Difference between revisions of "LlAtan2"
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(Corrected the 'compass' function.) |
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//a string with the literal compass-direction of that target towards your position | //a string with the literal compass-direction of that target towards your position | ||
//by Ramana Sweetwater 2009/01, any use allowed license :-) | //by Ramana Sweetwater 2009/01, any use allowed license :-) | ||
string compass (vector target) | string compass (vector target) | ||
{ | {//-1.2732395447351 == -4/PI | ||
vector | vector direction = target - llGetPos(); | ||
list DIRS = [ "NE", "E", "SE", "S", "SW", "W", "NW", "N" ]; | |||
list DIRS =[" | integer index = llRound((llAtan2(direction.y, direction.x) * -1.2732395447351)) % 8; | ||
return llList2String(DIRS, index); | |||
}</lsl> | }</lsl> | ||
[[/Compass QA]] | |||
|helpers | |helpers | ||
|also_functions= | |also_functions= | ||
Revision as of 09:06, 4 June 2010
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Summary
Function: float llAtan2( float y, float x );| 0.0 | Forced Delay |
| 10.0 | Energy |
Returns a float that is the 
arctangent2 of y, x.
| • float | y | |||
| • float | x |
Similar to the arctangent(y/x) except it utilizes the signs of x & y to determine the quadrant. Returns zero if x and y are zero.
The returned value is in the range [-PI, PI][1].
Examples
<lsl>default {
state_entry()
{
float num1 = llFrand(100.0);
float num2 = llFrand(100.0);
llOwnerSay("y = " + (string)num1);
llOwnerSay("x = " + (string)num2);
llOwnerSay("The arctangent of y divided by x is " + (string)llAtan2(num1, num2));
}
}</lsl><lsl>//Function with input of a vector determining the position of a target and returning //a string with the literal compass-direction of that target towards your position //by Ramana Sweetwater 2009/01, any use allowed license :-)
string compass (vector target) {//-1.2732395447351 == -4/PI
vector direction = target - llGetPos(); list DIRS = [ "NE", "E", "SE", "S", "SW", "W", "NW", "N" ]; integer index = llRound((llAtan2(direction.y, direction.x) * -1.2732395447351)) % 8; return llList2String(DIRS, index);
}</lsl>
/Compass QASee Also
Deep Notes
Footnotes
- ^ The ranges in this article are written in Interval Notation.
Signature |
|---|
function float llAtan2( float y, float x ); |