fix finding of discord-rpc

CMakeLists.txt

@@ -212,9 +212,12 @@ if (NOT DISABLE_DISCORD_RPC)
             include_directories(DISCORDRPC_PROCESS_INCLUDES)
         endif()
     elseif (APPLE AND MACOS_USE_DEPENDENCIES)
-        add_definitions(-D__ENABLE_DISCORD__)
-        set(HAVE_DISCORD_RPC TRUE)
-        message("Building with libdiscord-rpc.dylib")
+        find_package(discordrpc CONFIG REQUIRED)
+        if(${DISCORDRPC_FOUND})
+            add_definitions(-D__ENABLE_DISCORD__)
+            set(HAVE_DISCORD_RPC TRUE)
+            message("Building with libdiscord-rpc.dylib")
+        endif()
     elseif(NOT HAVE_DISCORD_RPC AND EXISTS "${ROOT_DIR}/discord-rpc")
         # Don't build discord's examples, some of which are in C and do not honour
         # the flags we set for C++. Also we don't use the provided examples.

cmake/discordrpcConfig.cmake

@@ -0,0 +1,34 @@
+# This file is modified from duktapeConfig.cmake
+
+# - Try to find discordrpc
+# Once done this will define
+#
+#  DISCORDRPC_FOUND - system has discordrpc
+#  DISCORDRPC_INCLUDE_DIRS - the discordrpc include directory
+#  DISCORDRPC_LIBRARIES - Link these to use discordrpc
+#  DISCORDRPC_DEFINITIONS - Compiler switches required for using discordrpc
+#
+
+PKG_CHECK_MODULES(PC_DISCORD_RPC QUIET discord-rpc libdiscord-rpc)
+
+find_path(DISCORDRPC_INCLUDE_DIR discord_rpc.h
+    HINTS ${PC_DISCORD_RPC_INCLUDEDIR} ${PC_DISCORD_RPC_INCLUDE_DIRS}
+    PATH_SUFFIXES discord-rpc)
+
+find_library(DISCORDRPC_LIBRARY
+    NAMES discord-rpc libdiscord-rpc
+    HINTS ${PC_DISCORD_RPC_LIBDIR} ${PC_DISCORD_RPC_LIBRARY_DIRS})
+
+include(FindPackageHandleStandardArgs)
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(discordrpc
+    REQUIRED_VARS DISCORDRPC_LIBRARY DISCORDRPC_INCLUDE_DIR)
+
+if (DISCORDRPC_FOUND)
+    set (DISCORDRPC_LIBRARIES ${DISCORDRPC_LIBRARY})
+    set (DISCORDRPC_INCLUDE_DIRS ${DISCORDRPC_INCLUDE_DIR} )
+endif ()
+
+MARK_AS_ADVANCED(
+    DISCORDRPC_INCLUDE_DIR
+    DISCORDRPC_LIBRARY
+)