Difference between revisions of "Category:LSL Vector"
m (Oops, fix also the variable) |
Frionil Fang (talk | contribs) (→Components: can access components only with variables, not literals or function returns) |
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float y = vec.y; // 2.0 | float y = vec.y; // 2.0 | ||
float z = vec.z; // 3.0 | float z = vec.z; // 3.0 | ||
</syntaxhighlight> | |||
Note that components can be only accessed with vector variables. Attempting to access the components of a vector literal or a return value from a function is illegal. | |||
<syntaxhighlight lang="lsl2"> | |||
// These are not valid component accesses | |||
float f1 = <0, 1, 2>.z; | |||
float f2 = llGetScale().x; | |||
</syntaxhighlight> | </syntaxhighlight> | ||
Latest revision as of 15:01, 15 October 2023
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Vector
A vector is a data type that contains a set of three float values.
Components
Each element can be accessed individually by appending .x, .y, or .z to the variable name.
vector vec = <1, 2, 3>;
float x = vec.x; // 1.0
float y = vec.y; // 2.0
float z = vec.z; // 3.0
Note that components can be only accessed with vector variables. Attempting to access the components of a vector literal or a return value from a function is illegal.
// These are not valid component accesses
float f1 = <0, 1, 2>.z;
float f2 = llGetScale().x;
Uses
Vectors are often used for...
- Position: x, y, and z are in metres.
- Velocity: x, y, and z are in meters per second.
- Colour: x is Red, y is Green, and z is Blue.
Operators
Vectors support the following operations:
Addition, Operator "+"
vector v = <1, 2, 3> + <0.5, 0.0, 3>; // <1.5, 2.0, 6.0>
Subtraction, Operator "-"
vector v = <1, 1, 1> - <0.5, 0.0, 3>; // <0.5, 1.0, -2.0>
Dot Product, Operator "*"
float f = <9, 2, 7> * <4, 8, 10>; // 122.0
Cross Product, Operator "%"
vector v = <2, 3, 4> % <5, 6, 7>; // <-3, 6, -3>
Scalar
A vector can be multiplied or divided by a Float or Integer to scale it.
Each component of the vector will be multiplied or divided by the same value.
vector v = <1, 2, 3> * 1.5; // <1.5, 3.0, 4.5>
vector v = <1, 2, 3> / 1.5; // <0.666667, 1.333333, 2.000000>
Rotation
A vector can be multiplied or divided by a Quaternion to rotate it.
// 45-degree rotation around the Z (up) axis
rotation r = llEuler2Rot(<0, 0, 45> * DEG_TO_RAD);
// Vector whose direction is 1 meter to the east
vector v = <1, 0, 0>;
// Vector whose direction is north-east
vector rotated = v * r; // <0.707107, 0.707107, 0.000000>
// Vector whose direction is south-east
// (division performs a rotation in the opposite direction)
vector rotated = v / r; // <0.707107, -0.707107, 0.000000>
Useful Snippets
Check whether a string value is a valid vector:
integer IsVector(string s)
{
list split = llParseString2List(s, [" "], ["<", ">", ","]);
if(llGetListLength(split) != 7)//we must check the list length, or the next test won't work properly.
return FALSE;
return !((string)((vector)s) == (string)((vector)((string)llListInsertList(split, ["-"], 5))));
//it works by trying to flip the sign on the Z element of the vector,
//if it works or breaks the vector then the values won't match.
//if the vector was already broken then the sign flip will have no affect and the values will match
//we cast back to string so we can catch negative zero which allows for support of ZERO_VECTOR
}//Strife Onizuka
Subcategories
This category has the following 2 subcategories, out of 2 total.
Pages in category "LSL Vector"
The following 6 pages are in this category, out of 6 total.