GLSL Shader not compiling (Android & LibGDX) and no log available

Question

I'm trying to get a "ripple"-shader working for OpenGL ES 2.0+ (using LibGDX).

However, I can't get it to compile, and for some reason ShaderProgram.getLog() returns an empty string even though the Shader didn't compile.

I am 100% confident that the vertex shader is correct.. here's the fragment shader (not written by me, but I modified it a bit long time ago.. when I had a desktop project - and it worked back then):

                #version 120
                precision mediump float;
                varying vec2 v_texCoords;
                uniform float time;
                uniform float alpha;
                uniform float waveLengthMultiplier;
                uniform sampler2D u_texture;
                void main()
                {
                    vec2 center = vec2(0.5, 0.5);
                    vec2 tc = v_texCoords.xy;
                    vec2 p = -1.0 + 2.0 * (tc - offset);
                    float len = length(p) * waveLengthMultiplier;
                    vec2 uv = tc + (p / len) * cos(len * 12.0 - time * 4.0) * 0.03;
                    vec3 col = texture2D(u_texture, uv).xyz;
                    gl_FragColor = vec4(col, alpha);
                }

I'm still not very well-versed with shaders, as I've used them only a little.. Like I said, getLog() returns an empty string, so I'm hoping someone spots an error in the code.

Answer 1

"offset" is not declared. Not sure why it would compile anywhere else, I doubt it.