Noel Grandin
81994cb2b8
(Second attempt at landing this) Image formats and graphics APIs use alpha, not transparency, so change our internal formats and data structures to work directly with alpha, so we don't need to modify data before we push it to graphics APIs. Add a couple of new Color constants to make the intention of the vcl code clearer. Notes (*) On macOS, tweaking the logic in CreateWithSalBitmapAndMask to more accurately reflect the requirements of the CGImageCreateWithMask function seems to fix some tests. (*) The vcl code does not properly support gradients with transparency. So the previous code was wrong, and this change is going to result in slightly different wrongness. Change-Id: I9e21c2e98d88ecfdc5f75db13bd1ffff7c38db98 Reviewed-on: https://gerrit.libreoffice.org/c/core/+/114168 Tested-by: Jenkins Reviewed-by: Patrick Luby <plubius@neooffice.org> Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
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.