Qt5 initializeopenglfunctions. This widget is controlled by OpenGL.


  1. Qt5 initializeopenglfunctions. 4, there are headers with version specific OpenGL Functions, so: #include <QOpenGLFunctions_3_3_Core> Or whatever version you want to use. 0 on Windows 7 (from qt-opensource-windows-x86-5. What I have so far in Qt, is the default main window and a Visualizer class which inherits from QOpenGLWidget and QOpenGLFunctions. To start viewing messages, select the forum that you want to visit from the selection below. 0+ functions within Qt without using glew. Maybe because it is a very new version, I'm not finding anything to help me out The QOpenGLContext class represents a native OpenGL context, enabling OpenGL rendering on a QSurface. The problem was me calling initializeGL in the constructor when the context was still NULL, so I removed the call since it would be called at some point when the window shows up. x or 4. The QOpenGLVersionProfile class represents the version and if applicable the profile of an OpenGL context. So far the articles on Qt uses the Qt Jan 17, 2022 · 社区首页 > 问答首页 > 关于initializeOpenGLFunctions返回假的问题 问 关于initializeOpenGLFunctions返回假的问题 EN Stack Overflow用户 提问于 2022-01-17 14:14:20 Dec 29, 2024 · 文章浏览阅读717次。QT做界面编程很方便，QT+OpenGL的使用也很方便，因为QT对原生的OpenGL API进行了面向对象化的封装。有些时候我们需要使用原生的OpenGL API，这在QT中也很方便，该怎么做呢？_qopenglfunctions if you want to use the old legacy OpenGL API you must add #include <GL/gl. Dec 21, 2021 · initializeOpenGLFunctions ()是QOpenGLFunctions中的函数，在使用OpenGL API之前，必须先调用一次initializeOpenGLFunctions ()函数，和使用glew访问现代OpenGL API一样，必须要先对glew库进行初始化。 Before Qt 5. I have tried this using the QtGui. 3 Core profile, but on a recent iMac running el Capitan, QOpenGLFunctions_3_3_Core::initializeOpenGLFunctions () returns false. This class was introduced in Qt 5. 0)。 原理： initializeOpenGLFunctions () 是 Qt 提供的，用于初始化当前 OpenGL 上下文下的函数指针（比如 glGenBuffers, glCreateShader 等）。glClearColor (…) 设置了在清屏时 Nov 24, 2020 · I was using QT5. The exact same code works fine on 2 different PC's running Linux. QOpenGLFunctions 说明 QOpenGLFunctions 类提供了跨平台的OpenGl ES2. I was initially Mar 28, 2018 · I was planning on writing a post on processing sound in Qt, but then I started getting back into OpenGL on Qt, so I ended writing this. The QAbstractOpenGLFunctions class is the base class of a family of classes that expose all functions for each OpenGL version and profile. 0 (x86), Qt version Qt 5. There is no need to call QAbstractOpenGLFunctions::initializeOpenGLFunctions Jan 20, 2019 · Initially they point to nothing. See full list on blog. Jan 30, 2015 · As you can see, I have a widget that renders OpenGL stuff, and a Qt push button that quits the window. 3. Using Qt 5. (and i don't have a w**doze machine to test) I read something about a "forward compatibility" setting is this what i need, and if Nov 9, 2020 · I am trying to add a QOpenGLWidget to my QGraphicsScene, but the application crashes when I call initializeOpenGLFunctions(). Each class follows the naming convention: \badcode QOpenGLFunctions_<MAJOR VERSION>_<MINOR VERSION> [_PROFILE] For OpenGL versions 1. The new (better) way with QT 5 is to use QOpenGLFunctions. 3, 0. Over 90 percent of OpenGL Window Example This example shows how to create a minimal QWindow based application for the purpose of using OpenGL. QOpenGLFunctions is a class that holds pointers to all the OpenGL functions. 13. Aug 17, 2025 · 使用QOpenGLFunctions的推荐方法是直接继承，同时在 初始化 函数中void initializeGL () 调用此接口initializeOpenGLFunctions () 进行初始化。 如下： OpenGL ES相对OpenGL删减了一切低效能的操作方式，有高性能的决不留低效能的，即只求效能不求兼容性 (和苹果的作风类似)。 Jan 20, 2019 · I also use it in every geometry/material/textre I make. Maybe because it is a very new version, I'm not finding anything to help me out on that. Welcome to Qt Centre. In the last few days, I read a lot about the Qt classes and how to initialize OpenGL and so on. Note that initializeOpenGLFunctions () can fail in some circumstances so check the return value. 5 Any reason to use such an old version? What OS? Did you try to update graphics driver? Jun 30, 2018 · I have a TestWidget inherited from QOpenGLWidget and QOpenGLFunctions_3_3_Core, which works fine on windows platform but failed on MacOS. So I made a QuickView with nothing really in it, in its ctor I placed a initializeOpenGLFunctions(); call. I am able to display the widget as a black box by setting MainWindow as the parent of Visualizer. It should be called exactly once for one instance of QOpenGLFunctions and there's rarely a reason to have more than one instance of that class so usually it should be called only once in your app. 0 specification. 1 since macOS BigSur Nov 24, 2020 · @ ManiRon said in How to integrate QT with OpenGl: I was using QT5. I am using a 32-bit kit: compiler MSVC 15. My application works fine in windows 7 (32 bit) . Qt QTBUG-104871 initializeOpenGLFunctions returning false for 2. GLint QOpenGLFunctions:: glGetUniformLocation (GLuint program, const char * name) Convenience function that calls glGetUniformLocation (program, name). 5 core profile. @ #include @8Observer8 You are calling initializeOpenGLFunctions and glGetStringi on two completely different instances. Oct 3, 2014 · Hello, I am getting started into developing a graphics framework using OpenGL 4, glew and Qt. import sys from PySide6. X documentation for glGetBufferParameteriv (). initializeOpenGLFunctions method to initialize the OpenGL Functions. I run this in Windows and Mac and it works fine, but for android not. Mar 24, 2014 · I use svn, and even when svn revert -ing to a previous version, the build fails. QOpenGLFunctions_ version Apr 6, 2016 · I used to work with Qt 5. 0 Detailed Description The Qt OpenGL page contains information about how to use the module. My program ASSERTS an Dec 23, 2016 · Hello Sir, Please find the query mentioned below we are not able to install qt 5. @ QT += opengl openglextensions @. I used to work with Qt 5. e (open source version) In file included from openglwindow. I want to use Qt for the UI and window portion of the framework and i would like to handle everything on OpenGL via an API class that I created. 6 and it seems like it is not straightforward the OpenGL application as 5. This simple examle demonstrates to using QOpenGLFunctions and QOpenGLContext. 4 to create a window and render with normal OpenGL functions some stuff in that window. create () returns false. [since 5. I realize I do not call initializeOpenGLFunctions () in my main widget, since all calls are done in other objects that also inherits QOpenGLFunctions_2_0. i guess it was happening before it init'd or sth Mar 22, 2014 · Re: How to use QOpenGLFunctions_2_1 properly OK. Now I've installed Qt 5. Jul 23, 2014 · I'm not an expert on the subject, but I believe you should use QQuickView's beforeRendering() or afterRendering() signals to call your render function and in Contribute to qtproject/learning-guides development by creating an account on GitHub. my macbook pro is the latest one and OpenGL3. 14. Jan 20, 2019 · Ohhhh now I get it! So I have to make it like static or some "globally" accessible stuff. Use initializeOpenGLFunctions () to change the object's context association. i was trying to swi Jun 1, 2015 · I am trying to port this code into Qt 5. pro file and re-run qmake. QtGui import QOpen Mar 26, 2016 · 8 You need to add initializeOpenGLFunctions(); into your GLWidget::initGL() function. 2. For some reason i need to run it in windows Detailed Description This class is a wrapper for functions from OpenGL 3. This example has no QWidget dependencies, it uses QOpenGLWindow, a convenience subclass of QWindow that allows easy implementation of windows that contain Jan 18, 2022 · question on initializeOpenGLFunctions returning false Asked 3 years, 6 months ago Modified 3 years, 6 months ago Viewed 451 times May 26, 2014 · QOpenGLFunctions seems to be missing important functions such as glInvalidateFramebuffer and glMapBuffer. 0. However, it can be difficult to use the functions from that subset because they need to be resolved manually on desktop systems. 0 API版本。 OpenGL 2. 1. this was my attempt at making a test case to wonder wtf is happening. but i don't see how using qwindow would prevent me from Jan 20, 2019 · But as it turns out, if I went to create VAO with glGenVertexArray (1,&vao) I got an error, Essentially I had to go on to that class and initializeOpenGLFunctions (), not only that, since that class needed texture which was another class, I had to go and do the same thing there too or else that buffer was crashing there. Note: QOpenGLExtraFunctions contains functionality that is not guaranteed to be available at runtime. How I rendered the triangle was through immediate mode; but if I am to be using shaders and the latest OpenGL functionality, how can I achieve this without using glew and through Qt's own classes? I know that QOpenGLFunctions_4_3_Core has the functions I need, but now I need to know I can I used to work with Qt 5. 1 that will enhance Qt's OpenGL support. 2 首先，新建立一个工程qtopengltest，使用ui designer，拖动一个widget到界面上，命名为glwidget。 根据 Initially they point to nothing. pro files documentation to do this). Sep 7, 2019 · Having had to replace a failing hard disk, I reinstalled Qt 5. On platforms where the OpenGL implementation is not dynamically loaded, the return value is determined during compile time and never changes. 5 the default behavior of QOpenGLWidget was to preserve the rendered contents between paintGL() calls. initializeGL method is called, inside of which I call the inherited QOpenGLFunctions. Qt now provides a family of classes which all inherit from QAbstractOpenGLFunctions which expose every core OpenGL function by way of a corresponding member function. The GL functions (even including it with #include <QOpenGLFunctions> returns "undefined reference". It should be called exactly once for one instance of QOpenGLFunctions and there's rarely a reason to We would like to show you a description here but the site won’t allow us. It is an interactive 3D environment that allows the user to, at any point, import a number of triangulated meshes (among other things). I am pretty sure that the context of OpenGLView is null and that is why Jan 19, 2020 · QT中使用opengl . If context is nullptr, then the resolver will be created for the current QOpenGLContext. 4, the old code contains Mesh, Shader, and Texture classes. void QOpenGLExtraFunctions:: glActiveShaderProgram (GLuint pipeline, GLuint program) Convenience function that calls glActiveShaderProgram (pipeline, program). So I made a QuickView with nothing really in it, in its ctor I placed a initializeOpenGLFunctions (); call. OpenGL 3. They are still usable and fully supported for applications depending on OpenGL directly. See reference pages on opengl. The compilation was imple QOpenGLFunctions Class Header: QOpenGLFunctions Since: Qt 5. x contexts. pro文件中添加 QT += opengl 1、使用指定版本的OpenGL如下使用opengl4. 0 API. 0 defines a subset of the OpenGL specification that is common across many desktop and embedded OpenGL implementations. x is support and Graphic card shows it support 3. The GL functions (even including it with #include returns "undefined reference". 0 functions via QOpenGLExtraFunctions in an application that works identically on desktop platforms with OpenGL 3. QOpenGLFunctions::OpenGLFeatures QOpenGLFunctions:: openGLFeatures () const Returns the set of features that are present on this system's OpenGL implementation. x, or OpenGL 3. This was in order to support OpenGL as the cross-platform graphics API that served as foundation for graphics in Qt. 5 the default behavior of QOpenGLWidget was to preserve the rendered contents between paintGL () calls. Also, unless you are planning on drawing a UI over/under your OpenGL scene, you should probably inherit from QWindow instead of QQuickView. 0 qmake: QT += gui Inherited By: QAbstract3DGraph and QOpenGLExtraFunctions Group: QOpenGLFunctions is part of Rendering in 3D Detailed Description OpenGL ES 2. Jul 23, 2014 · it seems i can eg create a quickview in main, call setformat and then initializeopenglfunctions just fine. well, i am doing exactly that. x as well. I am fairly new to OpenGL and Qt and so i have been relying on articles like the ones in RasterTek and the Qt forums. This code works for me (Linux 64-bit, Qt 5. This convenience function will do nothing on OpenGL ES 1. See also openGLModuleType (). 2, 0. x 4. The basicshapes-cpp example fails with a great number of errors, starting like this: QWindowsEGLStaticContext::create: Could not initialize EGL Mar 6, 2014 · If this is your first visit, be sure to check out the FAQ by clicking the link above. The GL functions (even includi Aug 30, 2021 · @nmthastings PySide accepts the double inherence in few cases so if possible it is better to use the composition. exe), and installed VS 2017 Community. But Member Function Documentation [static] QAbstractOpenGLFunctions *QOpenGLVersionFunctionsFactory:: get (const QOpenGLVersionProfile & versionProfile = QOpenGLVersionProfile (), QOpenGLContext * context = nullptr) Returns a pointer to an object that provides access to all functions for the versionProfile of the context. 1 and OpenGL used to work fine. Jan 10, 2015 · I dont know why but for Android compilation the OpenGLES2 are not being properly initialized by the initializeOpenGLFunctions (). To be more specific, I want to draw shapes with OpenGL on that The returned QOpenGLExtraFunctions instance is ready to be used and it does not need initializeOpenGLFunctions () to be called. Jan 21, 2023 · Thanks to @holtavolt 's comment, I was able to gain some insight from the example he provided and therefore was able to do some more digging until I found this QOpenGLWidget's context is null post. void QOpenGLFunctions:: glGetBufferParameteriv (GLenum target, GLenum pname, GLint * params) Convenience function that calls glGetBufferParameteriv (target, pname, params). Runtime availability depends on the platform, graphics driver, and the OpenGL version requested by the application. This widget is controlled by OpenGL. i was trying to switch from glew to qopenglfunctions stuff but this crashes for some odd reason. Hello everyone, I'm writing an app that (currently) targets OpenGL 3. Overview This example demonstrates easy, cross-platform usage of OpenGL ES 3. I also use QT WebEngine in my application. QOpenGLWidget provide cross-platform access to the OpenGL functions via context()->functions()->glxxxx. 0/2. not sure why what i was doing wasn't working. 4 i. 3 Core Profile support require for compile and run this demo. Then somewhere with a valid OpenGL context like QOpenGLWidget::initializeGL () create and initialise a QOpenGLFunctions object: QOpenGLFunctions_3_3_Core *fun = new QOpenGLFunctions_3_3_Core; fun->initializeOpenGLFunctions(); And then in your draw This only needs to be done once per instance with initializeOpenGLFunctions (). h> and link your app to your native platform opengl library (see QtCreator . Your extraFunc variable does not have the function pointers resolved. 04, Qt 5. 3 and mobile/embedded devices with OpenGL ES 3. Then I discover QOpenGLFunctions which is useful because : It wraps OpenGL for Desktop and OpenGL ES, making sure I am u May 15, 2013 · Does your build contain QOpenGLContext::versionFunctions() function? If so just call that to get a pointer to a QOpenGLFunctions__[_profile] object. Situations in which initialization can fail are if you have a functions object for a version or profile that contains functions that are not part of the context being used to resolve the function pointers. I'm trying to write a first program with using those libraries in Qt Creator that would draw in the QOpenGLWindow window an ordinary rectangle. Jan 30, 2015 · private: Ui::GLWindow *ui; };@ I performed the design and layout of the window through Qt Designer; so the widget therein is promoted to glWidget. The seg fault occurs and it just gives the location of the compiled code in the instruction queue. Maybe be Jun 5, 2014 · OpenGL and extensions live in a separate module. 4, 1. net Jan 30, 2015 · In Qt 5. Dec 23, 2023 · @ 8Observer8 You are calling initializeOpenGLFunctions and glGetStringi on two completely different instances. There is a class for every valid combination of OpenGL version and profile. Call initializeOpenGLFunctions () again to change the object’s context association. It is assumed that the QOpenGLContext associated with this function resolver is current. org for function documentation. Be sure to add it in your . 4, I'd like to be given some insight as to the proper way of being able to call OpenGL functions and do the Aug 30, 2021 · The issue comes when the inherited QOpenGLWidget. 5 Any reason to use such an old version? What OS? Did you try to update graphics driver? Mar 15, 2013 · This blog is the first in a series that will show how to use OpenGL with Qt 5. According to recent Qt 5. Qt Centre is a community site devoted to programming in C++ using the Qt framework. 4之前，可以自定义一个类，继承自QGLWidget来实现，后来推出了### QOpenGLWidget 这个类简化了流程。 QOpenGLWidegt 创建opengl窗口只需新建类继承于QOpenGLWidegt，再实现QOpenGL提供的三个虚函数，就可以完成opengl窗口的创建。 initializeGL ()—建立OpenGL的资源和状态。 Jun 30, 2015 · I want to use Qt 5. This class inherits from QQuickView, QOpenGLFunctions_3_0. 0 二、实现原理 （1）各函数作用与原理 initialize () 作用： 初始化 OpenGL 函数（initializeOpenGLFunctions ()） 设置背景清除颜色为 rgba (0. Detailed Description This class is a wrapper for functions from OpenGL 4. See also initializeOpenGLFunctions (). x systems. OpenGL ES 2. In this article, we shall take a very quick look at Qt's historical support for OpenGL and then go on to describe the first batch of new features coming in Qt 5. This function is only available in OpenGL ES 3. This function was introduced in Qt 5. my driver is fully capable (nvidia, modern hw). Aug 17, 2025 · 具体来说，就是： 初始化函数指针以便可以使用OpenGL的各种函数。 Qt帮我们提供了这么一个函数： initializeOpenGLFunctions() 只要调用就可以了。 如果不调用这个函数，则我们将无法使用OpenGL提供的函数。 启用一些flag 例如 glEnable(GL_DEPTH_TEST) 启用深度测试等。 Nov 11, 2024 · I am writing a program using Qt5 and OpenGL. [static] QOpenGLContext::OpenGLModuleType QOpenGLContext:: openGLModuleType () Returns the underlying OpenGL implementation type. [explicit] QOpenGLFunctions:: QOpenGLFunctions (QOpenGLContext * context) Constructs a function resolver for context. It should be called exactly once for one instance of QOpenGLFunctions and there's rarely a reason to Jan 20, 2019 · I also use it in every geometry/material/textre I make. For more information, see the OpenGL ES 2. QOpenGLFunctions provides a Aug 26, 2024 · initializeOpenGLFunctions() 是Qt框架中的一个函数，用于初始化当前上下文的OpenGL函数指针。 在使用OpenGL进行渲染时，需要调用各种OpenGL函数来执行不同的操作，例如创建和配置OpenGL对象、设置渲 Dec 23, 2015 · I have application created with QT5 and Visual Studio 2013. 5调用方法，使用指定版本的接口，必须设备图形显示设备支持对应OpenGL版本才可。Q：什么是CoreProfile和Compatibility Profile？A：在OpenG 在调用 initializeOpenGLFunctions () 指定上下文之前，无法使用解析器。 另请参阅 initializeOpenGLFunctions ()。 [explicit] QOpenGLFunctions:: QOpenGLFunctions (QOpenGLContext * context) 为 context 构建一个函数解析器。 如果 context 是 nullptr ，则将为当前的 QOpenGLContext 创建解析器。 In Qt 5, a replacement set of OpenGL-support classes were added to Qt Gui. A separate Qt OpenGL Widgets library provides a C++ widget class for rendering OpenGL graphics into widgets UIs. 1 is. Is it possible to use GLEW with qt 5 ? I used google first, and I found people who have come close, so this question is more of "have you done it successfully, and if so, how ?" and "Is this fundamentally a really difficult thing to do, or does it just appear that way?". initializeOpenGLFunctions (); //初始化OpenGL函数，将QT里的函数指针指向显卡的函数。 Oct 8, 2023 · 在Qt5. csdn. So that could be the problem. 7 framework for my program. Jul 20, 2016 · context. Mar 6, 2014 · So I'm trying to make a QGLWidget function with Qt Creator and I'm running into a strange issue trying to use regular OpenGL functions. 0 through to 3. . But do I need to? No. Like each object should have ptr to it. This just leads to a hard application crash - no errors, no stacktrace. I have a widget in my form. Call initializeOpenGLFunctions on it and use it to call any OpenGL function supported byt that version and Detailed Description This class is a wrapper for functions from OpenGL 3. I am using the Qt Creator IDE and the Qt 5. Call initializeOpenGLFunctions () again to change the object's context association. Just says the address of the instruction that caused it. QOpenGLFunctions implementation and the QtGui. 0, nVidia proprietary drivers): Jul 31, 2016 · Hi guys, I am new here and new to OpenGL ;) So I was trying to make something to appear on my screen, but unfortunately it always crashes at glDrawElements. 0 MSVC2017 32bit. 3] GLenum QOpenGLFunctions Aug 19, 2017 · QOpenGLFunctions的使用 1. The resolver cannot be used until initializeOpenGLFunctions () is called to specify the context. 3 core profile. From what I understand QOpenGLFunctions loads the intersection of both desktop OpenGL funct I a currently working on using Qt5 gui module to access to OpenGL functions. 0 documentation for glGetUniformLocation (). 0 提供了OpenGL中的子类集合，可以提供跨多个平台的桌面系统以及嵌入式OpenGL的实现。然而，却很难 Detailed Description The QOpenGLFunctions class provides cross-platform access to the OpenGL ES 2. But not all the legacy functions are provided Mar 20, 2023 · 首先，建议阅读和Qt OpenGL相关的类。本人对其中的一些类，做了一些翻译，例如：QOpenGLWidget。 环境：Ubuntu16. AHh got it thanks! now I get it :- ) so if my shader needs it then I can do something auto *funcs = render->openGLFunction OpenGL Window Example This example shows how to create a minimal QWindow based application for the purpose of using OpenGL. In Qt 6, these have been migrated to the Qt OpenGL module. But, my problem still remains; I need to find a way to be able to call OpenGL 4. 其中的initializeOpenGLFunctions用于初始化OpenGL函数，将Qt里的函数指针指向显卡的函数，之后调用的OpenGL函数才是可用的。 3. I got my code completely working with QOpenGLWidget using VAO's. Since Qt 5. initializeOpenGLFunctions () returns true for these, and initialize most openGL functions like I show in the picture, but not shader-related ones. 实验：实现“Hello World” 1）创建Qt项目 2）让其支持OpenGL step1：创建类TestOpenGLWidget step2：让该类继承自OpenGL相关的类，并初始化需要实现的虚 Jun 3, 2021 · I'm new at OpenGL and GLSL. Before Qt 5. Once initialized, the object can be used to call any OpenGL function for the corresponding version and profile. Initially they point to nothing. openGLFeatures() ¶ Return type: Combination of OpenGLFeature Returns the set of features that are present on this system’s OpenGL implementation. We would like to show you a description here but the site won’t allow us. You may have to register before you can post: click the register link above to proceed. initializeOpenGLFunctions actually looks them up and initializes them so that you can call those functions. 0 in rhel 6. For more information, see the OpenGL ES 3. The main question is: How do proceed for We would like to show you a description here but the site won’t allow us. 5 the default behavior is non-preserved because this provides better performance and the majority of applications have no need for the previous content. cpp:41 Jul 23, 2014 · hm, perhaps you're right. oweu 3d5r lqzxheu quyl1r cl6i ewsc vrqe h3pynin fe wrcfgnn