bundle pocketfft, drop pocketfft-dev dependency

- Copy pocketfft_hdronly.h into scipy/pocketfft/
- Change fft.h include to local relative path
- Remove pocketfft from CMake deps, target_link_libraries, README
- Remove pocketfft include from tests/Makefile
- Update core.h and README to reflect bundled status

Author: peng.li24

CMakeLists.txt

@@ -26,9 +26,8 @@ target_include_directories(scipycpp INTERFACE
 )
 target_compile_features(scipycpp INTERFACE cxx_std_17)
 
-# Transitive dependencies: scipycpp → pocketfft, Eigen3, numpcpp
+# Transitive dependencies: scipycpp → Eigen3, numpcpp
 target_link_libraries(scipycpp INTERFACE
-    pocketfft::pocketfft
     Eigen3::Eigen
     numpycpp::numpycpp
 )
@@ -81,15 +80,15 @@ set(CPACK_DEBIAN_FILE_NAME                 "scipycpp-dev-${CPACK_PACKAGE_VERSION
 set(CPACK_PACKAGING_INSTALL_PREFIX "/usr")
 
 # Recommend the required dependencies
-set(CPACK_DEBIAN_PACKAGE_DEPENDS "numpycpp-dev, libeigen3-dev, pocketfft-dev")
+set(CPACK_DEBIAN_PACKAGE_DEPENDS "numpycpp-dev, libeigen3-dev")
 
 include(CPack)
 add_custom_target(deb
     COMMAND cpack -G DEB --config CPackConfig.cmake
     COMMENT "Packaging scipycpp-dev-${CPACK_PACKAGE_VERSION}-Linux.deb")
 
 message(STATUS "scipycpp v${PROJECT_VERSION}  (header-only C++ library)")
-message(STATUS "  Dependencies: numpcpp + Eigen3 + pocketfft")
-message(STATUS "  KDTree: bundled ckdtree (O(log n) true kd-tree)")
+message(STATUS "  Dependencies: numpcpp + Eigen3")
+message(STATUS "  Bundled: pocketfft (FFT) + ckdtree (KDTree)")
 message(STATUS "  DEB:  make deb  →  scipycpp-dev-${CPACK_PACKAGE_VERSION}-Linux.deb")
 message(STATUS "  Test: cd tests/ && make  →  build + run alignment tests")

README.md

@@ -9,9 +9,10 @@
 **bit-level precision alignment** against Python scipy.
 
 Built on proven C++ libraries:
-- **[numpycpp](https://github.com/array2d/numpycpp)** — numpy primitives + SVML bridge
+- **[numpycpp](https://github.com/array2d/numpycpp)** — numpy primitives
 - **[Eigen3](https://eigen.tuxfamily.org/)** — linear algebra (solve, inv, det, eig, svd, cholesky)
-- **[pocketfft](https://github.com/mreineck/pocketfft)** — FFT (same library numpy/scipy use internally)
+- **pocketfft** (bundled) — FFT (same library numpy/scipy use internally)
+- **ckdtree** (bundled) — KDTree from scipy.spatial
 
 ## Quick Start
 
@@ -58,7 +59,6 @@ auto euler = rot.as_euler_vec("xyz");  // returns [rx, ry, rz]
 # Install dependencies
 sudo dpkg -i numpycpp-dev-*.deb
 sudo apt-get install libeigen3-dev
-sudo dpkg -i pocketfft-dev-*.deb
 
 # Install scipycpp
 mkdir build && cd build

scipy/core.h

@@ -1,6 +1,7 @@
 // Native C++ scipy implementations — header-only, zero pybind11 dependency.
 //
-// Based on: numpcpp (numpy primitives), Eigen3 (linalg), pocketfft (FFT).
+// Based on: numpcpp (numpy primitives), Eigen3 (linalg).
+// Bundles: pocketfft (FFT), ckdtree (KDTree).
 //
 // This is the main entry point that includes all scipy submodules.
 

scipy/fft.h

@@ -8,7 +8,7 @@
 
 #pragma once
 
-#include <pocketfft_hdronly.h>
+#include "pocketfft/pocketfft_hdronly.h"
 #include <vector>
 #include <complex>
 #include <cstddef>