Use ZLIB headers correctly in minizip and libpng

CMakeLists.txt

@@ -317,21 +317,41 @@ endif()
 if(UseInternalZLIB)
 	set(GlobalDefines ${GlobalDefines} "INTERNAL_ZLIB")
 	add_subdirectory(libs/zlib)
+else()
+	find_package(ZLIB)
+	if(NOT ZLIB_FOUND)
+		message(FATAL_ERROR "zlib dev files not found! Install it or set UseInternalZLIB ON")
+	endif()
 endif()
 
 if(UseInternalMiniZip)
 	set(GlobalDefines ${GlobalDefines} "INTERNAL_MINIZIP")
 	add_subdirectory(libs/minizip)
+else()
+	find_package(MiniZip)
+	if(NOT MINIZIP_FOUND)
+		message(FATAL_ERROR "minizip dev files not found! Install it or set UseInternalMiniZip ON")
+	endif()
 endif()
 
 if(UseInternalJPEG)
 	set(GlobalDefines ${GlobalDefines} "INTERNAL_JPEG")
 	add_subdirectory(libs/jpeg-9a)
+else()
+	find_package(JPEG)
+	if(NOT JPEG_FOUND)
+		message(FATAL_ERROR "libjpeg dev files not found! Install it or set UseInternalJPEG ON")
+	endif()
 endif()
 
 if(UseInternalPNG)
 	set(GlobalDefines ${GlobalDefines} "INTERNAL_PNG")
 	add_subdirectory(libs/libpng)
+else()
+	find_package(PNG)
+	if(NOT PNG_FOUND)
+		message(FATAL_ERROR "libpng dev files not found! Install it or set UseInternalPNG ON")
+	endif()
 endif()
 
 add_subdirectory(libs/mongoose)

libs/libpng/CMakeLists.txt

@@ -5,9 +5,7 @@
 
 # This only has effect in this directory (lib/png).
 include_directories(include/)
-if(UseInternalZLIB)
-	include_directories(${ZLIB_INCLUDE_DIRS})
-endif(UseInternalZLIB)
+include_directories(${ZLIB_INCLUDE_DIRS})
 
 if(MSVC)
 	add_definitions(-D_CRT_SECURE_NO_WARNINGS)

libs/minizip/CMakeLists.txt

@@ -19,8 +19,8 @@
 # The current bundled copy comes from the zlib 1.2.8 release.
 
 # These settings only apply to this directory.
-include_directories(${ZLIB_INCLUDE_DIRS})
 include_directories(include/minizip)
+include_directories(${ZLIB_INCLUDE_DIRS})
 
 if(MSVC)
 	add_definitions(-D_CRT_SECURE_NO_WARNINGS)

src/CMakeLists.txt

@@ -23,21 +23,9 @@ if (BuildMVMP OR BuildMVDED)
 	endif()
 
 	# zlib
-	if(NOT UseInternalZLIB)
-		find_package(ZLIB)
-		if(NOT ZLIB_FOUND)
-			message(FATAL_ERROR "zlib dev files not found! Install it or set UseInternalZLIB ON")
-		endif()
-	endif()
 	set(MVMPDEDIncludeDirs ${MVMPDEDIncludeDirs} ${ZLIB_INCLUDE_DIRS})
 
 	# minizip
-	if(NOT UseInternalMiniZip)
-		find_package(MiniZip)
-		if(NOT MINIZIP_FOUND)
-			message(FATAL_ERROR "minizip dev files not found! Install it or set UseInternalMiniZip ON")
-		endif()
-	endif()
 	set(MVMPDEDIncludeDirs ${MVMPDEDIncludeDirs} ${MINIZIP_INCLUDE_DIRS})
 
 	# Source
@@ -325,21 +313,9 @@ if (BuildMVMP)
 	set(MVMPIncludeDirs ${MVMPIncludeDirs} "${LIBDir}/eax")
 
 	# JPEG
-	if(NOT UseInternalJPEG)
-		find_package(JPEG)
-		if(NOT JPEG_FOUND)
-			message(FATAL_ERROR "libjpeg dev files not found! Install it or set UseInternalJPEG ON")
-		endif()
-	endif()
 	set(MVMPIncludeDirs ${MVMPIncludeDirs} ${JPEG_INCLUDE_DIR})
 
 	# PNG
-	if(NOT UseInternalPNG)
-		find_package(PNG)
-		if(NOT PNG_FOUND)
-			message(FATAL_ERROR "libpng dev files not found! Install it or set UseInternalPNG ON")
-		endif()
-	endif()
 	set(MVMPIncludeDirs ${MVMPIncludeDirs} ${PNG_INCLUDE_DIRS})
 
 	# Source