office-gobmx/slideshow
Bogdan Buzea f17e930b0f tdf#163486: PVS: The variable was assign the same value.
V1048 The 'bDirectionForward' variable was assigned the same value.

Change-Id: I83343be3cfe93f0be97eae01869dd00cd0814c67
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/175203
Tested-by: Jenkins
Reviewed-by: Xisco Fauli <xiscofauli@libreoffice.org>
2024-10-20 10:31:03 +02:00
..
inc/pch
opengl
qa
source tdf#163486: PVS: The variable was assign the same value. 2024-10-20 10:31:03 +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

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.