CMakeLists.txt

cmake_minimum_required(VERSION 3.16)
project(pngqrush VERSION 1.0.0 LANGUAGES C)

# Project directory structure
set(SRC_DIR ${CMAKE_CURRENT_SOURCE_DIR}/src)
set(THIRDPARTY_DIR ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty)

# Options
option(USE_SYSTEM_ZLIB "Use system zlib instead of bundled" OFF)
option(USE_SYSTEM_LIBPNG "Use system libpng instead of bundled" OFF)
option(USE_LIBDEFLATE "Enable libdeflate for better compression (levels 1-12)" ON)
option(USE_ZOPFLI "Enable Zopfli for maximum compression (very slow)" ON)

# Set C standard
set(CMAKE_C_STANDARD 11)
set(CMAKE_C_STANDARD_REQUIRED ON)

# =============================================================================
# Dependencies
# =============================================================================

if(USE_SYSTEM_ZLIB)
    find_package(ZLIB REQUIRED)
    message(STATUS "Using system zlib: ${ZLIB_VERSION_STRING}")
else()
    # Build bundled zlib
    set(ZLIB_BUILD_TESTING OFF CACHE BOOL "" FORCE)
    set(ZLIB_BUILD_SHARED OFF CACHE BOOL "" FORCE)
    set(ZLIB_BUILD_STATIC ON CACHE BOOL "" FORCE)
    set(ZLIB_INSTALL OFF CACHE BOOL "" FORCE)
    add_subdirectory(${THIRDPARTY_DIR}/zlib ${CMAKE_BINARY_DIR}/zlib)
    
    # Create an alias target for compatibility
    if(NOT TARGET ZLIB::ZLIB)
        add_library(ZLIB::ZLIB ALIAS zlibstatic)
    endif()
    
    # Make zlib headers available
    set(ZLIB_INCLUDE_DIR ${THIRDPARTY_DIR}/zlib ${CMAKE_BINARY_DIR}/zlib)
    message(STATUS "Using bundled zlib: 1.3.1.2")
endif()

if(USE_SYSTEM_LIBPNG)
    find_package(PNG REQUIRED)
    message(STATUS "Using system libpng: ${PNG_VERSION_STRING}")
else()
    # Build bundled libpng
    set(PNG_SHARED OFF CACHE BOOL "" FORCE)
    set(PNG_STATIC ON CACHE BOOL "" FORCE)
    set(PNG_TESTS OFF CACHE BOOL "" FORCE)
    set(PNG_TOOLS OFF CACHE BOOL "" FORCE)
    set(SKIP_INSTALL_ALL ON CACHE BOOL "" FORCE)
    
    # Tell libpng where to find zlib using ZLIB_ROOT (new method)
    if(NOT USE_SYSTEM_ZLIB)
        set(ZLIB_ROOT ${THIRDPARTY_DIR}/zlib CACHE PATH "" FORCE)
        set(ZLIB_INCLUDE_DIR ${THIRDPARTY_DIR}/zlib ${CMAKE_BINARY_DIR}/zlib CACHE PATH "" FORCE)
        set(ZLIB_LIBRARY zlibstatic CACHE STRING "" FORCE)
    endif()
    
    add_subdirectory(${THIRDPARTY_DIR}/libpng ${CMAKE_BINARY_DIR}/libpng)
    
    # Create an alias target for compatibility
    if(NOT TARGET PNG::PNG)
        add_library(PNG::PNG ALIAS png_static)
    endif()
    
    set(PNG_INCLUDE_DIR ${THIRDPARTY_DIR}/libpng ${CMAKE_BINARY_DIR}/libpng)
    message(STATUS "Using bundled libpng: 1.6.54")
endif()

# libdeflate (optional, for enhanced compression)
if(USE_LIBDEFLATE)
    set(LIBDEFLATE_BUILD_STATIC_LIB ON CACHE BOOL "" FORCE)
    set(LIBDEFLATE_BUILD_SHARED_LIB OFF CACHE BOOL "" FORCE)
    set(LIBDEFLATE_BUILD_GZIP OFF CACHE BOOL "" FORCE)
    set(LIBDEFLATE_GZIP_SUPPORT OFF CACHE BOOL "" FORCE)
    add_subdirectory(${THIRDPARTY_DIR}/libdeflate ${CMAKE_BINARY_DIR}/libdeflate)
    message(STATUS "Using bundled libdeflate: 1.22 (levels 1-12)")
endif()

# Zopfli (optional, for maximum compression - very slow)
if(USE_ZOPFLI)
    # Zopfli sources (we build as a library)
    set(ZOPFLI_SOURCES
        ${THIRDPARTY_DIR}/zopfli/src/zopfli/blocksplitter.c
        ${THIRDPARTY_DIR}/zopfli/src/zopfli/cache.c
        ${THIRDPARTY_DIR}/zopfli/src/zopfli/deflate.c
        ${THIRDPARTY_DIR}/zopfli/src/zopfli/gzip_container.c
        ${THIRDPARTY_DIR}/zopfli/src/zopfli/hash.c
        ${THIRDPARTY_DIR}/zopfli/src/zopfli/katajainen.c
        ${THIRDPARTY_DIR}/zopfli/src/zopfli/lz77.c
        ${THIRDPARTY_DIR}/zopfli/src/zopfli/squeeze.c
        ${THIRDPARTY_DIR}/zopfli/src/zopfli/tree.c
        ${THIRDPARTY_DIR}/zopfli/src/zopfli/util.c
        ${THIRDPARTY_DIR}/zopfli/src/zopfli/zlib_container.c
        ${THIRDPARTY_DIR}/zopfli/src/zopfli/zopfli_lib.c
    )
    add_library(zopfli_static STATIC ${ZOPFLI_SOURCES})
    target_include_directories(zopfli_static PUBLIC 
        ${THIRDPARTY_DIR}/zopfli/src/zopfli
    )
    # Suppress warnings in third-party code
    target_compile_options(zopfli_static PRIVATE -w)
    message(STATUS "Using bundled Zopfli (maximum compression, slow)")
endif()

# =============================================================================
# Main executable
# =============================================================================

# Main source files
set(PNGQRUSH_SOURCES
    ${SRC_DIR}/pngcrush.c
)

# Add libdeflate integration source if enabled
if(USE_LIBDEFLATE)
    list(APPEND PNGQRUSH_SOURCES ${SRC_DIR}/pngcrush_libdeflate.c)
endif()

# Add zopfli integration source if enabled
if(USE_ZOPFLI)
    list(APPEND PNGQRUSH_SOURCES ${SRC_DIR}/pngcrush_zopfli.c)
endif()

# Create executable
add_executable(pngqrush ${PNGQRUSH_SOURCES})

# Compile definitions
target_compile_definitions(pngqrush PRIVATE
    NO_GZ
    PNGCRUSH_TIMERS=11
    PNGCRUSH_USE_CLOCK_GETTIME=1
    $<$<BOOL:${USE_LIBDEFLATE}>:PNGCRUSH_USE_LIBDEFLATE=1>
    $<$<BOOL:${USE_ZOPFLI}>:PNGCRUSH_USE_ZOPFLI=1>
)

# Include directories
target_include_directories(pngqrush PRIVATE 
    ${SRC_DIR}
)

# libdeflate includes
if(USE_LIBDEFLATE)
    target_include_directories(pngqrush PRIVATE 
        ${THIRDPARTY_DIR}/libdeflate
    )
    target_link_libraries(pngqrush PRIVATE libdeflate_static)
endif()

# zopfli includes
if(USE_ZOPFLI)
    target_include_directories(pngqrush PRIVATE 
        ${THIRDPARTY_DIR}/zopfli/src/zopfli
    )
    target_link_libraries(pngqrush PRIVATE zopfli_static)
endif()

# Link against libpng (which links against zlib)
if(USE_SYSTEM_LIBPNG)
    target_link_libraries(pngqrush PRIVATE PNG::PNG)
else()
    target_link_libraries(pngqrush PRIVATE png_static)
    target_include_directories(pngqrush PRIVATE 
        ${THIRDPARTY_DIR}/libpng 
        ${CMAKE_BINARY_DIR}/libpng
    )
endif()

# Link math library
target_link_libraries(pngqrush PRIVATE m)

# Platform-specific: link rt for clock_gettime on older Linux
if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
    include(CheckLibraryExists)
    check_library_exists(rt clock_gettime "" HAVE_LIBRT)
    if(HAVE_LIBRT)
        target_link_libraries(pngqrush PRIVATE rt)
    endif()
endif()

# Compiler-specific flags
if(CMAKE_C_COMPILER_ID MATCHES "GNU|Clang")
    target_compile_options(pngqrush PRIVATE
        -Wall
        -Wextra
        $<$<CONFIG:Release>:-O3 -funroll-loops -fomit-frame-pointer>
        $<$<CONFIG:Debug>:-g -O0>
        $<$<CONFIG:RelWithDebInfo>:-O2 -g>
    )
endif()

if(MSVC)
    target_compile_options(pngqrush PRIVATE
        /W4
        $<$<CONFIG:Release>:/O2>
        $<$<CONFIG:Debug>:/Od /Zi>
    )
endif()

# Installation
install(TARGETS pngqrush
    RUNTIME DESTINATION bin
)

# Print configuration summary
message(STATUS "")
message(STATUS "=== PNGqrush Configuration Summary ===")
message(STATUS "Version:          ${PROJECT_VERSION}")
message(STATUS "C Compiler:       ${CMAKE_C_COMPILER_ID} ${CMAKE_C_COMPILER_VERSION}")
message(STATUS "Build Type:       ${CMAKE_BUILD_TYPE}")
message(STATUS "System zlib:      ${USE_SYSTEM_ZLIB}")
message(STATUS "System libpng:    ${USE_SYSTEM_LIBPNG}")
message(STATUS "libdeflate:       ${USE_LIBDEFLATE}")
message(STATUS "Zopfli:           ${USE_ZOPFLI}")
message(STATUS "Install prefix:   ${CMAKE_INSTALL_PREFIX}")
message(STATUS "======================================")
message(STATUS "")