From fdce587c74228f80b214121515baa2540d836f53 Mon Sep 17 00:00:00 2001
From: Matthias Schiffer <mschiffer@universe-factory.net>
Date: Tue, 24 Aug 2021 13:07:31 +0200
Subject: [PATCH] build: update to modern CMake, use pkg-config for zlib and
 libpng

Starting with CMake 3.7, we can avoid dealing with individual variables
for include dirs, libraries, ... for dependencies found using
pkg-config, and instead just reference them using an imported target.
---
 CMakeLists.txt     |  8 ++++----
 src/CMakeLists.txt | 12 ++++--------
 2 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 362fa58..70385e8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,9 +1,9 @@
-cmake_minimum_required(VERSION 2.8.12)
+cmake_minimum_required(VERSION 3.7)
 project(MINEDMAP CXX)
 
+find_package(PkgConfig REQUIRED)
 
-find_package(PNG REQUIRED)
-find_package(ZLIB REQUIRED)
-
+pkg_check_modules(ZLIB REQUIRED IMPORTED_TARGET zlib)
+pkg_check_modules(PNG REQUIRED IMPORTED_TARGET libpng16)
 
 add_subdirectory(src)
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 1eea2b3..0e4fd48 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,5 +1,4 @@
-include_directories(${ZLIB_INCLUDE_DIRS} ${PNG_INCLUDE_DIRS})
-add_definitions(${PNG_DEFINITIONS})
+add_compile_options(-std=c++11 -Wall)
 
 add_executable(MinedMap
   MinedMap.cpp
@@ -16,16 +15,14 @@ add_executable(MinedMap
   World/Region.cpp
   World/Section.cpp
 )
-set_target_properties(MinedMap PROPERTIES COMPILE_FLAGS "-std=c++11 -Wall")
-target_link_libraries(MinedMap ${ZLIB_LIBRARIES} ${PNG_LIBRARIES})
+target_link_libraries(MinedMap PkgConfig::ZLIB PkgConfig::PNG)
 
 add_executable(nbtdump
   nbtdump.cpp
   GZip.cpp
   NBT/Tag.cpp
 )
-set_target_properties(nbtdump PROPERTIES COMPILE_FLAGS "-std=c++11 -Wall")
-target_link_libraries(nbtdump ${ZLIB_LIBRARIES})
+target_link_libraries(nbtdump PkgConfig::ZLIB)
 
 add_executable(regiondump
   regiondump.cpp
@@ -34,7 +31,6 @@ add_executable(regiondump
   World/ChunkData.cpp
   World/Region.cpp
 )
-set_target_properties(regiondump PROPERTIES COMPILE_FLAGS "-std=c++11 -Wall")
-target_link_libraries(regiondump ${ZLIB_LIBRARIES})
+target_link_libraries(regiondump PkgConfig::ZLIB)
 
 install(TARGETS MinedMap RUNTIME DESTINATION bin)