Tag Archives: as3

Calculate Slope of a Line

Actionscript:
  1. // calculate the slope of a line
  2. function calculateSlope(x1:Number, y1:Number, x2:Number, y2:Number):Number {
  3.         // rise over run
  4.     var s:Number = (y1 - y2) / (x1 - x2);
  5.     /*if (x1==x2) {
  6.         // slope is Infinity or -Infinity
  7.     }*/
  8.     return s;
  9. }
  10.  
  11. /**
  12.  Test it out
  13. */
  14. function draw(x1:Number, y1:Number, x2:Number, y2:Number):void {
  15.     graphics.moveTo(x1, y1);
  16.     graphics.lineTo(x2, y2)
  17.     var txt:TextField =TextField(addChild(new TextField()));
  18.     txt.text = calculateSlope(x1, y1, x2, y2).toFixed(2);
  19.     txt.x = x2, txt.y = y2;
  20. }
  21.  
  22. graphics.lineStyle(0,0xFF0000);
  23. draw (100, 100, 200, 200);
  24.  
  25. draw(100, 100, 200, 150);
  26.  
  27. draw(100, 100, 200, 100);
  28.  
  29. draw(100, 100, 99, 200);

This snippet shows how to calculate the slope of a line ... It demos the function by drawing a few lines and showing the corresponding slope of each.

It will draw this:

If (x1 == x2), the slope will be -Infinity or Infinity... depending on where you're using this calculation you may want to reset the s variable to something else, return null etc... I commented it out for simplicity.

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