Some shader fooling. Copied a bunch of it from tuts/samples

moving-triangles.glsl

#define PI 3.14159265359
#define TWO_PI 6.28318530718

//POLYGON FUNCTION
float polygon(vec2 uv, vec2 pos, float size, float blur, int sides){
    uv = uv-pos;
    //Angle and radius of polygon
    float angle = atan(uv.x,uv.y)+PI;
    float rad = TWO_PI/float(sides);
    float dist = cos(floor(0.5+angle/rad)*rad-angle)*length(uv);
    float poly = smoothstep(size, size-blur, dist);
    poly -= smoothstep(size*0.9, size*0.9-blur, dist);
    return poly;
}

void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
    // Normalized pixel coordinates (from 0 to 1)
    vec2 uv = fragCoord.xy/iResolution.xy;
    uv.x = uv.x;
    uv.x *= iResolution.x / iResolution.y;
    
    // Time varying pixel color
    vec3 col = 0.5 + 0.5*cos(iTime+uv.xyx+vec3(0,2,4));

    // Output to screen
    fragColor = vec4(col,1.0);
    
    
    vec2 tri1 = vec2(0.5, 0.5);
    
    vec2 rot = vec2(sin(iTime), cos(iTime))/10.0;
    uv += rot;
	fragColor += polygon(uv, tri1, 0.1, 0.001, 3);
    fragColor += polygon(uv, tri1 + vec2(0.5, 0), 0.1, 0.001, 3);
    fragColor += polygon(uv, tri1 + vec2(0.4, 0), 0.1, 0.001, 3);
    fragColor += polygon(uv, tri1 + vec2(0.9, 0.2), 0.1, 0.001, 3);
    fragColor += polygon(uv, tri1 + vec2(-0.2, -0.3), 0.1, 0.001, 3);
    fragColor += polygon(uv, tri1 + vec2(-0.35, 0.4), 0.1, 0.001, 3);
    fragColor += polygon(uv, tri1 + vec2(0.5, 0.5), 0.1, 0.001, 3);
    
    
}