FreeImage with the CMake build system

• master FreeImage 3.17 with all formats
• only-png FreeImage 3.17 only with PNG enabled
• 3.18 FreeImage 3.18 only with BMP, JPEG and PNG enabled

Clone this repo (in the right branch) and use add_subdirectory in your root CMakeLists.txt file.

add_subdirectory(FreeImage)

# if you want RGB color order instead of BGR
# target_compile_definitions(FreeImage PUBLIC FREEIMAGE_COLORORDER=1)

# ...

target_include_directories(YourTarget PUBLIC ${FreeImage_SOURCE_DIR}/Source)
target_link_libraries(YourTarget FreeImage)