[PATCH weston 0/8] Fix pixman-renderer cropping

[Pekka Paalanen]

From: Pekka Paalanen <pekka.paalanen at collabora.co.uk>

Hi,

this is a series of relatively small changes to the Pixman-renderer, with the
major goals of a) clean up the draw_view/repaint_region machinery, and b)
properly implement source clipping. This is a follow-up to
http://lists.freedesktop.org/archives/wayland-devel/2015-March/020354.html

Before this series, you can see misrending in a particular case: launch Weston
with any visible backend using the Pixman-renderer, start weston-scaler and
rotate its window. Weston-scaler uses wl_viewport to crop the buffer so that no
red should appear. When rotated, Pixman-renderer fails to crop properly, and
the red area becomes visible.

This series fixes that case, and as a last step also implements the view
scissor for weston_view_set_mask() to be used by ivi-shell.

The patch series can be found at:
http://cgit.collabora.com/git/user/pq/weston.git/log/?h=pixmancomplex-2

I have tested that branch to show correct rendering all the cases:
- weston-terminal (has blended and opaque regions)
- weston-scaler (uses wl_viewport cropping)
while their windows are:
- in a normal state
- translucent (Mod+Alt+MouseWheel)
- rotated (Mod+RightButtonDrag)
- rotated and translucent
So all the combinations of those appear drawn right.

Additionally, I have tested that hacking ivi-shell to clip a window works
right.  This test was done with the branch:
http://cgit.collabora.com/git/user/pq/weston.git/log/?h=viewclip-5
which contains the non-upstreamable hacks. I ran Weston with Pixman-renderer
and ivi-shell, and then started a clipped app with:
	$ IVI_ID=555 ./weston-clickdot
This triggers the hacked hardcoded view clip.


Thanks,
pq

Pekka Paalanen (8):
  compositor: add weston_surface_to_buffer_region()
  pixman-renderer: put transformation computation into function
  pixman-renderer: refactor into region_intersect_only_translation()
  pixman-renderer: add view_transformation_is_translation()
  pixman-renderer: change repaint_region() arguments
  pixman-renderer: move code to draw_view_translated()
  pixman-renderer: implement source clipping
  pixman-renderer: implement view scissor

 src/compositor.c      |  36 ++++++
 src/compositor.h      |   5 +
 src/pixman-renderer.c | 342 +++++++++++++++++++++++++++++++++++++++-----------
 3 files changed, 308 insertions(+), 75 deletions(-)

-- 
2.0.5