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Caolán McNamara d33d592801 cid#1554791 COPY_INSTEAD_OF_MOVE and cid#1554819 COPY_INSTEAD_OF_MOVE cid#1554837 COPY_INSTEAD_OF_MOVE cid#1554881 COPY_INSTEAD_OF_MOVE cid#1554882 COPY_INSTEAD_OF_MOVE cid#1554884 COPY_INSTEAD_OF_MOVE cid#1554891 COPY_INSTEAD_OF_MOVE cid#1554892 COPY_INSTEAD_OF_MOVE cid#1554897 COPY_INSTEAD_OF_MOVE cid#1554904 COPY_INSTEAD_OF_MOVE cid#1554918 COPY_INSTEAD_OF_MOVE cid#1554928 COPY_INSTEAD_OF_MOVE cid#1554931 COPY_INSTEAD_OF_MOVE cid#1554944 COPY_INSTEAD_OF_MOVE cid#1554945 COPY_INSTEAD_OF_MOVE cid#1554959 COPY_INSTEAD_OF_MOVE cid#1554960 COPY_INSTEAD_OF_MOVE cid#1554963 COPY_INSTEAD_OF_MOVE cid#1554966 COPY_INSTEAD_OF_MOVE cid#1554969 COPY_INSTEAD_OF_MOVE cid#1554973 COPY_INSTEAD_OF_MOVE cid#1555011 COPY_INSTEAD_OF_MOVE cid#1555012 COPY_INSTEAD_OF_MOVE cid#1555015 COPY_INSTEAD_OF_MOVE cid#1555044 COPY_INSTEAD_OF_MOVE cid#1555051 COPY_INSTEAD_OF_MOVE cid#1555055 COPY_INSTEAD_OF_MOVE cid#1555063 COPY_INSTEAD_OF_MOVE cid#1555068 COPY_INSTEAD_OF_MOVE cid#1555073 COPY_INSTEAD_OF_MOVE cid#1555074 COPY_INSTEAD_OF_MOVE cid#1555078 COPY_INSTEAD_OF_MOVE cid#1555080 COPY_INSTEAD_OF_MOVE cid#1555091 COPY_INSTEAD_OF_MOVE cid#1555099 COPY_INSTEAD_OF_MOVE cid#1555101 COPY_INSTEAD_OF_MOVE cid#1555121 COPY_INSTEAD_OF_MOVE cid#1610739 COPY_INSTEAD_OF_MOVE cid#1608424 COPY_INSTEAD_OF_MOVE cid#1608059 COPY_INSTEAD_OF_MOVE cid#1607952 COPY_INSTEAD_OF_MOVE cid#1607653 COPY_INSTEAD_OF_MOVE cid#1607614 COPY_INSTEAD_OF_MOVE cid#1607592 COPY_INSTEAD_OF_MOVE Change-Id: Ie9f922a9fe1b8001dfab31e2741fe8bd5558e442 Reviewed-on: https://gerrit.libreoffice.org/c/core/+/170802 Tested-by: Jenkins Reviewed-by: Caolán McNamara <caolan.mcnamara@collabora.com>		2024-07-20 23:03:28 +02:00
..
inc/pch
opengl
qa
source	cid#1554791 COPY_INSTEAD_OF_MOVE	2024-07-20 23:03:28 +02:00
test
util
CppunitTest_slideshow.mk
CppunitTest_slideshow_engine.mk
IwyuFilter_slideshow.yaml
Library_OGLTrans.mk
Library_slideshow.mk
Makefile
manifest.txt
Module_slideshow.mk
Package_opengl.mk
README.md

README.md

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.hxx
slideshow/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.