Merge branch 'master' of https://github.com/prusa3d/PrusaSlicer into et_gcode_viewer

src/libslic3r/CMakeLists.txt

@@ -163,6 +163,8 @@ add_library(libslic3r STATIC
     PrintConfig.hpp
     PrintObject.cpp
     PrintRegion.cpp
+    PNGRead.hpp
+    PNGRead.cpp
     Semver.cpp
     ShortestPath.cpp
     ShortestPath.hpp
@@ -310,6 +312,8 @@ target_link_libraries(libslic3r
     TBB::tbb
     libslic3r_cgal
     ${CMAKE_DL_LIBS}
+    PNG::PNG
+    ZLIB::ZLIB
     )
 
 if (TARGET OpenVDB::openvdb)