FindSDL: Stay compatible with old input variables

Suggested-by: David Cole <[email protected]>

Modules/FindSDL_image.cmake

@@ -32,6 +32,10 @@
 # (To distribute this file outside of CMake, substitute the full
 #  License text for the above reference.)
 
+if(NOT SDL_IMAGE_INCLUDE_DIR AND SDLIMAGE_INCLUDE_DIR)
+  set(SDL_IMAGE_INCLUDE_DIR ${SDLIMAGE_INCLUDE_DIR} CACHE PATH "directory cache
+entry initialized from old variable name")
+endif()
 find_path(SDL_IMAGE_INCLUDE_DIR SDL_image.h
   HINTS
     ENV SDLIMAGEDIR
@@ -39,6 +43,10 @@ find_path(SDL_IMAGE_INCLUDE_DIR SDL_image.h
   PATH_SUFFIXES SDL SDL12 SDL11
 )
 
+if(NOT SDL_IMAGE_LIBRARY AND SDLIMAGE_LIBRARY)
+  set(SDL_IMAGE_LIBRARY ${SDLIMAGE_LIBRARY} CACHE FILEPATH "file cache entry
+initialized from old variable name")
+endif()
 find_library(SDL_IMAGE_LIBRARY
   NAMES SDL_image
   HINTS

Modules/FindSDL_mixer.cmake

@@ -32,6 +32,10 @@
 # (To distribute this file outside of CMake, substitute the full
 #  License text for the above reference.)
 
+if(NOT SDL_MIXER_INCLUDE_DIR AND SDLMIXER_INCLUDE_DIR)
+  set(SDL_MIXER_INCLUDE_DIR ${SDLMIXER_INCLUDE_DIR} CACHE PATH "directory cache
+entry initialized from old variable name")
+endif()
 find_path(SDL_MIXER_INCLUDE_DIR SDL_mixer.h
   HINTS
     ENV SDLMIXERDIR
@@ -39,6 +43,10 @@ find_path(SDL_MIXER_INCLUDE_DIR SDL_mixer.h
   PATH_SUFFIXES SDL SDL12 SDL11
 )
 
+if(NOT SDL_MIXER_LIBRARY AND SDLMIXER_LIBRARY)
+  set(SDL_MIXER_LIBRARY ${SDLMIXER_LIBRARY} CACHE FILEPATH "file cache entry
+initialized from old variable name")
+endif()
 find_library(SDL_MIXER_LIBRARY
   NAMES SDL_mixer
   HINTS

Modules/FindSDL_net.cmake

@@ -32,6 +32,10 @@
 # (To distribute this file outside of CMake, substitute the full
 #  License text for the above reference.)
 
+if(NOT SDL_NET_INCLUDE_DIR AND SDLNET_INCLUDE_DIR)
+  set(SDL_NET_INCLUDE_DIR ${SDLNET_INCLUDE_DIR} CACHE PATH "directory cache
+entry initialized from old variable name")
+endif()
 find_path(SDL_NET_INCLUDE_DIR SDL_net.h
   HINTS
     ENV SDLNETDIR
@@ -39,6 +43,10 @@ find_path(SDL_NET_INCLUDE_DIR SDL_net.h
   PATH_SUFFIXES SDL SDL12 SDL11
 )
 
+if(NOT SDL_NET_LIBRARY AND SDLNET_LIBRARY)
+  set(SDL_NET_LIBRARY ${SDLNET_LIBRARY} CACHE FILEPATH "file cache entry
+initialized from old variable name")
+endif()
 find_library(SDL_NET_LIBRARY
   NAMES SDL_net
   HINTS

Modules/FindSDL_ttf.cmake

@@ -32,6 +32,10 @@
 # (To distribute this file outside of CMake, substitute the full
 #  License text for the above reference.)
 
+if(NOT SDL_TTF_INCLUDE_DIR AND SDLTTF_INCLUDE_DIR)
+  set(SDL_TTF_INCLUDE_DIR ${SDLTTF_INCLUDE_DIR} CACHE PATH "directory cache
+entry initialized from old variable name")
+endif()
 find_path(SDL_TTF_INCLUDE_DIR SDL_ttf.h
   HINTS
     ENV SDLTTFDIR
@@ -39,6 +43,10 @@ find_path(SDL_TTF_INCLUDE_DIR SDL_ttf.h
   PATH_SUFFIXES SDL SDL12 SDL11
 )
 
+if(NOT SDL_TTF_LIBRARY AND SDLTTF_LIBRARY)
+  set(SDL_TTF_LIBRARY ${SDLTTF_LIBRARY} CACHE FILEPATH "file cache entry
+initialized from old variable name")
+endif()
 find_library(SDL_TTF_LIBRARY
   NAMES SDL_ttf
   HINTS