[libmupdf] add ocr feature

[simon987]

New libmupdf versions have optional support for OCR with leptonica and tesseract. In the upstream project, it is enabled when both libraries are available, using the OCR_DISABLED flag:

https://github.com/ArtifexSoftware/mupdf/blob/c5d3b65c8a3e1923cd816e8cb0eed726937a289d/include/mupdf/fitz/config.h#L216-L220

I added the feature in ports/libmupdf/vcpkg.json and updated the ports/libmupdf/CMakeLists.txt file. Changing OCR_FEATURE_IS_ENABLED from 0 to 1 does work on my machine but I can't figure out how to "link" this variable with the [ocr] feature flag (is there a is_feature_enabled() function or similar?).

• Changes comply with the maintainer guide
• SHA512s are updated for each updated download
• The "supports" clause reflects platforms that may be fixed by this new version
• Any fixed CI baseline entries are removed from that file.
• Any patches that are no longer applied are deleted from the port's directory.
• The version database is fixed by rerunning ./vcpkg x-add-version --all and committing the result.
• Only one version is added to each modified port's versions file.

[dg0yt]

Changing OCR_FEATURE_IS_ENABLED from 0 to 1 does work on my machine but I can't figure out how to "link" this variable with the [ocr] feature flag (is there a is_feature_enabled() function or similar?).

This port is unusual, it has the usual portfile (CMake script mode) and it adds a CMake build system to the upstream sources (CMake project mode). Keep this in mind. Cf. https://learn.microsoft.com/en-us/vcpkg/contributing/maintainer-guide#portfiles-are-run-in-script-mode

In script mode, the features are available in variable FEATURES. So the portfile can react in various ways. In particular, it needs to feed settings into the build system. For CMake build systems, there is vcpkg_check_features to support the common case of setting "input variables".

So, to the CMakeLists.txt, you could add:

option(ENABLE_OCR "Build with OCR" ON)

In the portfile you could use the maintainer functions:

vcpkg_check_features(
    OUT_FEATURE_OPTIONS FEATURE_OPTIONS
    FEATURES
        ocr ENABLE_OCR
)
...
vcpkg_cmake_configure(
    ...
    OPTIONS
        ${FEATURE_OPTIONS}
)

[simon987]

Thanks a lot @dg0yt!

[FrankXie05]

All features are tested successfully in the following triplet:

• x86-windows
• x64-windows
• x64-windows-stataic

[vicroms]

Need to increase the port-version in vcpkg.json and then run vcpkg x-add-version to correctly update the versions database.

Please mark PR as "Ready for review" once you have fixed this.

[simon987]

@vicroms I was told to delete the port-version field the last time :( I tried to re-add it at version 2 but I think that broke the CI, could you help me with that?

[dg0yt]

I was told to delete the port-version field the last time :( I tried to re-add it at version 2 but I think that broke the CI, could you help me with that?

port-version is relative to version[-...]. If you bump the version, the port version is reset. If the version is unchanged, the port-version must be incremented by one.

[dg0yt]

This jumps from (implicit) 0 to 2. But we need 1 now.

[simon987]

 port-version is relative to version[-...]. If you bump the version, the port version is reset. If the version is unchanged, the port-version must be incremented by one.

I see, this makes sense now. Thank you!