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Page: Platforms and Testing
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7 Platforms and Testing
dxtr edited this page 2026-10-17 04:41:51 +02:00
Table of Contents

Platforms and Testing

Requirements

Library Version Needed by
HarfBuzz (libharfbuzz) 7.0 or newer cl-textrender
ICU (libicuuc) 52 or newer cl-textrender
FreeType (libfreetype) 2.13.1 or newer cl-textrender/raster, cl-textrender/atlas

The Lisp dependencies are cl-icu, cl-harfbuzz, cl-ft2, cl-atlas and cl-sdf, and cl-ffi, which the bindings call C through, all from their git repositories. cl-atlas and cl-sdf are pure Lisp, so cl-textrender/sdf needs no library beyond HarfBuzz and ICU. See Getting Started for installing them.

ICU is found whatever its major version: cl-icu finds the version suffix of the ICU the process loads, so an ICU upgrade needs no recompile. On Windows, cl-icu uses the icu.dll that ships with Windows 10 version 1903 and later. See each library's documentation for where it looks for its shared library.

Lisp implementation

cl-textrender runs on SBCL. The code is portable Common Lisp apart from the locks and the finalizers that free faces and fonts, in the internal package cl-textrender/sys of the core system. Its bindings call C through cl-ffi.

Running the tests

The suite is cl-textrender/test, written with Parachute. It covers the core and all three optional systems. From a checkout of cl-textrender:

stift test

The summary at the end gives the number of tests passed and failed. asdf:test-system signals an error if any test fails, so the command exits unsuccessfully.

Fonts for the tests

The tests check exact positions, so they need particular fonts:

Font Debian/Ubuntu package Used for Override
DejaVu Sans fonts-dejavu-core Most tests: TrueType outlines, metrics, Hebrew and Arabic CL_TEXTRENDER_TEST_FONT
URW Bookman Light fonts-urw-base35 CFF (cubic) outlines, font fallback CL_TEXTRENDER_TEST_CFF_FONT
Droid Sans Fallback fonts-droid-fallback Vertical text: CJK with vertical metrics and a vert feature CL_TEXTRENDER_TEST_CJK_FONT

A variable font for the variation tests comes with cl-ft2's tests. To use fonts from other locations, set the environment variables to their paths.

On Debian or Ubuntu, everything the suite needs:

apt install libharfbuzz0b libicu-dev libfreetype6 \
            fonts-dejavu-core fonts-urw-base35 fonts-droid-fallback

Continuous integration

CI runs the suite on every push to main and every pull request, with SBCL 2.6.9 in a Debian forky container, installing the packages above.

Reporting a problem

When something is laid out wrongly, the useful details are the text (with code points for anything unusual), the font file and size, the arguments to layout-text, and what you expected. The versions of HarfBuzz and ICU matter too: cl-harfbuzz:harfbuzz-version and cl-icu:icu-version report them.

cl-textrender

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Guides

Reference