From b5f6ede37758a4c3865eef53fd6a2172da0a699f Mon Sep 17 00:00:00 2001
From: Roland Conybeare <rconybeare@gmail.com>
Date: Fri, 15 Mar 2024 19:41:33 -0400
Subject: [PATCH] build: streamline CMAKE_MODULE_PATH interaction

---
 .gitignore                      |  7 +++-
 CMakeLists.txt                  |  2 +-
 README.md                       | 70 +++++++++++++++++++++++++++++++++
 cmake/xo-bootstrap-macros.cmake | 12 ++++++
 4 files changed, 89 insertions(+), 2 deletions(-)
 create mode 100644 README.md
 create mode 100644 cmake/xo-bootstrap-macros.cmake

diff --git a/.gitignore b/.gitignore
index 378eac25..13c0afb7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,6 @@
-build
+# clangd working space (see emacs+lsp)
+.cache
+# typical cmake build directory (source-tree-nephew)
+.build*
+# symlink to builddir/compile_commands.json;  should be set manually in dev sandbox
+compile_commands.json
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2a1602f6..d044769a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,7 +4,7 @@ cmake_minimum_required(VERSION 3.10)
 
 project(xo_pykalmanfilter VERSION 1.0)
 
-include(xo_macros/xo-project-macros)
+include(cmake/xo-bootstrap-macros.cmake)
 
 xo_cxx_toplevel_options()
 
diff --git a/README.md b/README.md
new file mode 100644
index 00000000..7d7d1b11
--- /dev/null
+++ b/README.md
@@ -0,0 +1,70 @@
+# python bindings for c++ kalman filter library (xo-kalmanfilter)
+
+## Getting Started
+
+### build + install dependencies
+
+- [github/Rconybea/xo-kalmanfilter](https://github.com/Rconybea/xo-kalmanfilter)
+- [github/Rconybea/xo-pyreactor](https://github.com/Rconybea/xo-pyreactor)
+
+### build + install
+
+```
+$ cd xo-pykalmanfilter
+$ mkdir build
+$ cd build
+$ INSTALL_PREFIX=/usr/local  # or wherever you prefer, e.g. ~/local
+$ cmake \
+    -DCMAKE_MODULE_PATH=${INSTALL_PREFIX}/share/cmake \
+    -DCMAKE_PREFIX_PATH=${INSTALL_PREFIX} \
+    -DCMAKE_INSTALL_PREFIX=${INSTALL_PREFIX} ..
+$ make
+$ make install
+```
+(also see .github/workflows/main.yml)
+
+## Examples
+
+Assumes `xo-pykalmanfilter` installed to `~/local2/lib`
+```
+PYTHONPATH=~/local2/lib:$PYTHONPATH python
+>>> import xo_pykalmanfilter
+>>> dir(xo_pykalmanfilter)
+['KalmanFilter', 'KalmanFilterInput', 'KalmanFilterInputToConsole', 'KalmanFilterObservable', 'KalmanFilterSpec', 'KalmanFilterState', 'KalmanFilterStateEventStore', 'KalmanFilterStateExt', 'KalmanFilterStateToConsole', 'KalmanFilterStep', 'KalmanFilterSvc', 'KalmanFilterTransition', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__spec__', 'kf_engine_correct', 'kf_engine_correct1', 'kf_engine_extrapolate', 'kf_engine_gain', 'kf_engine_gain1', 'make_kalman_filter', 'make_kalman_filter_input', 'make_kalman_filter_input_printer', 'make_kalman_filter_state_printer', 'print_matrix', 'print_vector']
+>>>
+```
+
+## Development
+
+### build for unit test coverage
+```
+$ cd xo-pykalmanfilter
+$ mkdir build-ccov
+$ cd build-ccov
+$ cmake \
+    -DCMAKE_MODULE_PATH=${INSTALL_PREFIX}/share/cmake \
+    -DCMAKE_PREFIX_PATH=${INSTALL_PREFIX} \
+    -DCODE_COVERAGE=ON \
+    -DCMAKE_BUILD_TYPE=Debug ..
+```
+
+### LSP (language server) support
+
+LSP looks for compile commands in the root of the source tree;
+while Cmake creates them in the root of its build directory.
+
+```
+$ cd xo-pykalmanfilter
+$ ln -s build/compile_commands.json  # supply compile commands to LSP
+```
+
+### display cmake variables
+
+- `-L` list variables
+- `-A` include 'advanced' variables
+- `-H` include help text
+
+```
+$ cd xo-pykalmanfilter/build
+$ cmake -LAH
+```
diff --git a/cmake/xo-bootstrap-macros.cmake b/cmake/xo-bootstrap-macros.cmake
new file mode 100644
index 00000000..16644435
--- /dev/null
+++ b/cmake/xo-bootstrap-macros.cmake
@@ -0,0 +1,12 @@
+if (("${CMAKE_MODULE_PATH}" STREQUAL "") OR ("${CMAKE_MODULE_PATH}" STREQUAL "prefix"))
+    # default to typical install location for xo-project-macros
+    set(CMAKE_MODULE_PATH ${CMAKE_INSTALL_PREFIX}/share/cmake)
+endif()
+
+message("-- CMAKE_INSTALL_PREFIX=${CMAKE_INSTALL_PREFIX}")
+message("-- CMAKE_MODULE_PATH=${CMAKE_MODULE_PATH}")
+
+# needs to have been installed somewhere on CMAKE_MODULE_PATH,
+# (e.g. from xo-cmake with the same value for CMAKE_INSTALL_PREFIX)
+#
+include(xo_macros/xo-project-macros)