Commit Graph

46 Commits

Author SHA1 Message Date
Guldoman 5e80149295 Avoid having no `pixel_width`
On small scales `pixel_width` could become `0`. This caused the creation 
of buffers of size `0` with consequent overflows.
2021-08-28 15:56:35 +02:00
Adam Harrison e144ad3271 Removed legacy build system. 2021-07-15 20:47:44 -04:00
Francesco Abbate d0d6ad8d7d Fix problem with glyph spacing in subpixel mode
One more space is needed for subpixel positioning.

Otherwise some artifacts can be present
2021-03-07 18:38:47 +01:00
Francesco Abbate 6782533ad2 Fix heuristic to find font atlas optimal width 2021-03-07 17:30:11 +01:00
Francesco Abbate 9ff6a0325e Mostly fix problem of offset with cursor positioning when using mouse
In order to get right the cursor position on text on mouse clicks it is
needed to take into account text's subpixel positioning.

This fix mostly corrects the problem but cursor positioning is still
somewhat inaccurate for long lines due to repeated commands to draw a text
along a line. Repeated draw text calls make the subpixel information
lost and small errors will add-up.
2021-03-06 16:18:24 +01:00
Francesco Abbate 7abb36e5e8 Fix error with glyphs subpixel layout 2021-03-05 22:43:15 +01:00
Francesco Abbate ffb4773a0b Merge branch 'subpixel-font-positioning' 2021-03-05 09:14:25 +01:00
Francesco Abbate e441beae83 Add missing padding pixel to avoid artifacts
Using subpixel positioning we need one empty pixel as the left of each glyph.
2021-03-04 16:54:55 +01:00
Francesco Abbate bdc473435b Fix bug causing abort when glyph count was zero
Solve github's issue https://github.com/franko/lite-xl/issues/75
2021-03-03 18:49:27 +01:00
Francesco Abbate 294f3f14fb Implement subpixel font positioning
Subpixel positioning is only by 1/3 of pixel
2021-03-03 18:36:09 +01:00
Francesco Abbate ea8a8770ea Do not use nullptr and add check 2021-02-24 09:46:48 +01:00
Francesco Abbate a23986f171 Cleanup font's note markdown file 2021-02-23 17:14:22 +01:00
Francesco Abbate 35f31c8fbc Fix font rendering artifacts bug
Seen with some fonts like FiraSans, github issue:

https://github.com/franko/lite-xl/issues/46

The fix works essentially by looking to the bounds of each glyph to
accurately ensure that there are no overlaps between the glyphs.

The construction of the font atlas was changed to make some related
improvements now that the bounds of each glyph are know. The main
changes are:

- no longer align glyph on the baseline but align them on their upper
  bounds. We ensure this way that very tall fonts do not leak in the
  upper part
- terminate the row based on x bounds of the glyph to be more accurate
- for each row keep trace of the y of the more larger along y of the
  glyph. The value is used to start a new row to be sure that the new
  now does not overlap with the previous one
- sort glyphs by y size before drawing them. In this way the space
  utilization is better. The algorithm used is the very simple insert
  sort. It behaves like O(n^2) with the number of characters but should
  be ok since n is always small, typically below 128.
- compute the optimal image width and height for the given font's atlas
  for optimal memory usage. As a bonus now the lite's code don't have to
  try and repeat to get a good image size
2021-02-23 17:14:08 +01:00
Francesco Abbate a41754b382 Fix font hinting when using subpixel rendering
Ensure we set the font's size with freetype to the intended size so that
hinting works as expected and perform subpixel scaling using affine
matrix coefficient.
2020-12-11 14:36:32 +01:00
Francesco Abbate 71db2d439a Add libagg as a subproject
No longer required to be installed, the subproject will be used if not
found.
2020-06-30 17:02:50 +02:00
Francesco Abbate 0c09419001 Fix again the problem with C++ abs function 2020-06-29 18:20:36 +02:00
Francesco Abbate bc6cdd7711 Remove spurious typename keyword in C++ code 2020-06-29 17:02:45 +02:00
Francesco Abbate 1fc6d62b14 Fix Lua subproject ofr Mac OS X 2020-06-29 17:01:14 +02:00
Francesco Abbate fa649521d2 Fix usage of abs function with C++ 2020-06-29 16:58:42 +02:00
Francesco Abbate c23ef76179 Add execution flags to build script 2020-06-18 19:28:06 +02:00
Francesco Abbate 0e04030131 Fix and improve build script 2020-06-18 15:53:31 +02:00
Francesco Abbate f5ede27e91 No longer use gamma correction
Text looks more correct without the gamma correction. With gamma correction
text looks too bold in dark mode and too light in light mode. This
behavior is a sign that gamma correction is not the right thing to do.

The problem is seen with gamma at 1.5 used previously but is even worst
if a gamma value of 2.2, the theoretical value, is used.
2020-06-16 14:43:03 +02:00
Francesco Abbate 3c3662b3ba Add option to disable X axis font's pre-scaling
If used pre-scaling along X null the effect of the font's hinting.
2020-06-12 16:06:39 +02:00
Francesco Abbate 9e996a2d87 Rename FontRenderer to FR_Renderer 2020-06-11 23:19:08 +02:00
Francesco Abbate 93a36617f9 Bring back simple grayscale rendering option 2020-06-11 23:11:40 +02:00
Francesco Abbate 00c3983da6 Rename FontRenderer* symbols as FR_* 2020-06-11 18:12:47 +02:00
Francesco Abbate 117714390a Make the FontRenderer's Bitmap struct opaque outside the library 2020-06-11 17:52:00 +02:00
Francesco Abbate ce664f85b1 Move rendering buffers pointers computations inside FontRendererBlendGammaSubpixel
The logic is to disentangle the code between renderer.c and FontRenderer
so that this latter has a simple, logical interface.
2020-06-11 17:33:57 +02:00
Francesco Abbate 18865fd32f Remove font renderer debug code 2020-06-09 16:55:26 +02:00
Francesco Abbate ba4c8dbbb5 Remove unneeded checks in get_font_vmetrics 2020-06-08 09:36:07 +02:00
Francesco Abbate bddc947b99 Fix pixel off-by-one error in subpixel font renderer hspan 2020-06-08 09:35:52 +02:00
Francesco Abbate 74de184e50 Move notes.md inside lib/font_renderer 2020-06-07 16:00:06 +02:00
Francesco Abbate e82d766c2b Add more debug information in font's bitmap images 2020-06-07 00:15:38 +02:00
Francesco Abbate b978873a58 Fix font's descender rounding to integer 2020-06-07 00:14:41 +02:00
Francesco Abbate 81289d651e Move font resize in a separate function 2020-06-06 19:11:14 +02:00
Francesco Abbate 8e796831f2 Fixed integer signed comparison warning 2020-06-06 19:03:41 +02:00
Francesco Abbate 646a594e89 Add optional const qualifiers 2020-06-06 14:58:19 +02:00
Francesco Abbate 609b31a3b9 Remove unused debug code 2020-06-06 14:54:11 +02:00
Francesco Abbate 229037293b Fix error in glyph lcd convolution 2020-06-06 14:53:44 +02:00
Francesco Abbate dcf6b06629 Cleanup debug code 2020-06-06 13:08:39 +02:00
Francesco Abbate d17fde1b13 WIP: debugging stuff 2020-06-06 10:52:50 +02:00
Francesco Abbate 7b541b7de8 Do not use additional padding space in covers temporary array 2020-06-05 17:36:08 +02:00
Francesco Abbate ad8cdf2b92 Found a working condition but some details needs attention 2020-06-05 17:32:36 +02:00
Francesco Abbate 2e2db2d690 WIP testing ahead of time coverage convolution 2020-06-05 15:27:55 +02:00
Francesco Abbate baf8cec837 Cosmetic change to floor_div function 2020-06-05 14:16:08 +02:00
Francesco Abbate c5575de058 Move font renderer in a separate folder as a library 2020-06-04 18:52:01 +02:00