Does GL shader support really work?

[Caius Aérobus]

As far as I know, this code should work:

void
MyClass::draw()
{
  if (this->pshader->isLinked()) {
    int val_loc = this->pshader->attributeLocation("val");
    this->pshader->setUniformValue(val_loc, (GLfloat)1.0);
  }
  // OpenGL stuff
}

void
MyClass::draw()
{
  if (this->pshader->isLinked()) {
    int val_loc = this->pshader->attributeLocation("val");
    this->pshader->setUniformValue(val_loc, (GLfloat)1.0);
  }
  // OpenGL stuff
}

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Vertex shader:

uniform float val;
 
varying float new_val;
 
void main()
{
  new_val = val;
  gl_Position = ftransform();
}

uniform float val;

varying float new_val;

void main()
{
  new_val = val;
  gl_Position = ftransform();
}

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Fragment shader:

varying float new_val;
 
void main()
{
  if (new_val < 0.5)
    gl_FragColor = vec4(1.0,0.0,0.0,1.0);
  else
    gl_FragColor = vec4(0.0,0.0,1.0,1.0);
}

varying float new_val;

void main()
{
  if (new_val < 0.5)
    gl_FragColor = vec4(1.0,0.0,0.0,1.0);
  else
    gl_FragColor = vec4(0.0,0.0,1.0,1.0);
}

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but my object appears red...

[Caius Aérobus]

I tested the shader code by using the "classical" OpenGL functions to include it in OpenGL stuff and it works well, my object appearing blue as expected.
So I suspect there is really an issue with Qt integration of GLSL!

[wysota]

Where did you put this code? What is the superclass of MyClass?

[Caius Aérobus]

I fixed the problem: get attribute location and set uniform value!!!
My apologizes!
You can delete this thread now, at your convenience.