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2020-08-20Documentation: Guides: Application Writer's GuideChris Chinchilla
Provide a tutorial and walk through guide for writing an applications with libcamera. Signed-off-by: Chris Chinchilla <chris@gregariousmammal.com> [Reflow/Rework, update to mainline API] Signed-off-by: Jacopo Mondi <jacopo@jmondi.org> [Further reworks and review] Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2020-08-20Documentation: Guides: Developer's Guide to libcameraChris Chinchilla
Create an introduction and overview for new developers to libcamera. Provide an overview of the Camera Stack, and Architecture of libcamera and introduce the main concepts of libcamera. Signed-off-by: Chris Chinchilla <chris@gregariousmammal.com> [Kieran: Rework/Reflow, add diagrams, licensing] Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2020-06-16Documentation: Drop TCL_SUBST tag from Doxyfile.inLaurent Pinchart
The TCL_SUBST tag is deprecated and causes doxygen 1.18.8 to generate a warning. Drop it from Doxyfile.in. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
2020-06-09licenses: Add SPDX headers to the website builder and themeLaurent Pinchart
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2020-06-05docs: Markup LD_PRELOAD as codeMarvin Schmidt
LD_PRELOAD is an environment variable, use code markup to reflect that semantic Signed-off-by: Marvin Schmidt <marvin.schmidt1987@gmail.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2020-06-05docs: coding-style: Change full stop to colonMarvin Schmidt
Signed-off-by: Marvin Schmidt <marvin.schmidt1987@gmail.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2020-06-05docs: Remove trailing whitespaceMarvin Schmidt
Signed-off-by: Marvin Schmidt <marvin.schmidt1987@gmail.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2020-06-05docs: Remove stray HTML tagsMarvin Schmidt
Signed-off-by: Marvin Schmidt <marvin.schmidt1987@gmail.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2020-05-18meson: Rename variables storing headers listsLaurent Pinchart
The list of public, IPA and internal header files are stored in three meson variables, named libcamera_api, libcamera_ipa_api and libcamera_headers respectively. The lack of uniformity is a bit confusing. Fix it by renaming those variables to libcamera_public_headers, libcamera_ipa_headers and libcamera_internal_headers. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Jacopo Mondi <jacopo@jmondi.org> Acked-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2020-05-16libcamera: Move IPA headers from include/ipa/ to include/libcamera/ipa/Laurent Pinchart
The IPA headers are installed into $prefix/include/libcamera/ipa/, but are located in the source tree in include/ipa/. This requires files within libcamera to include them with #include <ipa/foo.h> while a third party IPA would need to use #include <libcamera/ipa/foo.h> Not only is this inconsistent, it can create issues later if IPA headers need to include each other, as the first form of include directive wouldn't be valid once the headers are installed. Fix the problem by moving the IPA headers to include/libcamera/ipa/. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Jacopo Mondi <jacopo@jmondi.org>
2020-05-16libcamera: Move internal headers to include/libcamera/internal/Laurent Pinchart
The libcamera internal headers are located in src/libcamera/include/. The directory is added to the compiler headers search path with a meson include_directories() directive, and internal headers are included with (e.g. for the internal semaphore.h header) #include "semaphore.h" All was well, until libcxx decided to implement the C++20 synchronization library. The __threading_support header gained a #include <semaphore.h> to include the pthread's semaphore support. As include_directories() adds src/libcamera/include/ to the compiler search path with -I, the internal semaphore.h is included instead of the pthread version. Needless to say, the compiler isn't happy. Three options have been considered to fix this issue: - Use -iquote instead of -I. The -iquote option instructs gcc to only consider the header search path for headers included with the "" version. Meson unfortunately doesn't support this option. - Rename the internal semaphore.h header. This was deemed to be the beginning of a long whack-a-mole game, where namespace clashes with system libraries would appear over time (possibly dependent on particular system configurations) and would need to be constantly fixed. - Move the internal headers to another directory to create a unique namespace through path components. This causes lots of churn in all the existing source files through the all project. The first option would be best, but isn't available to us due to missing support in meson. Even if -iquote support was added, we would need to fix the problem before a new version of meson containing the required support would be released. The third option is thus the only practical solution available. Bite the bullet, and do it, moving headers to include/libcamera/internal/. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Jacopo Mondi <jacopo@jmondi.org>
2020-05-13licenses: License all meson files under CC0-1.0Laurent Pinchart
In an attempt to clarify the license terms of all files in the libcamera project, the build system files deserve particular attention. While they describe how the binaries are created, they are not themselves transformed into any part of binary distributions of the software, and thus don't influence the copyright on the binary packages. They are however subject to copyright, and thus influence the distribution terms of the source packages. Most of the meson.build files would not meet the threshold of originality criteria required for copyright protection. Some of the more complex meson.build files may be eligible for copyright protection. To avoid any ambiguity and uncertainty, state our intent to not assert copyrights on the build system files by putting them in the public domain with the CC0-1.0 license. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Acked-by: Giulio Benetti <giulio.benetti@micronovasrl.com> Acked-by: Jacopo Mondi <jacopo@jmondi.org> Acked-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Acked-by: Naushir Patuck <naush@raspberrypi.com> Acked-by: Nicolas Dufresne <nicolas.dufresne@collabora.com> Acked-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> Acked-by: Paul Elder <paul.elder@ideasonboard.com> Acked-by: Show Liu <show.liu@linaro.org>
2020-05-11Documentation: coding-style: Fix ordered listsLaurent Pinchart
The syntax used for ordered lists is incorrect. Fix it. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
2020-04-15licenses: Add SPDX headers to Doxygen configurationLaurent Pinchart
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2020-04-15licenses: Add SPDX headers to RST documentationLaurent Pinchart
The documentation files are licensed under CC-BY-SA-4.0, but this has never been specified explicitly. Add corresponding SPDX headers. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2020-04-15licenses: Move developer's certificate of origin to Documentation/Laurent Pinchart
The developer's certificate of origin isn't a license, move it from LICENSES/ to Documentation/ by incorporating it in contributing.rst. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2020-03-06libcamera: controls: Add templates to convert a type T to a ControlTypeLaurent Pinchart
These will be used to implement ControlValue::get() and set() as template functions. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2020-03-06libcamera: Add a C++20-compliant std::span<> implementationJacopo Mondi
C++20 will contain a std::span<> class that provides view over a contiguous sequence of objects, the storage of which is owned by some other object. Add a compatible implementation to the utils namespace. This will be used to implement array controls. Signed-off-by: Jacopo Mondi <jacopo@jmondi.org> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2020-02-13libcamera: utils: Add string splitter utility functionLaurent Pinchart
Add a utils::split() function that splits a string for the purpose of iterating over substrings. It returns an object of unspecified type that can be used in range-based for loops. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2020-02-13libcamera: Define the threading modelLaurent Pinchart
Document the design of libcamera's threading support, and prepare to document thread-safety of classes and functions with a doxygen alias command. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
2020-01-31Documentation: Add linkcheck targetKieran Bingham
Sphinx provides a run-target to verify external links specified in the documentation. This requires an active connection to be able to validate the links. Add a meson target to integrate the linkcheck facility into our build and test system. Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2020-01-23libcamera: camera_manager: Move private data members to private implementationLaurent Pinchart
Use the d-pointer idiom ([1], [2]) to hide the private data members from the CameraManager class interface. This will ease maintaining ABI compatibility, and prepares for the implementation of the CameraManager class threading model. [1] https://wiki.qt.io/D-Pointer [2] https://en.cppreference.com/w/cpp/language/pimpl Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
2020-01-14meson.build: Switch to C++14Laurent Pinchart
C++14 is a minor release that doesn't introduce major new concepts or paradigms compared to C++11, but brings two useful changes for us: - std::make_unique allows dropping our custom implementation in utils. - Functions returning constexpr are not assumed to be const anymore, which is needed to create a standard-conformant span implementation. All the g++ and clang++ versions we support and test (g++-5 onwards and clang++6 onwards) support C++14. However, due to a defect in the original C++14 specification, solved in N4387 ([1]), compilation would fail on g++-5 due to the use of std::map::emplace() with a non-copyable value type. It turns out we can easily fix it by switching to the explicit piecewise emplace() overload. There is thus really nothing holding back the switch. Let's do it, and update the coding style accordingly. [1] http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4387 Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
2020-01-07libcamera: bound_method: Rename Bound*Method to BoundMethod*Laurent Pinchart
Most of the bound method classes are named with a BoundMethod prefix, except for BoundMemberMethod and BoundStaticMethod. Rename them to BoundMethodMember and BoundMethodStatic respectively to make the code more coherent. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
2020-01-07libcamera: bound_method: Manage BoundMethodPack through std::shared_ptrLaurent Pinchart
The bound method arguments pack will need to be accessed by the method invoker in order to retrieve the method return value when using a blocking connection type. We thus can't delete the pack unconditionally in the bound method target thread. We also can't delete it unconditionally in the invoker's thread, as for queued connections the pack will be used in the target thread after the invoker completes. This shows that ownership of the arguments pack is shared between two contexts. As a result, manage it using std::shared_ptr<>. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
2020-01-07libcamera: bound_method: Store method arguments in a classLaurent Pinchart
Create a new BoundMethodPack class to replace the PackType type alias. This will allow adding additional fields to the arguments pack, when adding support for propagation of bound method return values. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
2019-11-20ipa: Switch to the plain C APIJacopo Mondi
Switch IPA communication to the plain C API. As the IPAInterface class is easier to use for pipeline handlers than a plain C API, retain it and add an IPAContextWrapper that translate between the C++ and the C APIs. On the IPA module side usage of IPAInterface may be desired for IPAs implemented in C++ that want to link to libcamera. For those IPAs, a new IPAInterfaceWrapper helper class is introduced to wrap the IPAInterface implemented internally by the IPA module into an ipa_context, ipa_context_ops and ipa_callback_ops. Signed-off-by: Jacopo Mondi <jacopo@jmondi.org> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
2019-10-29libcamera: bound_method: Define connection type for method invocationJacopo Mondi
Define an enumeration of connection types to describe the delivery method of signals and method invocation. Signed-off-by: Jacopo Mondi <jacopo@jmondi.org> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
2019-10-23Documentation: theme: css: Really hide toc treesLaurent Pinchart
The toc trees are rendered as hidden but still take space due to their margin and padding. Really hide them. While at it, don't handle overflow with scrollbars in the content area, the whole page should be scrollable. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2019-10-23Documentation: theme: css: Make text darkerLaurent Pinchart
The text is currently rendered as a 50% gray, which is a bit painful to read in low light conditions. Make it darker. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2019-10-23Documentation: Hide the Getting Started informationLaurent Pinchart
The Getting Started information makes little sense on the generated documentation, as a developer with documentation compiled from a local libcamera source tree has already got started. We however want to keep the information in the top-level README.rst as it is useful there. In order to hide the Getting Started information from the front page while keeping it in README.rst, add comments to delimitate sections of README.rst, and include only a subset of the file in the front page. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2019-10-23Documentation: Set the index TOC max depth to 1Laurent Pinchart
We don't need more than one level in the main TOC tree, set the max depth to 1. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2019-10-23Documentation: Generate local TOC on demandLaurent Pinchart
All pages are generated with a local TOC, which is pointless on simple pages such as the front page, or other pages containing little content. Use the .. contents:: :local: directive instead to generate the local TOC on demand, and remove the automatic local TOC generation. Only the Docs page uses a local TOC. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2019-10-23Documentation: Link to API section in DocsLaurent Pinchart
The API belongs to the docs section. Link to it from docs.rst, and remove the shortcut in the navigation bar as links to a placeholder only. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2019-10-23Documentation: contributing: Remove Sphinx + Doxygen integrationLaurent Pinchart
Sphinx integration with Doxygen didn't produce the expected results, we will not go that way. Don't mention it on the contributing page. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2019-10-23Documentation: Move coding style under contributingLaurent Pinchart
The coding style isn't so important that it has to be displayed on the top contents bar. Move it to the contributing section. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2019-10-23Documentation: coding-style: Document order of includesLaurent Pinchart
We follow the Google C++ Style Guide rule on include ordering with a few tweaks. Document our rule explicitly. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
2019-10-23Documentation: coding-style: Document usage of C compatibility headersLaurent Pinchart
The C++ standard defines a set of C++ standard library headers, and for some of them, defines C compatibility headers. The former have a name of the form <cxxx> while the later are named <xxx.h>. The C++ headers declare names in the std namespace, and may declare the same names in the global namespace. The C compatibility headers declare names in the global namespace, and may declare the same names in the std namespace. We want to standardise on one set of headers through libcamera, and don't want to rely on optional behaviour. We can thus either use the C++ headers with an explicit std:: namespace qualifier through the code, or the C headers without the qualifier. Both set of headers are defined by the C++ standard, and are thus valid choices. After weighing pros and cons, we have decided to use the C compatibility headers, as nobody wanted to write std::uint32_t. Document this decision. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
2019-10-05libcamera: controls: Auto-generate control_ids.h and control_ids.cppLaurent Pinchart
Bring back auto-generation of control ids. In this version, both the header and the source files are generated from a single YAML file that stores all control definitions. This allows centralising controls in a single file, while the previous version required keeping both declarations (in a header) and documentation (in a the source) in sync manually. Using YAML as a format to store control definitions is a trade-off between ease of use (there are many YAML parsers available) and simplicity (XML was considered, but would have lead to more complex processing). A new build time dependency is added on python3-yaml, which should be available as a package in all distributions and build environments. The YAML format is likely to change over time as we improve documentation of controls, the first version simply copies the information currently available. Future improvements should also include a YAML schema to validate the YAML source file. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
2019-09-16Documentation: Fix warnings when compiling with Doygen 1.8.16Jacopo Mondi
Since doxygen version 1.8.16 the following warnings are reported: warning: Tag 'PERL_PATH' at line 2138 of file 'Documentation/Doxyfile.in' has become obsolete. This tag has been removed. warning: Tag 'MSCGEN_PATH' at line 2160 of file 'Documentation/Doxyfile.in' has become obsolete. This tag has been removed. Remove the two tags to fix the warnings. Signed-off-by: Jacopo Mondi <jacopo@jmondi.org> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2019-09-15libcamera: Move ipa includes to the same level as libcameraLaurent Pinchart
The ipa includes are located in include/libcamera/ipa/. This gives an incorrect impression that they are a sub-part of the rest of the libcamera API, while they are the API towards the IPA the same way that include/libcamera/ contains the API towards applications. To clarify this, move them to include/ipa/. The IPA headers are however still part of libcamera, so installing them to ${prefix}/include/ipa/ would make little sense. To fix this, move the application facing API to ${prefix}/include/libcamera/libcamera/ when installed, and the IPA to ${prefix}/include/libcamera/ipa/. When major versions of libcamera will be released, they could then be installed side by side in ${prefix}/include/libcamera-${version}/. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
2019-09-13Documentation: Exclude bound_method.{h,cpp}Laurent Pinchart
The bound method classes are not part of the public API, even though they need to be exposed to applications due to the Object and Signal template methods that use them. They are excluded from documentation generation through EXCLUDE_SYMBOLS, but the corresponding .h file is still listed in the generated documentation. Fix this by excluding the bound_method.{h,cpp} files themselves. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2019-08-17libcamera: signal: Split Slot implementation to reusable classesLaurent Pinchart
Move the Slot* classes to bound_method.{h,cpp} and rename them to Bound*Method*. They will be reused to implement asynchronous method invocation similar to cross-thread signal delivery. This is only a move and rename, no functional changes are included. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
2019-08-16readme: Move index page content to READMEKieran Bingham
Move the introduction content from the index.rst to the README.rst so that it can also be found quickly from the top level. Include the README.rst directly into the index.rst to continue serving it as the front page material. Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2019-07-12libcamera: add IPA proxyPaul Elder
Add an IPAProxy class whose implementations will act as a proxy between a pipeline handler and an isolated IPA interface. Also add an IPAProxyFactory that will construct the IPAProxy implementations as necessary. Update Doxygen to ignore the directory where IPAProxy implementations will reside. Signed-off-by: Paul Elder <paul.elder@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2019-07-10Documentation: Fix trivial spelling errorKieran Bingham
harware -> hardware Reported-by: Hans Verkuil <hverkuil@xs4all.nl> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2019-07-09libcamera: Rework automatic version generation to avoid rebuildsLaurent Pinchart
Commit b817bcec6b53 ("libcamera: Auto generate version information") generates version information in order to automatically include it various locations (Sphinx and Doxygen documentation, libcamera::version variable available at runtime, and version.h available at compile time). Unfortunately this causes lots of unnecessary rebuilds when modifying the git tree state, which hinders development. The problem is caused by the generated version.h being listed as a dependency for the whole libcamera. This is required as meson (to the best of my knowledge) doesn't provide a way to explicitly specify the dependency of a single object file (camera_manager.o in this case, as camera_manager.cpp is the only consumer of the generated version string) on the custom target used to generate version.h. The dependency can't be automatically detected at build time, like dependencies on normal headers that are generated by parsing the source, because the version.h header may not exist yet. The build could then fail in a racy way. This change attempts at solving the issue by generating a version.cpp instead of a version.h to set the git-based version. This minimises the number of files that need to be rebuild when then git tree state changes, while retaining the main purpose of the original automatic version generation, the ability to access the git-based version string at runtime. We however lose the ability to access git-based version information at build time in an application building against libcamera, but there is no expected use case for this. The version string is moved from the libcamera namespace to the CameraManager class in order to avoid including version.h inside libcamera (in version.cpp and in camera_manager.cpp), which would create dependencies causing more rebuild steps, as described above. On the other hand, major, minor and patch level version numbers are useful at build time. This commit changes the generation of version.h in order to add three macros named LIBCAMERA_VERSION_MAJOR, LIBCAMERA_VERSION_MINOR and LIBCAMERA_VERSION_PATCH for this purpose. version.h is not included by any other libcamera header or source file, and thus doesn't force a rebuild of the library. The Sphinx and Doxygen documentation keep their git-based version information, which is set during the configuration of the build and then doesn't track git commits. We may want to investigate how to improve this, but given that git-based version for the documentation has very few use cases outside of tagging nightly builds, this isn't considered an issue at the moment. The documentation install directory now uses the base version string, in order to avoid increasing the number of documentation directories needlessly. This shouldn't cause any issue as the API should not change without a change to the version number. The version number generation and handling code now also standardises the version variables to not start with a 'v' prefix in meson, in order to simplify their handling. The prefix is added when generating the relevant files. Note that we go back to specifying the fallback version in the main meson.build, in the call to the project() function. For the time being I believe this should be a good compromise to avoid unnecessary recompilation, and moving the fallback version to a different file for tarball releases can be built on top of this. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
2019-07-04Documentation: Wrap extended doc_install_dir lineKieran Bingham
The doc_install_dir is longer than 80 chars. Wrap it accordingly. Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2019-07-04libcamera: Auto generate version informationKieran Bingham
Generate a version string, and provide a global string object which allows applications to interrogate the current libcamera version information. The version header is automatically updated by meson on each build. The string roughly follows the semver [0] conventions of major.minor.patch-label as a value. [0] https://semver.org/ A script (utils/gen-version.sh) is provided which is modelled upon the processing from autoconf's git-version-gen. The gen-version.sh script will look for tags in the form vX.Y as starting points for the version string. While the repository does not have any matching tags, v0.0 will be assumed, resulting in versions with both major and minor being set to '0', and the patch count resulting from the number of patches in the history to that point. Finally, a uniquely identifying shortened hash is provided from git: v0.0.509+0ec0edf7 Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
2019-07-04Documentation: Make the project brief more expressiveKieran Bingham
The current project brief lacks any quotation marks, and causes the Doxygen API documents to show the header "libcameraframework". Replace the simplistic definition with a better brief, and ensure quotation marks are provided to maintain spacing. Fixes: 53c4d4c34fc4 ("Documentation: Generate source code documentation using Doxygen") Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>