MathGL 和 Cmake

Question

我正在尝试运行 mathgl 和 cmake，但我遇到了一些问题。 test001.cpp文件的代码如下：

#include <stdio.h>
#include <mgl2/qt.h>
int sample(mglGraph *gr)
{
  gr->Rotate(60,40);
  gr->Box();
  return 0;
}
int main(int argc,char **argv)
{
  mglQT gr(sample,"MathGL examples");
  return gr.Run();
}

我用这个编译它CMakeLists.txt

cmake_minimum_required(VERSION 2.8.3)
project (test001)
SET(CMAKE_MODULE_PATH ${test001_SOURCE_DIR})

# FIND_PACKAGE(Qt REQUIRED)
find_package(MathGL)
include_directories(
    ${MathGL_INCLUDE_DIRS}
)
add_executable(test001 test001.cpp)
target_link_libraries(test001 ${MathGL_LIBRARIES})

需要以下内容cmake module:

FIND_PATH(MATHGL_INCLUDE_DIR NAMES mgl2/mgl.h
  PATHS
  /opt/local/include
  /usr/include
  /usr/local/include
)

FIND_LIBRARY(MATHGL_LIB NAMES mgl
  PATHS
  /opt/local/lib
  /usr/local/lib
  /usr/lib
)

IF (MATHGL_INCLUDE_DIR AND MATHGL_LIB)
  SET(MATHGL_FOUND TRUE)
  MESSAGE(STATUS "MATHGL found")
  MESSAGE(STATUS "MATHGL Include dirs:" ${MATHGL_INCLUDE_DIR})
  MESSAGE(STATUS "MATHGL Library:" ${MATHGL_LIB})
ELSE (MATHGL_INCLUDE_DIR AND MATHGL_LIB)
  MESSAGE(STATUS "MATHGL was not found")
ENDIF(MATHGL_INCLUDE_DIR AND MATHGL_LIB)

所有文件都在同一个文件夹中。

我运行然后 cmake .. 在一个名为 build 的文件夹中，我显然得到了一个很好的答案：

-- The C compiler identification is GNU 4.9.2
-- The CXX compiler identification is GNU 4.9.2
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- MATHGL found
-- MATHGL Include dirs:/usr/include
-- MATHGL Library:/usr/lib/libmgl.so
-- Configuring done
-- Generating done
-- Build files have been written to: /home/fogg/dev/c/mathgl/build

但随后出现编译错误，好像我没有链接程序，但我在 CMakeLists.txt 文件中进行了链接。

Scanning dependencies of target test001
[100%] Building CXX object CMakeFiles/test001.dir/test001.cpp.o
Linking CXX executable test001
CMakeFiles/test001.dir/test001.cpp.o: In function `mglGraph::mglGraph(int, int, int)':
test001.cpp:(.text._ZN8mglGraphC2Eiii[_ZN8mglGraphC5Eiii]+0x3b): undefined reference to `mgl_create_graph_gl'
test001.cpp:(.text._ZN8mglGraphC2Eiii[_ZN8mglGraphC5Eiii]+0x57): undefined reference to `mgl_create_graph'
CMakeFiles/test001.dir/test001.cpp.o: In function `mglGraph::~mglGraph()':
test001.cpp:(.text._ZN8mglGraphD2Ev[_ZN8mglGraphD5Ev]+0x28): undefined reference to `mgl_use_graph'
test001.cpp:(.text._ZN8mglGraphD2Ev[_ZN8mglGraphD5Ev]+0x42): undefined reference to `mgl_delete_graph'
CMakeFiles/test001.dir/test001.cpp.o: In function `mglGraph::SetFontSize(double)':
test001.cpp:(.text._ZN8mglGraph11SetFontSizeEd[_ZN8mglGraph11SetFontSizeEd]+0x2a): undefined reference to `mgl_set_font_size'
CMakeFiles/test001.dir/test001.cpp.o: In function `mglGraph::Rotate(double, double, double)':
test001.cpp:(.text._ZN8mglGraph6RotateEddd[_ZN8mglGraph6RotateEddd]+0x4e): undefined reference to `mgl_rotate'
CMakeFiles/test001.dir/test001.cpp.o: In function `mglGraph::Box(char const*, bool)':
test001.cpp:(.text._ZN8mglGraph3BoxEPKcb[_ZN8mglGraph3BoxEPKcb]+0x2c): undefined reference to `mgl_box_str'
CMakeFiles/test001.dir/test001.cpp.o: In function `mglQT::mglQT(int (*)(mglGraph*), char const*)':
test001.cpp:(.text._ZN5mglQTC2EPFiP8mglGraphEPKc[_ZN5mglQTC5EPFiP8mglGraphEPKc]+0x34): undefined reference to `mgl_draw_graph'
test001.cpp:(.text._ZN5mglQTC2EPFiP8mglGraphEPKc[_ZN5mglQTC5EPFiP8mglGraphEPKc]+0x50): undefined reference to `mgl_create_graph_qt'
CMakeFiles/test001.dir/test001.cpp.o: In function `mglQT::Run()':
test001.cpp:(.text._ZN5mglQT3RunEv[_ZN5mglQT3RunEv]+0xd): undefined reference to `mgl_qt_run'
collect2: error: ld returned 1 exit status
make[2]: *** [test001] Error 1
make[1]: *** [CMakeFiles/test001.dir/all] Error 2
make: *** [all] Error 2

旁注：该程序在使用 g++ test001.cpp -lmgl-qt -lmgl -o test001 时编译得非常好。有什么想法吗？

Answer 1

我使用的是从 this site 下载的 FindMathGL.cmake，显然它包含一些错误。我更正了文件并 post 接下来，它可能对将来的人有用。

FIND_PATH(MathGL_INCLUDE_DIRS NAMES mgl2/mgl.h
  PATHS
  /opt/local/include
  /usr/include
  /usr/local/include
)

FIND_LIBRARY(MathGL_LIB NAMES mgl
  PATHS
  /opt/local/lib
  /usr/local/lib
  /usr/lib
)
FIND_LIBRARY(MathGL_QT_LIB NAMES mgl-qt
  PATHS
  /opt/local/lib
  /usr/local/lib
  /usr/lib
)


SET(MathGL_LIBRARIES ${MathGL_LIB} ${MathGL_QT_LIB})

IF (MathGL_INCLUDE_DIRS AND MathGL_LIBRARIES)
  SET(MathGL_FOUND TRUE)
  MESSAGE(STATUS "MathGL found")
  MESSAGE(STATUS "MathGL Include dirs:" ${MathGL_INCLUDE_DIRS})
  MESSAGE(STATUS "MathGL Library:" ${MathGL_LIB})
ELSE (MathGL_INCLUDE_DIRS AND MathGL_LIBRARIES)
  MESSAGE(STATUS "MathGL was not found")
ENDIF(MathGL_INCLUDE_DIRS AND MathGL_LIBRARIES)

Answer 2

对于寻找此问题的其他人：

从 sourceforge 下载的包中 mathgl-code 文件夹下的 scripts 文件夹中有一个名为 FindMathGL2.cmake 的文件。

要使用它，请在您的 CMakeLists.txt 文件中包含以下行：

set( CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} /path-to-mathgl-code-folder/scripts)
find_package(MathGL2 REQUIRED)
include_directories(${MATHGL2_INCLUDE_DIRS})
link_directories(${CMAKE_PREFIX_PATH}/lib/)

用合适的路径替换path-to-mathgl-code-folder。

比如我的项目中：

set( CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${PROJECT_SOURCE_DIR}/cmake_add/)

其中 cmake_add 是我项目中的一个文件夹，仅包含 FindMathGL2.cmake

P.S.: 您可以在文件 FindMathGL2.cmake 本身

中找到更多自定义说明

P.S.2: 在 ubuntu:

上安装 dev mathgl 包

sudo apt-get install libmgl-dev

Answer 3

对于查看@silgon 答案并尝试使其在 Mac 上运行的任何人：

默认情况下，brew 找不到 MathGL。添加水龙头：

酿造水龙头brewsci/homebrew-science
即使您现在尝试安装 MathGL，它也缺少 QT、FLTK 等支持。需要像这样从源安装：

brew 安装 --build-from-source mathgl --with-qt --with-wxmac
现在 headers 和库在版本化目录中，例如 /usr/local/Cellar/mathgl/2.3.5.1_4/lib/ 和 /usr/local/Cellar/mathgl/2.3.5.1_4/include/mgl2/ 和硬编码是我们要避免的事情。要使 CMake 在上面工作，请像这样修改它

FIND_PATH(MathGL_INCLUDE_DIRS 名称 mgl2/mgl.h 路径 /opt/local/include /usr/include /usr/local/include /usr/local/Cellar/mathgl/*/ PATH_SUFFIXES 库 )

每个 header 和您要使用的库都相同。

Answer 4

不严格相关，为了后代：与 MathGL 2.4 捆绑在一起的 FindMathGL2.cmake 版本出于某种原因不处理 GLUT 库（其他组件可能也没有链接）。

您必须添加一个部分以将 /usr/local/lib/libmgl-glut.so 添加到 MATHGL2_LIBRARY。

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