f401f85a5a
Core Text doesn't actually have a concept of DPI internally, as it doesn't rasterize anything by itself, it just generates vector paths that get passed along to Core Graphics. In practice this means Core Text operates in the classical macOS logical DPI of 72, with one typographic point corresponding to one point in the Core Graphics coordinate system, which for a normal bitmap context then corresponds to one pixel -- or two pixels for a "retina" context with a 2x scale transform. Scaling the font point sizes given to HarfBuzz to an assumed DPI of 96 is problematic with this in mind, as fonts with optical features such as 'trak' tables for tracking, or color glyphs, will then base the metrics off of the wrong point size compared to what the client asked for. This in turn causes mismatches between the metrics of the shaped text and the actual rasterization, which doesn't include the 72 to 96 DPI scaling. If a 96 DPI is needed, such as on the Web, the scaling should be done outside of HarfBuzz, allowing the client to keep the DPI of the shaping in sync with the rasterization. The recommended way to do that is by scaling the font point size, not by applying a transform to the target Core Graphics context, to let Core Text choose the right optical features of the target point size, as described in WWDC 2015 session 804: https://developer.apple.com/videos/play/wwdc2015/804/ |
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| .ci | ||
| .circleci | ||
| docs | ||
| m4 | ||
| src | ||
| test | ||
| util | ||
| .clang-format | ||
| .codecov.yml | ||
| .editorconfig | ||
| .travis.yml | ||
| AUTHORS | ||
| BUILD.md | ||
| CMakeLists.txt | ||
| COPYING | ||
| Makefile.am | ||
| NEWS | ||
| README | ||
| README.md | ||
| README.python.md | ||
| README.wine.md | ||
| RELEASING.md | ||
| THANKS | ||
| TODO | ||
| appveyor.yml | ||
| autogen.sh | ||
| azure-pipelines.yml | ||
| configure.ac | ||
| git.mk | ||
| harfbuzz.doap | ||
| mingw32.sh | ||
| mingw64.sh | ||
| replace-enum-strings.cmake | ||
README.md
This is HarfBuzz, a text shaping library.
For bug reports, mailing list, and other information please visit:
For license information, see the file COPYING.
Documentation: https://harfbuzz.github.io