Gabor Kelemen
c72c31de14
Change-Id: I48aa6e8d0b7d97914bf14947a5ce1b18ca6844e4 Reviewed-on: https://gerrit.collaboraoffice.com/c/online/+/3203 Tested-by: Jenkins CPCI <releng@collaboraoffice.com> Reviewed-by: Andras Timar <andras.timar@collabora.com> (cherry picked from commit 37fda958ab6ccb5fb0cab528fcc305ccf7ac6065) Reviewed-on: https://gerrit.libreoffice.org/c/core/+/205874 Tested-by: Jenkins Reviewed-by: Xisco Fauli <xiscofauli@libreoffice.org>
Impress Slideshow Engine
3D Transitions
The 3D transitions are slideshow transition engine using OpenGL and
are located in slideshow/source/engine/OGLTrans/. They were initially
written by GSOC student Shane.M.Mathews. Radek has later polished the
code a bit, added few new 3D transitions, added infrastructure for
vertex and fragment shaders. Wrote few transitions with fragment shader
too.
Physics Animation Effects
Physics animation effects are simulated by external 2d physics engine
library Box2D. They don't directly call Box2D functions but instead
use the wrapper in:
slideshow/source/inc/box2dtools.hxxslideshow/source/engine/box2dtools.cxx
The wrapper has two corresponding classes to manage the Box2D world
and Box2D bodies.
When a physics animation starts, a Box2DWorld is initiated and
populated with every shape that is part of the foreground (which are
shapes that do not belong to the master slide and not a background
shape).
After creation until the end of the slide (not the whole slideshow)
the Box2D World isn't destroyed and reused. But the bodies that
represent the shapes in the slide get destroyed when there's a point
in time that there's no physics animation in progress. And recreated
when another physics animation starts.
If there are multiple physics animations in parallel only one of them takes the role of stepping through the simulation.
If there are other animation effects that go in parallel which change
the shape position, rotation, or visibility - they also report the
change to Box2DWorld. These updates are collected in a queue in
Box2DWorld and processed before stepping through the simulation.
To achieve convincing results these updates are performed by setting
the Box2D body's linear velocity or angular velocity instead of
setting directly it's position or rotation.