Difference between revisions of "Label"
imported>QluIze m |
imported>Qazaaq m (rv) |
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Line 20: | Line 20: | ||
; update the loop counter | ; update the loop counter | ||
set var to var | set var to var + 1 | ||
; we only want to go through the loop three times, so check the loop counter | ; we only want to go through the loop three times, so check the loop counter | ||
Line 40: | Line 40: | ||
A more familiar For-loop in a normal programming language would look like this: | A more familiar For-loop in a normal programming language would look like this: | ||
<pre>for (i = 0; i < 5; i | <pre>for (i = 0; i < 5; i++) | ||
{ | { | ||
for (j = 0; j < 3 ; j | for (j = 0; j < 3 ; j++) | ||
{ | { | ||
//Do Something | //Do Something | ||
Line 56: | Line 56: | ||
Label 1 ; top of inner loop | Label 1 ; top of inner loop | ||
PrintToConsole "i = %.0f, j = %.0f" i, j | PrintToConsole "i = %.0f, j = %.0f" i, j | ||
set j to ( j | set j to ( j + 1 ) | ||
if ( j < 3 ) | if ( j < 3 ) | ||
GoTo 1 ; equivalent to RestoreIP 1 | GoTo 1 ; equivalent to RestoreIP 1 | ||
endif | endif | ||
set i to ( i | set i to ( i + 1 ) | ||
if ( i < 5 ) | if ( i < 5 ) | ||
GoTo 0 | GoTo 0 |
Latest revision as of 13:20, 19 September 2007
A command for Oblivion Script Extender
Syntax:
Label [labelID]
An alias for SaveIP. This command allows you to set up one or more named labels within a script. Using GoTo or RestoreIP causes script processing to jump to the label, allowing you to set up simple loops. By providing an optional label ID, multiple labels or nested loops can be defined.
Example:
begin onActivate ; declare a variable to keep track of the number of times we've gone through the loop long var set var to 0 ; save the current instruction pointer ; this records that the beginning of the loop is right before the PrintToConsole command SaveIP ; could also use Label ; print the current loop count PrintToConsole "loop %f" var ; update the loop counter set var to var + 1 ; we only want to go through the loop three times, so check the loop counter if var < 3 ; jump back to the saved location RestoreIP ; could also use Goto endif ; if we get here, we're done with the loop end
When activated, this script will print:
loop 0.0000 loop 1.0000 loop 2.0000
To support nested loops, the SaveIP and RestoreIP commands take an optional integer parameter specifying which 'slot' to save the instruction location in. If you don't specify a number, it defaults to 0. There are 256 slots in the internal list.
A more familiar For-loop in a normal programming language would look like this:
for (i = 0; i < 5; i++) { for (j = 0; j < 3 ; j++) { //Do Something } }
To create the same loop using OBSE functions:
short i short j Label 0 ; top of outer loop, equivalent to SaveIP 0 set j to 0 Label 1 ; top of inner loop PrintToConsole "i = %.0f, j = %.0f" i, j set j to ( j + 1 ) if ( j < 3 ) GoTo 1 ; equivalent to RestoreIP 1 endif set i to ( i + 1 ) if ( i < 5 ) GoTo 0 endif
Note that unless the above loop is wrapped inside a conditional statement or a block like OnActivate, it will restart the very next frame and every frame thereafter.
Notes[edit | edit source]
- Be careful to make sure your loop has an exit condition, otherwise you run the risk of creating an infinite loop, which can freeze the game and make it impossible for the player to exit.
- For the most part, scripts will run one at a time and different scripts can use the same label IDs without any problems. However, result scripts and scripts with onActivate blocks will run instantly when called via script (SetStage and ObjectRef.Activate player, 1, respectively), before the next line of code proceeds. For those two script types, make sure the IDs are unique.
- If you use a label ID in the calling script, and then the same ID in the called script, the ID will be set to the location in the called script. If the calling script uses Goto ID, when that ID is set to another script, it will act as a Return.