gistfile1.txt

local framebuffer1 = love.graphics.newCanvas();
local framebuffer2 = love.graphics.newCanvas();
local framebuffer3 = love.graphics.newCanvas();

local pos = {x = 20,y = 20}
local drawLines = true 
local effect = fishEye 

local barrel
local blur
local fishEye

function love.load()
  barrel = love.graphics.newPixelEffect [[
		vec2 distort(vec2 p)
		{
			const float barrelPower = 1.05;

			float theta = atan(p.y,p.x);
			float radius = length(p);
			radius = pow(radius,barrelPower);

			p.x = radius * cos(theta);
			p.y = radius * sin(theta);

			return 0.5 * (p + 1.0);
		}

		vec2 distort2(vec2 p)
		{
			const float ax = 0.01;
			const float ay = 0.01;

			float len = length(p);
			float len2 = len*len;

			float xx = len/(1.0 - ax * len2);
			float yy = len/(1.0 - ay * len2);

			return ( p / vec2(1.0-ax*xx*xx,1.0-ay*yy*yy)+1) * 0.5;
		}

		vec4 effect(vec4 color, Image tex,vec2 tc,vec2 pc)
		{
			mat3 forwardTransform = mat3(	2.0,0.0,-1.0,
											0.0,2.0,-1.0,
											0.0,0.0, 0.0);

			mat3 backwardTransform = mat3(	0.5,0.0,1.0,
											0.0,0.5,1.0,
											0.0,0.0,0.0);
			vec2 coord = (vec3(tc,1.0) * forwardTransform).xy;
			coord = distort(coord);
			//coord = (backwardTransform * vec3(coord,1.0)).xy;
			return texture2D(tex,coord);

			//return texture2D(texture,clamp(distort(tc),0.0,1.0));
		}
	]]

	blur = love.graphics.newPixelEffect [[
		extern float blurSize;
		extern float fade;

		vec4 effect(vec4 color,Image tex,vec2 tc,vec2 pc)
		{
			vec4 sum = vec4(0.0);

			sum += (texture2D(tex,vec2(tc.x - 4.0*blurSize,tc.y)) * 0.05 ) - fade;
			sum += (texture2D(tex,vec2(tc.x - 3.0*blurSize,tc.y)) * 0.09 ) - fade;
			sum += (texture2D(tex,vec2(tc.x - 2.0*blurSize,tc.y)) * 0.12 ) - fade;
			sum += (texture2D(tex,vec2(tc.x - 1.0*blurSize,tc.y)) * 0.15 ) - fade;

			sum += (texture2D(tex,vec2(tc.x,tc.y)) * 0.181 ) - fade;

			sum += (texture2D(tex,vec2(tc.x + 4.0*blurSize,tc.y)) * 0.05 ) - fade;
			sum += (texture2D(tex,vec2(tc.x + 3.0*blurSize,tc.y)) * 0.09 ) - fade;
			sum += (texture2D(tex,vec2(tc.x + 2.0*blurSize,tc.y)) * 0.12 ) - fade;
			sum += (texture2D(tex,vec2(tc.x + 1.0*blurSize,tc.y)) * 0.15 ) - fade;

			sum.a = 1.0;

			return sum * color;// + vec4(0.1,0.1,0.1,0.1);
		}
	]]

	fishEye = love.graphics.newPixelEffect [[
	
		float aperture = 180.0;
		const float PI = 3.1415926535;
	
		vec4 effect(vec4 color,Image texture,vec2 tc,vec2 sc) 
		{
			//Pass throught what ever the current texel is
			//return texture2D(texture,tc);
		
			float apertureHalf = 0.5 * aperture * (PI/180);	

			float maxFactor = sin(apertureHalf);

			vec2 pos = 2.0 * tc.st - 1.0;

			float len = length(pos);
			if(len > 1.0) {
				return vec4(0.0,0.4,0.0,1.0);
			} else { 	
				float x = maxFactor * pos.x;
				float y = maxFactor * pos.y;

				float n = length(vec2(x,y));
	
				float z = sqrt(1.0 - n * n);
	
				float r = atan(n,z) / PI;
	
				float phi = atan(y,x);

				float u = r * cos(phi) + 0.5;
				float v = r * sin(phi) + 0.5;

				return texture2D(texture,vec2(u,v));
			}
		}
	]]
	
	effect = barrel 
end


function love.draw()
	love.graphics.setPixelEffect()
	love.graphics.setCanvas(framebuffer1)
	love.graphics.draw(framebuffer2)

----------------- Draw Stuff --------------------
	love.graphics.push();
	love.graphics.translate(pos.x,pos.y)

	love.graphics.setColor(0,255,0)
	
	--Draw a triangle
	love.graphics.line(0,0,10,0)
	love.graphics.line(10,0,5,20)
	love.graphics.line(5,20,0,0)

	love.graphics.pop();
	love.graphics.print("Hello world",100,200)


----------------- Draw some lines ---------------

if drawLines then
	for var=0,600,50 do
		love.graphics.push()
		love.graphics.translate(0,var)
		love.graphics.line(0,0,800,0);
		love.graphics.pop()
	end

	for var=0,800,50 do
		love.graphics.push()
		love.graphics.translate(var,0)
		love.graphics.line(0,0,0,600);
		love.graphics.pop()
	end
end
-------------------------------------------------

	love.graphics.setCanvas(framebuffer2)
	love.graphics.setPixelEffect(blur)
	blur:send('fade',0.01);
	blur:send('blurSize',1/4096);
	love.graphics.draw(framebuffer1)

	love.graphics.setCanvas()
	love.graphics.setPixelEffect(blur)
	blur:send('fade',0.0);
	blur:send('blurSize',1/4096);
	love.graphics.draw(framebuffer2)

------- Third Rendering Pass for Ctr Effect------
	love.graphics.setCanvas(framebuffer3)
	love.graphics.setPixelEffect(effect)
	love.graphics.draw(framebuffer2)
-------------------------------------------------

-- FINALLY draw to the real screen
	love.graphics.setCanvas()
	love.graphics.draw(framebuffer3)
end

function love.update(dt)
	pos["x"] = pos["x"]+(dt*10)
	pos["y"] = pos["y"]+(dt*10)
end