pipboy.txt

uniform shader iChunk;
uniform float iFrame;

//2D normalized hash function (returns a random unit vector)
half2 hash2_norm(half2 p)
{
	return normalize(fract(cos(p*float2x2(12.98,78.37,69.42,13.14))*3956.4)-0.5);
}

half4 main(float2 xy)
{
	//Intensity of scanline effect
	const half SCANLINE_INTENSITY = 0.2;
	//Scanline width in pixels
	const half SCANLINE_WIDTH = 2;
	//Scanline endpoint (should be between P1 and 1)
	const half SCANLINE_P0 = 1;
	//Scanline startpoint (should be between 0 and 1)
	const half SCANLINE_P1 = 0.2;
	
	//Intensity of pulsing animation
	const half PULSE_INTENSITY = 0.02;
	//Pulse width in pixels (times tau)
	const float PULSE_WIDTH = 100;
	//Pulse animation speed
	const float PULSE_RATE = 40;
	
	//Bloom parameters:
	//Radius multiplier
	const float RADIUS = 4;
	//Number of blur samples. More samplers = smoother but costlier
	const float SAMPLES = 32;
	
	//Oscillate between -1 and +1 for scanlines
	half scanline_ridge = abs(mod(xy.y/SCANLINE_WIDTH,2)-1);
	//Compute scanline value with approximate average of 1.
	half scanline = smoothstep(SCANLINE_P0, SCANLINE_P1, scanline_ridge) + 0.5;
	//Dampen scanline intensity amount
	scanline = mix(1, scanline, SCANLINE_INTENSITY);
	
	//Initialize glow average and total weight
	half2 bloom = half2(0);
	
	//Start with a random sample point
	float2 point = hash2_norm(xy)*RADIUS;
	//Golden angle rotation matrix (look up Fibonacci or Vogel disks)
	const float2x2 rot = float2x2(-0.737369, 0.675490, -0.675490, -0.737369);
	
	//Iterate through samples
	for(float i = 0; i<SAMPLES; i++)
	{
		//Rotate sample point
		point *= rot;
		//Add gamma-encoded sample and diminish edges
		bloom += half2(smoothstep(.3,.7,iChunk.eval(xy+point*sqrt(i)).g),1)/sqrt(i+.01);
	}
	half4 color = half4(1);
	color.rgb = bloom[0] / bloom[1] * half3(.2,1,.3);
	color.rgb *= PULSE_INTENSITY*cos(xy.x/PULSE_WIDTH+iFrame*PULSE_RATE) + scanline;
	//Average samples and decode gamma
	return color;
}