cmake

cmake/README.md

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+CMake module for finding FFTW 3 using find_package
+
+# Usage
+
+Once added to your project, this module allows you to find FFTW libraries and headers using the CMake `find_package` command:
+
+```cmake
+find_package(FFTW [REQUIRED] [QUIET] [COMPONENTS component1 ... componentX] )
+```
+
+This module sets the following variables:
+- `FFTW_FOUND`                  ... true if fftw is found on the system
+- `FFTW_[component]_LIB_FOUND`  ... true if the component is found on the system (see components below)
+- `FFTW_LIBRARIES`              ... full paths to all found fftw libraries
+- `FFTW_[component]_LIB`        ... full path to one of the components (see below)
+- `FFTW_INCLUDE_DIRS`           ... fftw include directory paths
+
+The following variables will be checked by the module:
+- `FFTW_USE_STATIC_LIBS`        ... if true, only static libraries are found, otherwise both static and shared.
+- `FFTW_ROOT`                   ... if set, the libraries are exclusively searched under this path.
+
+This package supports the following components:
+- `FLOAT_LIB`
+- `DOUBLE_LIB`
+- `LONGDOUBLE_LIB`
+- `FLOAT_THREADS_LIB`
+- `DOUBLE_THREADS_LIB`
+- `LONGDOUBLE_THREADS_LIB`
+- `FLOAT_OPENMP_LIB`
+- `DOUBLE_OPENMP_LIB`
+- `LONGDOUBLE_OPENMP_LIB`
+
+and the following linking targets
+
+- `FFTW::Float`
+- `FFTW::Double`
+- `FFTW::LongDouble`
+- `FFTW::FloatThreads`
+- `FFTW::DoubleThreads`
+- `FFTW::LongDoubleThreads`
+- `FFTW::FloatOpenMP`
+- `FFTW::DoubleOpenMP`
+- `FFTW::LongDoubleOpenMP`
+
+# Adding to your project
+
+## Automatic download from CMake project
+
+Copy the following into the `CMakeLists.txt` file of the project you want to use FindFFTW in:
+```cmake
+configure_file(downloadFindFFTW.cmake.in findFFTW-download/CMakeLists.txt)
+execute_process(COMMAND ${CMAKE_COMMAND} -G "${CMAKE_GENERATOR}" .
+        RESULT_VARIABLE result
+        WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/findFFTW-download )
+if(result)
+    message(FATAL_ERROR "CMake step for findFFTW failed: ${result}")
+    else()
+    message("CMake step for findFFTW completed (${result}).")
+endif()
+execute_process(COMMAND ${CMAKE_COMMAND} --build .
+        RESULT_VARIABLE result
+        WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/findFFTW-download )
+if(result)
+    message(FATAL_ERROR "Build step for findFFTW failed: ${result}")
+endif()
+
+set(findFFTW_DIR ${CMAKE_CURRENT_BINARY_DIR}/findFFTW-src)
+
+set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${findFFTW_DIR}")
+```
+
+And add a file called `downloadFindFFTW.cmake.in` to your project containing the following:
+```cmake
+cmake_minimum_required(VERSION 2.8.2)
+
+project(findFFTW-download NONE)
+
+include(ExternalProject)
+
+ExternalProject_Add(findFFTW_download
+    GIT_REPOSITORY    "https://github.com/egpbos/findfftw.git"
+    CONFIGURE_COMMAND ""
+    BUILD_COMMAND     ""
+    INSTALL_COMMAND   ""
+    TEST_COMMAND      ""
+    SOURCE_DIR        "${CMAKE_CURRENT_BINARY_DIR}/findFFTW-src"
+    BINARY_DIR        ""
+    INSTALL_DIR       ""
+)
+```
+
+After this, `find_package(FFTW)` can be used in the `CMakeLists.txt` file.
+
+## Manual
+
+Clone the repository into directory `PREFIX/findFFTW`:
+```sh
+git clone https://github.com/egpbos/findfftw.git PREFIX/findFFTW
+```
+
+Then add the following to your `CMakeLists.txt` to allow CMake to find the module:
+```cmake
+set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "PREFIX/findFFTW")
+```