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1. #QT 5.5 OPENGL 4.4 HOW TO#
2. #QT 5.5 OPENGL 4.4 MANUAL#
3. #QT 5.5 OPENGL 4.4 SERIES#
4. #QT 5.5 OPENGL 4.4 WINDOWS#

For example: // Set a vertex attribute divisor QWarning( 'Could not obtain OpenGL versions object' ) įrom that point on we can simply use member functions on the QOpenGLFunctions_4_3_Core object. m_funcs is declared as: QOpenGLFunctions_4_3_Core* m_funcs Obtain a functions object and resolve all entry points Make the context current on this window Specify the format and create platform-specific surfaceįtProfile( QSurfaceFormat::CoreProfile ) Tell Qt we will use OpenGL for this window To do so is as simple as: Window::Window( QScreen* screen ) Say we have created a QWindow sub-class on which to render and we now wish to create an OpenGL 4.3 Core profile context and resolve every function. However, it is often a pain to get these to play nicely with Qt in termsĮnter QOpenGLContext::versionFunctions()! This unassuming little function is your gateway to OpenGL entry point utopia 🙂 This function can be used to obtain a pointer to an object with member functions for every function in the requested OpenGL version and profile. Alternatively it is possible to use an external function resolver such as GLEW or GLee.

#QT 5.5 OPENGL 4.4 MANUAL#

The issues are that QOpenGLFunctions is limited in what it exposes (the above mentioned subset of OpenGL 2 and ES 2) and manual resolving of entry points is extremely tedious and error-prone. These helpers are great, as far as they go. The former can be used to perform manual resolution of entry points, whilst the latter is a class that has member functions mapping to the common subset of functions in OpenGL 2 and OpenGL ES 2. To assist with this Qt has provided a couple of helpful utilities: QOpenGLContext::getProcAddress() and QOpenGLFunctions. That is nearly all of functions used in a modern OpenGL application! For example, on Microsoft Windows, the address of any function introduced since OpenGL 1.1 must be resolved at run-time. One of the major reasons for this pain is the need to resolve entry point addresses dynamically at runtime rather than the build time linker being able to do so. OpenGL is, to put it bluntly, a bit of a pain to work with on some platforms. With Qt 5.1, we are beginning the adventure of exposing more and more OpenGL functionality so as to make using OpenGL with Qt simple, elegant and hopefully fun! To this end, KDAB has invested significant resources into pushing the boundaries with Qt and OpenGL. Just use QOpenGLContext and save yourself from some grey hairs! No more messing around with the idiosyncrasies of various platforms to create a context that can support the OpenGL Core profile.

#QT 5.5 OPENGL 4.4 WINDOWS#

In addition to the Qt 4.8 functionality, Qt 5.0 also makes it very easy to create native windows and OpenGL contexts on any platform. This also happens to be the functionality needed by Qt Quick 2.

Qt 5.0 exposed basically the same subset of OpenGL functionality as Qt 4.8 did, which is pretty much the intersection of OpenGL 2 and OpenGL ES 2. For new code, the QOpenGL* classes from QtGui are recommended. Also, the new QOpenGL* classes can be used as direct replacements for the older QGL* classes. The reason for these changes is that the new Qt Quick 2 renderer is based upon OpenGL and so is now a core part of Qt’s graphical offerings. In addition to these, Qt also offers some helpful wrappers around other OpenGL object types such as QGLShaderProgram, QGLFramebufferObject, QGLBuffer etc.ĭuring the design of Qt 5, these QGL* classes were marked as “Done” and shiny new QOpenGL* replacements were introduced and placed directly into the QtGui library. These allow drawing with raw OpenGL or with the convenience of the QPainter API respectively. Most Qt developers are aware of QGLWidget and maybe the various incarnations of the OpenGL-based paint engines. Qt has a long history of supporting drawing with OpenGL.

#QT 5.5 OPENGL 4.4 SERIES#

Upcoming blogs in this series will describe more features and show some simple examples of how easy it is to use Qt for OpenGL development. 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 5.1 that will enhance Qt’s OpenGL support.

#QT 5.5 OPENGL 4.4 HOW TO#

This blog is the first in a series that will show how to use OpenGL with Qt 5.