Light shader

gistfile1.txt

- (NSString *)getFragmentShaderString
{
    NSString *const kFragmentShaderString = SHADER_STRING
    (
     varying highp vec2 textureCoordinate;

     uniform sampler2D inputImageTexture;

     void main()
     {
         highp vec2 position = -1.0 + 2.0 * textureCoordinate.xy;
         highp float dist = length(position);

         highp float x = sin(atan(position.y, position.x) * 15.0 + sin(0.01) * dist * 6.0);

         highp vec3 brightColor = vec3(1.0, 1.0, 1.0);
    
         gl_FragColor = vec4(brightColor * x, 1.0);
     }
     
     );

    return kFragmentShaderString;
}