Lua Programming Help Thread

here change your animation calls to look like this:

Code:

---

if currentFrame == 1 then --draw first frame
      screen:blit(Back3.x - 370,50,frame1)
  elseif currentFrame == 2 then --draw second frame
      screen:blit(Back3.x - 370,50,frame2)
  elseif currentFrame == 3 then --draw third frame
      screen:blit(Back3.x - 370,50,frame3)
  end

---

As you can see, the rain doesn't quite match up with the clouds, but to fix that all you have to do is tinker around with how much you subtract from Back3.x.
-= Double Post =-
heh, I went ahead and figured it out for you, even added a few lines to double the size of the animation:

Code:

---

if currentFrame == 1 then --draw first frame
      screen:blit(Back3.x - 480,50,frame1)
      screen:blit(Back3.x - 397,50,frame2)
  elseif currentFrame == 2 then --draw second frame
      screen:blit(Back3.x - 480,50,frame2)
      screen:blit(Back3.x - 397,50,frame3)
  elseif currentFrame == 3 then --draw third frame
      screen:blit(Back3.x - 480,50,frame3)
      screen:blit(Back3.x - 397,50,frame1)
  end

---

thank you so much :ROFL: :Punk: :Jump:

hehe, no problem, I haven't had this much fun with a programming language in years

and here's another way to do it:

Code:

---

for i = 536,314, -83 do
  if currentFrame == 1 then --draw first frame
        screen:blit(Back3.x - i,50,frame1)
      elseif currentFrame == 2 then --draw second frame
        screen:blit(Back3.x - i,50,frame2)
      elseif currentFrame == 3 then --draw third frame
        screen:blit(Back3.x - i,50,frame3)
        end
end

---

-= Double Post =-
ok, I really need some help with this. First, I have my tile loader function. When my program runs through this, it appears to be loading the images like I want it to:

Code:

---

tiles = {}    -- store tile images
tfiles = {}    -- store tile filenames

-- load all images from tiles folder
function loadtiles()
        screen:clear()
        screen:fontPrint(hyperion, 100, 100, "loading tiles", red)
        screen:flip()
  screen:clear()
        local files = System.listDirectory("./tiles")
  tiles[(table.getn(files))] = {}
        for i = 3, table.getn(files) do
                tiles[i-2] = Image.load("./tiles/"..files[i].name)
                tfiles[i-2] = (files[i].name)
                end
        screen:fontPrint(hyperion, 100, 150, "done", blue)
        screen:flip()
  for i = 1, 100000 do end
        return
end

---

However, when I try to display one of the tiles like this:

Code:

---

  screen:blit(xpos, ypos, tiles[currenttile])
  screen:flip()

---

nothing shows up on the screen

*edit*

nvm,LOL

the problem was with my algorithm to determine the xpos and ypos

merick what kind of game are you making?

Well, right now I'm not actually making a game. What I'm working on is a program to draw game maps using graphics tiles.

hey guys, when i use math.floor, i want to round off to the nearest whole number, but it is rounding me off to the first decimal place. any solutions?

can we see how you're using it? I just did a small test, and using math.floor(199.99) gave me the result of 199, so it's probably something to do with the way you're coding it

Code:

---

function math.round(a)
        if a-math.floor(a) >= 0.5 then
                return math.ceil(a)
        else
                return math.floor(a)
        end
end

---

Zitat:

---

Zitat von Merick

can we see how you're using it? I just did a small test, and using math.floor(199.99) gave me the result of 199, so it's probably something to do with the way you're coding it

---

well i have a timer, but i don't want it to show it in milliseconds, so i used:

Code:

---

gametime = math.floor((10000 - timer1:time())/10) -- it shows 10000 - time because it is supposed to be counting down

---

-= Double Post =-
actually, now that i think about it i think i put the "/ 10" after the math.floor, which would, in any case that the number was not divisible by ten, make the number a decimal again.

and eyece, thanks for teaching me that there was a such thing as math.ceil. I understand why ceiling and floor were named what they are now lol.

what does floor in math.floor stand for?

Zitat:

---

what does floor in math.floor stand for?

---

it drops a decimal number to the last (next lowest) whole number.
http://lua-users.org/wiki/MathLibraryTutorial

arrg, I'm really not getting tables. I'm trying to create a table for a map grid, where I can set point x,y in the grid as number like so:

map point x,y = number of the tile to be displayed

no matter how I try to set it up, I keep getting errors like "attempt to index field '?' (a nil value)" or "table index is nil"

i assume you loop through the table when processing tiles? if so, make sure your loop starts at 1.

otherwise show me some code.

Code:

---

a = {}

for i= 1, 10 do
  for j = 1, 10 do
      count = count +1
    a[i,j] = count -- right here i get this: ']' expected near ','
  end
end

--

a = {}

for i= 1, 10 do
  for j = 1, 10 do
      count = count +1
    a[i],[j] = count  -- unexpected symbol near '['
  end
end

--

a = {}

for i= 1, 10 do
  for j = 1, 10 do
      count = count +1
    a[i][j] = count --attempt to index field '?' (a nil value)
  end
end

--
b = {}
a[b] = {} --attempt to index field '?' (a nil value)

for i= 1, 10 do
  for j = 1, 10 do
      count = count +1
    a[i].j  = count
  end
end

---

-= Double Post =-
It's been a long time and my memory is kinda fuzzy, but i remember it being much easier do to this kind of thins in quickbasic
-= Double Post =-
I just want something that will let me declare a table as a matrix array with xsize number of columns and ysize number of rows, then will let me say that point x,y is equal to some number
-= Double Post =-
.

why does this always happen to me? I struggle for hours to figure something out, but I come up with an answer only after I post a question about it:

Code:

---

a = {}

for i= 1, 10 do
  a[i] = {}
  for j = 1, 10 do
      count = count +1
    a[i][j]  = count
  end
end

---

i'm not sure how to make a table into an array as you are talking about, but you could always use seperate tables like:

Code:

---

row1 = {}
row2 = {}
row3 = {}
row4 = {}
row5 = {}
for i = 1, 5 do
row1[i] = i
row2[i] = i
row3[i] = i
row4[i] = i
row5[i] = i
end

---

lol, look in my last double post merge post above, I have found the answer I was looking for

Code:

---

a = {}

for i= 1, x do
  a[i] = {}
  for j = 1, y do
      a[i][j] ={}
  end
end

---

this bit of code creates a matrix array of x columns by y rows. Since I'm not assigning any values here, all points are = nil, but once this bit of code has run, you can access any point in the matrix with: a[xpos][ypos]

Could someone give me examples/tell me how to use these functions?

Gu.light, Gu.lightAtt, Gu.lightColor, Gu.lightMode, Gu.lightSpot

I don't even know where to begin. I just started 3D, and I can at least tinker (poorly) with all the other functions, but the best I get from these is an error.

aphonia, i just took a crack at Gu.light, i got nothing also, so i had a look at the function to see how many arguments it did need, 6 apparently. 1st one looks to be an id i don't know what the next 2 do, but then the other 3 should be the xyz of the light:

Code:

---

static int lua_sceGuLight(lua_State *L) {
        int argc = lua_gettop(L);
        if (argc != 6) return luaL_error(L, "wrong number of arguments");
        ScePspFVector3 v;
        v.x = luaL_checknumber(L, 4);
        v.y = luaL_checknumber(L, 5);
        v.z = luaL_checknumber(L, 6);
        sceGuLight(luaL_checkint(L, 1), luaL_checkint(L, 2), luaL_checkint(L, 3), &v);
        return 0;
}

---

but, i have tried and failed maybe my source is different for some reason, could someone enlighten me please :P

EDIT:
lol, my bad the num of arguments error was coming from line 136, not the line 146 with Gu.light, so i just spent 15 minutes trying to fix something that wasn't broken, it'll try again. - ignore the last part of my post :P

Zitat:

---

Zitat von Merick

lol, look in my last double post merge post above, I have found the answer I was looking for

---

lol, i didn't see it

can anyone point me to some code that can rotate an image?

Zitat:

---

Zitat von Merick

can anyone point me to some code that can rotate an image?

---

With or without the GU?

hmm...

well, right now my program is only using 2d, I haven't even looked at the 3d GU yet, but if the GU can be combined with my 2d stuff without problems, and if it works better than a 2d function would....

Basically, I'm making a tile map editor and I'd like to be able to rotate the tile images by 1/4, 1/2, and 3/4 turns

gu works better than any other way. but i dont know if it will cooperate with your 2d stuff easily

Doing it without the GU is (very?) slow but still possible.

This will help: http://forums.qj.net/f-psp-developme...lua-98105.html

thanks, I will eventually be looking into the gu, but for now it looks like this will do what I need

Round a number:

Code:

---

function roundnum(roundnum_num)
return math.floor(roundnum_num+0.5)
end

---

Or just use

Code:

---

math.floor(number+0.5)

---

hii all,
I want to copy a file, but i don't know how...
It shoud work like when you are in level 5 of my game a photo need to be copied
to the photo map

Sulfer, do you mean like copy a file that's already on your memcard, or do you want to make a screenshot or something?

Hey in netlib you need netget(id)? Becuase i looked at some online games and they dont use netget when reciing from yourgame_room..room_numbe r. They just netrecv() and netvalue, so I took out netget from the example and it didn't work?? Is there a reason for this.

@Merick, i want copy file's that are already on my memstick, could you help me whit that? thx
(ps don't flame me for my english :o )

Is it possible to disable a button in lua?....like lets say the "home" button. if so how

this will copy a file:

Code:

---

file = io.open("filename.ext","r")
filecopy = file:read("*a")
file:close()

copiedfile = io.open("newfile.ext", "w")
copiedfile:write(filecopy)
copiedfile:close()

---

wont that just copy whats in a file and paste it in a already created file?

only if "newfile.ext" already exists. If you use the io.open and write commands with a filename for a file that doesn't exist, then it will create a new file with that name to write to

Zitat:

---

Zitat von the undead

Is it possible to disable a button in lua?....like lets say the "home" button. if so how

---

No, there is not. If you would like to disable people from using the HOME button, modify the LuaPlayer src to disable the callbacks. Takes about 5 seconds.

Well, I have successfully integrated KleptoOne's image rotate function into my prog. It works fine, except that the rotated images it produces end up a bit distorted. It'll do for now but eventually I'll need to find a better way.

Zitat:

---

Zitat von Access_Denied

No, there is not. If you would like to disable people from using the HOME button, modify the LuaPlayer src to disable the callbacks. Takes about 5 seconds.

---

ok, so do i need to install psptoolchain and cgwin or w/e?

Zitat:

---

Zitat von Merick

Well, I have successfully integrated KleptoOne's image rotate function into my prog. It works fine, except that the rotated images it produces end up a bit distorted. It'll do for now but eventually I'll need to find a better way.

---

I found out the best way is to use the GU. what you do is draw four triangles with starting points in the center forming a square. Then you texture your image over it and modify the z value to change its size and (depending on how you drew the triangles) modify the roll to rotate. If you want some sample code, let me know.

2 triangles would be easier, or one rectangle.
and using gu over top of the rest of your game is kind of a bad idea, make it all gu rendered or none of it gu rendered.

Zitat:

---

Zitat von the undead

ok, so do i need to install psptoolchain and cgwin or w/e?

---

Well yah because you would need to recompile it after you disables the callbacks.