vo_calc_window_geometry2 (VCWG2) calculates both the pixelaspect and
the autofit sizes based on one "screen" rectangle.
However, these two calculations might need two different "screen"
rects if the fit should take into account decorations and/or taskbar
etc, while pixelaspect should be based on the full (monitor) rect.
VCWG3 does just that. It's the same as VCWG2, but with an additional
monitor rect which is used exclussively to calculate pixelaspect,
while the "screen" argument is used for fitting (like before).
VCWG2 now uses/calls VCWG3 with the same screen and monitor rects.
Currently yet unused.
m_geometry_apply() will read and modify the dummy variable. It's not
actually used for anything, but valgrind will still warn against
uninitialized data. I'm not sure whether this was UB, but in any case
it's annoying when running valgrind.
Scale the window by the assumed DPI scaling factor, using 96 DPI as
base. For example, a screen that reports 192 DPI is assumed to have a
DPI scale factor 2. The window will then be created with twice the size.
For robustness reasons, we accept only integer DPI scales between 1 and
9. We also error out if the X and Y scales are very different, as this
most likely indicates a multiscreen system with botched size reporting.
I'm not sure if reading the X server's DPI is such a good idea - maybe
the Xrdb "Xft.dpi" value should be used instead. The current method
follows what xdpyinfo does.
This can be disabled with --hidpi-window-scale=no.
MPlayer traditionally always used the display aspect ratio, e.g. 16:9,
while FFmpeg uses the sample (aka pixel) aspect ratio.
Both have a bunch of advantages and disadvantages. Actually, it seems
using sample aspect ratio is generally nicer. The main reason for the
change is making mpv closer to how FFmpeg works in order to make life
easier. It's also nice that everything uses integer fractions instead
of floats now (except --video-aspect option/property).
Note that there is at least 1 user-visible change: vf_dsize now does
not set the display size, only the display aspect ratio. This is
because the image_params d_w/d_h fields did not just set the display
aspect, but also the size (except in encoding mode).
Fixes#1472.
(Maybe these options should have been named --autofit-max and
--autofit-min, but since --autofit-larger already exists, use
--autofit-smaller for symmetry.)
Currently, vo_reconfig() calculates the requested window size and sets
the vo->dwidth/dheight fields _if_ VOCTRL_UPDATE_SCREENINFO is
implemented by the VO or the windowing backend. The window size can be
different from the display size if e.g. the --geometry option is used.
It will also set the vo->dx/dy fields and read vo->xinerama_x/y.
It turned out that this is very backwards and actually requires the
windowing backends to workaround these things. There's also
MPOpts.screenwidth/screenheight, which used to map to actual options,
but is now used only to communicate the screen size to the vo.c code
calculating the window size and position.
Change this by making the window geometry calculations available as
separate functions. This commit doesn't change any VO code yet, and just
emulates the old way using the new functions. VO code will remove its
usage of VOCTRL_UPDATE_SCREENINFO and use the new functions directly.
