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Map isn't scaling properly with lighting

Posted: Wed Aug 23, 2023 10:49 pm
by Sammm
Hello! I'm using the lighworld library for lighting, as seen here: https://github.com/tanema/light_world.lua

I followed the example code very closely, and the lights work my map at a scaling of 1 (e.g. no scaling at all), but when I try to scale the map up to 2, the light appears offset improperly with the map. This is my `main.lua` code:

Code: Select all

local Camera = require("lib.camera")
local map = require("scripts.map")

local LightWorld = require("lib.lightworld")

function love.load()
    love.graphics.setBackgroundColor(love.math.colorFromBytes(41, 45, 65))

    love.physics.setMeter(64)
    world = love.physics.newWorld(0, 9.81*64, true)

    windowWidth = love.graphics.getWidth()
    windowHeight = love.graphics.getHeight()

    lightWorld = LightWorld({
        ambient = {0.21, 0.21, 0.21},
    })

    lightMouse = lightWorld:newLight(0, 0, 1, 0.49, 0.24, 300)
    lightMouse:setGlowStrength(0.3)

    map:load()
end

function love.update(dt)
    if love.keyboard.isDown('escape') then love.event.quit() end

    lightWorld:update(dt)
    lightWorld:setTranslation(0, 0, map.scale)
    lightMouse:setPosition(love.mouse.getX(), love.mouse.getY())
end

function love.draw()
    love.graphics.push()

    love.graphics.scale(map.scale)
    lightWorld:draw(function()
        map:draw()
    end)

    love.graphics.pop()
end
and `map.lua`:

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local sti = require("lib.sti")

local map = {
    scale = 2
}

function map:load()
    self.map = sti("maps/testmap.lua")
    
    self.width = self.map.width * self.map.tilewidth * self.scale
    self.height = self.map.height * self.map.tileheight * self.scale

    local solidColliders = {}
    for i, obj in pairs(self.map.layers["Solids"].objects) do
        solidColliders.body = love.physics.newBody(world, (obj.x + obj.width/2) * self.scale, (obj.y + obj.height/2) * self.scale, "static")
        solidColliders.shape = love.physics.newRectangleShape(obj.width * self.scale, obj.height * self.scale)
        solidColliders.fixture = love.physics.newFixture(solidColliders.body, solidColliders.shape)
        solidColliders.fixture:setUserData("Solids")

        lightWorld:newRectangle((obj.x + obj.width/2) * self.scale, (obj.y + obj.height/2) * self.scale, obj.width * self.scale, obj.height * self.scale)

    end
end

function map:draw()
    self.map:drawImageLayer("Map")
end

return map
If someone could help me fix this, that would be great!

Here is the full source and `.love` file that you can try out (scaling is set to 2)
lighting.love
(8.01 MiB) Downloaded 46 times

Re: Map isn't scaling properly with lighting

Posted: Thu Aug 24, 2023 5:47 am
by GVovkiv
I think this happening because you didn't apply scaling offset to your mouse calculations:

Code: Select all

lightMouse:setPosition(love.mouse.getX() / map.scale, love.mouse.getY() / map.scale)
Instead of:

Code: Select all

 lightMouse:setPosition(love.mouse.getX(), love.mouse.getY())
Reason why it worked is because on 1 scale there no offsets happening and if we take formulas above as example:
if mouse x will be 100; 100 * 1 (which is map scale) = 100
if you even slightly change scale, let's say 1.5;
100 * 1.5 = 150 - this is what *corrected* mouse x should look like, but since you didn't applied scaling, you still passing 100 to your lighting library, so it obviously draw light sources on wrong place.