[Bug 36815] New: XFORM matrix rotation is not supported by BitBlt()

[wine-bugs at winehq.org]

https://bugs.winehq.org/show_bug.cgi?id=36815

            Bug ID: 36815
           Summary: XFORM matrix rotation is not supported by BitBlt()
           Product: Wine
           Version: 1.7.19
          Hardware: x86
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: gdi32
          Assignee: wine-bugs at winehq.org
          Reporter: sashoalm at gmail.com

Created attachment 48892
  --> https://bugs.winehq.org/attachment.cgi?id=48892
Demo project.

When a rotation is specified using the XFORM matrix, and later a bitmap is
drawn using BitBlt(), it is rotated in Windows, but it is not rotated in Wine
(it seems to be scaled instead).

Demo project:
https://drive.google.com/file/d/0B9PGUhmmnsm1Z3YtRXJxdnNpNUE/edit?usp=sharing,
also added as attachment.

Screenshot under Windows:
https://drive.google.com/file/d/0B9PGUhmmnsm1Uzg4d1l0TS1FVlU/edit?usp=sharing
Screenshot under Wine:
https://drive.google.com/file/d/0B9PGUhmmnsm1NHFjSWxGdlpiU28/edit?usp=sharing

These are the most relevant parts of the demo code. Here the XFORM matrix is
prepared, and the BitBlt() is called:

======
    // Set the XFORM rotation.
    XFORM xform;
    memset(&xform, 0, sizeof(xform));
    double angle = 0.785398163;
    xform.eM11 = cos(angle);
    xform.eM12 = sin(angle);
    xform.eM21 = -sin(angle);
    xform.eM22 = cos(angle);
    xform.eDx = 0;
    xform.eDy = 0;
    SetGraphicsMode(hdc, GM_ADVANCED);
    SetWorldTransform(hdc, &xform);

    // Draw the bitmap on the paint .
    BitBlt(hdc, r->left, r->top, r->right-r->left, r->bottom-r->top, hMemDC, 0,
0, SRCCOPY);
======

How to specify rotation in the XFORM matrix is described in MSDN's at
http://msdn.microsoft.com/en-us/library/windows/desktop/dd145228(v=vs.85).aspx:

Operation    eM11    eM12    eM21    eM22
Rotation    Cosine    Sine    Negative sine    Cosine

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