I use the Emacs text editor for editing my files, and have been looking into using OpenGL in my programs. However, I have had trouble including the GLFW header into my program.
Here is my code for the #include statements and essentially test if the files linked properly, which comes from the hyperlink later on.
#include <iostream>
#include <GL/glew.h>
#include <GLFW/glfw3.h>
using namespace std;
int main()
{
glewExperimental = true;
if(!glfwInit())
{
cout << "Failed to initialize" << endl;
return -1;
}
return 0;
}
I hit M-x compile then g++ file.cpp -lglut -lGL -lGLEW -lGLU -o file.out and get the following error
g++ anotherGL.cpp -lglut -lGL -lGLEW -lGLU -o anotherGL.out
anotherGL.cpp:5:10: fatal error: GLFW/glfw3.h: No such file or directory
#include <GLFW/glfw3.h>
^~~~~~~~~~~~~~
I followed the instructions for downloading the OpenGL tutorial page, under the section Building on Linux, but the instructions diverge after it moves on to the section where the packages are linked to the IDE.
(http://www.opengl-tutorial.org/beginners-tutorials/tutorial-1-opening-a-window/)
Is there a M-x command I can use in place of what I have to perform the link?
On "debian" and "red hat" systems, the include file GLFW/glfw3.h is under /usr/include a la /usr/include/GLFW/glfw3.h. Your include statement is correct as /usr/include is implicitly searched by gcc/g++. You've just missed installing the glfw development package. On "debian" or apt-based systems this is in libglfw3-dev. On "red hat" or rpm based systems this is glfw-devel. You may also need to add the flag -lglfw to your compile command.
Related
I've always used Xcode to compile OpenCV based code in c++. The procedure in Xcode was quite simple, I just had to mention the paths and add the necessary lib files to the project. Theres this app called CodeRunner 2 for macOS. Theres no proper documentation on how to include external libraries to compile code in this app. Is it possible to link OpenCV headers and compile them in CodeRunner ? If yes, could someone post the steps?
You can run OpenCV in CodeRunner by setting up a new language. Go to Preferences -> Languages, right-click C++, and select Duplicate. Name the new language "C++ OpenCV". On the right side of the preferences window, click Settings then the Edit Script button. Look for this line (or something similar):
xcrun clang++ -x c++ -lc++ -o "$out" "${files[#]}" "${#:1}"
Add the clang++ command line parameters for OpenCV after "$out". Here's my version:
xcrun clang++ -x c++ -lc++ -o "$out" -I/usr/local/opt/opencv3/include -L/usr/local/opt/opencv3/lib -lopencv_core -lopencv_highgui -lopencv_imgproc -lopencv_imgcodecs -lopencv_videoio -lopencv_calib3d "${files[#]}" "${#:1}"
Modify the -I and -L parameters to match your OpenCV install path. On this machine I used Homebrew to install OpenCV so it was installed in /usr/local/opt. On other machines I've compiled from source so OpenCV is installed in /usr/local/lib.
Modify the -l parameters to include the libraries you typically use.
After saving the compile script, go back to Preferences -> Languages and select the Templates button. You can set up a template for OpenCV programs. Here's mine:
#include <iostream>
#include "opencv2/core.hpp"
#include "opencv2/imgproc.hpp"
#include "opencv2/highgui.hpp"
using namespace std;
int main(int argc, char *argv[]) {
cv::Mat image;
// read an image
if (argc < 2)
image = cv::imread("img.jpg");
else
image = cv::imread(argv[1]);
if (!image.data) {
std::cout << "Image file not found\n";
return 1;
}
// create image window named "asdfasdf"
cv::namedWindow("asdfasdf");
// show the image on window
cv::imshow("asdfasdf", image);
// wait for key
cv::waitKey(0);
return 0;
}
The previous reply by SSteve is great and also helps me sort out linking Boost library in CodeRunner.
Because the solution in the previous reply is specific to OpenCV library, a carelessly adding to the clang++ command line for external libraries in general might just generate massive building errors, which was the case when I tried to link Boost library.
Here, I want to clarify the unclear bit in SSteve's reply so everyone knows how and where to modify the command line before compiling their code with external library in Mac OS system.
I will use my case to explain, but in some point I will inform you of the tricky bits in CodeRunner setting or general command line typing.
I use macport to install the Boost library by
sudo port install boost
header file is located at /opt/local/include
library is located at /opt/local/lib/
If you cannot find the specific sub-library in Boost, open your terminal and type
cd /opt/local/lib/
find . -iname "*boost*"
and you should see all sub-libraries of Boost ( static library ends with .a and dynamic library ends with .dylib ) as below.
Before you start to modify the original command line ( supporting c++ 14 version ) such as
xcrun clang++ -x c++ -std=c++14 -stdlib=libc++ -lc++ -o "$out" "${files[#]}" "${#:1}" ${CR_DEBUGGING:+-g}
you need to know the directory of header file is after -I and the directory of Boost library is after -L, like
-I /opt/local/include/
-L /opt/local/lib/
In order to use a compiled static or dynamic sub-library in Boost ( see figure above ), you have to include it specifically after -L /opt/local/lib/. However, simply copying the library name without file extension either .a or .dylib would never let CodeRunner find the library you expect to run !!!
The detail is explained here and I just quota the important bit below
clang -dynamiclib -o libtest.dylib file1.o file2.o -L/some/library/path -lname_of_library_without_lib_prefix
To run such an example code in Boost Quickstart Document
#include <boost/regex.hpp>
#include <iostream>
#include <string>
int main()
{
std::string line;
boost::regex pat( "^Subject: (Re: |Aw: )*(.*)" );
while (std::cin)
{
std::getline(std::cin, line);
boost::smatch matches;
if (boost::regex_match(line, matches, pat))
std::cout << matches[2] << std::endl;
}
}
the way to include <boost/regex.hpp> now is by
xcrun clang++ -x c++ -std=c++14 -stdlib=libc++ -lc++ -o "$out" -I /opt/local/include/ -L /opt/local/lib -lboost_regex-mt "${files[#]}" "${#:1}" ${CR_DEBUGGING:+-g}
By using this command line, you should be able to compile the example code with Boost library.
Just remember to replace the prefix -lib with -l and exclude the file extension in the command line.
At last, there are some alternative solution to include the external library by using Xcode, which is in here
I am trying to get an OpenGL program working on both linux and windows.
Here's my code [file=main.cc]:
#include <iostream>
#include "GL/glew.h"
using namespace std;
int main(int argc, char *argv[]){
cout << "Hello World\n";
return 0;
}
Simple enough. I'm on Linux and using
g++ main.cc -lGL -lGLEW -lSDL2
to compile my program. It works perfectly fine and if I run ./a.out I get a Hello World on my screen.
Then I try to compile it on Linux for Windows using the command
x86_64-w64-mingw32-g++ main.cc -lGL -LGLEW -LSDL2
Then however i get the error:
main.cc:3:21: fatal error: GL/glew.h: No such file or directory
#include "GL/glew.h"
^
compilation terminated.
I've already tried adding the -I/inclulde/path option with paths like /usr/include /usr/include/GL usr/include and the like, yet nothing wants to compile.
The Libraries that I'm using (or planning to) were installed using
#apt install libgl-dev libglew-dev libsdl2-dev
Any help would be very much appreciated (although I feel this is an incredibly easy fix that I'm just too stupid to figure out on my own)
I can't seem to compile this program. I have other people in my class that are having no problem compiling this code. I'm using the same command to try to compile the program and installed the frameworks in the same directory as them. /Library/Frameworks. I also installed eclipse and followed the zamma.co.uk tutorial to setup sdl2 and that didn't work either. Here is the command i'm running when compiling
g++ -std=c++11 -o Gravity main.cpp Game.cpp Particle.cpp Point.cpp -I/Library/Frameworks/SDL2.framework/Headers -framework SDL2 -framework Cocoa
Note: I have tried both
#include <SDL.h>
and
#include <SDL2/SDL.h>
and neither work
The ld linker error you mention in your comments suggests you may need to pass the -F option or -L in case your features/library search path is not finding your SDL2 installation.
Your problem sounds similar to:
linker command failed, sdl
How do you include files in C++ from the /Library/Framework folder in MAC
I'm trying to write an OpenGL program which I'm compiling through MinGW. I've managed to successfully link OpenGL, GLUT, GLFW and GLM to my main.cpp file. Given the following headers:
#include "GL/glut.h"
#include "GLFW/glfw3.h"
#include "GL/glew.h"
#include "glm/vec3.hpp"
And the following cmd line:
g++ -o leaf.exe -Wall physics.cpp -mwindows lib/glut32.lib -lopengl32 -lglu32 -lglfw3dll -lglew32 -IC:/MinGW/include/GL
I manage to get it to compile successfully. However, when placing the .a files in MinGW/lib, the .dll file in source folder and the .h file in C:\MinGW\include and adding
#include "GL/glew.h"
With the following command line
g++ -o leaf.exe -Wall physics.cpp -mwindows lib/glut32.lib -lopengl32 -lglu32 -lglfw3dll -lglew32 -IC:/MinGW/include/GL
Then I get a long list of errors including:
In file included from physics.cpp:6:0:
c:\mingw\include\gl\glew.h:85:2: error: #error gl.h included before glew.h
#error gl.h included before glew.h
In file included from physics.cpp:6:0:
c:\mingw\include\gl\glew.h:1814:94: error: 'GLchar' does not name a type
typedef void (GLAPIENTRY * PFNGLBINDATTRIBLOCATIONPROC) (GLuint program, GLuint index, const GLchar* name);
My first time trying to make something without using Visual Studio or Eclipse. Been trying lots of fixes for it I've found here but nothing concrete.
Thanks for reading this far!
You need to reorder your includes:
#include "GL/glew.h"
#include "GL/glut.h"
#include "GLFW/glfw3.h"
#include "glm/vec3.hpp"
GLFW (and GLUT?) automatically include GL.h, which is what GLEW is complaining about. Not sure why you're using GLUT and GLFW in the same build, they don't exactly go together...
I am trying to compile the following code which has the headers:
#include <SDL2/SDL.h>
#include <SDL2_image/SDL_image.h>
However after running the following makefile:
g++ -std=c++11 src/main.cpp -lSDL2 -lSDL2_image
I get the following error:
fatal error: SDL2_image/SDL_image.h: No such file or directory
#include <SDL2_image/SDL_image.h>
Any suggestions? Not entirely sure about my installation of SDL_image. I am running this on Ubuntu.
This problem can be solved through installing libsdl2-image-dev package:
apt install libsdl2-image-dev
Run apt-file search SDL_image.h
The result will tell you the location of the include file.
For instance, /usr/include/SDL2/SDL_image.h was returned.
So, when you want to include SDL_image.h, write everything after the include/ in between < >.
Thus, includes should look like the following:
#include <SDL2/SDL.h>
#include <SDL2/SDL_image.h>
See the question's comments for the original discussion regarding this solution.
From SDL documentation, it says that add 'lSDL_image' to the end of the compile line.
cc -o myprogram mysource.o `sdl-config --libs` -lSDL_image
or
gcc -o myprogram mysource.c `sdl-config --libs` -lSDL_image
Here is the reference -> https://www.libsdl.org/projects/docs/SDL_image/SDL_image.html
Section 2.2 Compiling.
So for SDL2, you just need to change 'lSDL_image' to 'lSDL2_image'.
For Windows + SDL2-2.0.8 + SDL_image-2.0.4 + Codeblocks you've got the add both Runtime Binaries and Development Libraries to the compiler and linker. Or else, you'll get the error SDL2_image not found, even with having the dll in your program's directory, this occurs. Hopefully others find this helpful; I had to figure it out myself. Example: If your resources are separate, you'll be adding the two plus your standard SDL2 paths to your compiler and linker. Warning: SDL2_image.h has it's headers assuming that the headers are in the same folder as the SDL2 framework. If you get errors about the image header, include the sub-folder SDL2 from SDL framework in the path and then you should be including SDL2 in the program as: include <SDL.h> rather than include <SDL2/SDL.h>.