love2d gaussian blur test

main.lua

local graphics = love.graphics

function love.load()

	local program = ([[
		const float kernel[5] = float[](0.2270270270, 0.1945945946, 0.1216216216, 0.0540540541, 0.0162162162);
		vec4 effect(vec4 color, sampler2D tex, vec2 tex_coords, vec2 pos) {
			color = texture2D(tex, tex_coords) * kernel[0];
			for(int i = 1; i < 5; i++) {
				color += texture2D(tex, vec2(tex_coords.x + i * %f, tex_coords.y)) * kernel[i];
				color += texture2D(tex, vec2(tex_coords.x - i * %f, tex_coords.y)) * kernel[i];
			}
			return color;
		}
	]]):format(1 / graphics.getWidth(), 1 / graphics.getWidth())
	fx = graphics.newPixelEffect(program)

	local program = ([[
		const float kernel[5] = float[](0.2270270270, 0.1945945946, 0.1216216216, 0.0540540541, 0.0162162162);
		vec4 effect(vec4 color, sampler2D tex, vec2 tex_coords, vec2 pos) {
			color = texture2D(tex, tex_coords) * kernel[0];
			for(int i = 1; i < 5; i++) {
				color += texture2D(tex, vec2(tex_coords.x, tex_coords.y + i * %f)) * kernel[i];
				color += texture2D(tex, vec2(tex_coords.x, tex_coords.y - i * %f)) * kernel[i];
			}
			return color;
		}
	]]):format(1 / graphics.getHeight(), 1 / graphics.getHeight())
	fy = graphics.newPixelEffect(program)


	print(fx:getWarnings())
	print(fy:getWarnings())


	canvas_x = graphics.newCanvas(graphics.width, graphics.height)
	canvas_y = graphics.newCanvas(graphics.width, graphics.height)
end

t = 0

function love.draw()
	t = t + 0.02
	local x = 400 + math.sin(t) * 400
	local y = 300 + math.sin(t * 0.8) * 300


	graphics.setCanvas(canvas_x)
	graphics.push()
	graphics.translate(x, y)
	graphics.rotate(t * 1.3)
	graphics.rectangle("fill", -10, -50, 20, 100)
	graphics.pop()


	graphics.setPixelEffect(fx)
	graphics.setCanvas(canvas_y)
	graphics.draw(canvas_x, 0, 0)

	graphics.setPixelEffect(fy)
	graphics.setCanvas(canvas_x)
	graphics.draw(canvas_y, 0, 0)

	graphics.setPixelEffect()
	graphics.setCanvas()
	graphics.draw(canvas_x, 0, 0)
end