I think this looks less jarring than the yellowish selection color,
and the translucency looks nicer than changing the fg color completely
black as it did previously.
* gui: improve mouse text selection
* implement mouse press capture between the terminal and UI, so when you
start selecting text from the terminal the tabs won't activate and
vice-versa
* selecting from the top and bottom lines won't scroll the viewport
anymore, it will only scroll if the mouse is moved out of line bounds
* change cell selection so that it behaves like text selection usually
does in other popular software
refs: https://github.com/wez/wezterm/issues/1199
refs: https://github.com/wez/wezterm/issues/1386
refs: https://github.com/wez/wezterm/issues/354
Previously, we'd just default the resize quirk on for all programs on
Windows.
That pessimizes the otherwise fine behavior of `wezterm ssh` or mux
connections to unixy platforms.
This commit moves the quirk out of the config trait and makes it
a runtime property of the terminal, and then arranges for it
to be set when we know that we set up a conpty for the terminal.
refs: #1265
* #217 DECSDM, and commented pseudocode for improved handling of transparent image cells
* oops forgot cargo fmt --all
* #217 set initial palette colors to match VT340
* #217 cleanup color_map initialization, fix sixel scrolling
* #217 remove large comment - transparency discussion for another time
This change also allows removing the dep on the palette crate,
which I found to be difficult to use (API changed often, and relied
on a lot of `.into` that was hard to follow and reconcile across
upgrades). We already pulled in the csscolorparse crate as an indirect
dep of colorgrad, so we can replace the color conversion we need for
sixel with that crate while we're in here.
refs: #1615
Previously overlooked because we didn't render or otherwise
change behavior: after running vttest and running ls, some
lines still had double width/height set.
This ensures that we remove that attribute when clearing
the screen.
This was used by the mux client when the session is tardy.
I've heard feedback that the greying out is distracting and not
especially useful, so I don't think this is any great loss.
This commit allows the following configuration:
```
wezterm -n --config 'colors = { selection_fg = "clear", selection_bg = "rgba:50% 50% 50% 50%" }'
```
which sets the selection_bg to fully transparent, and selection_bg to
50% transparent gray.
When selection_fg is fully transparent we'll use the normal fg color.
When selection_bg is partially (or fully!) transparent, it will be
alpha blended over the current cell background color.
To support this, the config file will now accept rgba colors specified
as 4 whitespace delimited numeric values. If a value ends with `%` it
is interpreted as a number in the range 0-100. Otherwise, it is
interpreted as a number in the range 0-255. The 4 values are
red, green, blue, alpha.
At this time, only the selection_fg and selection_bg settings accept
alpha values.
refs: #1615
Resolves a little bit of the awkward duplication of color types
between some of the crates by factoring them a little bit better.
This is prep for allowing specifying alpha for some colors
in the config.
This commit refines bidi property handling:
* experimental_bidi has been split into two new configuration settings;
`bidi_enabled` (which controls whether the terminal performs implicit
bidi processing) and `bidi_direction` which specifies the base
direction and whether auto detection is enabled.
* The `Line` type can now store those bidi properties (they are actually
split across 3 bits representing enabled, auto-detection and
direction)
* The terminal now has a concept of active bidi properties and default
bidi properties
* The default properties are pulled from the wezterm configuration
* active bidi properties are potentially set via escape sequences,
BDSM (which sets bidi_enabled) and SCP (which sets bidi_direction).
We don't support the 2501 temporary dec private mode suggested by
the BIDI recommendation doc at this time.
* When creating new `Line`'s or clearing from the start of a `Line`, the
effective bidi properties are computed (from the active props,
falling back to default propr) and applied to the `Line`.
* When rendering the line, we now look at its bidi properties instead
of just the global config.
The default bidi properties are `bidi_enabled: false` and
`bidi_direction: LeftToRight` which corresponds to the typical
bidi-unaware mode of most terminals.
It is possible to live reload the config to change the effective
defaults, but note that they apply, by design, to new lines being
processed through the terminal. That means existing output is
left unaffected by a config reload, but subsequently printed lines
will respect it. Pressing CTRL-L or otherwise contriving to have
the running application refresh its display should cause the
refreshed display to update and apply the new bidi mode.
refs: #784
This setting now allows specifying what the canonical format is;
previously it was a boolean that meant "don't change anything"
if false, and rewrite to CRLF if true.
It's now an enum with None, CR, LF, and CRLF variants that express
more control.
The config accepts true (maps to CRLF) and false (maps to None)
for backwards compatibility.
The default behavior is unchanged by this commit, however, I did
uncover a bug in the canonicalizer for inputs like `\r\r\n`.
refs: #1575
This commit enables the following config to work for local (not mux yet!)
panes:
```lua
local wezterm = require 'wezterm'
wezterm.on("format-tab-title", function(tab, tabs, panes, config, hover, max_width)
if tab.is_active then
return {
{Background={Color="blue"}},
{Text=" " .. tab.active_pane.title .. " "},
}
end
local has_unseen_output = false
for _, pane in ipairs(tab.panes) do
if pane.has_unseen_output then
has_unseen_output = true
break;
end
end
if has_unseen_output then
return {
{Background={Color="Orange"}},
{Text=" " .. tab.active_pane.title .. " "},
}
end
return tab.active_pane.title
end)
return {
}
```
refs: https://github.com/wez/wezterm/discussions/796
This commit decomposes the main get_semantic_zones method into two
parts:
* A per-line portion, where the line ranges are cached (invalidated on
change)
* The overall screen portion, where the line ranges are merged
This changes the overall complexity of computing zones from
O(width * scrollback-height)
To an incremental:
O((width * number of changed lines since last query) + scrollback-height)
You can see some samples of elapsed time below; those show the times for
running both the old and the new implementation on the same data. The
number of lines/zones in the scrollback increases with each call and you
can see that the new implementation is a bit faster anyway at low
volumes but is significantly faster as the number of lines/zones
increases, because the amount of work is reduced.
```
get_semantic_zones: 71.708µs
get_semantic_zones_new: 59.041µs
get_semantic_zones: 71.166µs
get_semantic_zones_new: 9.166µs
get_semantic_zones: 44.291µs
get_semantic_zones_new: 4.208µs
get_semantic_zones: 69.791µs
get_semantic_zones_new: 10.291µs
get_semantic_zones: 59.375µs
get_semantic_zones_new: 7.958µs
get_semantic_zones: 52.5µs
get_semantic_zones_new: 4.5µs
get_semantic_zones: 91.791µs
get_semantic_zones_new: 20.916µs
get_semantic_zones: 229.916µs
get_semantic_zones_new: 109.208µs
get_semantic_zones: 224.125µs
get_semantic_zones_new: 15.208µs
get_semantic_zones: 291.791µs
get_semantic_zones_new: 11.833µs
get_semantic_zones: 238.875µs
get_semantic_zones_new: 12.625µs
get_semantic_zones: 468.458µs
get_semantic_zones_new: 126.583µs
get_semantic_zones: 460.5µs
get_semantic_zones_new: 25.666µs
get_semantic_zones: 358.291µs
get_semantic_zones_new: 19.541µs
get_semantic_zones: 436.833µs
get_semantic_zones_new: 17.875µs
get_semantic_zones: 313.166µs
get_semantic_zones_new: 15.25µs
get_semantic_zones: 333.958µs
get_semantic_zones_new: 16.541µs
get_semantic_zones: 364.666µs
get_semantic_zones_new: 14.041µs
```
* #1457 Initial commit compiles but doesn't yet work
* #1457 Fix cell offsets
* #1457 refactor, ClickPosition
* fix nits
* #1457 filter per-pixel motion when not in SGR-Pixels mode
* Much cleaner match condition for filtering mouse events based on encoding protocol
It's a little ambiguous whether we should cancel the mode when moving
the cursor explicitly; I opted to do it when we move it due to newline
processing, or when its y position is changed.
refs: #1539
user vars were stubbed out. This commit adds storage for them
in the mux client and adds a new notification that publishes each
var as it is changed. That differential stream is applied to the
storage in the mux client when it is received.
```lua
local wezterm = require 'wezterm'
wezterm.on("update-right-status", function(window, pane)
local woot = pane:get_user_vars().woot
window:set_right_status(tostring(woot))
end);
return {
unix_domains = {
{name="unix"},
},
}
```
then running:
* `wezterm connect unix`
* in that session: `printf "\033]1337;SetUserVar=%s=%s\007" woot `echo -n nice | base64``
causes `nice` to show in the status area.
refs: #1528
We need 100% of the info for it to work correctly, so this commit:
* Exposes the keyboard encoding mode via the Pane trait
* Adds the scan code to the RawKeyEvent
* Has the GUI perform the encoding if the keyboard is set that way
* Removes the basic encoder from termwiz in favor of the gui level one
The net result is that we bypass the Pane::key_up/Pane::key_down methods
in almost all cases when the encoding mode is set to win32-input-mode.
There is now a config option: allow_win32_input_mode that can be
used to prevent using this mode.
refs: #1509
This commit causes the terminal to emit win32-input-mode encoded key up
and down events for a limited subset of keys When win32-input-mode is
enabled.
We limit them to keys where we know the VK key code equivalent,
and where those keys are either not representable (eg: modifier
only key events), or may generate ambiguous output (eg: CTRL-SPACE
in different keyboard layouts).
However, in my experiments, modifier only key presses confuse powershell
and cause it to emit `@`, so I've disabled that in the code for now.
refs: https://github.com/wez/wezterm/issues/318
refs: https://github.com/wez/wezterm/issues/1509
refs: https://github.com/wez/wezterm/issues/1510
Nothing generates them right now, and the mux client has no
way to represent them on the wire.
I'm considering constraining them to just win32 for now.
refs: https://github.com/wez/wezterm/issues/1509
This is a baby step that formalizes the different encoding schemes into
an enum, and hooks up the decset sequence for win32-input-mode.
It doesn't change any of the actual encoding at this time.
refs: #1509
Previously, we would implicitly set it to the special SEQ_ZERO
value, but since that value always flags the row as changed,
it causes some over-invalidation issues downstream in wezterm.
This commit makes that parameter required, so that the code that
is creating a new Line always passes down the seqno from that event.
refs: #1472
ConPTY emits a sequence that sets the title to the name of the
program that is initially launched into it.
This commit tries to ignore that sequence in that circumstance,
so that the logic in b5d156c282
can more dynamically set the tab title.
Poking around at an issue, and thinking that some more context
might be nice.
Haven't managed to reproduce the issue so far though :-/
refs: https://github.com/wez/wezterm/issues/1156
Not 100% sure why this only really manifested on Windows, but
the symptoms were:
* Run powershell in a tab
* Run `dir`
* Hit enter a couple of times to show a couple of prompts
* Try using the mouse to select across the prompt boundaries
The selection would get invalidated crossing the boundaries.
I traced this down to the lines around those regions having
SEQ_ZERO as their sequence, so this commit ensures that lines
that are created as part of scrolling the screen are correctly
tagged with the current seqno from the terminal display.
Why only windows? Not totally sure; perhaps it is related to
something funky happening in the conpty layer and sending us
unusual escapes (eg: scroll margins?)
This isn't ideal, as we're discarding information, but in #1422
where the problem codepoint is a unicode bidi control, we can't and
don't use that information anyway.
We'll need to figure out how to incorporate that when we get to it.
For now, this makes the presentation work correctly.
refs: #1422
permits iTerm2 images to be drawn anywhere on screen without
scrolling the cursor, including the bottom row.
Also included is a check in fcwrap.rs to_range_set(), without which
was causing a panic at runtime due to subtraction from unsigned
leading to overflow.
This helps us correctly set the size of the image cell
for the case where we have a partial cell at the right/bottom
edge of an image being mapped across cells.
refs: #1270
Adds some plumbing to allow the GUI to implement a download handler
and connect that up for iterm2 image/file transfers that have their
inline property set to false.
Previously we'd just log an error.
Now we will by default download the file to the user's download
directory.
This behavior can be turned off via the new `allow_download_protocols`
configuration setting.
File transfers can be initiated on a remote host via the
https://iterm2.com/utilities/it2dl script.
When the download completes, a toast notification is shown that will
open the file when clicked.
refs: https://github.com/wez/wezterm/discussions/1450
The texture coordinates into the source image weren't quite right;
previously we'd do this math:
num_cells = (image_size / cell_size).ceil()
delta = num_cells / image_size
that would result in the image being stretched to fit across the rounded
up number of cells, leading to a distored image.
This commit changes the delta calculation to be based on the remaining
number of pixels in a given dimension relative to the cell size.
refs: #1300
refs: #1270
While the description at DEC STD-070 04-31 does not mention Left Right
Margin Mode (it does mention the left and right margins), the code at
04-34 sets it to FIXED (the reset state, the set state is SETABLE).
From esctest:
DECSETTests.test_DECSET_DECLRMM_ModeResetByDECSTR
As promised in the previous commit, this one implements an escape
sequence to control the unicode version.
Unknown to me in the previous commit, iTerm2 already defines such
an escape sequence, so we simply implement it here with the same
semantics.
refs: #1231
refs: #997
This is a fairly far-reaching commit. The idea is:
* Introduce a unicode_version config that specifies the default level
of unicode conformance for each newly created Terminal (each Pane)
* The unicode_version is passed down to the `grapheme_column_width`
function which interprets the width based on the version
* `Cell` records the width so that later calculations don't need to
know the unicode version
In a subsequent diff, I will introduce an escape sequence that allows
setting/pushing/popping the unicode version so that it can be overridden
via eg: a shell alias prior to launching an application that uses a
different version of unicode from the default.
This approach allows output from multiple applications with differing
understanding of unicode to coexist on the same screen a little more
sanely.
Note that the default `unicode_version` is set to 9, which means that
emoji presentation selectors are now by-default ignored. This was
selected to better match the level of support in widely deployed
applications.
I expect to raise that default version in the future.
Also worth noting: there are a number of callers of
`unicode_column_width` in things like overlays and lua helper functions
that pass `None` for the unicode version: these will assume the latest
known-to-wezterm/termwiz version of unicode to be desired. If those
overlays do things with emoji presentation selectors, then there may be
some alignment artifacts. That can be tackled in a follow up commit.
refs: #1231
refs: #997
This was a bit of a PITA to run down; the essence of the problem
was that the shaper was returning an x_advance of 0 for U+3000,
which caused wezterm's shaping layer to elide that glyph.
I eventually tracked down the x_advance to be the result of
scaling by an x_scale of 0, which in turn is the result of
harfbuzz not knowing the font size.
The critical portion of this diff is the line that advises
harfbuzz that the font has changed after we've applied the
font size.
The rest is just stuff to make it easier to debug and verify.
This:
```
printf "x\u3000x."
```
Now correctly renders on screen as "x x".
fixes: #1161
Fast-clicking users generally expect to be able to rapidly do regular selections
or otherwise cancel double/triple/quad clicks, so significant mouse movement should end the streak.
Allowing tiny pixel movements to account for touchpads is necessary.
Fortunately, the position here is already in character grid cells, which provides enough margin for this.
Other code editors like gedit also seem to do this based on the character grid.
This will enable eg: a lua helper function to serialize keycodes to
assist in some key rebinding scenarios (see:
https://github.com/wez/wezterm/pull/1091#issuecomment-910940833 for the
gist of it) but also makes it a bit easier to write unit tests for key
encoding so that situations like those in #892 are potentially less
likely to occur in the future.
A while back I made the line lengths lazily grown; the reduction
in memory was nice, and it helped with render performance for
really wide screens.
Unfortunately, it puts a bunch of reallocation into the hot path
of the parser and updating the terminal model when people run
the inevitable `cat giant-file.txt` benchmark.
This commit reinstates pre-allocating lines to match the physical
terminal width, and tweaks the code a bit to take advantage of
const Cell allocation and to avoid some clones (a really micro
optimization).
For simple graphemes, we can avoid subsequently calling
grapheme_column_width and cache that information in TeenyString.
Make blank TeenyString and Cell initializations const.
Tag CursorPosition with the seqno of the cursor move instead.
This should avoid over-invalidating lines and the selection
if it was just the cursor that moved.
Terminal now maintains a sequence number that increments
for each Action that is applied to it.
Changes to lines are tagged with the current sequence number.
This makes it a bit easier to reason about when an individual
line has changed relative to some point in "time"; the consumer
of the terminal can sample the current sequence number and then
can later determine which lines have changed since that point
in time.
refs: https://github.com/wez/wezterm/issues/867
We were previously only remembering the most recently pressed
button, but that's a lossy thing to do.
This commit remembers the button presses so that we can correctly
report all press/release events.
refs: #973
An implementation detail in wezterm is that it doesn't model
image placements as a separate entity; they are all bound to
the image cells in the terminal model.
The semantics of the kitty image protocol are that placements
are "permanent" wrt. overwriting a cell with text, except for
the explicit EraseInLine/EraseInDisplay sequences that are
used for clearing.
This commit takes a pass at implementing that semantic in
the wezterm data model.
refs: #986
We were actually moving it during placement, and then restoring
the original placement. That could potentially lead to the
screen being scrolled, so we want to avoid that.
refs: #986
As of this commit, `kitty +kitten icat ~/Downloads/fast-parallax.gif`
(wherein the icat kitten decodes the gif into frames and sends them
to the terminal to animate) behaves equivalently in wezterm and kitty.
(There appears to be an issue with the background color/deltas in
the icat kitten in kitty-0.21.1-1.fc33.x86_64 which I have installed,
so both wezterm and kitty have a funky black background for this
particular gif).
refs: #986
Since we can now mutate individual frames, we need to avoid
falsely caching across a change; switch from using (image_id, frame_idx)
to frame_hash.
refs: #986
Adds a use_image feature to termwiz that enables an optional
dep on the image crate. This in turn allows decoding of animation
formats (gif, apng) from file data, but more crucially, allows
modeling animation frames at the termwiz layer, which is a pre-req
for enabling kitty img protocol animation support.
refs: #986
This adds a simple garbage collection scheme; when adding an image,
check to see if we're over budget on the total amount of RAM used
by the image data.
If we are, remove unreferenced images (images that are not placed)
until we're below the budget.
refs: #986
I noticed when running the notcurses demo that we're spending a
decent amount of time decoding png data whenever we need to
re-do the texture atlas.
Let's avoid that by allowing for ImageData at the termwiz layer
to represent both the image file format and decoded rgba8 data.
This commit is a bit muddy and also includes some stuff to try
to delete placements from the model. It's not perfect by any
means--more expensive than I want, and there's something funky
that causes a large number of images to build up during some
phases of the demo.
refs: #986
This isn't complete; many of the placement options are not supported,
and the status reporting is missing in a number of cases, including
querying/probing, and shared memory objects are not supported yet.
However, this commit is sufficient to allow the kitty-png.py script
(that was copied from
https://sw.kovidgoyal.net/kitty/graphics-protocol/#a-minimal-example)
to render a PNG in the terminal.
This implementation routes the basic image display via the same
code that we use for iterm2 and sixel protocols, but it isn't
sufficient to support the rest of the placement options allowed
by the spec.
Notably, we'll need to add the concept of image placements to
the data model maintained by the terminal state and find a way
to efficiently manage placements both by id and by a viewport
range.
The renderer will need to manage separate quads for placements
and order them by z-index, and adjust the render phases so that
images can appear in the correct plane.
refs: #986
This teaches termwiz to recognize and encode the APC
sequences used by the kitty image protocol.
This doesn't include support for animations, just the
transmit, placement and delete requests.
refs: #986
This commit hooks up DECRQM so that we can report that we implement
synchronized updates, and then refines the code that manages sending
data to the terminal model; the first cut at synchronized updates
was a bit simplistic, and now we make a point of "flushing" pending
actions when we start a sync point, and again as soon as we release
the sync point.
This smooths out the jaggies around the orca that I mentioned in
dcbbda7702
and while testing this, I realized that recent parser changes had
mangled processing bundled dec private mode sequences where multiple
modes were specified in the same overall escape sequence. I've
added the missing unit test case for this and made that work again.
refs: https://github.com/wez/wezterm/issues/955
refs: https://github.com/wez/wezterm/issues/882
This implementation doesn't include a timeout, but should be
recoverable via a SoftReset.
There's no query response either: I think I'm missing DECRQM
entirely at the moment.
refs: https://github.com/wez/wezterm/issues/882
This commit introduces a 4th draw pass for rendering sixel and
iterm images that are attached to cells.
Previously, a cell could container either text or an image from
the perspective of the renderer. If it had an image then the glyph
bitmap would be ignored in favor of the image.
However, that causes sixel behavior to diverge from other terminals
(https://github.com/wez/wezterm/issues/942) so we need to be render
both of these.
The simplest way to achieve this is to add a distinct set of texture
coordinates for the attached image and then add a draw pass to alpha
blend it over the glyph content.
The sixel/iterm image processing stage is also adjusted to preserve
the prior cell information and "simply" attach the image info to
the cell. Previously, the cell would be replaced with a blank cell
with the image attached.
The result of this is that the notcurses-demo intro section can
now render the orca "enveloped in the soft glow of glyphs" rather
than caged in a black box.
Note that there are some cases where the render turns blocky but
I suspect that that is due to some other misunderstanding between
wezterm and notcurses and that we'll root cause it as a follow up.
This commit causes a window-config-reloaded event to trigger
when the appearance (dark/light mode) is changed on macos.
It also arranges to propagate the window level config to newly
spawned panes and tabs, created both via the gui and via the
CLI/mux interface.
refs: https://github.com/wez/wezterm/issues/894
refs: https://github.com/wez/wezterm/issues/806
This allows window-level config overrides to apply
to panes contained within the window.
For instance, this allows setting a window-level
color scheme.
Add the third device attributes (DA3) query+reply,
eliminating "unknown/unspecified CSI" error. Like
XTerm, simply reply with zeroes as opposed to site
codes or unique IDs.
https://vt100.net/docs/vt510-rm/DA3.html
This adjusts the cursor position after emitting a sixel.
@dankamongmen: I don't have much of a sixel test suite to speak
of (cat snake.six :-p); I'd appreciate it if you could run
notcurses against this and confirm that it is doing something
sane!
At the very least, we shouldn't be warning about the unhandled
mode any more!
refs: https://github.com/wez/wezterm/issues/863
refs: https://github.com/dankamongmen/notcurses/issues/1743
neovim doesn't like it when multiple drag events with the same
coordinates are received; it appears to treat that as though
the mouse button was double clicked.
This commit teaches the mouse report encoding to suppress multiple
drag events in succession that have the same payload.
refs: https://github.com/wez/wezterm/discussions/823
Use a similar hsv transformation to that used to dim inactive panes
instead of the treatment that made the black look grey, which felt
like a flash instead of a dim.
Two issues here:
* The hue angles need adjusting to work with the palette library
* The resultant RGB color had the wrong gamma level, resulting in
an overly bright image.
refs: https://github.com/wez/wezterm/issues/775
There were two bugs here:
* \u8D (the utf8 encoded representation of 0x8d, aka: RI) was not
recognized as a C1 code and was instead passed through as printable
text.
* The \u8D is a zero-width sequence which means that a subsequent
set_cell call on the new empty-by-default line wouldn't allocate
any cells in the line array, and the assigment to the line would
panic.
This commit avoids the panic for the second case, and then fixes up
the vtparser to correctly recognize the sequence as a C1 control.
refs: https://github.com/wez/wezterm/issues/768
When the title, icon, OSC 7 and SetUserVars sequences are processed,
notify the embedding application.
The gui layer uses this to trigger a titlebar update.
refs: #647
This has the effect of reducing the memory and scroll cost
for lines that are shorter than the physical width of the
terminal matrix.
refs: https://github.com/wez/wezterm/issues/740
It is only used by applications that repaint on a resize event,
and us rewrapping makes it harder to have an ideal view afterwards.
This change makes us more consistent with VTE's behavior in this case.
This helps with https://github.com/wez/wezterm/issues/574 but doesn't
completely resolve it.
I didn't realize that xterm inherited some additional mappings from
the X server, so this commit should make us more comformant with
xterms behavior.
Verified this by comparing `showkey -a` under both xterm and wezterm:
```
wezterm -n --config disable_default_key_bindings=true --config debug_key_events=true start -- showkey -a
```
refs: https://github.com/wez/wezterm/issues/236
refs: https://github.com/wez/wezterm/discussions/556
I've been meaning to do this for a while; this commit moves
the escape sequence parsing into the thread that reads the
pty output which achieves two goals:
* Large escape sequences (eg: image protocols) that span multiple
4k buffers can be processed without ping-ponging between the
reader thread and the main gui thread
* That parsing can happen in the reader thread, keeping the gui
thread more responsive.
These changes free up the CPU during intensive operations such
as timg video playback.
This is a slight layering violation, in that this processing
really belongs to local pane (or any pane that embeds Terminal),
rather than generically at the Mux layer, but it's not any
worse a violation than `advance_bytes` already was.
refs: https://github.com/wez/wezterm/issues/537
The default downscaling provided by the GPU can result in noisy
artifacts on highly detailed images.
This commit employs a cubic Catmull-Rom sampling filter for the
case where we have a single frame image that is being reduced
in size. This isn't the highest quality filter but strikes
a good balance with speed vs appearance and is strictly better
than the GPU texture sampling options that I could try.
