Add option (PD_BUILD_STATIC_OBJECTS) to build static objects (for plu…

…gdata|libpd|pd4web and others).

When set PD_BUILD_STATIC_OBJECTS=ON, pd.cmake compiles static libraries
for the objects. It can be useful when using libpd for standalone apps
like plugdata, Emscripten (like pd4web), and others.

The list for all the objects compiled for project can be acessed using
``` cmake
get_property(all_static_targets GLOBAL PROPERTY
"${PROJECT_NAME}_STATIC_LIBRARIES")
target_link_libraries(MyApp PRIVATE all_static_targets)
```

pd.cmake

@@ -1,6 +1,6 @@
 # check if cmake version is higher than 3.19, we need cmake_language
 if(${CMAKE_VERSION} VERSION_LESS "3.19")
-    message(FATAL_ERROR "CMake version must be at least 3.19")
+    message(FATAL_ERROR "pd.cmake requires Cmake Version 3.19 or newer")
 endif()
 
 # ╭──────────────────────────────────────╮
@@ -26,6 +26,13 @@ set(PD_INSTALL_LIBS
     ON
     CACHE BOOL "Install Pd Externals on PDLIBDIR")
 
+set(PD_BUILD_STATIC_OBJECTS
+    OFF
+    CACHE
+        BOOL
+        "Enable building static objects. Useful when using self-contained objects with libpd, such as in embedded systems or standalone applications."
+)
+
 # ╭──────────────────────────────────────╮
 # │         Get default PDLIBDIR         │
 # ╰──────────────────────────────────────╯
@@ -95,7 +102,8 @@ if(NOT PD_SOURCES_PATH)
             HINTS ${PDBINDIR})
         find_path(PD_HEADER_PATH m_pd.h PATHS ${PD_SOURCES_PATH})
         if(NOT PD_HEADER_PATH)
-            message(FATAL_ERROR "<m_pd.h> not found in C:\\Program Files\\Pd\\src, is Pd installed?")
+            message(
+                FATAL_ERROR "<m_pd.h> not found in C:\\Program Files\\Pd\\src, is Pd installed?")
         endif()
 
     elseif(APPLE)
@@ -105,12 +113,18 @@ if(NOT PD_SOURCES_PATH)
                 get_filename_component(PD_SOURCES_PATH "${app}/Contents/Resources/src/" ABSOLUTE)
             endforeach()
         else()
-            message(FATAL_ERROR "PD_SOURCES_PATH not set and no Pd.app found in /Applications, is Pd installed?")
+            message(
+                FATAL_ERROR
+                    "PD_SOURCES_PATH not set and no Pd.app found in /Applications, is Pd installed?"
+            )
         endif()
 
         find_path(PD_HEADER_PATH m_pd.h PATHS ${PD_SOURCES_PATH})
         if(NOT PD_HEADER_PATH)
-            message(FATAL_ERROR "<m_pd.h> not found in /Applications/Pd.app/Contents/Resources/src/, is Pd installed?")
+            message(
+                FATAL_ERROR
+                    "<m_pd.h> not found in /Applications/Pd.app/Contents/Resources/src/, is Pd installed?"
+            )
         endif()
         message(STATUS "PD_SOURCES_PATH not set, using ${PD_SOURCES_PATH}")
 
@@ -138,7 +152,8 @@ endif()
 macro(set_pd_external_path EXTERNAL_PATH)
     message(
         DEPRECATION
-            "set_pd_external_path was removed, you can set PDLIBDIR and run cmake with '-DPD_INSTALL_LIBS=ON' instead")
+            "set_pd_external_path was removed, you can set PDLIBDIR and run cmake with '-DPD_INSTALL_LIBS=ON' instead"
+    )
 endmacro(set_pd_external_path)
 
 # ──────────────────────────────────────
@@ -157,13 +172,19 @@ function(pd_add_datafile OBJ_TARGET DATA_FILE)
     if(${OBJ_TARGET} MATCHES "~$")
         string(REGEX REPLACE "~$" "_tilde" OBJ_TARGET ${OBJ_TARGET})
     endif()
+
+    if(OBJ_TARGET STREQUAL PROJECT_NAME)
+
+    endif()
+
     foreach(DATA_FILE ${DATA_FILE})
         if(IS_DIRECTORY ${DATA_FILE})
             install(DIRECTORY ${DATA_FILE} DESTINATION ${PDLIBDIR}/${PROJECT_NAME})
         else()
             install(FILES ${DATA_FILE} DESTINATION ${PDLIBDIR}/${PROJECT_NAME})
         endif()
     endforeach()
+
 endfunction(pd_add_datafile)
 
 # ──────────────────────────────────────
@@ -206,14 +227,18 @@ macro(pd_set_lib_ext OBJ_TARGET_NAME)
         endif()
 
         if(NOT PD_EXTENSION)
-            message(FATAL_ERROR "Not possible to determine the extension of the library, please set PD_EXTENSION")
+            message(
+                FATAL_ERROR
+                    "Not possible to determine the extension of the library, please set PD_EXTENSION"
+            )
         endif()
         set_target_properties(${OBJ_TARGET_NAME} PROPERTIES SUFFIX ${PD_EXTENSION})
     endif()
 endmacro(pd_set_lib_ext)
 
 # ──────────────────────────────────────
 function(pd_add_external PD_EXTERNAL_NAME EXTERNAL_SOURCES)
+
     set(BOOLEAN_ARGS) # No args for now
     set(ONE_ARGS TARGET) # Define optional arg for TARGET
     set(MULTI_ARGS CXX_FLAGS C_FLAGS LINK_LIBRARIES) # Define multi args, CXX_FLAGS C_FLAGS
@@ -233,14 +258,20 @@ function(pd_add_external PD_EXTERNAL_NAME EXTERNAL_SOURCES)
         set(OBJ_TARGET_NAME ${PD_EXTERNAL_NAME})
     endif()
 
-    if(EMSCRIPTEN)
+    if(EMSCRIPTEN OR PD_BUILD_STATIC_OBJECTS)
         add_library(${OBJ_TARGET_NAME} STATIC ${EXTERNAL_SOURCES})
-        set_target_properties(${OBJ_TARGET_NAME} PROPERTIES OUTPUT_NAME ${PD_EXTERNAL_NAME}) # External name output
+        set_target_properties(${OBJ_TARGET_NAME} PROPERTIES OUTPUT_NAME ${PD_EXTERNAL_NAME}
+        )
+        set_property(GLOBAL APPEND PROPERTY ${PROJECT_NAME}_STATIC_LIBRARIES ${OBJ_TARGET_NAME})
     else()
         add_library(${OBJ_TARGET_NAME} SHARED ${EXTERNAL_SOURCES})
         set_target_properties(${OBJ_TARGET_NAME} PROPERTIES PREFIX "")
-        # remove lib prefix
         set_target_properties(${OBJ_TARGET_NAME} PROPERTIES OUTPUT_NAME ${PD_EXTERNAL_NAME})
+        pd_set_lib_ext(${OBJ_TARGET_NAME})
+        get_property(
+            PD_EXTENSION
+            TARGET ${OBJ_TARGET_NAME}
+            PROPERTY SUFFIX)
     endif()
 
     # Check if CXX_FLAGS is defined, if true set the flags
@@ -257,9 +288,7 @@ function(pd_add_external PD_EXTERNAL_NAME EXTERNAL_SOURCES)
     if(DEFINED PD_EXTERNAL_LINK_LIBRARIES)
         target_link_libraries(${OBJ_TARGET_NAME} PRIVATE ${PD_EXTERNAL_LINK_LIBRARIES})
     endif()
-
     target_include_directories(${OBJ_TARGET_NAME} PRIVATE ${PD_SOURCES_PATH}) # Add Pd Includes
-
     if(WIN32)
         if(PD_FLOATSIZE EQUAL 64)
             target_link_libraries(${OBJ_TARGET_NAME} PRIVATE "${PDBINDIR}/pd64.lib")
@@ -284,12 +313,6 @@ function(pd_add_external PD_EXTERNAL_NAME EXTERNAL_SOURCES)
         target_compile_definitions(${OBJ_TARGET_NAME} PRIVATE PD_FLOATSIZE=64)
     endif()
 
-    pd_set_lib_ext(${OBJ_TARGET_NAME})
-    get_property(
-        PD_EXTENSION
-        TARGET ${OBJ_TARGET_NAME}
-        PROPERTY SUFFIX)
-
     pd_add_datafile(${PROJECT_NAME} ${CMAKE_BINARY_DIR}/${PD_EXTERNAL_NAME}${PD_EXTENSION})
 
 endfunction(pd_add_external)
@@ -315,9 +338,12 @@ function(add_pd_external PROJECT_NAME EXTERNAL_NAME EXTERNAL_SOURCES)
 
     foreach(OUTPUTCONFIG ${CMAKE_CONFIGURATION_TYPES})
         string(TOUPPER ${OUTPUTCONFIG} OUTPUTCONFIG)
-        set_target_properties(${PROJECT_NAME} PROPERTIES LIBRARY_OUTPUT_DIRECTORY_${OUTPUTCONFIG} ${CMAKE_BINARY_DIR})
-        set_target_properties(${PROJECT_NAME} PROPERTIES RUNTIME_OUTPUT_DIRECTORY_${OUTPUTCONFIG} ${CMAKE_BINARY_DIR})
-        set_target_properties(${PROJECT_NAME} PROPERTIES ARCHIVE_OUTPUT_DIRECTORY_${OUTPUTCONFIG} ${CMAKE_BINARY_DIR})
+        set_target_properties(${PROJECT_NAME} PROPERTIES LIBRARY_OUTPUT_DIRECTORY_${OUTPUTCONFIG}
+                                                         ${CMAKE_BINARY_DIR})
+        set_target_properties(${PROJECT_NAME} PROPERTIES RUNTIME_OUTPUT_DIRECTORY_${OUTPUTCONFIG}
+                                                         ${CMAKE_BINARY_DIR})
+        set_target_properties(${PROJECT_NAME} PROPERTIES ARCHIVE_OUTPUT_DIRECTORY_${OUTPUTCONFIG}
+                                                         ${CMAKE_BINARY_DIR})
     endforeach(OUTPUTCONFIG CMAKE_CONFIGURATION_TYPES)
 
     if(WIN32)
@@ -342,8 +368,4 @@ function(add_pd_external PROJECT_NAME EXTERNAL_NAME EXTERNAL_SOURCES)
     pd_set_lib_ext(${PROJECT_NAME})
     pd_add_datafile(${PROJECT_NAME} "${CMAKE_CURRENT_BINARY_DIR}/${PD_EXTERNAL_NAME}${PD_EXTENSION}")
 
-    if(PD_INSTALL_LIBS)
-
-    endif()
-
 endfunction(add_pd_external)