While trying to compile a simple example openGL example to display text, I ran into the problem with 'glWindowPos2i' could not be resolved. glWindowPos2i seemed to compile fine as a C program under GCC, but for a could not be resolved error under eclipse as a c++ program with g++. (solution below)
The environment is eclipse (juno) under ubuntu 13.04 with openGL 3.3.0 (NVIDIA 310.44) GLEW version 1.8.0
The issue was that glWindowPos2i is an extension and in order compile with c++, glWindowPos2i needed to be defined by its address. At the top of the program, just after the includes glWindowPos2i needs to be defined as a global.
PFNGLWINDOWPOS2IPROC glWindowPos2i;
Then in the body of the program, after the glutInit, a value needs to be assigned to the global variable.
glWindowPos2i = (PFNGLWINDOWPOS2IPROC) glutGetProcAddress("glWindowPos2i");
The glutGetProcAddress is defined by an include for and the definition for PFNGLWINDOWPOS2IPROC comes from
The full list of the includes I'm using are
#include <GL/glew.h>
#include <GL/glext.h>
#include <GL/freeglut.h>
#include <GL/freeglut_ext.h>
The linker includes I'm using are
-lGL -lm -lglut -lGLEW -lGLU
Related
I'm following this tutorial to learn OpenGL, but I'm having trouble compiling since the compiler can't find one of the header files.
This is the file I'm trying to compile:
#include <glad/glad.h>
#include <GLFW/glfw3.h>
int main() {
return 0;
}
To compile, I'm using
$ gcc -o sandbox sandbox.cpp -lGL -lGLU -lglut
and I get the following error:
sandbox.cpp:1:23: fatal error: glad/glad.h: No such file or directory
#include <glad/glad.h>
^
compilation terminated.
I followed the first two sections of this wiki
to install OpenGL and libraries.
I think the problem is either the wrong compile command or a flaw in my OpenGL installation.
GLAD is a function loader for OpenGL. This tutorial explains how to set it up.
The tutorial explains the purpose of GLAD:
Since there are many different versions of OpenGL drivers, the location of most of its functions is not known at compile-time and needs to be queried at run-time.
Setup of GLAD involves using a web server to generate source and header files specific to your GL version, extensions, and language. The source and header files are then placed in your project's src and include directories.
If you are looking at this simple GLFW example you can remove the glad/gl.h include, and the
gladLoadGL(glfwGetProcAddress);
line further down.
If you are on linux, ubuntu for example,
you don't need glad, just add these 2 headers instead:
#include <GLES2/gl2.h>
#include <EGL/egl.h>
If the example is saved as glfw_ex2.c you can compile it at the command line like this:
g++ glfw_ex2.c -lglfw -lGLESv2
Of course, linmath.h must be present in the same directory for this example.
If anything is missing, you can install it like this and try compiling again:
sudo apt install libglfw3-dev libgles2-mesa-dev libegl1-mesa-dev
sudo apt install build-essential
then run it like this:
./a.out
I have played around with C++ for a while and just recently started to get into SDL and SDL2.
I was able to get the dot demo program to work.
But other programs, such as Lazy Foo' Productions's copied and pasted don't seem to work.
I have both SDL and SDL2 installed (and uninstalled and reinstalled.) I am on Ubuntu 15.04 and I have the IDE CodeBlocks linked (-ISDL2)
The errors are SDL_Window - SDL_WINDOWPOS_UNDEFINED - SDL_WINDOW_SHOWN - SDL_CreateWindow - SDL_GetWindowSurface - SDL_UpdateWindowSurface and finally, SDL_DestroyWindow -- was not declared in this scope.
Also, I include:
#include </usr/include/SDL/SDL.h>
#include </usr/include/SDL2/SDL.h>
#include <stdio.h>
I'm pretty sure that I don't need all of that location, but it didn't work without it either. One other note, when I type the #includes, CodeBlocks will suggest SDL2/SDL.h but not SDL/SDL.h.
What am I missing?
I don't think I can put Lazy Foo' code here - I didn't get permission...
The code you listed;
#include </usr/include/SDL/SDL.h>
#include </usr/include/SDL2/SDL.h>
#include <stdio.h>
Why don't you change it to
#include <SDL2/SDL.h>
#include <stdio.h>
as the first header is where SDL_CreateWindow and other SDL2 functions are declared?
Also you don't need to include both SDL and SDL2 headers. Indeed that could very well be the source of your problem as you would only need to include the version you're using.
If you're following the tutorials from lazyfoo's site, you can check if the ones you're following are using SDL1.2 or SDL2 from their table of contents, as the site actually have the tutorials for both versions.
UPDATE:
I didn't notice that your platform is a Linux platform. Then it is so much easier to solve your problem. The demo that you followed previously was done using SDL-1.2, whereas the gcc error hinted that you're using SDL-2.0, hence SDL_CreateWindow and other undefined errors. You should install SDL-2.0 library and SDL-2.0 development files (which will provide you with the necessary SDL-2.0 headers). You may refer this to SDL-2.0 packages provided by your platform distribution.
As for the compilation, it'll be the same as the tutorial you've followed with a minor change, instead of gcc sdltest.o -lSDL -o sdltest, you'll issue gcc sdltest.o -lSDL2 -o sdltest to indicate that you're linking your code against SDL2 library.
EDIT
A simple SDL program to test your environment. You can use any of the simpler text editor such as nano or gedit or others to edit this, and run the compilation command above to test your setup.
The simplest way to do this is by copy the code, then from your terminal, issue cat > sdltest.cpp and paste the code, then hit [ENTER] and [CTRL-C] to end it. Then you can issue the compilation command as mentioned previously,g++ sdltest.cpp -lSDL2 -o sdltest.
Code;
#include <SDL2/SDL.h>
#include <stdio.h>
int main()
{
SDL_Window *p;
SDL_Renderer *w;
p = SDL_CreateWindow("Game",SDL_WINDOWPOS_UNDEFINED,
SDL_WINDOWPOS_UNDEFINED,800,640,SDL_WINDOW_SHOWN);
w = SDL_CreateRenderer(p, -1, 0);
SDL_RenderClear(w);
SDL_SetRenderDrawColor(w,255,0,0,255);
SDL_Rect Rect = {220,140,200,200};
SDL_RenderFillRect(w,&Rect);
SDL_RenderPresent(w);
SDL_Delay(3000);
SDL_DestroyRenderer(w);
SDL_DestroyWindow(p);
SDL_Quit();
return 0;
}
Hope that helps.
I am learning OpenGL with the Redbooks v8 at the moment. But I'm stuck at the glPrimitiveRestartIndex() function, because it cannot be resolved.
My setup:
OS: ubuntu 14.04,
Compiler: g++ v4.8.4,
Linked GL and glut.
the exact error message is:
error: ‘glPrimitiveRestartIndex’ was not declared in this scope
I included the following libs:
#include <GL/freeglut.h>
#include <GL/glew.h>
enter code here
Any idea why this function could not be resolved?
What additional information is needed to fix this issue?
Minimal test compiles fine:
#include <GL/glew.h>
#include <GL/freeglut.h>
int main(void) {
glPrimitiveRestartIndex(0);
return 0;
}
Compilation line is gcc test.c -lGLEW -Wall.
If you have problems with that minimal example - then something is fundamentally wrong with your setup, but I bet it isn't the case. If it is, please let me know.
If it compiles but your code doesn't - then it is a mistake in your code, either include order or defines (both direct #define and -D compiler flags).
trying to use this tutorial on 64-bit windows 8 with netbeans and cygwin 4.8.1.
i get many errors like this: /usr/include/w32api/GL/glu.h:68:79: error: expected ‘)’ before ‘*’ token.
on statements like this: void APIENTRY gluQuadricCallback(GLUquadric *qobj,GLenum which,void (CALLBACK *fn)());
the pointer on error message points to the * before the fn().
edit: including windef.h gets rid of the compiler error messages.
i am left with a bunch of undefined references like: glfwInit
edit2: using André Fischer's ideas, i can get a clean compile (you need to add the directory and a -l option for the linker).
i now have a: skipping incompatible ../../../../../Windows/SysWOW64/opengl32.dll when searching for -lopengl32 and: undefined reference to `_imp_vsnprintf'. so it looks like i have a 32/64 bit problems and an undefined external.
there must be a saner way to get opengl working on windows.
I assume you mean Tutorial 1: Opening a Window and are using Netbeans' builtin build system instead of CMake.
The order in which you include the header files is important (source). Try it like this:
#include <windef.h> // According to comments above
#include <GL/glew.h> // Before any gl headers
#include <GL/gl.h>
//#include <GL/glext.h> // Linux headers
//#include <GL/wglext.h> // Windows headers - Not sure which ones cygwin needs. Just try it
#include <GL/glu.h> // Always after gl.h
#include <GL/glfw.h> // When all gl-headers have been included
Create a directory named "include" in your project directory with a subfolder "GL".
Grab the binaries (32 bit, MinGW) from the GLFW Download Site and put the .dll/.so into your build-folder (Or extract them somewhere and add them to the search directories) and the header files into "include/GL".
Also the glfw code in the tutorial is slightly outdated; It does not work with glfw3 anymore.
You'll have to update it using GLFW's conversion guide/try this version (which I haven't been able to test, since I'm currently not at home) or use glfw2.
Finally download the GLEW sources and build it by following the instructions in the README.txt. Put the .dll/.so into your build-folder (or add to search directories) and the header files into "include/GL".
Add following to your Compiler-Flags:
-Iinclude/
Finally add following arguments to your Linker:
-L/lib -lglu32 -lopengl32 -lGL -lGLU -lglfw -lglew
You should be able to compile the tutorial now.
Edit: Added instructions for building GLEW, GLFW and completed my answer to include building everything from scratch.
Edit2: Linked glfw3-version of the tutorial-code.
Edit3: Added missing linker options.
I'm using C++ and Opengl, and I'm trying to use SOIL, but when I compile, I get undefined reference to glBindTexture, glTexImage2D, etc. However, this is only coming from SOIL.c, not my own source code. This is what the error produces:
http://pastebin.com/sKrQaBhz
My graphics card is NVIDIA GeForce GTX 680 and my drivers are fully updated. I have everything linked and I'm using premake to manage my project. I'm developing on a linux machine, however, I'm trying to cross compile it onto my windows machine, which gives this error. If I compile it on linux, it's completely fine. This is my premake4.lua file:
http://pastebin.com/T4hsbdz0
My include files is this:
#include "opengl/gl_core_3_3.hpp"
#include <GLFW/glfw3.h>
#include <SOIL/SOIL.h>
#include <glm/glm.hpp>
#include <glm/gtx/transform.hpp>
#include <glm/gtc/type_ptr.hpp>
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include "loadshader.hpp"
I'm using mingw32 to compile my code. Before I was using SOIL, everything was fine. I downloaded SOIL from their webpage at lonesock.net, which I then copied over the libSOIL.a and their include files, but it just doesn't work.
Links order matters for g++.
Try this order:
links { "SOIL", "glfw3", "opengl32", "gdi32", "glu32" }
(edit: fixed the OP answer according to the duplicated question in Premake forum: http://industriousone.com/topic/how-use-premake-compile-static-library)
Looking at SOIL homepage, they said that it must be linked staticly. So, instead of using dynamic linking ('-l' in gcc compiler), try to specify the full path of the library.
This post illustrate what I want to say: https://stackoverflow.com/a/4156190/2293156
gcc -lsome_dynamic_lib some_static_lib.a code.c