[LUA] Any tips against lag

[Predricted]

If I use the for loop for enemies and I make more then 3 enemies the PSP acts sloww is there anything I can do against this??

[dan369]

your doing something wrong because 3 enemies shouldn't cause no slow down

post your code.

[Predricted]

Originally Posted by dan369

your doing something wrong because 3 enemies shouldn't cause no slow down

post your code.

for i=1, enemes do
if player.x < enemy[i].x then
enemy[i].x = enemy[i].x+1 
enemy[i].image=Image.load("enm_right.png")
end
if player.y < enemy[i].y then
enemy[i].y = enemy[i].y+1 
enemy[i].image=Image.load("enm_down.png")
end
if player.x > enemy[i].x then
enemy[i].x = enemy[i].x-1 
enemy[i].image=Image.load("enm_left.png")
end
if player.y < enemy[i].y then
enemy[i].y = enemy[i].y-1
enemy[i].image=Image.load("enm_up.png" )
end
screen_startDraw()
screen.blit(enemy[i].x, enemy[i].y,enemy[i].imageload
screen_endDraw()
end

[slicer4ever]

it's this: Image.load("enm_up.png" ) which is causing the slowdown insead do:

enm_right = image.load("enm_right");
enm_left = image.load("enm_left"); 
//etc

while true do
for i=1, enemys do
if player.x < enemy[i].x then
enemy[i].x = enemy[i].x+1 
enemy[i].image=enm_right //<-----this
end
//etc
end

that should speed it up, try and not load anything in your main loop continuosly

[dan369]

screen_startDraw()
screen.blit(enemy[i].x, enemy[i].y,enemy[i].imageload
screen_endDraw()

outside the for-loop

Your loading 4 images every loop, these should be outside the loop.

have like

up = Image.load("enm_up.png" )
down = Image.load("enm_down.png")
etc.

---In your for-loop
if player.y < enemy[i].y then
enemy[i].y = enemy[i].y-1
enemy[i].image= up;
end

if player.y < enemy[i].y then
enemy[i].y = enemy[i].y+1 
enemy[i].image= down
end
etc.

Indent!

Edit: damn, slicer beat me to it :P

[slicer4ever]

Originally Posted by dan369

Indent!

1. u didn't, but u probably whipped it up on the spot like i did=-)
2. agreed

[dan369]

Originally Posted by slicer4ever

1. u didn't, but u probably whipped it up on the spot like i did=-)
2. agreed

exactly

[Predricted]

Originally Posted by slicer4ever

it's this: Image.load("enm_up.png" ) which is causing the slowdown insead do:

enm_right = image.load("enm_right");
enm_left = image.load("enm_left"); 
//etc

while true do
for i=1, enemys do
if player.x < enemy[i].x then
enemy[i].x = enemy[i].x+1 
enemy[i].image=enm_right //<-----this
end
//etc
end

that should speed it up, try and not load anything in your main loop continuosly

Okay I didnt post the exactly code but this is the exactly code and it don't got any image.load() in it but it still slows the game with every enemy that enters..
This is the exactly code:

screen.startDraw()
for i=1, enemies do
if enemy[i].x > player1[1].x then
enemy[i].x=enemy[i].x-1
enemy[i].image="images/enemy/imp_left.png"
end
if enemy[i].x < player1[1].x then
enemy[i].x=enemy[i].x+1
enemy[i].image="images/enemy/imp_right.png"
end
if enemy[i].y > player1[1].y then
enemy[i].y=enemy[i].y-1
enemy[i].image="images/enemy/imp_up.png"
end
if enemy[i].y < player1[1].y then
enemy[i].y=enemy[i].y+1 
enemy[i].image="images/enemy/imp_down.png"
end
enemy[i].imageload = Image.load(enemy[i].image)
Image.blit(enemy[i].x,enemy[i].y,enemy[i].imageload)
if i == enemies then
i=0
end
random=math.random (1, 70)
end
end
screen.endDraw()

Are there any other ways to speed up the game?

[dan369]

Just use the EXACT way slicer & I showed up.

if i == enemies then
i=0
end

Delete this. No need for it.

[Predricted]

Originally Posted by dan369

Image.blit(enemy[i].x,enemy[i].y,enemy[i].imageload)

do you read? honestly don't have this in a for-loop!
Just use the EXACT way slicer & I showed up.

if i == enemies then
i=0
end

Delete this. No need for it.

Okay you got any other idea where to blit the image?
I could do this
if enemy == 1 then
image.blit(enemy[1].x,enemy[1].y,image)
end
if enemy == 2 then
image.blit(enemy[1].x,enemy[1].y,enemy[1].image)
image.blit(enemy[2].x,enemy[2].y,enemy[2].image)
end
and that all the way up to 10 but is there a other way?

and this

[dan369]

My bad just released what you are actually doing, don't do what i previously said leave it in the for-loop. I remember what your trying todo from your previous posts.

[Predricted]

Damm this helped loading 30+ enemies without any lagg thanks guyss
HAHAHA MASSIVE SLAUGTHERR THIS GAME

[dan369]

Depending on the Luaplayer your using, you should get a good 100+ enemies easy.

[slicer4ever]

predicted your misunderstanding, what not to do is commented from your previous code:

//first of all indent(see below)
screen.startDraw()
for i=1, enemies do
if enemy[i].x > player1[1].x then
enemy[i].x=enemy[i].x-1
enemy[i].image="http://forums.qj.net/images/enemy/imp_left.png"//<--stupid to save the paths
end
if enemy[i].x < player1[1].x then
enemy[i].x=enemy[i].x+1
enemy[i].image="http://forums.qj.net/images/enemy/imp_right.png"
end
if enemy[i].y > player1[1].y then
enemy[i].y=enemy[i].y-1
enemy[i].image="http://forums.qj.net/images/enemy/imp_up.png"
end
if enemy[i].y < player1[1].y then
enemy[i].y=enemy[i].y+1 
enemy[i].image="http://forums.qj.net/images/enemy/imp_down.png" 
end
enemy[i].imageload = Image.load(enemy[i].image) //<---still loading an image in the main loop, what did i say?!!!!!!!!!!!!!
Image.blit(enemy[i].x,enemy[i].y,enemy[i].imageload)
if i == enemies then  //<---these 3 lines, not needed!, i=1 up their at the for loop takes care of this!
i=0
end
random=math.random (1, 70)
end
end
screen.endDraw()

what to do after all the changes:

enm_left = Image.load("http://forums.qj.net/images/enemy/imp_left.png");
enm_right = Image.load("http://forums.qj.net/images/enemy/imp_right.png");
enm_up = Image.load("http://forums.qj.net/images/enemy/imp_up.png");
enm_down = Image.load("http://forums.qj.net/images/enemy/imp_down.png");

while true do
//assuming that while true do is right here
   screen.startDraw()
   for i=1, enemies do
      if enemy[i].x > player1[1].x then
         enemy[i].x=enemy[i].x-1
         enemy[i].image=enm_left;
      end
      if enemy[i].x < player1[1].x then
          enemy[i].x=enemy[i].x+1
          enemy[i].image=enm_right;
      end
      if enemy[i].y > player1[1].y then
         enemy[i].y=enemy[i].y-1
         enemy[i].image=enm_up;
      end
      if enemy[i].y < player1[1].y then
         enemy[i].y=enemy[i].y+1 
         enemy[i].image=enm_down;
      end
      Image.blit(enemy[i].x,enemy[i].y,enemy[i].image)
   end
   random=math.random (1, 70)
   end
   screen.endDraw()
end

that's your issue, still loading in the main freaking loop, that should take care of it

edit: confused, it's working now?

edit2: ok, i understand, didn't see you other post saying u figured it out, i'll leave this up incase you have any other questions that you may wish answered

[Predricted]

Originally Posted by slicer4ever

predicted your misunderstanding, what not to do is commented from your previous code:

//first of all indent(see below)
screen.startDraw()
for i=1, enemies do
if enemy[i].x > player1[1].x then
enemy[i].x=enemy[i].x-1
enemy[i].image="http://forums.qj.net/images/enemy/imp_left.png"//<--stupid to save the paths
end
if enemy[i].x < player1[1].x then
enemy[i].x=enemy[i].x+1
enemy[i].image="http://forums.qj.net/images/enemy/imp_right.png"
end
if enemy[i].y > player1[1].y then
enemy[i].y=enemy[i].y-1
enemy[i].image="http://forums.qj.net/images/enemy/imp_up.png"
end
if enemy[i].y < player1[1].y then
enemy[i].y=enemy[i].y+1 
enemy[i].image="http://forums.qj.net/images/enemy/imp_down.png" 
end
enemy[i].imageload = Image.load(enemy[i].image) //<---still loading an image in the main loop, what did i say?!!!!!!!!!!!!!
Image.blit(enemy[i].x,enemy[i].y,enemy[i].imageload)
if i == enemies then  //<---these 3 lines, not needed!, i=1 up their at the for loop takes care of this!
i=0
end
random=math.random (1, 70)
end
end
screen.endDraw()

what to do after all the changes:

enm_left = Image.load("http://forums.qj.net/images/enemy/imp_left.png");
enm_right = Image.load("http://forums.qj.net/images/enemy/imp_right.png");
enm_up = Image.load("http://forums.qj.net/images/enemy/imp_up.png");
enm_down = Image.load("http://forums.qj.net/images/enemy/imp_down.png");

while true do
//assuming that while true do is right here
   screen.startDraw()
   for i=1, enemies do
      if enemy[i].x > player1[1].x then
         enemy[i].x=enemy[i].x-1
         enemy[i].image=enm_left;
      end
      if enemy[i].x < player1[1].x then
          enemy[i].x=enemy[i].x+1
          enemy[i].image=enm_right;
      end
      if enemy[i].y > player1[1].y then
         enemy[i].y=enemy[i].y-1
         enemy[i].image=enm_up;
      end
      if enemy[i].y < player1[1].y then
         enemy[i].y=enemy[i].y+1 
         enemy[i].image=enm_down;
      end
      Image.blit(enemy[i].x,enemy[i].y,enemy[i].image)
   end
   random=math.random (1, 70)
   end
   screen.endDraw()
end

that's your issue, still loading in the main freaking loop, that should take care of it

edit: confused, it's working now?

edit2: ok, i understand, didn't see you other post saying u figured it out, i'll leave this up incase you have any other questions that you may wish answered

Yea that was some nice help from you guys, if i had any other question then it would be those enemies are overlaying eachother so I want them to bounce when they reach the same x and y so

if enemy1x == enemy 2 xx and enemy1y==enemy2y then
enemy1x == enemy1x-random.math(-25,25)
enemy1y == enemy1x-random.math(-25,25)
end

but the problem is I am working with tables
so it should be like this

if enemy[i].x == enemy[all enemies but not i].x and enemy[i].y == enemy[all enemies but not i].y then
blablabla
end

-=Double Post Merge =-

Originally Posted by dan369

Depending on the Luaplayer your using, you should get a good 100+ enemies easy.

Thats possible cause I use LuaPlayerHM and its even not showing a little bit of lag at 30 enemies.... soo it would be possible

[slicer4ever]

i'd suggest pge lua if your making games, as for the collision, 1: you can't do if x == x2, y == y2, not that simple, that'd be asking that your characters fall on the exact same pixel, which is pretty rare, instead you need rectangle collision

if (x1 > x2 and x1< x2+width2) or (x1+width1 > x2 and x1+width1 < x2+width2) then
   if (y1 > y2 and y1 < y2+height2) or (y1+height1 > y2 and y1+height1 < y2+height2) then
      //collision response here
   end
end

basically you have to check that each point on object a does not fall inside the 4 points on object b, or vice versa, if they do, than do the appropriate collision response

their's two methods i know on how to achieve going through your enemy list:

1.

   for i=1, enemys do
   //movement code
      for d=1, enemys do
         if i not d then
             //check collision, and respond if their is
         end
       end
    end

this method is slower but picks up on collisions immidiatly

however the faster method is:

2.

int CurrentEnemyCheck = 1;
while true do
   for i=1, enemys do
   //movement code

       if i not CurrentEnemyCheck then
          //check collision and use the CurrentEnemyCheck to fill in for object b
       end
    end
    CurrentEnemyCheck++; //add 1 to the var, don't know if this is legal in lua
    if CurrentEnemyCheck>CurrentEnemys then
        CurrentEnemyCheck = 1;
    end
end

if you have large, i mean very large numbers of enemy's i'd suggest the latter method, doing a second loop could be a drastic speed loss, however if it's a low number, or you control areas of enemy's thusly to lower the number of enemy's than go with the former so that you always have perfect collision

edit: if anyone knows another method, i'd be glad to hear it

[dan369]

It's best to have only one for-loop checking collision against the enemies, it's like slicer sadi could lead to a "drastic speed loss".
'++' isn't as you say legal.
One way of doing making collision faster is to as i say check if there 'in-range', really it's pretty stupid to just check every enemie, what if that enemie is on the other side of the screen or on a totally different part of a map(just an example).
you could do something like:

for =1, #enemies do
     if (player.x + player.width + 20) > enemies[i].x or (player.y + player.height + 20) > enemies[i].y then
           ---check collision
     else
end         ---do nothing

[Predricted]

Opps thats my dumb mistake i made enemy enemies lol sorry fixed it

btw can we load 2 variables like i in a for loop
so for example
for i=1, enemies and for d=1, enemies do
end
so we don't need to load 2 for loops?
just a idea haha

[slicer4ever]

no, as far as i know what you did is not possible, however i may be incorrect, regardless it wouldn't make sense to do that, you'd just be counting both at the same time and thusly you'd not be doing anything, as for dan, if anything that's simple creating a third check if that check holds true, i guess it's a weighing situation, how often do u plan your enemy's to come into contact, if often i'd suggest just always checking, if not than simple do your method, but either way it's adding to a possible check list

at the same time you can also condense my two if statements into one, in the end i personally find it easier to always check, regardless a check needs to be done somewhere, their's no way to magically say, one is across the unverse without comparing each of them in someway

edit: however as i think about it, you could create a hierarchical list of objects, seperate them based on distance, than when one group of objects gets close to another they combine into one larger group, thusly, if a series of objects in on the left, only the left objects will be checked against themselfs, and if a series of objects is on the right, the same for only right objects, it can cut down on going throught all the enemy's with each and every object, and limiting to a small set of enemy's that each object checks itself against, but it'd require alot of thinking and code to effective put place(if this doesn't make sense it's because i'm partly thinking of it at the same time i'm writing it and am half talking to myself on the idea)

edit2:

just thought of a less complex idea, however i'm not certain if it'd save any speed, and could potential cause worse problems than you want:

for i=1, enemys, do
   //move
end
for i=1, enemys do
   for d=i+1, enemys do
      //check collision
    end
end

efffectivly, as i increases, the number of objects needed to be checked against decreases, however doing the whole loop again might not be as benifical as i'm thinking

[yaustar]

There is an alternative method that can potentially cut down on the number of checks you need to do but requires a sorted list of objects by their position and still has a worse case scenario of the code above. For sake of this example lets assume a Super Mario Bros game, the moving objects are sorted by x position then by y position:

   
for i=1, enemys do
    for j=i, enemys do
        if enemy[i].x +enemy[i].width < enemy[j].x then
            break
        else
            -- check against the y axis for collision
        end
    end
end

As long as the enemy table is sorted, when (enemy[i].x +enemy[i].width) is less the enemy[j].x, no other enemy in the table beyond j can collide with enemy i.