Box-drawing characters in the Fira Mono font are not connected in the latest preview version of Terminal #13064
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Area-Rendering
Text rendering, emoji, complex glyph & font-fallback issues
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It either shouldn't be doing this or needs an investigation.
Product-Terminal
The new Windows Terminal.
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MatejKafka
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ghost
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Out of curiosity. And you did not update the Fira Code font files in between the WT updates? To me this looks like a metric change. Box drawing characters are never easy to be rendered from font files in a monospaced grid system (TEs), and because of that, most terminals do implement pixel perfect rendering for certain codepoints explicitly, bypassing the font file all along for them. |
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This issue has been automatically marked as stale because it has been marked as requiring author feedback but has not had any activity for 4 days. It will be closed if no further activity occurs within 3 days of this comment. |
Nope, I installed both versions of WT side-by-side and used the same font for both. |
ghost
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I have the same problem with Cascadia Code (I have WT 1.16.10261.0). vs this screenshot from cmd.exe: |
carlos-zamora
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Apr 26, 2023
This is practically a from scratch rewrite of AtlasEngine. The initial approach used a very classic monospace text renderer, where the viewport is subdivided into cells and each cell is assigned one glyph texture, just like how real terminals used to work. While we knew that it would have problems with overly large glyphs, like those found in less often used languages, we didn't expect the absolutely massive number of fonts that this approach would break. For one, the assumption that monospace fonts are actually mostly monospace has turned out to be a complete lie and we can't force users to use better designed fonts. But more importantly, we can't just design an entire Unicode fallback font collection from scratch where every major glyph is monospace either. This is especially problematic for vertical overhangs which are extremely difficult to handle in a way that outperforms the much simpler alternative approach: Just implementing a bog-standard, modern, quad-based text renderer. Such an approach is both, less code and runs faster due to a less complex CPU-side. The text shaping engine (in our case DirectWrite) has to resolve text into glyph indices anyways, so using them directly for text rendering allows reduces the effort of turning it back into text ranges and hashing those. It's memory overhead is also reduced, because we can now break up long ligatures into their individual glyphs. Especially on AMD APUs I found this approach to run much faster. A list of issues I think are either obsolete (and could be closed) or resolved with this PR in combination with #14255: Closes #6864 Closes #6974 Closes #8993 Closes #9940 Closes #10128 Closes #12537 Closes #13064 Closes #13527 Closes #13662 Closes #13700 Closes #13989 Closes #14022 Closes #14057 Closes #14094 Closes #14098 Closes #14117 Closes #14533 Closes #14877 ## PR Checklist * Enabling software rendering enables D2D mode ✅ * Both D2D and D3D: * Background appears correctly ✅✅ * Text appears correctly * Cascadia Code Regular ✅✅ * Cascadia Code Bold ✅✅ * Cascadia Code Italic ✅✅ * Cascadia Code block chars leave (almost) no gaps ✅✅ * Terminus TTF at 13.5pt leaves no gaps between block chars ✅✅ * ``"`u{e0b2}`u{e0b0}"`` in Fira Code Nerd Font forms a square ✅✅ * Cursor appears correctly * Legacy small/medium/large ✅✅ * Vertical bar ✅✅ * Underscore ✅✅ * Empty box ✅✅ * Full box ✅✅ * Double underscore ✅✅ * Changing the cursor color works ✅✅ * Selection appears correctly ✅✅ * Scrolling in various manners always renders correctly ✅✅ * Changing the text antialising mode works ✅✅ * Semi-transparent backgrounds work ✅✅ * Scroll-zooming the font size works ✅✅ * Double-size characters work ✅✅ * Resizing while text is printing works ✅✅ * DWM `+Heatmap_ShowDirtyRegions` shows that only the cursor region is dirty when it's blinking ✅✅ * D2D * Margins are filled with background color ❌ They're filled with the neighboring's cell background color for convenience, as D2D doesn't support `D3D11_TEXTURE_ADDRESS_BORDER` * D3D * Margins are filled with background color ✅ * Soft fonts work ✅ * Custom shaders enable continous redraw if time constant is used ✅ * Retro shader appears correctly ✅ * Resizing while a custom shader is running works ✅
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Windows Terminal version
1.13.10983.0
Windows build number
10.0.19044.0
Other Software
No response
Steps to reproduce
echo "╦═════════`n╚╣"Expected Behavior
In both versions, the glyphs should be connected into uniform lines.
Actual Behavior
Terminal Preview v1.13.10983.0:
disconnected glyphs – the vertical line is always broken, the horizontal line is rendered correctly at some font sizes, and incorrectly at others
Terminal (Stable) v1.12.10982.0:
rendered correctly
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