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Change-Id: I7bbcc08786843d6d289b3170248ce2696e57f3b2 Reviewed-on: https://gerrit.libreoffice.org/c/core/+/177602 Reviewed-by: Ilmari Lauhakangas <ilmari.lauhakangas@libreoffice.org> Tested-by: Jenkins |
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.. | ||
inc | ||
opengl | ||
qa/cppunit | ||
source | ||
workben | ||
CppunitTest_canvas_test.mk | ||
Executable_canvasdemo.mk | ||
IwyuFilter_canvas.yaml | ||
Library_cairocanvas.mk | ||
Library_canvasfactory.mk | ||
Library_canvastools.mk | ||
Library_directx9canvas.mk | ||
Library_gdipluscanvas.mk | ||
Library_oglcanvas.mk | ||
Library_simplecanvas.mk | ||
Library_vclcanvas.mk | ||
Makefile | ||
Module_canvas.mk | ||
Package_opengl.mk | ||
README.md | ||
README.vars | ||
StaticLibrary_directxcanvas.mk |
UNO-based Graphics Backend
UNO-based graphics backend, lesser impedance to modern graphics APIs than vcl.
The canvas Framework
The canvas
framework is the successor of the system GUI and graphics
backend VCL. Basic functionality is available, supplying just as much
features as necessary to provide a VCL-equivalent feature set (except
proper BiDi/CTL support).
The canvas
framework consists of the following two modules, canvas
and
cppcanvas
. Additionally, a new generic graphics tooling is used (but
not exclusively by the canvas, Armin's drawinglayer module also make
use of it), which resides in basegfx
.
The UNO API used by the canvas is primarily under
css::rendering
, with css::rendering::XCanvas
being the central interface.
The slideshow Engine
The slideshow
engine has replaced the former Impress-embedded
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
rendering.
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 Works
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.