# Math
Math related methods


- - -

## SRL.Modulo
```pascal
function TSRL.Modulo(X, Y: Double): Double; static;
function TSRL.Modulo(X, Y: Int32): Int32; static; overload;
```
This function returns the remainder from the division of the first argument by the second.
It will always returns a result with the same sign as its second operand (or zero).

Example:
```pascal
  Writeln(SRL.Modulo(a, b));
```


- - -

## SRL.CrossProduct
```pascal
function TSRL.CrossProduct(ry,ry, px,py, qx,qy: Double): Double; static;
function TSRL.CrossProduct(r, p, q: TPoint): Int64; static; overload;
```
Cross-product of rp and rq vectors.


- - -

## SRL.DeltaAngle
```pascal
function TSRL.DeltaAngle(DegA, DegB: Double; R: Double = 360): Double; static;
```
Returns the shortest difference between two given angles.


- - -

## SRL.DistToLine
```pascal
function TSRL.DistToLineEx(pt, sA, sB: TPoint; out Nearest: TPoint): Double; static;
function TSRL.DistToLine(pt, sA, sB: TPoint): Double; static;
```
Returns the distance to the nearest point on the line `sA`..`sB`


- - -

## TRectangle.NearestEdge
```pascal
function TRectangle.NearestEdge(P: TPoint): TPoint; constref;
```
Returns the closest edge point (think Rect.ToTPA.Connect) to the TPoint `P`.


- - -

## SRL.LinesIntersect
```pascal
function TSRL.LinesIntersect(p1,p2, q1,q2:TPoint; out i: TPoint): Boolean; static;
function TSRL.LinesIntersect(p1,p2, q1,q2:TPoint): Boolean; static; overload;
```
Check if 2 lines cross each other.


- - -

## SRL.PointInTriangle
```pascal
function TSRL.PointInTriangle(const pt: TPoint; t1,t2,t3: TPoint): Boolean; static;
```
Returns True if the TPoint 'pt' is inside or on the edge triangle


- - -

## SRL.PointInRect
```pascal
function TSRL.PointInRect(const pt, a,b,c,d: TPoint): Boolean; static;
function TSRL.PointInRect(const pt: TPoint; const rect: TRectangle): Boolean; static; overload;
```
Returns true if the TPoint 'pt' is in a rect (defined by four point.

Example:
```pascal
Writeln(SRL.PointInRect(Point(100, 100), [0,0], [200,1], [201,201], [0,225]));
```


- - -

## SRL.PointInCircle
```pascal
function TSRL.PointInCircle(const pt, center: TPoint;const radius: Double): Boolean; static;
```
Returns True if the TPoint 'pt' is inside the circle


- - -

## SRL.PointInEllipse
```pascal
function TSRL.PointInEllipse(pt, Center:TPoint; YRad, XRad: Double): Boolean; static;
```
Returns True if the TPoint 'pt' is inside the ellipse


- - -

## SRL.PointInPoly
```pascal
function TSRL.PointInPoly(pt: TPoint; poly: TPointArray): Boolean; static;
```
Check if a point is within a polygon/shape by the given outline points (poly)
The points must be in order, as if you would draw a line trough each point.

```{note}
Uses winding number algorithm
```


- - -

## SRL.PointInCuboid
```pascal
function TSRL.PointInCuboid(pt: TPoint; Top, Btm: TRectangle): Boolean; static;
```
Check if a point is within a cuboid defined by top and bottom rectangle.