Collision Detection in love2d(lua) - lua

Question

I am doing a game development course by cs50 where Colton Ogden teaches love2d which is in lua. I am facing a problem in collision detection. The below code/logic works fine when the object is not rotating example love.graphics.draw(texture, x, y, r).
Here x and y is some value and r(rotation is 0). Value of x and y keeps on changing.
function Projectile:collides(target)
if self.x > target.x + target.width or target.x > self.x + self.width then
return false
end
if self.y > target.y + target.height or target.y > self.y + self.height then
return false
end
return true
end
But the above code doesn't work for target which is rotating i.e., r has some value which keeps on changing.
Below is how i am rotating an object.
function Meteor:init(speed)
self.r = math.random(-1, 1)
end
function Meteor:update(dt)
if self.r > 0 then
self.r = self.r + math.pi/9 * dt
elseif self.r < 0 then
self.r = self.r - math.pi/9 * dt
else
self.r = self.r
end
if self.y < VIRTUAL_HEIGHT + 110 then
self.y = self.y + self.speed * dt
else
self.remove = true
end
end
function Meteor:render()
love.graphics.drawLayer(self.meteor, self.type, self.x, self.y, self.r)
end

Answer 1

Sometimes it is easier and sufficient to just approximate an object's collision. In LÖVE you can specify the texture offset in love.graphics.draw(). Let the texture rotate at its center and see if an approximation works.
If you really need rectangles, which are not axis aligned, you may want to use a collision library. HardonCollider works perfect.
If you plan on adding physics too, then the LÖVE physics module makes more sense.

Answer 2

As #Luke100000 wrote LÖVE has already a collision detection in love.physics implemented.
Read and try: https://love2d.org/wiki/Tutorial:PhysicsCollisionCallbacks
For a zero gravity world i use for example...
function love.load()
local meter=4.5
love.physics.setMeter(meter)
ZeroGravity=love.physics.newWorld(0,0,true)
ZeroGravity:setCallbacks(Hit,Release,preSolve,postSolve) -- <Collision Callbacks>
end
And for example the "Hit" callback function...
-- <Collision Callback Functions>
Hit=function(a,b)
a:getBody():setUserData(os.date('%H:%M:%S'))
b:getBody():setUserData(os.date('%H:%M:%S'))
a:getUserData():emit(256)
b:getUserData():emit(256)
return true
end
The particlesystem that emitting 256 parts at "Hit" is assigned to the fixture in userdata of an physics body at creation...
function addAsteroid(x,y,r,kind)
local body=love.physics.newBody(ZeroGravity,x,y,kind)
local shape=love.physics.newCircleShape(r)
local fixture=love.physics.newFixture(body,shape,.01)
fixture:setUserData(psystem:clone()) -- Particlesystem for emitting
fixture:setDensity(1)
fixture:setFriction(1)
fixture:setRestitution(1)
--fixture:setFilterData(1,1,-1)
fixture:getUserData():start()
return body
end
A particle system can be very complex but it is worth for learning it.
Here i give you an example of mine that works with quads...
-- planets.lua
fields=1
quads={love.graphics.newImage("planets.png")
}
local assets={x=0,y=0,size=.1,time=-1,
[1]=love.graphics.newQuad(138,33,300,300,quads[1]:getDimensions()),
[2]=love.graphics.newQuad(505,37,300,300,quads[1]:getDimensions()),
[3]=love.graphics.newQuad(871,21,300,300,quads[1]:getDimensions()),
[4]=love.graphics.newQuad(1238,22,300,300,quads[1]:getDimensions()),
[5]=love.graphics.newQuad(1606,15,300,300,quads[1]:getDimensions()),
[6]=love.graphics.newQuad(1974,11,300,300,quads[1]:getDimensions()),
[7]=love.graphics.newQuad(1976,349,300,300,quads[1]:getDimensions()),
[8]=love.graphics.newQuad(136,382,300,300,quads[1]:getDimensions()),
[9]=love.graphics.newQuad(504,379,300,300,quads[1]:getDimensions()),
[10]=love.graphics.newQuad(871,366,300,300,quads[1]:getDimensions()),
[11]=love.graphics.newQuad(1236,362,300,300,quads[1]:getDimensions()),
[12]=love.graphics.newQuad(19,724,300,300,quads[1]:getDimensions()),
[13]=love.graphics.newQuad(1047,698,300,300,quads[1]:getDimensions()),
[14]=love.graphics.newQuad(1376,687,300,300,quads[1]:getDimensions()),
[15]=love.graphics.newQuad(1721,686,300,300,quads[1]:getDimensions()),
[16]=love.graphics.newQuad(2042,684,300,300,quads[1]:getDimensions()),
[17]=love.graphics.newQuad(347,704,660,300,quads[1]:getDimensions())
}
pquads={x=0,y=0,size=1,time=-1}
for i=12,12 do table.insert(pquads,assets[i]) end -- recall
assets=empty
psystem=love.graphics.newParticleSystem(quads[1],72)
psystem:setBufferSize(4096)
psystem:setLinearAcceleration(-150,-150,150,150) -- Random movement in all directions.
psystem:setEmissionArea('ellipse',145,145,math.rad(math.random(360)),false)
psystem:setQuads(pquads)
psystem:setSpread(75)
--[[psystem:setColors({love.math.random(),
love.math.random(),
love.math.random(),
0.3},{love.math.random(),
love.math.random(),
love.math.random(),
0.6},{love.math.random(),
love.math.random(),
love.math.random(),
0.3})]]--
--psystem:setColors({1,0,0,1},{0,0,1,1},{1,0,0,1})
--psystem:setColors({0,0,1,1},{1,1,1,1},{1,1,0,1},{1,0,0,1})
psystem:setSizes(math.random()*.05,0)
--psystem:setSizes(.1,.2,.3,.4,.3,.2,.1)
psystem:setSizeVariation(0)
psystem:setEmitterLifetime(pquads.time)
psystem:setParticleLifetime(pquads.size*11)
psystem:setEmissionRate(pquads.size*.11)
psystem:setInsertMode('top')
-- psystem:setPosition(-150,-150)
The assets i am using i get from...
https://opengameart.org/art-search?keys=planets