 #include "wx/msw/dib.h"
 
 #ifdef __WXWINCE__
@@ -96,39 +96,33 @@ bool wxDIB::Create(int width, int height, int depth)
         depth = 24;
 
     // allocate memory for bitmap structures
-    static const int sizeHeader = sizeof(BITMAPINFOHEADER);
+    BITMAPINFO info;
+    wxZeroMemory(info);
 
-    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;
+    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 = (WORD)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"));
@@ -286,7 +280,7 @@ bool wxDIB::Load(const wxString& filename)
     m_handle = (HBITMAP)::LoadImage
                          (
                             wxGetInstance(),
-                            filename,
+                            filename.fn_str(),
                             IMAGE_BITMAP,
                             0, 0, // don't specify the size
                             LR_CREATEDIBSECTION | LR_LOADFROMFILE
@@ -307,6 +301,7 @@ bool wxDIB::Save(const wxString& filename)
 {
     wxCHECK_MSG( m_handle, false, _T("wxDIB::Save(): invalid object") );
 
+#if wxUSE_FILE
     wxFile file(filename, wxFile::write);
     bool ok = file.IsOpened();
     if ( ok )
@@ -335,6 +330,9 @@ 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 )
     {
@@ -566,7 +564,7 @@ HGLOBAL wxDIB::ConvertFromBitmap(HBITMAP hbmp)
         return NULL;
     }
 
-    if ( !ConvertFromBitmap((BITMAPINFO *)(void *)GlobalPtr(hDIB), hbmp) )
+    if ( !ConvertFromBitmap((BITMAPINFO *)(void *)GlobalPtrLock(hDIB), hbmp) )
     {
         // this really shouldn't happen... it worked the first time, why not
         // now?
@@ -775,14 +773,26 @@ wxImage wxDIB::ConvertToImage() const
             dst[1] = *src++;
             dst[0] = *src++;
 
-            dst += 3;
-
             if ( is32bit )
             {
                 if ( alpha )
-                    *alpha++ = *src;
+                {
+                    // 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;
+                    }
+                }
+
                 src++;
             }
+
+            dst += 3;
         }
 
         // pass to the previous line in the image
@@ -800,4 +810,3 @@ wxImage wxDIB::ConvertToImage() const
 #endif // wxUSE_IMAGE
 
 #endif // wxUSE_WXDIB
-