frei0r 过了好几年增加 aech0r 滤镜

register_param(factor, "Fade Factor", "Disappearance rate of the echo"); // 0 No fade, 1 No Trace
register_param(bright, "Direction", "Darker or Brighter echo"); // Add or Substract data
register_param(flag_r, "Keep RED", "Influence on Red channel"); // 0 Fade canal, 1 Keep canal data
register_param(flag_g, "Keep GREEN", "Influence on Green channel"); // 0 Fade canal, 1 Keep canal data
register_param(flag_b, "Keep BLUE", "Influence on Blue channel"); // 0 Fade canal, 1 Keep canal data
register_param(strobe_period, "Strobe period", "Rate of the stroboscope: from 0 to 8 frames");

factor = 0.15; // Quasi full echo has default
bright = false; // Dark mode has default    
flag_r = false; // No RGB flag has default
flag_g = false;
flag_b = false;
strobe_period = 0; // No strobe has default

f0r_param_double factor;
f0r_param_bool bright;
f0r_param_bool flag_r;
f0r_param_bool flag_g;
f0r_param_bool flag_b;
f0r_param_double strobe_period;