Important: Please read the Qt Code of Conduct -

An question about using different version of GLSL in QtOpenGL

  • Recently I am using shadering language of OpenGL and I try to use QtOpenGL ,however,the default version of GLSL in QtOpenGL is ES2.0 (QOpenGLShaderProgram) , its grammar is a little different from other versions .Could I just use GLSL in other version like 3.30 becauese I couldn't compile the following shader:

    static const char *vertexShaderSource2=
            "#version 330\n"
            "layout (location = 0) in vec3 a_pos;\n"
            "layout (location = 1) in vec3 a_normal;\n"
            "layout (location = 2) in vec2 a_uv;\n"
            "uniform float u_linewidth;\n"
            "uniform mat4  modelViewMatrix;\n"
            "uniform mat4  projectionMatrix;\n"
            "out vec2 uv;\n"
            "void main() {\n"
                "vec4 delta = vec4(a_normal * u_linewidth/2, 0);\n"
                "vec4 pos   = modelViewMartrix * vec4(a_pos ,1);\n"
                    "gl_Position = projectionMatrix * (pos +delta) ;\n"
                "uv = a_uv;\n"
    static const char *fragmentShaderSource2 =
            "#version 330\n"
            "uniform vec4 u_color;\n"
            "uniform sampler2D u_sampler;\n"
            "in vec2 uv;\n"
            "void main() {\n"
                "gl_FragColor = texture(u_sampler, uv) + vec4(u_color.rgb, 0);\n"

    But the compiler shows

    So how can I use other version GLSL correctly?

    Here is the shader example which is compiled correctly:

    static const char *vertexShaderSource =
        "attribute highp vec4 posAttr;\n"
        "attribute lowp vec4 colAttr;\n"
        "varying lowp vec4 col;\n"
        "uniform highp mat4 matrix;\n"
        "void main() {\n"
        "   col = colAttr;\n"
        "   gl_Position = matrix * posAttr;\n"
    static const char *fragmentShaderSource =
        "varying lowp vec4 col;\n"
        "void main() {\n"
        "   gl_FragColor = col;\n"

  • Hi @MartinChan-0

    Assuming you derive from QOpenGlWidget, you can use QSurfaceFormat to set the OpenGL version and so indirectly the shader langauge in your class's constructor. There are functions like setMajorVersion, setMinorVersion, etc. You are right, without this the default is OpenGL 2.0 and its corresponding shader language.

    	QSurfaceFormat format;


  • @m.sue Thx !Now I can compile ~

Log in to reply