[Bug 59810] New: Buffered paint alpha/clear operations are missing

[WineHQ Bugzilla]

http://bugs.winehq.org/show_bug.cgi?id=59810

            Bug ID: 59810
           Summary: Buffered paint alpha/clear operations are missing
           Product: Wine
           Version: 11.10
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: uxtheme
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Applications using the buffered paint API can fail to render themed/translucent
controls correctly because Wine does not perform the clear and alpha operations
requested through BufferedPaintClear() and
    BufferedPaintSetAlpha().

  These calls are used after BeginBufferedPaint() to prepare or adjust the
backing buffer before EndBufferedPaint() copies the result to the target DC. On
Windows, callers can clear a sub-rectangle of the paint buffer and
  apply a uniform alpha value to a sub-rectangle. Wine currently leaves those
operations ineffective.

  Expected behavior:
  - BufferedPaintClear(buffer, NULL) clears the whole buffered paint area.
  - BufferedPaintClear(buffer, rect) clears the requested rectangle, clipped to
the buffer.
  - BufferedPaintSetAlpha(buffer, NULL, alpha) applies alpha to the whole
buffered paint area.
  - BufferedPaintSetAlpha(buffer, rect, alpha) applies alpha to the requested
rectangle, clipped to the buffer.
  - Empty rectangles should succeed without changing pixels.

  Impact:
  Applications that depend on these operations may leave stale pixels in the
buffered paint surface, lose expected transparency, or draw themed controls
with incorrect backgrounds/alpha.

  One possible implementation direction would be to update the DIB-backed
buffer directly for these operations, clipping the requested rectangle to the
buffer bounds. For non-DIB-backed buffers, BufferedPaintClear() could
  clear through the memory DC.

-- 
Do not reply to this email, post in Bugzilla using the
above URL to reply.
You are receiving this mail because:
You are watching all bug changes.