ENH: Allow using system GMP and MPFR

To make it easier to test newer versions, or apply system specific
patches.

In the case of Flatpak builds, GMP and MPFR are already available
in the Freedesktop runtime.

Author: hadess

deps/CGAL/CGAL.cmake

@@ -7,7 +7,7 @@ bambustudio_add_cmake_project(
     URL      https://github.com/CGAL/cgal/archive/refs/tags/v5.4.zip
     URL_HASH SHA256=d7605e0a5a5ca17da7547592f6f6e4a59430a0bc861948974254d0de43eab4c0
     PATCH_COMMAND git apply ${CGAL_DIRECTORY_FLAG} --verbose --ignore-space-change --whitespace=fix ${CMAKE_CURRENT_LIST_DIR}/0001-clang19.patch
-    DEPENDS ${BOOST_PKG} dep_GMP dep_MPFR
+    DEPENDS ${BOOST_PKG} ${GMP_PKG} ${MPFR_PKG}
     CMAKE_ARGS
         -DCMAKE_POLICY_VERSION_MINIMUM=3.5
 )

deps/CMakeLists.txt

@@ -43,6 +43,8 @@ option(DEP_BUILD_GLFW "Compile GLFW" ON)
 option(DEP_BUILD_BLOSC "Compile Blosc" ON)
 option(DEP_BUILD_FREETYPE "Compile freetype" ON)
 option(DEP_BUILD_WXWIDGETS "Compile wxWidgets" ON)
+option(DEP_BUILD_GMP "Compile GMP" ON)
+option(DEP_BUILD_MPFR "Compile MPFR" ON)
 option(DEP_BUILD_FFMPEG "Compile ffmpeg" ON)
 option(DEP_BUILD_LIBHARU "Compile libharu" ON)
 
@@ -256,8 +258,16 @@ endif ()
 include(OpenEXR/OpenEXR.cmake)
 include(OpenVDB/OpenVDB.cmake)
 
-include(GMP/GMP.cmake)
-include(MPFR/MPFR.cmake)
+set(GMP_PKG "")
+if (DEP_BUILD_GMP)
+    include(GMP/GMP.cmake)
+    set(GMP_PKG dep_GMP)
+endif ()
+set(MPFR_PKG "")
+if (DEP_BUILD_MPFR)
+    include(MPFR/MPFR.cmake)
+    set(MPFR_PKG dep_MPFR)
+endif ()
 include(CGAL/CGAL.cmake)
 
 include(NLopt/NLopt.cmake)

deps/MPFR/MPFR.cmake

@@ -46,6 +46,6 @@ else ()
         CONFIGURE_COMMAND env "CFLAGS=${_gmp_ccflags}" "CXXFLAGS=${_gmp_ccflags}" ./configure ${_cross_compile_arg} --prefix=${DESTDIR}/usr/local --enable-shared=no --enable-static=yes --with-gmp=${DESTDIR}/usr/local ${_gmp_build_tgt}
         BUILD_COMMAND make -j
         INSTALL_COMMAND make install
-        DEPENDS dep_GMP
+        DEPENDS ${GMP_PKG}
     )
 endif ()