# File:world raycast callback example.png

Size of this preview: 768 × 599 pixels. Other resolution: 308 × 240 pixels.
Original file ‎(806 × 629 pixels, file size: 41 KB, MIME type: image/png)

A screenshot of a World:rayCast example for LÖVE 0.8.0.

    function worldRayCastCallback(fixture, x, y, xn, yn, fraction)
    	local hit = {}
    	hit.fixture = fixture
    	hit.x, hit.y = x, y
    	hit.xn, hit.yn = xn, yn
    	hit.fraction = fraction

    	table.insert(Ray.hitList, hit)

    	return 1 -- Continues with ray cast through all shapes.
    end

    function createStuff()
    	-- Cleaning up the previous stuff.
    	for i = 1, #Terrain.Stuff do
    		Terrain.Stuff[i].Fixture:destroy()
    		Terrain.Stuff[i] = nil
    	end

    	-- Generates some random shapes.
    	for i = 1, 30 do
    		local p = {}

    		p.x, p.y = math.random(100, 700), math.random(100, 500)
    		local shapetype = math.random(3)
    		if shapetype == 1 then
    			local w, h, r = math.random() * 10 + 40, math.random() * 10 + 40, math.random() * math.pi * 2
    			p.Shape = love.physics.newRectangleShape(p.x, p.y, w, h, r)
    		elseif shapetype == 2 then
    			local a = math.random() * math.pi * 2
    			local x2, y2 = p.x + math.cos(a) * (math.random() * 30 + 20), p.y + math.sin(a) * (math.random() * 30 + 20)
    			p.Shape = love.physics.newEdgeShape(p.x, p.y, x2, y2)
    		else
    			local r = math.random() * 40 + 10
    			p.Shape = love.physics.newCircleShape(p.x, p.y, r)
    		end

    		p.Fixture = love.physics.newFixture(Terrain.Body, p.Shape)

    		Terrain.Stuff[i] = p
    	end
    end

    function love.keypressed()
    	createStuff()
    end

    function love.load()
    	-- Setting this to 1 to avoid all current scaling bugs.
    	love.physics.setMeter(1)

    	-- Start out with the same random stuff each start.
    	math.randomseed(0xfacef00d)

    	World = love.physics.newWorld()

    	Terrain = {}
    	Terrain.Body = love.physics.newBody(World, 0, 0, "static")
    	Terrain.Stuff = {}
    	createStuff()

    	Ray = {
    		x1 = 0,
    		y1 = 0,
    		x2 = 0,
    		y2 = 0,
    		hitList = {}
    	}
    end

    function love.update(dt)
    	local now = love.timer.getMicroTime()

    	World:update(dt)

    	-- Clear fixture hit list.
    	Ray.hitList = {}

    	-- Calculate ray position.
    	local pos = (math.sin(now/4) + 1.2) * 0.4
    	Ray.x2, Ray.y2 = math.cos(pos * (math.pi/2)) * 1000, math.sin(pos * (math.pi/2)) * 1000

    	-- Cast the ray and populate the hitList table.
    	World:rayCast(Ray.x1, Ray.y1, Ray.x2, Ray.y2, worldRayCastCallback)
    end

    function love.draw()
    	-- Drawing the terrain.
    	love.graphics.setColor(255, 255, 255)
    	for i = 1, #Terrain.Stuff do
    		if Terrain.Stuff[i].Shape:getType() == "polygon" then
    			love.graphics.polygon("line", Terrain.Body:getWorldPoints( Terrain.Stuff[i].Shape:getPoints() ))
    		elseif Terrain.Stuff[i].Shape:getType() == "edge" then
    			love.graphics.line(Terrain.Body:getWorldPoints( Terrain.Stuff[i].Shape:getPoints() ))
    		else
    			local x, y = Terrain.Body:getWorldPoints(Terrain.Stuff[i].x, Terrain.Stuff[i].y)
    			love.graphics.circle("line", x, y, Terrain.Stuff[i].Shape:getRadius())
    		end
    	end

    	-- Drawing the ray.
    	love.graphics.setLineWidth(3)
    	love.graphics.setColor(255, 255, 255, 100)
    	love.graphics.line(Ray.x1, Ray.y1, Ray.x2, Ray.y2)
    	love.graphics.setLineWidth(1)

    	-- Drawing the intersection points and normal vectors if there were any.
    	for i = 1, #Ray.hitList do
    		local hit = Ray.hitList[i]
    		love.graphics.setColor(255, 0, 0)
    		love.graphics.print(i, hit.x, hit.y)				-- print point№...
    		love.graphics.circle("line", hit.x, hit.y, 3)
    		love.graphics.setColor(0, 255, 0)
    		love.graphics.line(hit.x, hit.y, hit.x + hit.xn * 25, hit.y + hit.yn * 25)
    	end
    end

## File history

Click on a date/time to view the file as it appeared at that time.

| Date/Time | Thumbnail | Dimensions | User | Comment

- You cannot overwrite this file.

## File usage

The following page links to this file:

- World:rayCast