Question

I’m trying to divide a line into multiple segments. Because of that i’ve created a function below to try get sub points between two points. It’s not quite working, but almost there. Ideally, i’d like to use it something like this:

subPoint(point1, point2, 5, 10);  // this would return the half way point
subPoint(point1, point2, 1, 10);  // this would return a point 1 tenth towrds point2

Here’s the rough code below – any tips or pointers very welcome.

Vector subPoint(Vector startPoint, Vector endPoint, int segment, int totalSegments) {

  int division = (int)(totalSegments / segment);

  PVector divPoint = new PVector();

  int midX=(int)(startPoint.x+((endPoint.x-startPoint.x)/division));
  int midY=(int)(startPoint.y+((endPoint.y-startPoint.y)/division));

  divPoint.set(midX, midY, 0);

  return(divPoint);
}

Answer 1

Try replacing your calculations with the following:

int midX = (startPoint.x + (int) ((double) (endPoint.x - startPoint.x) / (double) totalSegments) * segment);
int midY = (startPoint.y + (int) ((double) (endPoint.y - startPoint.y) / (double) totalSegments) * segment);

I transformed the values to doubles in order to make the calculations a little more accurate. You may want to consider keeping the values as doubles as that will give you better accuracy on line segments.