cmake_minimum_required(VERSION 3.1)
cmake_policy(VERSION 3.1)

project(libpng C)

# Copyright (C) 2007-2010 Glenn Randers-Pehrson

# This code is released under the libpng license.
# For conditions of distribution and use, see the disclaimer
# and license in png.h

set(PNGLIB_MAJOR 1)
set(PNGLIB_MINOR 2)
set(PNGLIB_RELEASE 59)
set(PNGLIB_NAME "libpng${PNGLIB_MAJOR}${PNGLIB_MINOR}")
set(PNGLIB_VERSION "${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_RELEASE}")

# Allow users to specify location of zlib.
# Useful if zlib is being built alongside this as a sub-project.
option(PNG_BUILD_ZLIB "Custom zlib Location, else find_package is used" OFF)

if(NOT PNG_BUILD_ZLIB)
  find_package(ZLIB REQUIRED)
endif()

find_library(M_LIBRARY m)
if(NOT M_LIBRARY)
  message(STATUS
    "math library 'libm' not found - floating point support disabled")
endif()

option(PNG_NO_CONSOLE_IO "FIXME" YES)
option(PNG_NO_STDIO      "FIXME" YES)
option(PNG_DEBUG         "Build with debug output" NO)
option(PNGARG            "FIXME" YES)
#TODO:
# PNG_CONSOLE_IO_SUPPORTED

# maybe needs improving, but currently I don't know when we can enable what :)
if(CMAKE_SYSTEM_PROCESSOR MATCHES "^.*i[1-9]86.*$")
  set(png_asm_tmp ON)
else()
  set(png_asm_tmp OFF)
endif()

# SET LIBNAME
set(PNG_LIB_NAME "png${PNGLIB_MAJOR}${PNGLIB_MINOR}")


# OUR SOURCES
set(libpng_sources
  png.h
  pngconf.h
  png.c
  pngerror.c
  pngget.c
  pngmem.c
  pngpread.c
  pngread.c
  pngrio.c
  pngrtran.c
  pngrutil.c
  pngset.c
  pngtrans.c
  pngwio.c
  pngwrite.c
  pngwtran.c
  pngwutil.c
)
# SOME NEEDED DEFINITIONS

add_definitions(-DPNG_CONFIGURE_LIBPNG)
add_definitions(-DZLIB_DLL)
add_definitions(-DLIBPNG_NO_MMX)
add_definitions(-DPNG_NO_MMX_CODE)


if(PNG_CONSOLE_IO_SUPPORTED)
  add_definitions(-DPNG_CONSOLE_IO_SUPPORTED)
endif()

if(PNG_NO_CONSOLE_IO)
  add_definitions(-DPNG_NO_CONSOLE_IO)
endif()

if(PNG_NO_STDIO)
  add_definitions(-DPNG_NO_STDIO)
endif()

if(PNG_DEBUG)
  add_definitions(-DPNG_DEBUG)
endif()

if(NOT M_LIBRARY)
  add_definitions(-DPNG_NO_FLOATING_POINT_SUPPORTED)
endif()

# NOW BUILD OUR TARGET
add_library("${PNG_LIB_NAME}" SHARED ${libpng_sources})
target_link_libraries("${PNG_LIB_NAME}" "${ZLIB_LIBRARY}" "${M_LIBRARY}")
target_include_directories("${PNG_LIB_NAME}" PUBLIC "$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>")
foreach(zlib_include_dir IN LISTS ZLIB_INCLUDE_DIRS)
  target_include_directories("${PNG_LIB_NAME}" PUBLIC "$<BUILD_INTERFACE:${zlib_include_dir}>")
endforeach()


# SET UP LINKS
set_target_properties("${PNG_LIB_NAME}" PROPERTIES
# VERSION 0.${PNGLIB_RELEASE}.1.2.59
  VERSION "0.${PNGLIB_RELEASE}.0"
  SOVERSION 0
  CLEAN_DIRECT_OUTPUT 1)