I have been working in Optix for my ray tracing project, i went through its classes and function , I know that all the display function and call backs are handled in glutmainloop() and it will never end, my question is I cannot find any function or .c file where glutmainloop() is defined? is it hidden?
Can anyone help me?
glutMainLoop is a function from the GL Utility Toolkit (GLUT). On Windows the library gets linked in and thus no source code is provided. Precisely it is provided from the open source freeglut:
GLUT
Most OptiX samples use the GLUT toolkit. Freeglut ships with the Windows OptiX distribution. GLUT is installed by default on Mac OSX. A GLUT installation is required to build samples on Linux.
Take a look at github's mirror for its code
More information here: opengl glutmainloop()
Related
I've installed Qt 5.12 , When i want to compile my project show this
errors:
Errors :
QOpenGLShaderProgram::uniformLocation(qt_Matrix): shader program is not linked
ensureInitialized(141): D3D compiler module not found.
QOpenGLShader::link: D3D compiler module not found.
shader compilation failed:
"D3D compiler module not found.\n"
Welcome to SO!
First of all, let's clarify what the error means.
Qt uses ANGLE on Windows, which is a layer that allows to run OpenGL software on systems where OpenGL is not available, by traslanting the OpenGL calls into DirectX calls. Qt decides whether to go with pure OpenGL or ANGLE depending on the configuration of the machine (video card model, video drivers version, etc).
More details on that are available at https://wiki.qt.io/Qt_5_on_Windows_ANGLE_and_OpenGL.
Even if you are not writing any OpenGL code yourself, the qml runtime surely has a lot of OpenGL calls that again, may go through ANGLE.
That is why the confusing error message (looking for the D3D shader compiler while dealing with OpenGL code!).
Now, the Qt project bugtracker reports the same issue you have https://bugreports.qt.io/browse/QTBUG-71510, although at the time of writing no solution has been provided. I would suggest to have a look at the bugtracker now and then to monitor the progress on this issue.
A couple of workarounds you may try:
Copy the d3dcompiler_xx.dll in the same directory where your exe is;
Force Qt to use OpenGL instead of DirectX, by setting the environment variable QT_OPENGL to desktop (more details on that are at http://doc.qt.io/qt-5/windows-requirements.html)
According to bugreports.qt this issue is now fixed from version QT 5.12.1.
https://bugreports.qt.io/browse/QTBUG-71510
I have the same issue on my older Del laptop. Placing d3dcompiler_43.dll in the exe folder does solve the issue. I found using one of the following commands also works, which I assume avoids ANGLE all together.
//To use pure OpenGL :
QCoreApplication::setAttribute(Qt::AA_UseDesktopOpenGL);
//Or use software emulated OpenGL :
QCoreApplication::setAttribute(Qt::AA_UseSoftwareOpenGL);
I just include the first pure OpenGL setting in the "int main(int argc, char *argv[])" bracket in main.cpp
Where do I get the OpenGL libraries from? I am using fedora but I don't know what ones I need to get. Is it just:
sudo yum install freeglut-devel
I already have the g++ and stuff. Is there any other libraries I need to install to make a simple OpenGL application.
On various internet tutorials they are using glaux, glut etc...
Could someone advice on which one I should use. I need it to create a music visualization program.
At first you have to understand why freeglut libraries is used for, what is Opengl and which version of Opengl you are going to used. Glut is an outdated library and freeglut or GLFW is a best alternative. Freeglut/GLFW is used to create opengl window and provide many callback function to handle keyboard, mouse, joystick and timer. If you are using ancient version of opengl (version less than 2) then you can call the opengl API function just including freeglut/glut. But if you are using Modern Opengl version (upto latest version 4.x) you can't call the opengl API function just include freeglut because in modern version Opengl API function are called at run time rather than compile time. So,you need a library to handle run time access of Openg API function and best library is GLEW. In ancient version of Opengl math function like glScalef, glRotatef,glTranslatef are provided but these are absent in modern Opengl. You have to do your math by yourself or you can use GLM library to do math.
Don't use ancient version of OpenGL use modern OpenGL. You need following things to start modern opengl.
freeglut or GLFW library to create opengl window and handle keyboard,mouse, joystick and other things.
GLEW to access OpenGL API function at run time.
GLM to do math operation.
Don't get ahead of yourself stop following old tutorials. Here are the best modern OpenGL tutorials follow them.
Link 1
Link 2
Link 3
I'm using GLFW and Netbeans to develop in C++. I'm able to render with immediate mode functions no problem. However, when I try to use core profile functions I get errors like this:
error: ‘glCreateShader’ was not declared in this scope
I get one of these errors for each core profile function I try. I did some research and found that GLFW doesn't provide any gl headers and just #includes the headers found on my system (at /usr/include/GL/).
Presumably this means that the gl.h and related files found here only contain the old style OpenGL API. I can't make sense of the hex code, but the gl.h file #defines GL_VERSION as 0x1F02.
If I perform this command in terminal: glxinfo | grep -i opengl it assures me that my OpenGL version string is "4.2.0 NVIDIA 304.88" -- Although I think that's reflected in the driver, unrelated to the gl.h file. Running this line in C++ code in my application yields the same string: printf("%s\n", glGetString(GL_VERSION)); For the same reason, no doubt.
Where can I source the appropriate OpenGL header files for OpenGL 3+ development on Ubuntu 13.04 x64?
I have installed these packages as suggested by most tutorials (to no avail): xorg-dev libglu1-mesa-dev
glCreateShader (...) is an OpenGL 2.0 function.
Short of OS X, I cannot think of any platforms that ship with OpenGL 2.0 without requiring runtime extension. On Microsoft Windows, you are guaranteed the full feature set of OpenGL 1.1 and anything beyond that requires calls to wglGetProcAddress (...) to load the function entry-points for the rest of the OpenGL API. The situation is the same on Linux, though it is more difficult to define what the "minimum" feature set is. In any case, to use glCreateShader (...) you are going to have to call glXGetProcAddress (...) in order to get the entry-point from the driver.
Libraries like GLEW will make your life easier by loading the entry-point for every function for each extension and core version of OpenGL your driver supports, on Ubuntu there should even be a package you can install that contains GLEW. Nevertheless, see the official project site for more details on actually using GLEW.
Recently I migrated over to SDL from Glut to get more control over the main loop. I've had shadow maps in my application for a while now using calls like bind framebuffer and gen framebuffer. After migrating over to SDL, I get an error for undeclared Identifier for only these calls. I downloaded the SDL off the website today and imported SDL2/SDL.h and SDL2/SDL_opengl.h. When I open the declaration for one of these "missing calls" it gives it to me, in OpenGl/glext.h. I noticed that the SDL OpenGL imports the OpenGL/gl.h which imports glext.h. Is there a file I'm importing wrong? All the other OpenGl calls work in the rest of my program, so I have no idea what the problem is. Any help would be appreciated. Thanks.
EDIT: I was able to delve deeper into glut and was able to come up with this to get it to work:
#pragma comment (lib, "glu32.lib")
#include <OpenGL/glu.h>
Is this ok?
Everything that goes a certain version of OpenGL (Windows: 1.1, Linux 1.2) must be dynamically loaded through the so called extension mechanism. The OpenGL headers and including them are not enough. The typical recommendation is to use a loading library like GLEW or glload to do the tedious work.
It depends on the platform you're using, but glBindFramebuffer<ARB|EXT> (...) is an extension on many. It was integrated into the core of OpenGL 3.0, so if your platform does not guarantee support for OpenGL 3.0 you are probably going to have to use an extension loading library (e.g. GLEW). If your driver provides OpenGL 3.0, you may still have to use the run-time extension mechanism to load the core function glBindFramebuffer (...).
The fact that "glext.h" contains it does not say a whole lot. That header is where prototypes, enumerants / constants and typedefs for parts of OpenGL that are extended at run-time are defined. You still have to setup a function pointer in your software and ask the driver for the address before you can call them - this is what extension loading libraries do in a nutshell.
EDIT1:
No, that is not okay. glBindFramebuffer (...) is part of OpenGL 3.0. Microsoft Windows implements OpenGL 1.1, and GLU should not change this at all. If forcing MSVC to link against GLU fixes unresolved linker errors to an OpenGL 3.0 function something is seriously wrong.
EDIT2:
Judging by the discussion in the comments, you are not only moving from SDL to GLUT, but also from OS X to Win32. On Win32 you have to use wglGetProcAddress (...) or an extension loading library to use glBindFramebuffer (...). You have been spoiled by Mac OS X, which is more of the exception than the rule when it comes to API completeness out-of-the-box.
I am trying compile a simple program using openGL and SDL but I can't seem to link the library in monodevelop
I tried following This guide but neither SDL nor GL are on the packages list
You need to download the Tao Framework and add the SDL and OpenGL dlls to the project references.
See here for more details.