## Summary of the Pull Request
Identifies and scales glyphs in the box and line drawing ranges U+2500-U+259F to fit their cells.
## PR Checklist
* [x] Closes#455
* [x] I work here.
* [x] Manual tests. This is all graphical.
* [x] Metric ton of comments
* [x] Math spreadsheet included in PR.
* [x] Double check RTL glyphs.
* [x] Why is there the extra pixel?
* [x] Scrolling the mouse wheel check is done.
* [x] Not drawing outline?
* [x] Am core contributor. Roar.
* [x] Try suppressing negative scale factors and see if that gets rid of weird shading.
## Detailed Description of the Pull Request / Additional comments
### Background
- We want the Terminal to be fast at drawing. To be fast at drawing, we perform differential drawing, or only drawing what is different from the previous frame. We use DXGI's `Present1` method to help us with this as it helps us compose only the deltas onto the previous frame at drawing time and assists us in scrolling regions from the previous frame without intervention. However, it only works on strictly integer pixel row heights.
- Most of the hit testing and size-calculation logic in both the `conhost` and the Terminal products are based on the size of an individual cell. Historically, a cell was always dictated in a `COORD` structure, or two `SHORT` values... which are integers. As such, when we specify the space for any individual glyph to be displayed inside our terminal drawing region, we want it to fall perfectly inside of an integer box to ensure all these other algorithms work correctly and continue to do so.
- Finally, we want the Terminal to have font fallback and locate glyphs that aren't in the primary selected font from any other font it can find on the system that contains the glyph, per DirectWrite's font fallback mechanisms. These glyphs won't necessarily have the same font or glyph metrics as the base font, but we need them to fit inside the same cell dimensions as if they did because the hit testing and other algorithms aren't aware of which particular font is sourcing each glyph, just the dimensions of the bounding box per cell.
### How does Terminal deal with this?
- When we select a font, we perform some calculations using the design metrics of the font and glyphs to determine how we could fit them inside a cell with integer dimensions. Our process here is that we take the requested font size (which is generally a proxy for height), find the matching glyph width for that height then round it to an integer. We back convert from that now integer width to a height value which is almost certainly now a floating point number. But because we need an integer box value, we add line padding above and below the glyphs to ensure that the height is an integer as well as the width. Finally, we don't add the padding strictly equally. We attempt to align the English baseline of the glyph box directly onto an integer pixel multiple so most characters sit crisply on a line when displayed.
- Note that fonts and their glyphs have a prescribed baseline, line gap, and advance values. We use those as guidelines to get us started, but then to meet our requirements, we pad out from those. This results in fonts that should be properly authored showing gaps. It also results in fonts that are improperly authored looking even worse than they normally would.
### Now how does block and line drawing come in?
- Block and Line drawing glyphs are generally authored so they will look fine when the font and glyph metrics are followed exactly as prescribed by the font. (For some fonts, this still isn't true and we want them to look fine anyway.)
- When we add additional padding or rounding to make glyphs fit inside of a cell, we can be adding more space than was prescribed around these glyphs. This can cause a gap to be visible.
- Additionally, when we move things like baselines to land on a perfect integer pixel, we may be drawing a glyph lower in the bounding box than was prescribed originally.
### And how do we solve it?
- We identify all glyphs in the line and block drawing ranges.
- We find the bounding boxes of both the cell and the glyph.
- We compare the height of the glyph to the height of the cell to see if we need to scale. We prescribe a scale transform if the glyph wouldn't be tall enough to fit the box. (We leave it alone otherwise as some glyphs intentionally overscan the box and scaling them can cause banding effects.)
- We inspect the overhang/underhang above and below the boxes and translate transform them (slide them) so they cover the entire cell area.
- We repeat the previous two steps but in the horizontal direction.
## Validation Steps Performed
- See these commments:
- https://github.com/microsoft/terminal/issues/455#issuecomment-620248375
- https://github.com/microsoft/terminal/issues/455#issuecomment-621533916
- https://github.com/microsoft/terminal/issues/455#issuecomment-622585453
Also see the below one with more screenshots:
- https://github.com/microsoft/terminal/pull/5743#issuecomment-624940567
This commit introduces a github action to check our spelling and fixes
the following misspelled words so that we come up green.
It also renames TfEditSes to TfEditSession, because Ses is not a word.
currently, excerpt, fallthrough, identified, occurred, propagate,
provided, rendered, resetting, separate, succeeded, successfully,
terminal, transferred, adheres, breaks, combining, preceded,
architecture, populated, previous, setter, visible, window, within,
appxmanifest, hyphen, control, offset, powerpoint, suppress, parsing,
prioritized, aforementioned, check in, build, filling, indices, layout,
mapping, trying, scroll, terabyte, vetoes, viewport, whose
Generated by https://github.com/jsoref/spelling `f`; to maintain your repo, please consider `fchurn`
I generally try to ignore upstream bits. I've accidentally included some items from the `deps/` directory. I expect someone will give me a list of items to drop, I'm happy to drop whole files/directories, or to split the PR into multiple items (E.g. comments/locals/public).
Closes#4294
This PR creates a Universal entrypoint for the Windows Terminal solution
in search of our goals to run everywhere, on all Windows platforms.
The Universal entrypoint is relatively straightforward and mostly just
invokes the App without any of the other islands and win32 boilerplate
required for the centennial route. The Universal project is also its own
packaging project all in one and will emit a relevant APPX.
A few things were required to make this work correctly:
* Vcxitems reuse of resources (and link instructions on all of them
for proper pkg layout)
* Move all Terminal project CRT usages to the app ones (and ensure
forwarders are only Nugetted to the Centennial package to not pollute
the Universal one)
* Fix/delay dependencies in `TerminalApp` that are not available in
the core platform (or don't have an appropriate existing platform
forwarder... do a loader snaps check)
* vcpkg needs updating for the Azure connection parser
* font fallbacks because Consolas isn't necessarily there
* fallbacks because there are environments without a window handle
Some of those happened in other small PRs in the past week or two. They
were relevant to this.
Note, this isn't *useful* as such yet. You can run the Terminal in this
context and even get some of the shells to work. But they don't do a
whole lot yet. Scoping which shells appear in the profiles list and only
offering those that contextually make sense is future work.
* Break everything out of App except the base initialization for XAML. AppLogic is the new home.
* deduplicate logics by always using the app one (since it has to be there to support universal launch).
* apparently that was too many cross-boundary calls and we can cache it because winrt objects are magic.
* Put UWP project into solution.
* tabs in titlebar needs disabling from uwp context as the non-client is way different. This adds a method to signal that to logic and apply the setting override.
* Change to use App CRT in preparation for universal.
* Try to make project build again by setting winconpty to static lib so it'll use the CRT inside TerminalConnection (or its other consumers) instead of linking its own.
* Remove test for conpty dll, it's a lib now. Add additional commentary on how CRT linking works for future reference. I'm sure this will come up again.
* This fixes the build error.
* use the _apiset variant until proven otherwise to match the existing one.
* Merge branch 'master' into dev/miniksa/uwp3
* recorrect spacing in cppwinrt.build.pre.props
* Add multiple additional fonts to fallback to. Also, guard for invalid window handle on title update.
* Remove ARMs from solution.
* Share items resources between centennial and universal project.
* cleanup resources and split manifest for dev/release builds.
* Rev entire solution to latest Toolkit (6.0.0 stable release).
* shorten the items file using include patterns
* cleanup this filters file a bit.
* Fix C26445 by using string_view as value, not ref. Don't build Universal in Audit because we're not auditing app yet.
* some PR feedback. document losing the pointer. get rid of 16.3.9 workarounds. improve consistency of variable decl in applogic.h
* Make dev phone product ID not match prod phone ID. Fix universal package identity to match proposed license information.
* Fix OpenConsole.psm1 to use vswhere
I'm not sure this is good, since I don't write a lot of powershell, and
I don't know the project very well, but hopefully it's good!
* Do as @DHowett-MSFT says and use VSSetup
whee!
* try to do what @heaths is recommending
* fix `Import-LocalModule`
* fix openconsole.psm1 for hopefully the last time
Submitting first draft of spec template, and `contributing.md` outlining our guidance on how to engage with us, file issues, suggest features, submit changes, etc.
Michael Niksa
Josh Soref
nicole mazzuca
Rich Turner
adiviness
Joel Bennett
Ian Frosst
Dustin Howett
Gilles Khouzam