path: root/canvas/README
diff options
Diffstat (limited to 'canvas/README')
1 files changed, 20 insertions, 0 deletions
diff --git a/canvas/README b/canvas/README
index 0110f5adfd55..2fb141c48148 100644
--- a/canvas/README
+++ b/canvas/README
@@ -24,3 +24,23 @@ presentation framework with a fully independent UNO component, and it
is based on the canvas. Some features used there are only available
from canvas, like double-buffering, and hardware-accelerated
alpha-blending (currently not on all platforms).
+== Cairo canvas ==
+cairo canvas is one of backends of canvas component. canvas is mostly
+used for slideshow rendering and also for emf+ rendering. we hoped it
+will even be used by drawing layer, but it didn't happen (yet?) for
+API look at offapi/com/sun/star/rendering/, the implementation is in
+canvas and cppcanvas modules.
+cairo canvas backend uses cairo library for rendering. main advantage
+is support of alpha transparency and in some cases accelerated
+the backend itself is quite old and stable, not many changes in that
+area lately, mostly changes for emf+ rendering, communication with
+vcl and bugfixes
+FUTURE work: look at cairo canvas and situation when it is used
+(mostly slideshow). TODO there still might be more cases when we
+can save some roundtrips when exchanging data with vcl.