[OLEAUT32] Multiple fixes to OLEPicture implementation
a_villacis at palosanto.com
a_villacis at palosanto.com
Wed May 26 10:43:46 CDT 2004
It seems that the best way to shake bugs in OLE Automation in
Wine is to try to exercise it with Visual Basic 6. The
following problems were found when trying to run VB6 with Wine,
all of them involving OLEPicture:
* Icon rendering fails when contained within an OLEPicture. The
root cause is that the PIXEL --> HIMETRIC transformation
applied to bitmaps is not applied to icons too - the pixel
dimensions are reported as-is into the HIMETRIC properties.
* Some BMPs are misidentified as icons in OLEPictureImpl_Load().
The root cause is that the IStream header validation is not
strict enough, and marks as valid IStream headers some BMP
* GIF loading code fails to account for interlaced images.
* GIF loading code fails to pad scanlines at DWORD boundaries.
* Palette-based BMPs (colordepth 8 or less) were horribly
displayed. Root cause: misuse of DIB_PAL_COLORS at
the creation of the HBITMAP - it means not that image is
palette-based on the stream, but rather that palette
indexes are actually indexes into the currently realized
palette in the target DC.
* All of the save features of OLEPicture were unimplemented
and reported failure under VB6. This lead to a series of
\"System error xxxxx\" when a form containing a picture was
Changelog (against 20040505 tarball):
* Apply HIMETRIC transformation on icon dimensions as well as
* Made IStream header validation more strict - known image
headers (BMP, GIF, JPEG) are now checked for and the header
is considered not an IStream header if any of them is found.
* Loadtime IStream header is remebered, in order to restore it
* Added interlaced support for GIFs
* Added DWORD padding for GIFs.
* HBITMAP creation when loading BMPs now always uses
DIB_RGB_COLORS, even on palette based images.
* Added bIsDirty flag to OLEPicture. This flag is set to FALSE
on constructor and Load, and is set to TRUE on the
PictureChanged method (which is presumably to inform the
OLEPicture that the bitmap just changed).
* Added save support to OLEPicture. The save support honors
the bIsDirty flag and just saves the image buffer if this
flag is set to FALSE. If the flag is set to TRUE, a number
of serialization methods are provided (ICON, GIF, BMP,
JPEG still unimplemented :-( ).
However, when the Windows application is run on an X set at
PseudoColor visual, the GIF serialization mangles the palette
because of some as-yet unidentified bug in palette reporting
in GetDIBits(). Probably the palette corruption also affects
BMP images when the app is run in an X display at
PseudoColor visual (8bpp).
My next goal is to check the problems on the palette support
in Wine on PseudoColor visual. Any help would be appreciated.
Alex Villacís Lasso
Mail enviado desde PortalMail 1.4.2 Web based email system.
PaloSanto Solutions, Sunnyvale CA.
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