SFML Game Development [Parameter <name> was not found in shader]

[FreezingEngine]

Hey Guys,
i have a problem with the shader-class of the book in the topic.
I receive only this output:



This is one shader:

uniform sampler2D       source;
uniform vec2            offsetFactor;

void main()
{
        vec2 textureCoordinates = gl_TexCoord[0].xy;
        vec4 color = vec4(0.0);
        color += texture2D(source, textureCoordinates - 4.0 * offsetFactor) * 0.0162162162;
        color += texture2D(source, textureCoordinates - 3.0 * offsetFactor) * 0.0540540541;
        color += texture2D(source, textureCoordinates - 2.0 * offsetFactor) * 0.1216216216;
        color += texture2D(source, textureCoordinates - offsetFactor) * 0.1945945946;
        color += texture2D(source, textureCoordinates) * 0.2270270270;
        color += texture2D(source, textureCoordinates + offsetFactor) * 0.1945945946;
        color += texture2D(source, textureCoordinates + 2.0 * offsetFactor) * 0.1216216216;
        color += texture2D(source, textureCoordinates + 3.0 * offsetFactor) * 0.0540540541;
        color += texture2D(source, textureCoordinates + 4.0 * offsetFactor) * 0.0162162162;
        gl_FragColor = color;
}

I have copied the code for the effect class out of the book.

Sorry for my bad english.

[HavingPhun]

I have very little experience with shaders, though I doubt we will be able to know what is wrong unless you post some of your code and the vertex shader.

[Rhimlock]

As far as I know. GLSL throws away unused variables.
So even if you have a variable in your shader-source, it might be missing at runtime, if it is not used.

[Grimshaw]

Looking at diagonally, the code seems correct, are you sure the shader is successfully being compiled?