OpenGL shader functions not working

[Jordan69]

Hi, i am using Qt version 5.4.1. My gpu can support OpenGL version 4.2 but functions such as glCreateShader or glCompileShader etc. do not work. Other functions such as glGenBuffers work perfectly fine. I am using QOpenGLFunctions and i have called initializeOpenGLFunctions in my initializeGL() function. I am very sorry if this is a noob question as i am new to Qt and OpenGL. Thanks!

[A Former User]

Hi Jordan69!

There is an example in the docs that shows how to use QOpenGLShaderProgram: http://doc.qt.io/qt-5/qtquick-scenegraph-openglunderqml-example.html

Hope that helps :-)

[Jordan69]

@Wieland

Thanks ill check it out!

[Jordan69]

@Wieland

Ok I got a question, with QOpenGLShaderProgram, all I have to do is add the header right?

[A Former User]

@Jordan69 Yes:

#include <QtGui/QOpenGLShaderProgram>

[Jordan69]

@Wieland

Thank you so much Wieland.

[Jordan69]

@Wieland

Am I meant to put shaders in a specific function like initializeGL?

[A Former User]

@Jordan69 No, you can compile your shaders and link them whenever you need them. But keep in mind that your shaders are compiled by the GPU at runtime. So, compilation takes time and you can't afford to do this everytime you render a single frame. Thus it's wise to have some init function that is called only on startup or when you need to make changes to your shader program(s).