rolling-shutter.shadron

#include <math_constants>
#include <multisample>

const int SIZE = 480;

param int SAMPLES = 3 : logrange(1, 16);
param float RPM = 60 : logrange(1, 10000);
param float shutterDelay;

glsl float spinner(vec2 pos, float rotation) {
    float r = length(pos);
    float a = atan(-pos.y, pos.x)-rotation;
    float t = max(0.5+0.5*sin(3.0*a), 0.1875);
    return step(0.125, r)-step(t, r);
}

glsl vec4 rollingShutter(vec2 p) {
    float rowTime = shadron_Time+(0.5-p.y)*shutterDelay;
    float angle = TAU/60.0*RPM*rowTime;
    float fill = spinner(1.0625*(2.0*p-1.0), angle);
    return vec4(vec3(1.0-0.8375*fill), 1.0);
}

animation RollingShutter = glsl(multisample<rollingShutter, SAMPLES>, SIZE);