When set, the grid contents is centered in the window. I.e. the
left/right and top/bottom margins are equal (+- 1px).
This causes the content to “jump” while doing an interactive resize,
but may still be preferred in e.g. a tiling WM.
Closes#273
When tweak.allow-overflowing-double-width-glyphs=yes, then certain
glyphs are allowed to overflow into the neighbouring cell.
However, if the cell “owning” the double-width glyph is erased (_only_
that cell), then the cell overflowed into is not redrawn, causing
part of the double-width glyph to remain on screen.
To avoid checking for these glyphs when printing to the terminal (i.e
at parse time), simply mark both cells as dirty when we render the
overflowing glyph.
Yes, this means that the cells will always be re-rendered. We count on
them only making up a small portion of the screen.
Shutdown the terminal when the client process terminates, not when the
ptmx file descriptor is closed.
This fixes an issue where the terminal remains running after the
client process has terminated, if it spawned child processes that
inherited the ptmx file descriptor.
This _should_ only happen when we’re doing a partial PGO build, since
then the script is run in the parent terminal. In this case, the user
is expected to use --rows/--cols anyway.
This _should_ only happen when we’re doing a partial PGO build, since
then the script is run in the parent terminal. In this case, the user
is expected to use --rows/--cols anyway.
We use pre-multiplied alpha color channels, but were having bad
rounding errors due to the alpha divider being truncated to an
integer.
The algorithm for pre-multiplying a color channel is:
alpha_divider = 0xffff / alpha
pre_mult_color = color / alpha_divider
In order to fix the rounding errors, we could turn ‘alpha_divider’
into a double.
That however would introduce a performance penalty since now we’d need
to do floating point math for each cell.
The algorithm can be trivially converted to:
pre_mult_color = color * alpha / 0xffff
Since both color and alpa values are < 65536, the multiplication is
“safe”; it will not overflow an uint32_t.
Closes#249
We use pre-multiplied alpha color channels, but were having bad
rounding errors due to the alpha divider being truncated to an
integer.
The algorithm for pre-multiplying a color channel is:
alpha_divider = 0xffff / alpha
pre_mult_color = color / alpha_divider
In order to fix the rounding errors, we could turn ‘alpha_divider’
into a double.
That however would introduce a performance penalty since now we’d need
to do floating point math for each cell.
The algorithm can be trivially converted to:
pre_mult_color = color * alpha / 0xffff
Since both color and alpa values are < 65536, the multiplication is
“safe”; it will not overflow an uint32_t.
Closes#249
This extends the new ‘dpi-aware’ option with a new default value,
‘auto’.
When set to ‘auto’, fonts are sized using monitors’ DPI when output
scaling is disabled. When output scaling is enabled, fonts are instead
sized using the scaling factor.
The reasoning here is that a user that has enabled output scaling is
obviously *not* relying on DPI scaling.
Output scaling can also be a way to compensate for different viewing
distances, in which case we do *not* want to break that by using DPI
scaling.
Users can still force DPI-only font sizing by setting ‘dpi-aware=yes’,
or disable it completely by setting ‘dpi-aware=no’.
Take ‘\E(#0’ for example - this is *not* the same as ‘\E(0’.
Up until now, foot has however treated them as the same escape,
because the handler for ‘\E(0’ didn’t verify there weren’t any _other_
private characters present.
Fix this by turning the ‘private’ array into a single 4-byte
integer. This allows us to match *all* privates with a single
comparison.
Private characters are added to the LSB first, and MSB last. This
means we can check for single privates in pretty much the same way as
before:
switch (term->vt.private) {
case ‘?’:
...
break;
}
Checking for two (or more) is much uglier, but foot only supports
a *single* escape with two privates, and no escapes with three or
more:
switch (term->vt.private) {
case 0x243f: /* ‘?$’ */
...
break;
}
The ‘clear’ action remains simple (and fast), with a single write
operation.
Collecting privates is potentially _slightly_ more complex than
before; we now need mask and compare, instead of simply comparing,
when checking how many privates we already have.
We _could_ add a counter, which would make collecting privates easier,
but this would add an additional write to the ‘clean’ action which is
really bad since it’s in the hot path.
