uniform sampler2D inputImageTexture;
uniform sampler2D noiseTexture;
varying vec2 textureCoordinate;

uniform  float time;

float noise(vec2 p)
{
    float s = texture2D(noiseTexture,vec2(1.,2.*cos(time))*time*8. + p*1.).x;
    s *= s;
    return s;
}

float onOff(float a, float b, float c)
{
    return step(c, sin(time + a*cos(time*b)));
}

float ramp(float y, float start, float end)
{
    float inside = step(start,y) - step(end,y);
    float fact = (y-start)/(end-start)*inside;
    return (1.-fact) * inside;
}

float stripes(vec2 uv)
{
    float noi = noise(uv*vec2(0.5,1.) + vec2(1.,3.));
    return ramp(mod(uv.y*4. + time/2.+sin(time + sin(time*0.63)),1.),0.5,0.6)*noi;
}

vec3 getVideo(vec2 uv)
{
    vec2 look = uv;
    float window = 1./(1.+20.*(look.y-mod(time/4.,1.))*(look.y-mod(time/4.,1.)));
    look.x = look.x + sin(look.y*10. + time)/50.*onOff(4.,4.,.3)*(1.+cos(time*80.))*window;
    float vShift = 0.4*onOff(2.,3.,.9)*(sin(time)*sin(time*20.) +
                                        (0.5 + 0.1*sin(time*200.)*cos(time)));
    look.y = mod(look.y + vShift, 1.);
    vec3 video = vec3(texture2D(inputImageTexture,look));
    return video;
}

vec2 screenDistort(vec2 uv)
{
    uv -= vec2(.5,.5);
    uv = uv*1.2*(1./1.2+2.*uv.x*uv.x*uv.y*uv.y);
    uv += vec2(.5,.5);
    return uv;
}

void main()
{
    vec2 uv = textureCoordinate;
    uv = screenDistort(uv);
    vec3 video = getVideo(uv);
    float vigAmt = 3.+.3*sin(time + 5.*cos(time*5.));
    float vignette = (1.-vigAmt*(uv.y-.5)*(uv.y-.5))*(1.-vigAmt*(uv.x-.5)*(uv.x-.5));
    
    video += stripes(uv);
    video += noise(uv*2.)/2.;
    video *= vignette;
    video *= (12.+mod(uv.y*30.+time,1.))/13.;
    
    gl_FragColor = vec4(video,1.0);   
}