Distance from a Point to a Line

[Joe123]

Well, I wrote this for Gleeok, but I'm sure other people might want to make lasers or tripwires or something too, so I thought I'd post it here.

int DistancePointToLine(int x1,int y1,int x2,int y2,int distx,int disty){
 int dx = x2-x1;
 if(dx != 0){
	int m = (y2-y1)/dx;
  int c = y1 - m*x1;
  return (Abs(-m*distx + disty - c))/Sqrt(m*m + 1);
 }
 else return Abs(distx-x1);
}

Pretty self explanitory, the inputs go:
(LineXcoord1,LineYcoord1)(LineXcoord2,LineYcoord2) (PointtomeausretoX,PointtomeasuretoY)

In that order.


Might not look so interesting, but don't be fooled!
Coupled with Screen->Line, it's actually quite fun =P

ffc script laser{
	void run(){
	int i;
	int x1 = 128; int y1 = 0;
	int x2 = 160; int y2 = 168;
		while(true){
			while(i<256){
				Screen->Line(4,x1,y1,i,y2,Rand(120)+1,1,0,0,0,128);
				if(DistancePointToLine(x1,y1,i,y2,Link->X+8, Link->Y+8) < 2) Game->PlaySound(36);
				i+=2;
			Waitframe();
  			}
			while(i>0){
				Screen->Line(4,x1,y1,i,y2,Rand(120)+1,1,0,0,0,128);
				if(DistancePointToLine(x1,y1,i,y2,Link->X+8, Link->Y+8) < 2) Game->PlaySound(36);
				i-=2;
			Waitframe();
			}
		}
	}
}

Here's a little example of how you might use it.
At the moment, it only plays a sound effect if Link gets hit.
But imagine what it could do!