ComputerCraft Wiki - User contributions [en]

Paintutils (API)

2015-06-14T13:47:49Z

Superaxander:

{{lowercase}}
Paintutils is a default API for advanced systems which can draw [[paintutils.drawPixel|pixels]] and [[paintutils.drawLine|lines]], [[paintutils.loadImage|load]] and [[paintutils.drawImage|draw]] image files. You can use [[Colors (API)|colors API]] for easier color manipulation.

{{API table|paintutils|image=Grid disk.png|2=

{{API table/row
|[[paintutils.loadImage]]({{type|string}} path)
|{{type|table}} image
|Loads and returns an image object from <var>path</var>.
|odd}}

{{API table/row
|[[paintutils.drawImage]]({{type|table}} image, {{type|number}} x, {{type|number}} y)
|{{type|nil}}
|Draws an image at (<var>x</var>, <var>y</var>) where <var>image</var> is an image object.
|}}

{{API table/row
|[[paintutils.drawPixel]]({{type|number}} x, {{type|number}} y [, {{type|number}} color*])
|{{type|nil}}
|Draws a pixel at (<var>x</var>, <var>y</var>) in the specified color.
|odd}}

{{API table/row
|[[paintutils.drawLine]]({{type|number}} startX, {{type|number}} startY, {{type|number}} endX, {{type|number}} endY [, {{type|number}} color*])
|{{type|nil}}
|Draws a line from (<var>startX</var>, <var>startY</var>) to (<var>endX</var>, <var>endY</var>) in the specified color.
|}}

{{API table/row
|[[paintutils.drawBox]]({{type|number}} startX, {{type|number}} startY, {{type|number}} endX, {{type|number}} endY [, {{type|number}} color])
|{{type|nil}}
|Draws a box from (<var>startX</var>, <var>startY</var>) to (<var>endX</var>, <var>endY</var>) in the specified color. ''Requires version 1.64 or newer.''
|odd}}

{{API table/row
|[[paintutils.drawFilledBox]]({{type|number}} startX, {{type|number}} startY, {{type|number}} endX, {{type|number}} endY [, {{type|number}} color])
|{{type|nil}}
|Draws a filled box from (<var>startX</var>, <var>startY</var>) to (<var>endX</var>, <var>endY</var>) in the specified color. ''Requires version 1.64 or newer.''
|}}
}}
''<nowiki>*</nowiki> Note: In builds prior to ComputerCraft 1.6, the "color" parameter required by [[paintutils.drawPixel|paintutils.drawPixel()]] and [[paintutils.drawLine|paintutils.drawLine()]] is optional. From ComputerCraft 1.6 the parameter is required, but it was changed back to optional in ComputerCraft 1.64.''

[[Category:APIs]]

Talk:Paintutils (API)

2015-06-14T13:43:49Z

Superaxander:

What does this mean?:
* Note: In builds prior to ComputerCraft 1.6, the "color" parameter required by paintutils.drawPixel() and paintutils.drawLine() is optional. The current background colour will be used if it's omitted. This was changed back to optional in version 1.64.
--[[User:Superaxander|Superaxander]] ([[User talk:Superaxander|talk]]) 14:44, 11 June 2015 (UTC)

How about this:
* Note: In builds prior to ComputerCraft 1.6, the "color" parameter required by paintutils.drawPixel() and paintutils.drawLine() is optional. From ComputerCraft 1.6 the parameter is required, but it was changed back to optional in ComputerCraft 1.64.
--[[User:MKlegoman357|MKlegoman357]] ([[User talk:MKlegoman357|talk]]) 19:59, 11 June 2015 (UTC)

Looks good I wasn't sure what way around it was. I'll change it to that in the article
--[[User:Superaxander|Superaxander]] ([[User talk:Superaxander|talk]]) 13:43, 14 June 2015 (UTC)

Talk:Paintutils (API)

2015-06-11T14:44:13Z

Superaxander: Created page with "What does this mean?: * Note: In builds prior to ComputerCraft 1.6, the "color" parameter required by paintutils.drawPixel() and paintutils.drawLine() is optional. The current..."

Metatable

2015-02-02T15:19:09Z

Superaxander: Add an example of the __eq metatable property

{{NeedsWork|Not enough info, perhaps incorrect info}}

A metatable is an addition on to normal tables for adding metamethods, making classes as well as protecting functions.

== Setting and getting a metatable ==

You will use setMetatable and getMetatable to set and get metatables.

You use getMetatable(table) to get your metatable from a table. It will return the __metatable metafield
in the table.

setMetatable(table, metatable) to set your table's metatable. It will error if the __metatable metafield
is set.

However, if the table has a metatable with the metafield __metatable, it will error when you use setMetatable and return what it is set to when getMetatable is called.

== Metamethods ==

A metamethod is a type of function which changes the default way a table acts. The table below demonstrates what each
one is called, and how each one is used. <br/>

{| class="wikitable"
|-
| Name || Description || Arguments passed
|-
| __index
| Used when table[variable] is called.
| The variable.
|-
| __newindex
| Used like __index, but it is only called when the variable matches an empty space in the table.
| The variable.
|-
| __call
| A metamethod to turn a table's name into a function, or whatever you want it to do.
| Function, Tuple
|-
| __metatable
| Used for protecting metatables, called when getmetatable() is used on the table, setmetatable() just errors.
| Nothing (as far as Unit158 knows)
|-
| __mul
| Used as an operator overloader for multiplication.
| The two objects being "multiplied".
|-
| __div
| Used as an operator overloader for division.
| The two objects being "divided".
|-
| __sub
| Used as an operator overloader for substraction.
| The two objects being "subtracted".
|-
| __add
| Used as an operator overloader for addition.
| The two objects being "added".
|-
| __mod
| Used as an operator overloader for modulo.
| The two objects being "divided".
|-
| __pow
| Used as an operator overloader for exponentiation operation.
| The two objects being exponentiated.
|-
| __unm
| I am not exactly sure how this one works, it is for negatives though.
| The table being changed into a negative. 
|-
| __eq
| __eq is an operator overloader for comparison.
| The two objects being compared
|-
| __lt
| Less than.
| The two objects being compared
|-
| __le
| Less than or equal to.
| The objects being compared
|-
| __concat
| The objects being concatenated
| The two objects being concatenated
|-
| __len
| The # operator.
| The object having the operation performed on it.
|-
|}

== Examples ==
{{Example
|desc=Use __eq to check if two tables are equal
|code=table1 = {x=0, y=1, z=0}
table2 = {x=1, y=1, z=0}
metatable = {__eq = function(operand1, operand2, type)
if operand1.x == operand2.x and operand1.y == operand2.y and operand1.z then --Note: In reality you might want to first check if your these variables actually exist
return true
else
return false
end }
setmetatable(table1, metatable)
setmetatable(table2, metatable)
if table1 == table2 then
print("Equal")
else
print("Not equal")
end
}}
== External links ==
* [http://www.lua.org/manual/5.1/manual.html#2.8 Lua 5.1 Reference Manual: Metatables]

[[Category:Tutorials]]

Label

2015-02-02T15:07:08Z

Superaxander: Add another example

{{Stub|Needs more info about the program itself, perhaps an image?}}
Label is a [[CraftOS Shell|built in program for computers and turtles]] that will create a label for the computer, which will result in the label being assigned to the ID of the computer.

This prevents loss of programs in the event of destruction of the computer or turtle, with the added benefit of allowing turtles to retain fuel between being broken.

You can either '''set''' or '''clear''' the label on any computer or turtle.

{{Example
|desc=Set the label of the computer to "Foo"
|code=label set foo
}}
{{Example
|desc=Clears the label on the computer
|code=label clear
}}
{{Example
|desc=Gets the label on the computer
|code=label get
}}

[[Category:Programs]]

User:Superaxander

2013-03-29T03:09:32Z

Superaxander:

'''Welcome to my page'''

I Will try to make this wiki better. So we can all profit from that.

User:Superaxander

2013-03-29T03:09:12Z

Superaxander: Created page with "'''Welcome to page''' I Will try to make this wiki better. So we can all profit from that."

'''Welcome to page'''

I Will try to make this wiki better. So we can all profit from that.

Fs (API)

2013-03-29T03:07:28Z

Superaxander:

The FS API allows you to mess around with the filesystem.

<table style="width: 100%; border: solid 1px black; margin: 2px; border-spacing: 0px;">
<tr><td colspan="2" style="font-weight: bold; font-size: large; padding-bottom: .3em; border-bottom: solid #C9C9C9 1px; background: #D3FFC2; line-height:28px;">
[[File:Grid_disk.png|24px]]  
Fs (API)
</td></tr>

<tr><td style="width: 350px; background: #E0E0E0; padding: .4em; font-weight:bold;">Method Name</td><td style="background: #E0E0E0; padding: .4em; font-weight:bold;">Description</td></tr>

<tr style="background-color: #FFFFFF;"><td style="border-top: solid #C9C9C9 1px; padding: .4em;">[[fs.list]](path)</td>
<td style="border-top: solid #C9C9C9 1px; padding: .4em;">Lists the directories and files in the given directory</td></tr>

<tr style="background-color: #E8E8E8;"><td style="border-top: solid #C9C9C9 1px; padding: .4em;">[[fs.exists]](path)</td>
<td style="border-top: solid #C9C9C9 1px; padding: .4em;">Checks if a path refers to an existing file or directory</td></tr>

<tr style="background-color: #FFFFFF;"><td style="border-top: solid #C9C9C9 1px; padding: .4em;">[[fs.isDir]](path)</td>
<td style="border-top: solid #C9C9C9 1px; padding: .4em;">Checks if a path refers to an existing directory</td></tr>

<tr style="background-color: #E8E8E8;"><td style="border-top: solid #C9C9C9 1px; padding: .4em;">[[fs.isReadOnly]](path)</td>
<td style="border-top: solid #C9C9C9 1px; padding: .4em;">Checks if a path is read-only (i.e. cannot be modified)</td></tr>

<tr style="background-color: #FFFFFF;"><td style="border-top: solid #C9C9C9 1px; padding: .4em;">[[fs.getName]](path)</td>
<td style="border-top: solid #C9C9C9 1px; padding: .4em;">Gets the final component of a pathname</td></tr>

<tr style="background-color: #E8E8E8;"><td style="border-top: solid #C9C9C9 1px; padding: .4em;">[[fs.getDrive]](path)</td>
<td style="border-top: solid #C9C9C9 1px; padding: .4em;">Gets the type of storage medium holding a file or directory</td></tr>

<tr style="background-color: #FFFFFF;"><td style="border-top: solid #C9C9C9 1px; padding: .4em;">[[fs.getSize]](path)</td>
<td style="border-top: solid #C9C9C9 1px; padding: .4em;">Gets the size of a file and returns in bytes</td></tr>

<tr style="background-color: #FFFFFF;"><td style="border-top: solid #C9C9C9 1px; padding: .4em;">[[fs.getFreeSpace]](path)</td>
<td style="border-top: solid #C9C9C9 1px; padding: .4em;">Gets the remaining space in the given directory.</td></tr>

<tr style="background-color: #E8E8E8;"><td style="border-top: solid #C9C9C9 1px; padding: .4em;">[[fs.makeDir]](path)</td>
<td style="border-top: solid #C9C9C9 1px; padding: .4em;">Makes a directory</td></tr>

<tr style="background-color: #FFFFFF;"><td style="border-top: solid #C9C9C9 1px; padding: .4em;">[[fs.move]](fromPath, toPath)</td>
<td style="border-top: solid #C9C9C9 1px; padding: .4em;">Moves a file or directory to a new location</td></tr>

<tr style="background-color: #E8E8E8;"><td style="border-top: solid #C9C9C9 1px; padding: .4em;">[[fs.copy]](fromPath, toPath)</td>
<td style="border-top: solid #C9C9C9 1px; padding: .4em;">Copies a file or directory to a new location</td></tr>

<tr style="background-color: #FFFFFF;"><td style="border-top: solid #C9C9C9 1px; padding: .4em;">[[fs.delete]](path)</td>
<td style="border-top: solid #C9C9C9 1px; padding: .4em;">Deletes a file or directory</td></tr>

<tr style="background-color: #E8E8E8;"><td style="border-top: solid #C9C9C9 1px; padding: .4em;">[[fs.combine]](basePath, localPath)</td>
<td style="border-top: solid #C9C9C9 1px; padding: .4em;">Combines two path components, returning a path consisting of the local path nested inside the base path</td></tr>

<tr style="background-color: #FFFFFF;"><td style="border-top: solid #C9C9C9 1px; padding: .4em;">[[fs.open]](path, mode)</td>
<td style="border-top: solid #C9C9C9 1px; padding: .4em;">Opens a file so it can be read or written</td></tr>
</table>

[[Category:APIs]]

==Path Names==
All of these functions except for [[fs.combine]] refer solely to <em>absolute paths</em>.<br />
This means that the current working directory, as set by the <code>cd</code> command or the [[shell.setDir]] function, is ignored. Each path name consists of a list of nonempty path components separated by forward slashes, and those path components are taken one by one with the first being contained in the root directory of the computer.

If you need to deal with paths provided by the user that may be absolute or may be relative to the current working directory, use [[shell.resolve]].

Unlike most real-world operating systems, ComputerCraft's absolute path name system does not need to be started with a forward slash ( / ). Making the directory "a/b/c" is the same as making "/a/b/c". Leaving the slashes is just a matter of preference to the coder.

Fs.getFreeSpace

2013-03-29T03:05:12Z

Superaxander:

{{lowercase}}
{{Function
|name=fs.getFreeSpace
|args=[[String(type)|string]] path
|api=fs
|returns=[[Number_(type)|number]] the amount of free space in bytes
|desc=returns the amount of free space in the given directory
|examples=
{{Example
|desc=Computes the amount of free space on the computer
|code=print(tostring(fs.getFreeSpace("/")))
|output=10(can be different)
}}
}}
[[Category:Lua_Core_Functions]]

Talk:Terminate (event)

2013-03-27T22:45:44Z

Superaxander: Created page with "Is this enough to remove the "This Page Needs Some Serious TLC Stat" --~~~~"

Is this enough to remove the "This Page Needs Some Serious TLC Stat"
--[[User:Superaxander|Superaxander]] 02:45, 28 March 2013 (MSK)

Terminate (event)

2013-03-27T22:44:29Z

Superaxander:

{{NeedsWork|A demonstration on the use and handling of this event would be beneficial. ''[[User:AfterLifeLochie|AfterLifeLochie]] 16:13, 30 November 2012 (MSK)''}}

{{Event
|name=terminate
|desc=Fired when CTRL+T is held to terminate the running program.
}}
{{Example
|desc=This overides the [[os.pullEvent]] function to display a custom message when a program is terminated
|code= function os.pullEvent(_sFilter)
local event = { os.pullEventRaw(_sFilter) }
if event[1] == "terminate" then
error("Terminate Event Found", 0)
end
return unpack(event)
end
}}

Terminate (event)

2013-03-27T22:44:01Z

Superaxander:

Terminate (event)

2013-03-27T22:42:59Z

Superaxander:

{{NeedsWork|A demonstration on the use and handling of this event would be beneficial. ''[[User:AfterLifeLochie|AfterLifeLochie]] 16:13, 30 November 2012 (MSK)''}}

{{Event
|name=terminate
|desc=Fired when CTRL+T is held to terminate the running program.
}}
{{Example
|desc=This overides the [[os.pullEvent]] function to display a custom message when a program is terminated
|code=function os.pullEvent(_sFilter)
local event = { os.pullEventRaw(_sFilter) }
if event[1] == "terminate" then
error("Terminate Event Found", 0)
end
return unpack(event)
end
}}

Terminate (event)

2013-03-27T22:42:36Z

Superaxander:

{{NeedsWork|A demonstration on the use and handling of this event would be beneficial. ''[[User:AfterLifeLochie|AfterLifeLochie]] 16:13, 30 November 2012 (MSK)''}}

{{Event
|name=terminate
|desc=Fired when CTRL+T is held to terminate the running program.
}}
{{Example
|desc=This overides the [[os.pullEvent()]] function to display a custom message when a program is terminated
|code=function os.pullEvent(_sFilter)
local event = { os.pullEventRaw(_sFilter) }
if event[1] == "terminate" then
error("Terminate Event Found", 0)
end
return unpack(event)
end
}}

Fs.getFreeSpace

2013-03-27T21:45:25Z

Superaxander:

{{lowercase}}
{{Function
|name=fs.getFreeSpace
|args=[[String_(type)|string]] path
|api=fs
|returns=[[String_(type)|string]] the amount of free space in bytes
|desc=returns the amount of free space in the given directory
|examples=
{{Example
|desc=Computes the amount of free space on the computer
|code=print(tostring(fs.getFreeSpace("/")))
|output=10(can be different)
}}
}}
[[Category:Lua_Core_Functions]]

Fs.getFreeSpace

2013-03-27T21:45:08Z

Superaxander:

Fs.getFreeSpace

2013-03-27T19:20:04Z

Superaxander:

Fs.getFreeSpace() get's the free space in bytes of the path you give it

{example}{

--Example Usage of fs.getFreeSpace
print(tostring(fs.getFreeSpace("/")))
}

Fs.getFreeSpace

2013-03-27T19:17:14Z

Superaxander: Created page with "Fs.getFreeSpace() get's the free space in bytes of the path you give it == example == <nowiki> --Example Usage of fs.getFreeSpace print(tostring(fs.getFreeSpace("/"))) </no..."

Fs.getFreeSpace() get's the free space in bytes of the path you give it

== example ==

<nowiki>
--Example Usage of fs.getFreeSpace
print(tostring(fs.getFreeSpace("/")))
</nowiki>