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330916 |
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14-Mar-2018 |
eadler |
MFC r315418,r315480,r316019:
Add teken_256to16() to convert xterm-256 256-color codes to xterm 16-color codes. This will be used to fix bright colors.
Improve teken_256to8(). Use a lookup table instead of calculations. The calculations were inaccurate since they used indexes into the xterm-256 6x6x6 color map instead of actual xterm colors. Also, change the threshold for converting to a primary color: require the primary's component to be 2 or more higher instead of just higher. This affects about 1/5 of the table entries and gives uniformly distributed colors in the 6x6x6 submap except for greys (35 entries each for red, green, blue, cyan, brown and magenta, instead of approx. only 15 each for the mixed colors). Even more mixed colors would be better for matching colors, but uniform distribution is best for preserving contrast.
For teken_256to16(), bright colors are just the ones with luminosity >= 60%. These are actually light colors (more white instead of more saturation), while xterm bright colors except for white itself are actually saturated with no white, so have luminosity only 50%.
These functions are layering violations. teken cannot do correct conversions since it shouldn't know the color maps of anything except xterm. Translating through xterm-16 colors loses information. This gives bugs like xterm-256 near-brown -> xterm-16 red -> VGA red.
------------------------------------------------------------------------ r315480 | bde | 2017-03-18 11:13:54 +0000 (Sat, 18 Mar 2017) | 51 lines
Fix bright colors for syscons, and make them work for the first time for vt. Restore syscons' rendering of background (bg) brightness as foreground (fg) blinking and vice versa, and add rendering of blinking as background brightness to vt.
Bright/saturated is conflated with light/white in the implementation and in this description.
Bright colors were broken in all cases, but appeared to work in the only case shown by "vidcontrol show". A boldness hack was applied only in 1 layering-violation place (for some syscons sequences) where it made some cases seem to work but was undone by clearing bold using ANSI sequences, and more seriously was not undone when setting ANSI/xterm dark colors so left them bright. Move this hack to drivers.
The boldness hack is only for fg brightness. Restore/add a similar hack for bg brightness rendered as fg blinking and vice versa. This works even better for vt, since vt changes the default text mode to give the more useful bg brightness instead of fg blinking.
The brightness bit in colors was unnecessarily removed by the boldness hack. In other cases, it was lost later by teken_256to8(). Use teken_256to16() to not lose it. teken_256to8() was intended to be used for bg colors to allow finer or bg-specific control for the more difficult reduction to 8; however, since 16 bg colors actually work on VGA except in syscons text mode and the conversion isn't subtle enough to significantly in that mode, teken_256to8() is not used now.
There are still bugs, especially in vidcontrol, if bright/blinking background colors are set.
Restore XOR logic for bold/bright fg in syscons (don't change OR logic for vt). Remove broken ifdef on FG_UNDERLINE and its wrong or missing bit and restore the correct hard-coded bit. FG_UNDERLINE is only for mono mode which is not really supported.
Restore XOR logic for blinking/bright bg in syscons (in vt, add OR logic and render as bright bg). Remove related broken ifdef on BG_BLINKING and its missing bit and restore the correct hard-coded bit. The same bit means blinking or bright bg depending on the mode, and we want to ignore the difference everywhere.
Simplify conversions of attributes in syscons. Don't pretend to support bold fonts. Don't support unusual encodings of brightness. It is as good as possible to map 16 VGA colors to 16 xterm-16 colors. E.g., VGA brown -> xterm-16 Olive will be converted back to VGA brown, so we don't need to convert to xterm-256 Brown. Teken cons25 compatibility code already does the same, and duplicates some small tables. This is mostly for the sc -> te direction. The other direction uses teken_256to16() which is too generic.
------------------------------------------------------------------------ r316019 | bde | 2017-03-27 10:48:28 +0000 (Mon, 27 Mar 2017) | 30 lines
Oops, my fix for bright colors broke bright black some more (in cases that used to work via the bold hack).
Fix the table entry for bright black. Fix spelling of plain black in nearby table entries (use the macro for black everywhere everywhere). Fix the currently-unused non-bright color table to not have bright colors in entries 9-15.
Improve nearby comments. Start converting to the xterm terminology and default rendering of "bright" instead of "light" for bright colors.
Syscons wasn't affected by the bug since I optimized it a little by converting colors 0-15 directly. This also fixes the layering of the conversion for these colors.
Apply the same optimization to vt (actually the layer above it). This also moves the conversion 1 closer to the correct layer for colors 0-15.
The optimization of just avoiding 2 calls to a trivial function is worth about 10% for simple output to the virtual buffer with occasional rendering. The optimization is so large because the 2 calls are done on every character, so although there are too many other calls and other instructions per character, there are only about 10 times as many. Old versions of syscons were about 10 times faster for simple output, by using a fast path with about 12 instructions per character. Rendering to even slow hardware takes relatively little time provided it is rarely actually done.
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221698 |
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09-May-2011 |
ed |
Add proper build infrastructure for teken.
I'm not sure whether we should install teken as a library on any stock FreeBSD installation, but I can imagine people want to tinker around with it now and then. Create a /sys/teken/libteken, which holds a Makefile to install a shared library version of the terminal emulator, complete with a manpage.
Also add Makefiles for the demo/stress applications, to build it against the shared library.
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