Lua Programming Help Thread

[Judas]

Could anyone tell me how to print the OS time with a custom TTF font?
I have this now:

See this line that was posted above yours?

math.randomseed(os.time())

screen:fontPrint(font_top,210,25,os.time(),black)

Haven't coded lua in a while, but it should work.

[KleptoOne]

Does anyone know how to take what is on the screen front buffer and blit it to the back buffer without reblitting all items and without blitting to a storage image first.

What I want to do is,

screen:blit(x,y,image)
screen:blit(x,y,image)
screen.flip()

screen:blit(0,0,screen)

I know its a wierd request, but it has to do with some userforms I'm developing.

funny thing is that this process works in windows luaplayer, but not on the psp. Any help would be greatly appreciated. (and this does need to be quick so saving and loading a screen shot would not be a useful technique.)

[FaT3oYCG]

why not use a .txt file load it let the user enter the data and use a save button or something

[Judas]

Does anyone know how to take what is on the screen front buffer and blit it to the back buffer without reblitting all items and without blitting to a storage image first.

What I want to do is,

screen:blit(x,y,image)
screen:blit(x,y,image)
screen.flip()

screen:blit(0,0,screen)

I know its a wierd request, but it has to do with some userforms I'm developing.

funny thing is that this process works in windows luaplayer, but not on the psp. Any help would be greatly appreciated. (and this does need to be quick so saving and loading a screen shot would not be a useful technique.)

I'm not sure what you're asking, but do you want to basically stick two pictures together as one? If so, load the first image. Then, blit the second, but not to the screen, to the other image. I know the C graphics library has it (blitAlphaImagetoImage), but I'm not sure what the Lua function is. You could also modify the Lua source code to make the save image function to save into the RAM.

[KleptoOne]

I'm not sure what you're asking, but do you want to basically stick two pictures together as one? If so, load the first image. Then, blit the second, but not to the screen, to the other image. I know the C graphics library has it (blitAlphaImagetoImage), but I'm not sure what the Lua function is. You could also modify the Lua source code to make the save image function to save into the RAM.

The lua function is image:blit(x,y,loadedimag e). Thats not what I'm trying to do though. Basically I'm making vba like userforms, and I would like to be able to call them on the fly without worrying about the background. When the form is called, it is stuck within a loop until the user finishes input, so I would like to reblit the already existing front buffer to a temp image and reblit that within my form loop. All I want is to be able to access the front or back buffer in the screen object, but doing a pairs printout of the screen table, it doesn't look like that will be possible, oh well.

[dsi]

i don't think you can run 1.50 homebrew on a slim. try the 1.00 Eboot version maybe.

No, that one doesn't work, it gives me a crash message. Team Noobz recommended the 1.50 version, which does start. The only problem is it can't find the script file for some reason, as I mentioned above.

[FaT3oYCG]

The lua function is image:blit(x,y,loadedimag e). Thats not what I'm trying to do though. Basically I'm making vba like userforms, and I would like to be able to call them on the fly without worrying about the background. When the form is called, it is stuck within a loop until the user finishes input, so I would like to reblit the already existing front buffer to a temp image and reblit that within my form loop. All I want is to be able to access the front or back buffer in the screen object, but doing a pairs printout of the screen table, it doesn't look like that will be possible, oh well.

yes it would it would be quite simple

e.g.

make a menu say the third option was a form
 
if
pad:cross()
and
current == 3
then
whichever form = true
end
 
if
whichever form == true
then
-->form code<--
end

-= Double Post =-

The lua function is image:blit(x,y,loadedimag e). Thats not what I'm trying to do though. Basically I'm making vba like userforms, and I would like to be able to call them on the fly without worrying about the background. When the form is called, it is stuck within a loop until the user finishes input, so I would like to reblit the already existing front buffer to a temp image and reblit that within my form loop. All I want is to be able to access the front or back buffer in the screen object, but doing a pairs printout of the screen table, it doesn't look like that will be possible, oh well.

yes it would it would be quite simple

e.g.

make a menu say the third option was a form
 
if
pad:cross()
and
current == 3
then
whichever form = true
end
 
if
whichever form == true
then
-->form code<--
end

[myschoo]

why
do
you
type
your
code
like
this?

[FaT3oYCG]

because
i
find
it
easier
to
understand
in
this
format

is
that
ok
with
you
???

[myschoo]

proof that number of lines doesnt mean anything

[FaT3oYCG]

proof that number of lines doesnt mean anything

i agree with that but i have not once bragged about how many lines of code anything i have made has

[KleptoOne]

yes it would it would be quite simple

e.g.

make a menu say the third option was a form
 
if
pad:cross()
and
current == 3
then
whichever form = true
end
 
if
whichever form == true
then
-->form code<--
end

-= Double Post =-


yes it would it would be quite simple

e.g.

make a menu say the third option was a form
 
if
pad:cross()
and
current == 3
then
whichever form = true
end
 
if
whichever form == true
then
-->form code<--
end

Using a state system defeats the purpose of creating a vba like form (for my purpose). I'm trying to generalize the process and not make it specific to my application, so that I can load a userform library into whatever application I am working on and have it function the same way each time.

Edit
if you've ever worked with vba, it would be the same as creating a dialog window, specifying what type of form you are creating and where you would like it to display within the window. But all of this is irrelevent, all I wanted to know was if there was a quick way to transfer the front buffer to the back buffer, nothing else.

[FaT3oYCG]

OK i have a question what i want to do is load a file e.g. a txt file a lua file and put the text on the screen nothing else no movement i can do that myself

basically i can get it to put the text on the screen on different lines but i want it to follow on a line instead of going off the screen

e.g.

if i had a really long line like this one then it would go off the edge of the psp's screen

what i am asking is how would i make it do something
like this does by going onto the next line automatically
but not chopping off bits of words

also

on a different note does anyone know how i would backup the entire flash of my psp by coding it in lua i have used many different ways and none of them seem to work

[nataku92]

i agree with that but i have not once bragged about how many lines of code anything i have made has

Uh...yes you have >_> :

i have done all of the code myself and there are 9 files with over one hundred lines some with more

[Anti-QuickJay]

lol
PWN'd!

[FaT3oYCG]

Uh...yes you have >_> :

ok i take that back lol

anyway

OK i have a question what i want to do is load a file e.g. a txt file a lua file and put the text on the screen nothing else no movement i can do that myself

basically i can get it to put the text on the screen on different lines but i want it to follow on a line instead of going off the screen

e.g.

if i had a really long line like this one then it would go off the edge of the psp's screen

what i am asking is how would i make it do something
like this does by going onto the next line automatically
but not chopping off bits of words

also

on a different note does anyone know how i would backup the entire flash of my psp by coding it in lua i have used many different ways and none of them seem to work

could someone help me with that

[Anti-QuickJay]

Print the text and if the text is going to reach the end of the screen start printing it on the next line.
Simple, or will it take a month to code it? lol

[Judas]

You have to figure out how many characters can be put on a line. Then, when the number of characters you are printing gets close to the max number, find the nearest space, and break it off, and start printing on the next line.

[myschoo]

is there function to replace character?

ie. i have string = "hello" and i want to replace all "o" characters wth "0" so it would look like "hell0"

anyone?

edit. nvm got it:

string = string.gsub(string, "o", "0")

[Judas]

Does anyone know if you can use switch loops in Lua?

[FaT3oYCG]

You have to figure out how many characters can be put on a line. Then, when the number of characters you are printing gets close to the max number, find the nearest space, and break it off, and start printing on the next line.

easily said not so easily done

or does someone want to post some code and completeley rip me again

[Judas]

easily said not so easily done

or does someone want to post some code and completeley rip me again

Easily said, and easily done. The font is 8 pixels wide, so the screen can hold 60 characters across. Seek to the 60th character in the file. Check to see if it's a space. If it is, print on a new line. If it's not, start seeking backwards checking for spaces. When you find one, break it off there, and print on a new line. If for some reason, you don't find a space, because you have a 61 character long word, insert a hyphen after character 59, and then print on the next line.

[michaelp]

Does anyone know if you can use switch loops in Lua?

You mean like switch case statements in C/C++? If that's what you mean, then no.

[myschoo]

hmm when i use function file:read(), it only reads 1st line from the file.. is that ok? o_O

[Anti-QuickJay]

Easily said, and easily done. The font is 8 pixels wide, so the screen can hold 60 characters across. Seek to the 60th character in the file. Check to see if it's a space. If it is, print on a new line. If it's not, start seeking backwards checking for spaces. When you find one, break it off there, and print on a new line. If for some reason, you don't find a space, because you have a 61 character long word, insert a hyphen after character 59, and then print on the next line.

But the problem is he dont know how to do that.

[myschoo]

yeah lol exactly...

but it just takes few string manipulations...

[Judas]

But the problem is he dont know how to do that.

Then he's not a very good coder. That's fairly simple to do.

Anyway, I found the answer to my other question on switch-case loops. Here's the documentation in case anyone else wants it.

http://lua-users.org/wiki/SwitchStatement

[Merick]

Does anyone know if you can use switch loops in Lua?

Lua doesn't have switch/select case, but you can rig an approximation using a table of functions (pseudocode):

select = {}
function select.case1()
     code...
end

function select.case2()
    code...
end

function select.case3()
     code...
end

case = "case1"

select[case]()

*edit*
lol, you beat me to it..

myschoo, file:read("*a") will put the entire text of the file into a single variable.

alternately, you can use this to read each line from the file into a table:

data = {}
for line in io.lines(filename) do 
     table.insert(data, line)
end

note: io.lines will automatically open the file for reading and then close it once the entire file has been read

file:lines() will do the same thing for an already opened file, and will keep the file open after it's been read

[myschoo]

merick: i know io.lines but i didnt want to use it. thx 4 answer

[myschoo]

merick: umm ... *a doesnt work... tried a and a+ and that didnt help