llAtan2
Revision as of 12:05, 24 April 2009 by Strife Onizuka (talk | contribs)
LSL Portal | Functions | Events | Types | Operators | Constants | Flow Control | Script Library | Categorized Library | Tutorials |
Summary
Function: float llAtan2( float y, float x );3 | Function ID |
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]
Caveats
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) {
vector me = llGetPos(); float distance = llVecDist(me, target); list DIRS =["W","NW","N","NE","E","SE","S","SW","W"]; return llList2String(DIRS,llCeil(4.5-((4*llAtan2((target.y-me.y)/distance,(target.x-me.x)/distance))/PI)));}</lsl>