Floats

From SA-MP Wiki

Floats are a type of tagged variable in PAWN and they are "floating point numbers", hence the name Float. This basically means that they support decimal places, such as 1.2, 1.1, 5.32, 64.21 - where as normal integers (untagged) don't support decimal places.

Contents 1 Initializing a Float variable 1.1 Some examples 1.1.1 Get the players position 1.1.2 Dropping a player 1.1.3 Creating a sine wave of objects 2 Why are Floats important? 3 Converting floats 3.1 Floats and Strings 3.1.1 Float -> String 3.1.2 String -> Float 3.2 Floats and Integers 3.2.1 Float -> Integer 3.2.2 Integer -> Float 4 The float library 4.1 Float library functions 4.2 Documentation

Initializing a Float variable

To initialize a Float variable, all you have to do is assign it the Float tag:

new Float:fMyFloat;

You can now assign it floating point numbers:

new Float:fMyFloat;
 
/* All of the assignments below are valid examples. */
fMyFloat = 5.3;
fMyFloat = 5.33;
fMyFloat = 5.395293;
 
new Float:fMyHugeFloat = 9995499.24;
new Float:fMyFloatPI   = 3.1415926535;
/* ... */

Some examples

Get the players position

//Create variables for each coordinate.
new Float:X,
    Float:Y,
    Float:Z;
 
//Assign each variable the players position.
GetPlayerPos( playerid, X, Y, Z );

Dropping a player

//Define our offset to drop them at.
const Float:DROP_HEIGHT = 50.0;
 
//Create a new Float array to store each coordinate into.
new Float:a_fPlayerPos[ 3 ];
 
//Assign the newly created array each coordinate (X, Y, Z).
GetPlayerPos( playerid, a_fPlayerPos[ 0 ], a_fPlayerPos[ 1 ], a_fPlayerPos[ 2 ] );
 
//Now that we have the position of the player, we can set their Z position to their current one, plus the offset.
SetPlayerPos( playerid, a_fPlayerPos[ 0 ], a_fPlayerPos[ 1 ], (a_fPlayerPos[ 2 ] + DROP_HEIGHT) );

Creating a sine wave of objects

const nObjModel     = 1337;
const nSteps        = 100 ;
const nAmp          = 15  ;
const Float:nFreq   = 0.03;
 
//Make a new array, assign the players position to it.
new Float:cPos[ 3 ];
 
GetPlayerPos( playerid, cPos[ 0 ], cPos[ 1 ], cPos[ 2 ] );
 
//Run for the specified amount of iterations.
for( new i = (0); i != nSteps; i++ )
{
    //The formula to calculate the position of the object.
    new Float:formula = (floatsin(i*nFreq)*nAmp);
 
    //Create an object in place of the sine wave iteration.
    CreateObject( nObjModel, cPos[ 0 ], cPos[ 1 ] + i, ( cPos[ 2 ] + formula ), 0, 0, 0 );
}

Why are Floats important?

Floats are important because they are used through SA-MP's native functions, mostly for the coordinate system of GTA:SA. Floats are however, used for other things than just the coordinate system - such as the player's health, armour, vehicle health, velocity, rotation and lots more.

Converting floats

Most of the time floats need to be converted into a different type, such as an integer or even a string. Here are a couple of conversion samples:

Floats and Strings

---

Float -> String

A Float can be converted to a string by using %f in format:

new Float:fMyFloat = 53.155;
new szStr[ 32 ];
 
format( szStr, sizeof szStr, "%f", fMyFloat );
 
//szStr is now "53.155".

It should be noted that if you want to convert a float to a string to a certain amount of decimal places, you'd specify it between the % and the f of %f, in the format %.(number of decimal places)f:

new Float:fMyFloat = 64.532115;
new szStr[ 32 ];
 
format( szStr, sizeof szStr, "%.2f", fMyFloat ); //To 2 decimal places
//szStr is now "64.53".
 
format( szStr, sizeof szStr, "%.3f", fMyFloat ); //To 3 decimal places
//szStr is now "64.532".
 
format( szStr, sizeof szStr, "%.4f", fMyFloat ); //To 4 decimal places
//szStr is now "64.5321".

By default, if no precision is set (It's just %f), then a string will only hold a floating point value to a maximum of 6 decimal places.

String -> Float

A string can be converted to a Float using the function floatstr:

new szStr[ 4 ] = "5.1";
new Float:fMyFloat = floatstr( szStr );
 
//fMyFloat is now 5.1.

Floats and Integers

---

Float -> Integer

Converting a float to an integer is quite easy, as an integer doesn't have a tag and a float does. All we have to do is change the tag:

new Float:fMyFloat = 1.3;
new nSomeInt = _:fMyFloat;
 
//nSomeInt is now 1.

You can also convert floats to integers with floatround:

new Float:fMyFloat = 1.3;
new nSomeInt = floatround( fMyFloat );
 
//nSomeInt is now 1.

Integer -> Float

Converting an integer to a Float can be done various ways:

new nSomeInt = 5;
new Float:fMyFloat;
 
//By changing the tag:
fMyFloat = Float:nSomeInt;
 
//By using float():
fMyFloat = float( nSomeInt );
 
//Or just by assigning it:
fMyFloat = nSomeInt;
 
//fMyFloat is now 5.0.

The float library

The float library can be included into your script by inserting the following code:

#include <float>

However, this is quite useless, as a_samp includes this library by default; and it is probably already included.

Float library functions

Here is a list of functions provided by the float library:

• float - Converts integer to a float.
• floatabs - Return the absolute value of a float.
• floatadd - Adds two floats together.
• floatcmp - Compares two floats.
• floatcos - Gets cosine from angle.
• floatdiv - Divides two floats.
• floatfract - Returns the fractional portion of a float.
• floatlog - Gets logarithm.
• floatmul - Multiplies two floats.
• floatpower - Raises given value to a power of exponent.
• floatround - Rounds float to integer.
• floatsin - Gets sine from angle.
• floatsqroot - Calculates square root of given value.
• floatstr - Converts string to float.
• floatsub - Subtracts two floats.
• floattan - Returns tangent from angle.

Documentation

The full documentation for the float library can be found here:

• Floating Point Support