Enabled system API for begin/end gfx transactions, initSize, setGraphicsMode.
Function setGraphicsMode will use optional params to trigger 3d rendering
and switch to proper SDL Gfx manager.
Normally with SDL, a mouse motion event will be sent after the
system mouse cursor has been moved by a call to
SDL_WarpMouseInWindow, but if the system cursor cannot be moved
(e.g. because the window does not have mouse focus), games still
need to receive these mouse events so they can successfully update
the mouse position internally. Otherwise, games continue to think
the mouse is still in the original position and will continue to
try to perform whatever action is associated with that mouse
position.
Refs Trac#9689.
The only reason we show the system cursor outside the game area is
to show users where their mouse is when the window is resized and
the mouse is outside the game area. If the game cannot be
interacted with, then the mouse also does not need to be shown in
the black areas.
This patch refactors the OpenGL and SDL graphics backends,
primarily to unify window scaling and mouse handling, and to
fix coordinate mapping between the ScummVM window and the
virtual game screen when they have different aspect ratios.
Unified code for these two backends has been moved to a new
header-only WindowedGraphicsManager class, so named because it
contains code for managing graphics managers that interact with
a windowing system and render virtual screens within a larger
physical content window.
The biggest behavioral change here is with the coordinate
system mapping:
Previously, mouse offsets were converted by mapping the whole
space within the window as input to the virtual game screen
without maintaining aspect ratio. This was done to prevent
'stickiness' when the mouse cursor was within the window but
outside of the virtual game screen, but it caused noticeable
distortion of mouse movement speed on the axis with blank
space.
Instead of introducing mouse speed distortion to prevent
stickiness, this patch changes coordinate transformation to
show the system cursor when the mouse moves outside of the virtual
game screen when mouse grab is off, or by holding the mouse inside
the virtual game screen (instead of the entire window) when mouse
grab is on.
This patch also improves some other properties of the
GraphicsManager/PaletteManager interfaces:
* Nullipotent operations (getWidth, getHeight, etc.) of the
PaletteManager/GraphicsManager interfaces are now const
* Methods marked `virtual` but not inherited by any subclass have
been de-virtualized
* Extra unnecessary calculations of hardware height in
SurfaceSdlGraphicsManager have been removed
* Methods have been renamed where appropriate for clarity
(setWindowSize -> handleResize, etc.)
* C++11 support improved with `override` specifier added on
overridden virtual methods in subclasses (primarily to avoid
myself accidentally creating new methods in the subclasses
by changing types/names during refactoring)
Additional refactoring can and should be done at some point to
continue to deduplicate code between the OpenGL and SDL backends.
Since the primary goal here was to improve the coordinate mapping,
full refactoring of these backends was not completed here.
This change allows:
* Engines to update their target rendering surface/size and pixel
format with the backend multiple times during gameplay;
* Users to resize the ScummVM window without having it reset
size/position every time an engine updates its target surface
format;
* Conversions/scaling to continue to run efficiently in hardware,
instead of requiring engines to pick their maximum possible
output format once and upscale inefficiently in software;
* The window to reset size once when an engine calls to set its
initial output size, and to reset again once ScummVM returns to
the launcher.
This is relevant for at least SCI32 and DreamWeb engines, which
perform graphics mode switches during games.
Sadly this also requires us to extend GraphicsManager for this SDL specific
feature. However, since that's only used in the SDL backend and Tizen it
should be fine for now...
