Provide simplified ad-hoc C++ wrapper for C-compiled libcerf

Core/CMakeLists.txt

@@ -10,13 +10,6 @@ set(lib BornAgain${name})
 file(GLOB source_files */*.cpp)
 file(GLOB include_files RELATIVE ${CMAKE_CURRENT_SOURCE_DIR} */*.h)
 
-if((NOT Cerf_IS_CPP) AND (NOT WIN32)) # TEMPORARY
-    list(APPEND source_files ${CMAKE_SOURCE_DIR}/ThirdParty/Core/cerf_wrapper/cerf_ptr.c)
-endif()
-if(${Cerf_IS_CPP})
-    string(APPEND CMAKE_CXX_FLAGS " -DCERF_AS_CPP=ON")
-endif()
-
 # --- make the library ---
 
 MakeLib(${name} ${lib} ${CMAKE_CURRENT_BINARY_DIR}/Wrap)
@@ -34,7 +27,7 @@ target_include_directories(${lib}
     PUBLIC ${CMAKE_SOURCE_DIR}
     ${tspectrum_INCLUDE_DIR}
     ${Cerf_INCLUDE_DIR}
-    ${CMAKE_SOURCE_DIR}/ThirdParty/Core/cerf_wrapper # TEMPORARY
+    ${CMAKE_SOURCE_DIR}/ThirdParty/Core/ # TEMPORARY
     )
 target_link_libraries(${lib}
     ${tspectrum_LIBRARY} ${Cerf_LIBRARIES})

Core/Computation/RoughMultiLayerComputation.cpp

@@ -22,7 +22,8 @@
 #include "Sample/RT/ILayerRTCoefficients.h"
 #include "Sample/Slice/LayerInterface.h"
 #include "Sample/Slice/LayerRoughness.h"
-#include <cerf.h>
+
+#include "cerfcpp.h"
 
 // Diffuse scattering from rough interfaces is modelled after
 // Phys. Rev. B, vol. 51 (4), p. 2311 (1995)

ThirdParty/Core/cerf_wrapper/cerf

-// -*- mode: c++ -*-
-
-#include <cerf_ptr.h>
-
-std::complex<double> cerfcx(std::complex<double> z) {
-    std::complex<double> ret;
-    p_cerfcx((void*)&z, (void*)&ret);
-    return ret;
-}

ThirdParty/Core/cerf_wrapper/cerf_ptr.c

-#include "cerf_ptr.h"
-#include "cerf.h"
-#include <string.h>
-
-void p_cerfcx(void* z, void* ret)
-{
-    double _Complex val = cerfcx(*(double _Complex*)(z));
-    memcpy(ret, &val, 2*sizeof(double));
-}

ThirdParty/Core/cerf_wrapper/cerf_ptr.h

-#ifdef __cplusplus
-extern "C" {
-#endif
-
-void p_cerfcx(void* z, void* ret);
-
-#ifdef __cplusplus
-} // extern "C"
-#endif

ThirdParty/Core/cerfcpp.h

+/*
+This is an ad-hoc solution to make the C-compiled libcerf callable from C++ code.
+
+TODO:
+- Either, distribute this along with liberf.
+- Or, make sure the Debian, Homebrew etc packages distribute a libcerfcpp along with libcerf.
+
+*/
+
+#include <cerf.h>
+#include <complex>
+
+std::complex<double> cerfcx(const std::complex<double>& z)
+{
+    const _cerf_cmplx ret = cerfcx(*((_cerf_cmplx*)(&z)));
+    return {reinterpret_cast<const double(&)[2]>(ret)[0],
+            reinterpret_cast<const double(&)[2]>(ret)[1]};
+}

cmake/BornAgain/Dependences.cmake

@@ -19,6 +19,9 @@ else()
 endif()
 
 find_package(Cerf REQUIRED)
+if(Cerf_IS_CPP)
+    add_compile_definitions(CERF_AS_CPP=ON)
+endif()
 
 # --- Boost ---
 set(Boost_NO_BOOST_CMAKE ON) # prevent shortcut