Watch the stars fly!

[Kingdaro]

A little somethin' I decided to whip up in a couple hours.

Stars.love

(2.28 KiB) Downloaded 426 times

Stars ver 2.love

(2.51 KiB) Downloaded 516 times

[arquivista]

A little somethin' I decided to whip up in a couple hours.

Stars.love

Hi! That remember more snow fall than stars but is always a nice effect. Look, shouldn't be a Mac issue but it seems that from time to time things stop a bit. Let's wait for other reports to see if it's only happening here. Also stars animation/trail isn't quite smooth. Probably something could be improved. Keep the good work in this demo!

[Kingdaro]

A little somethin' I decided to whip up in a couple hours.

Stars.love

Hi! That remember more snow fall than stars but is always a nice effect. Look, shouldn't be a Mac issue but it seems that from time to time things stop a bit. Let's wait for other reports to see if it's only happening here. Also stars animation/trail isn't quite smooth. Probably something could be improved. Keep the good work in this demo!

Thanks for the feedback.

I plan to add a stars counter at the top of the screen (already did) and I want to make it more customizable, like setting speed or color or image or direction, etc.

From the stars counter I concluded that the game gets slower/laggier because of the amount of stars in the game constantly increasing. Here's my part of the script to fix it, and what came up when I tried to do this. The chunk added in is surrounded by comment brackets, and the number sign is where the error occurred, according to the blue screen of death.

Code: Select all

stars = {}
time = 1
function love.update(dt)
	if math.random(1,2) == 2 then
		local star = {}
		star.x = math.random(0,640)
		star.y = -100
		star.size = math.random(0.4,2.5)
		table.insert(stars,star)
	end
	
	for i=1, #stars do
		if stars[i] ~= nil then
			stars[i].y = stars[i].y+(150*dt*stars[i].size)
		end
	end
--[[
	for i=1, #stars do 
		if stars[i].y >= 480 then --#main.lua.24 attempt to index field ? (a nil value)
			table.remove(stars,i) 
		end
	end
--]]
	if time >= 1 then
		love.graphics.setCaption("Watch the stars fly! ("..love.timer.getFPS().." FPS)")
		time = 0
	else
		time = time+dt
	end
end

I can't seem to find a way to fix this.

[Mud]

Here's an attempt at using the particle system for a star field (move mouse around to 'turn'):

Code: Select all

local stars, center

function love.load()
   center = {
      x = love.graphics.getWidth()/2,
      y = love.graphics.getHeight()/2,
   }
   stars = love.graphics.newParticleSystem( love.graphics.newImage('fire.png'), 300 )
   stars:setPosition(center.x, center.y)
   stars:setBufferSize( 2000 )
   stars:setEmissionRate( 300 )
   stars:setLifetime( -1 )
   stars:setParticleLife( 6 )
   stars:setColor( 55, 55, 55, 0, 255, 255, 255, 255 )
   stars:setSize( 0.16, 0.1, 1 )
   stars:setSpeed( 30, 80  )
   stars:setSpread( math.rad(360) )
   stars:setRadialAcceleration( 20 )
end

function love.keypressed(key)
   if key == 'escape' then os.exit() end
end

function love.update(dt)
   local x, y = love.mouse.getPosition()
   stars:setOffset((x-center.x) * -5, (y-center.y) * -5)
   stars:update(dt)
end

function love.draw()
   love.graphics.draw(stars, 0, 0)
end

[TechnoCat]

Code: Select all

love.graphics.draw(love.graphics.newImage("star.png"),stars[i].x,stars[i].y,0,stars[i].size/4)

nonononono

Create the image only once!
for instance, look in love.load and love.draw for stars.image:

Code: Select all

math.randomseed( os.time() )

function love.load()
	win = love.graphics.setMode(640,480)
	stars = {}
	time = 1
	stars.image = love.graphics.newImage("star.png")
	f = love.graphics.newFont(12)
	love.graphics.setFont(f)
end

function love.update(dt)
	if math.random(1,2) == 2 then
		local star = {}
		star.x = math.random(0,640)
		star.y = -128
		star.size = math.random(0.5,2)
		table.insert(stars,star)
	end
	
	for i,star in ipairs(stars) do
		if star.y < 480 then
			star.y = star.y+(150*dt*star.size)
		else
			table.remove(stars,i)
		end
	end
	
	if time >= 1 then
		love.graphics.setCaption("Watch the stars fly! ("..love.timer.getFPS().." FPS)")
		time = 0
	else
		time = time+dt
	end
end

function love.draw()
	for _,star in ipairs(stars) do
		love.graphics.draw(stars.image,star.x,star.y,0,star.size/4)
	end
end

And by the way, there is a problem with this in your love.update(dt):

Code: Select all

	if math.random(1,2) == 2 then
		local star = {}
		star.x = math.random(0,640)
		star.y = -40
		star.size = math.random(0.5,2)
		table.insert(stars,star)
	end

Since you are tying it to frame instead of time, people with higher framerates will get more stars falling.
Simply making it something like

Code: Select all

if math.random(1,2) == 2 and time>=1 then

should fix it for now. But you'll probably want the frequency to be greater than an expected star every 2 seconds.

[kikito]

Code: Select all

love.graphics.draw(love.graphics.newImage("star.png"),stars[i].x,stars[i].y,0,stars[i].size/4)

nonononono

I fully support this nonononono.

EDIT: fixed misquote

[Robin]

I support the nonononono, but I don't support the misquote.

[nomnom]

A little somethin' I decided to whip up in a couple hours.

Stars.love

Hi! That remember more snow fall than stars but is always a nice effect.

Yea

Look, shouldn't be a Mac issue but it seems that from time to time things stop a bit. Let's wait for other reports to see if it's only happening here.

It is happening here too! You are not the only one...

It is well done Stay tuned (I hope the translations service of my choice choosed the right idiom )

[Kingdaro]

Thanks everyone for the ideas! The current state of the demo is excellent! I couldn't have done it without all your help.

Also, I'm much more comfortable with using for i=1, #table since it's what I've been using ever since I started using Lua and I never really bothered to get the concept of pairs/ipairs. (I'd rather not have anybody explain it to me. )

So, here's the demo in all it's beautified and updated glory. (See first post.)

[Mud]

I'm much more comfortable with using for i=1, #table [..] I never really bothered to get the concept of pairs/ipairs

Iterating arrays that way can be faster (eliminating iterator function call overhead), but only if you index the table you're iterating no more than ~1-2 times in the loop body, and it only works for arrays. For instance:

Code: Select all

for i=1, #stars do
   stars[i].y = stars[i].y+(speed*dt*(stars[i].size/2))
end

for i,star in ipairs(stars) do
   star.y = star.y+(speed*dt*(star.size/2))
end

The second loop is faster, because we eliminate 3 table lookups, which saves more time than we lose from the iterator call (I also find it easier to read).

here's the demo in all it's beautified and updated glory. (See first post.)

The line "star.x = math.random(-640,1280)" is generating ~65% of your stars off-screen where they will never be seen.