// demo10.cpp
uniform = glGetUniformLocation(ss->m_activeShader->m_programObject, "CameraPosition");
    glUniformMatrix3fv(uniform, 1, GL_FALSE, (float*)&ss->m_activeCamera->getPosition()[0]);

// shader
float GetTessLevel(float distance0, float distance1)
{
    //3. some logic based on distances
    float avgDst = (distance0 + distance1) / 2.0f;
    if(avgDst > 0.5){
        return 1;
    }else if(avgDst > 0.2){
        return 2;
    }else{
        return 3;
    }
}

float d0 = distance(CameraPosition, wcPosition[0]);
gl_TessLevelOuter[0] = GetTessLevel(d1, d2);