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c++openglglslfragment-shaderopengl-4

WARN: Variable cannot be bound (it either doesn't exist or has been optimized away)

I am trying to pass a variable timeVar (a float initially set to 0.0) that changes in my display() method with the line 

timeVar = time(0);

to my fragment shader. Then I do this 

safe_glUniform1f(h_uTime, timeVar);

and pass it to my shader program like so

h_uTime = safe_glGetAttribLocation(h_program, "uTime");

But I keep getting this error. Please help!

WARN: uTime cannot be bound (it either doesn't exist or has been optimized 
away). safe_glAttrib calls will silently ignore it.
Solution

  • Since uTime is a uniform and not an attribute, using glGetAttribLocation will always result in an error. One has to use glGetUniformLocation instead.