CLion无法识别SDL2_image

Question

I have got SDL2_image library installed on /usr/include/SDL2 (in this directory I can find SDL_image.h).

When I compile with CLion all works fine but, in the editor, either include and functions of SDL2_image librarie appear with error (this library is found by the compiler but It is not found by the editor).

This is my CMake:

cmake_minimum_required(VERSION 3.2)
project(sdl)

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")

set(SOURCE_FILES main.cpp)
add_executable(sdl ${SOURCE_FILES} Game.cpp Game.h)

INCLUDE(FindPkgConfig)

PKG_SEARCH_MODULE(SDL2 REQUIRED sdl2)
PKG_SEARCH_MODULE(SDL2IMAGE REQUIRED SDL2_image>=2.0.0)

INCLUDE_DIRECTORIES(${SDL2_INCLUDE_DIRS} ${SDL2IMAGE_INCLUDE_DIRS})
TARGET_LINK_LIBRARIES(${PROJECT_NAME} ${SDL2_LIBRARIES}  ${SDL2IMAGE_LIBRARIES})

add_custom_command(TARGET sdl POST_BUILD
COMMAND ${CMAKE_COMMAND} -E copy_directory
    ${CMAKE_SOURCE_DIR}/assets
    $<TARGET_FILE_DIR:sdl>/assets)

What is the problem?

Answer 1

Use this FindSDL2_image.cmake file:

# Locate SDL2_image library
# This module defines
# SDL2_IMAGE_LIBRARY, the name of the library to link against
# SDL2_IMAGE_FOUND, if false, do not try to link to SDL2_image
# SDL2_IMAGE_INCLUDE_DIR, where to find SDL_image.h
#
# Additional Note: If you see an empty SDL2_IMAGE_LIBRARY_TEMP in your configuration
# and no SDL2_IMAGE_LIBRARY, it means CMake did not find your SDL2_Image library
# (SDL2_image.dll, libsdl2_image.so, SDL2_image.framework, etc).
# Set SDL2_IMAGE_LIBRARY_TEMP to point to your SDL2 library, and configure again.
# Similarly, if you see an empty SDL2MAIN_LIBRARY, you should set this value
# as appropriate. These values are used to generate the final SDL2_IMAGE_LIBRARY
# variable, but when these values are unset, SDL2_IMAGE_LIBRARY does not get created.
#
# $SDL2 is an environment variable that would
# correspond to the ./configure --prefix=$SDL2
# used in building SDL2.
# l.e.galup 9-20-02
#
# Modified by Eric Wing.
# Added code to assist with automated building by using environmental variables
# and providing a more controlled/consistent search behavior.
# Added new modifications to recognize OS X frameworks and
# additional Unix paths (FreeBSD, etc).
# Also corrected the header search path to follow "proper" SDL2 guidelines.
# Added a search for SDL2main which is needed by some platforms.
# Added a search for threads which is needed by some platforms.
# Added needed compile switches for MinGW.
#
# On OSX, this will prefer the Framework version (if found) over others.
# People will have to manually change the cache values of
# SDL2_IMAGE_LIBRARY to override this selection or set the CMake environment
# CMAKE_INCLUDE_PATH to modify the search paths.
#
# Note that the header path has changed from SDL2/SDL.h to just SDL.h
# This needed to change because "proper" SDL2 convention
# is #include "SDL.h", not <SDL2/SDL.h>. This is done for portability
# reasons because not all systems place things in SDL2/ (see FreeBSD).
#
# Ported by Johnny Patterson. This is a literal port for SDL2 of the FindSDL.cmake
# module with the minor edit of changing "SDL" to "SDL2" where necessary. This
# was not created for redistribution, and exists temporarily pending official
# SDL2 CMake modules.
# 
# Note that on windows this will only search for the 32bit libraries, to search
# for 64bit change x86/i686-w64 to x64/x86_64-w64

#=============================================================================
# Copyright 2003-2009 Kitware, Inc.
#
# CMake - Cross Platform Makefile Generator
# Copyright 2000-2014 Kitware, Inc.
# Copyright 2000-2011 Insight Software Consortium
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# * Neither the names of Kitware, Inc., the Insight Software Consortium,
# nor the names of their contributors may be used to endorse or promote
# products derived from this software without specific prior written
# permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distribute this file outside of CMake, substitute the full
# License text for the above reference.)

FIND_PATH(SDL2_IMAGE_INCLUDE_DIR SDL_image.h
    HINTS
    ${SDL2}
    $ENV{SDL2}
    $ENV{SDL2_IMAGE}
    PATH_SUFFIXES include/SDL2 include SDL2
    i686-w64-mingw32/include/SDL2
    x86_64-w64-mingw32/include/SDL2
    PATHS
    ~/Library/Frameworks
    /Library/Frameworks
    /usr/local/include/SDL2
    /usr/include/SDL2
    /sw # Fink
    /opt/local # DarwinPorts
    /opt/csw # Blastwave
    /opt
)

# Lookup the 64 bit libs on x64
IF(CMAKE_SIZEOF_VOID_P EQUAL 8)
    FIND_LIBRARY(SDL2_IMAGE_LIBRARY_TEMP
        NAMES SDL2_image
        HINTS
        ${SDL2}
        $ENV{SDL2}
        $ENV{SDL2_IMAGE}
        PATH_SUFFIXES lib64 lib
        lib/x64
        x86_64-w64-mingw32/lib
        PATHS
        /sw
        /opt/local
        /opt/csw
        /opt
    )
# On 32bit build find the 32bit libs
ELSE(CMAKE_SIZEOF_VOID_P EQUAL 8)
    FIND_LIBRARY(SDL2_IMAGE_LIBRARY_TEMP
        NAMES SDL2_image
        HINTS
        ${SDL2}
        $ENV{SDL2}
        $ENV{SDL2_IMAGE}
        PATH_SUFFIXES lib
        lib/x86
        i686-w64-mingw32/lib
        PATHS
        /sw
        /opt/local
        /opt/csw
        /opt
    )
ENDIF(CMAKE_SIZEOF_VOID_P EQUAL 8)

SET(SDL2_IMAGE_FOUND "NO")
    IF(SDL2_IMAGE_LIBRARY_TEMP)
    # Set the final string here so the GUI reflects the final state.
    SET(SDL2_IMAGE_LIBRARY ${SDL2_IMAGE_LIBRARY_TEMP} CACHE STRING "Where the SDL2_image Library can be found")
    # Set the temp variable to INTERNAL so it is not seen in the CMake GUI
    SET(SDL2_IMAGE_LIBRARY_TEMP "${SDL2_IMAGE_LIBRARY_TEMP}" CACHE INTERNAL "")
    SET(SDL2_IMAGE_FOUND "YES")
ENDIF(SDL2_IMAGE_LIBRARY_TEMP)

INCLUDE(FindPackageHandleStandardArgs)

FIND_PACKAGE_HANDLE_STANDARD_ARGS(SDL2_IMAGE REQUIRED_VARS SDL2_IMAGE_LIBRARY SDL2_IMAGE_INCLUDE_DIR)

in my source tree I have a folder called cmake_modules with the above find FindSDL2_image.cmake file in there.

you can read the bottom of that .cmake file to see the library and include names to use: FIND_PACKAGE_HANDLE_STANDARD_ARGS(SDL2_IMAGE REQUIRED_VARS SDL2_IMAGE_LIBRARY SDL2_IMAGE_INCLUDE_DIR)

Then in my cmake file looks something like this:

PROJECT(project_name)

SET(SRC_FILES xxx.c xxx.c xxx.c xxx.c)

FIND_PACKAGE(SDL2 REQUIRED)
INCLUDE_DIRECTORIES(${SDL2_INCLUDE_DIR})

FIND_PACKAGE(OPENGL REQUIRED)
INCLUDE_DIRECTORIES( ${OPENGL_INCLUDE_DIR})

FIND_PACKAGE(SDL_IMAGE REQUIRED)
INCLUDE_DIRECTORIES( ${SDL2_IMAGE_INCLUDE_DIR})

ADD_LIBRARY(project_name SHARED ${SRC_FILES})
TARGET_LINK_LIBRARIES(project_name ${SDL2_LIBRARY} ${OPENGL_LIBRARIES} ${SDL2_IMAGE_LIBRARY})

Answer 2

FindPkgConfig module invoke pkg-config command to get the link/compiler flags. In your case it's possible that the pkg-config does not find the settings, so CMake failed to get that information.

Please try opening the console/terminal (or msys, msys2, whatever you're using). Then calls pkg-config SDL2_image --libs . If it works properly you should see something like (I use MSYS2 on Windows, in other platform it would be a bit different) :-

$ pkg-config SDL2_image --libs
-LC:/msys64/mingw64/lib -lSDL2_image -lmingw32 -lSDL2main -lSDL2

Note: the command is case-sensitive.

If it does not work then you might have to update the pkgconfig file manually. This is different from systems to systems (the default on Linux is /usr/lib/pkgconfig , but again this could vary between distros). In worst case, you would have to write the pkgconfig file manually.

Anyway it would be better if you can specify what the operating system and platform you are currently working on.

Answer 3

depends what compiler you are using, and maybe other factors, depending on what error you are getting exactly.

on your

TARGET_LINK_LIBRARIES(${PROJECT_NAME} ${SDL2_LIBRARIES} ${SDL2IMAGE_LIBRARIES})

you might need more linkers or they might not be picking up correctly for some reason.

mine looks about like this for a similar project

target_link_libraries(${PROJECT_NAME} -lmingw32 -lSDL2main -lSDL2 -lSDL2_image)

using the mingw compiler, and it seems to work okay.