Pybind11

[alexlib]

No description provided.

[Copilot]

Pull request overview

Introduces Python (pybind11) bindings and wheel-building/CI tooling, while reorganizing native dependencies and removing fmt from the core build.

Changes:

• Add pybind11 module (piv_bindings.cpp) plus Python packaging (pyproject.toml, setup.py, manifest, package init).
• Rework vcpkg manifest dependencies into feature flags and update CMake/CI scripts/workflows for local + CI builds.
• Replace fmt usage in the logger with an in-house {} formatter and remove fmt linkage across targets.

Reviewed changes

Copilot reviewed 24 out of 26 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
vcpkg.json	Moves dependencies into feature-based groups (tests/examples) and clears base deps.
test/CMakeLists.txt	Removes fmt dependency from tests/benchmarks.
setup.py	Adds setuptools-based build that invokes CMake and packages the shared library.
scripts/test_cmake_workflow.sh	Adds local script to mimic CI CMake workflow.
scripts/test_cmake_docker.sh	Adds Docker wrapper for local CI-like testing.
scripts/README.md	Documents local testing options (direct, Docker, act).
scripts/Dockerfile.cmake-test	Adds Docker image for reproducing CI build environment locally.
pyproject.toml	Adds PEP 621 metadata + cibuildwheel configuration for building wheels.
piv_bindings.cpp	Adds pybind11 bindings exposing cross_correlate and piv_process.
openpiv_cpp_pkg/init.py	Exposes binding functions at package top-level.
openpiv/core/log.h	Removes fmt include and replaces formatting with a custom {} formatter.
openpiv/CMakeLists.txt	Removes fmt linkage from core library build.
external/vcpkg	Updates vcpkg submodule pointer.
examples/process/CMakeLists.txt	Removes fmt linkage from example.
examples/example_python_usage.py	Adds a Python usage example for the bindings.
examples/average_subtract/CMakeLists.txt	Removes fmt linkage from example.
PYTHON_README.md	Adds user-facing documentation for installing/using Python bindings.
PYTHON_INTEGRATION.md	Adds conceptual docs for multiple Python integration approaches.
MANIFEST.in	Adds packaging manifest for source distributions/wheels.
LOCAL_TESTING.md	Adds documentation for reproducing CI workflows locally.
CMakeLists.txt	Adds OPENPIV_BUILD_TESTS/EXAMPLES toggles to control builds.
BUILD_WHEELS.md	Adds documentation for building manylinux wheels with cibuildwheel.
.gitignore	Extends ignore patterns for Python/wheel build artifacts.
.github/workflows/wheels.yml	Adds wheel-building workflow via cibuildwheel and PyPI publish on tags.
.github/workflows/cmake.yml	Updates CMake CI workflow (deps, vcpkg bootstrap, Ninja generator, feature flags).

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[Copilot]

piv_bindings.cpp uses std::sqrt, std::min, and std::max later, but <cmath> and <algorithm> are not included. This will fail to compile on standard-compliant toolchains; add the missing headers near the other standard includes.

Suggested change

	#include <memory>
	#include <memory>
	#include <cmath>
	#include <algorithm>

[Copilot]

The loader is detected from file1 only and then re-used to load file2. If the two files are different image formats (or if detection relies on stream properties specific to the file), loading file2 can fail or mis-parse. Prefer detecting a loader for is2 separately (or explicitly validate both files are compatible with the chosen loader and raise a clear error).

Suggested change

	auto loader = core::image_loader_registry::find(is1);
	if (!loader) {
	throw std::runtime_error("Cannot find image loader for: " + file1);
	}
	core::gf_image img1, img2;
	loader->load(is1, img1);
	loader->load(is2, img2);
	auto loader1 = core::image_loader_registry::find(is1);
	if (!loader1) {
	throw std::runtime_error("Cannot find image loader for: " + file1);
	}
	core::gf_image img1, img2;
	loader1->load(is1, img1);
	auto loader2 = core::image_loader_registry::find(is2);
	if (!loader2) {
	throw std::runtime_error("Cannot find image loader for: " + file2);
	}
	loader2->load(is2, img2);

[Copilot]

The shared-library patterns are exact names (libopenpivcore.so / .dylib). CMake installs/builds often produce version-suffixed files (e.g., libopenpivcore.so.1), or only produce symlinks depending on platform/toolchain. Consider widening the patterns (e.g., lib…so* / lib…dylib*) and picking the best match deterministically; otherwise wheel builds can fail with “Could not locate built openpivcore library”.

[Copilot]

Clearing all base dependencies removes tiff (and other previously-core ports) from vcpkg resolution. This is inconsistent with the build/CI expectations elsewhere in the PR (multiple scripts/workflows install libtiff on Linux/macOS, and the core code includes image loaders). In particular, the Windows CI path does not install a system TIFF library, so builds are likely to fail there. Add required “always-needed” native deps (e.g., tiff) back to the root dependencies, or add an explicit Windows dependency installation strategy (vcpkg/system) that matches how the library is built.

[Copilot]

The built extension is configured as openpiv_cpp_pkg.openpiv_cpp (and the package exposes cross_correlate/piv_process via openpiv_cpp_pkg/__init__.py). Importing openpiv_cpp directly is unlikely to work in an installed wheel, so this example will fail for users. Update the example to import from openpiv_cpp_pkg (either import openpiv_cpp_pkg as piv or from openpiv_cpp_pkg import piv_process, cross_correlate).

Suggested change

	import openpiv_cpp
	import openpiv_cpp_pkg as openpiv_cpp

[Copilot]

The replacement formatter silently drops extra arguments when there are fewer {} slots than args (it appends the remaining format text and returns without consuming ts...). This can hide logging mistakes and lose important context, especially if existing call sites previously relied on fmt’s validation/formatting. Consider handling “extra args” explicitly (e.g., append them in a consistent way, or add a debug assertion), and document that only {} is supported (no format specs, no escaped braces).

[Copilot]

This statement is outdated: GitHub’s ubuntu-latest runner version changes over time and is no longer guaranteed to match 22.04. Reword to avoid a strict equivalence (e.g., “similar to” / “historically matched”) or pin the claimed runner version explicitly if that’s the intent.

Suggested change

	This uses `ubuntu:22.04` which matches GitHub's `ubuntu-latest` runner.
	This uses `ubuntu:22.04`, which is similar to GitHub's `ubuntu-22.04` runner (note that `ubuntu-latest` may point to a different Ubuntu version over time).

[Copilot]

The “building from source” requirements omit native build/runtime deps that the rest of the PR assumes (e.g., CMake/Ninja and TIFF development headers; CI/scripts explicitly install libtiff-dev / libtiff). Document these system prerequisites (and platform-specific package names) so source installs don’t fail unexpectedly.

Suggested change

	- C++17 compiler (for building from source)
	- C++17 compiler (for building from source)
	- Build tools (for building from source):
	- CMake (e.g. `cmake` >= 3.18)
	- Ninja or another supported build backend (e.g. `ninja`)
	- TIFF development headers and libraries (for TIFF image support when building from source):
	- Debian/Ubuntu: `libtiff-dev`
	- Fedora/RHEL: `libtiff-devel`
	- Arch Linux: `libtiff`
	- macOS (Homebrew): `brew install tiff`
	- Windows: install TIFF development libraries via vcpkg or your preferred package manager