Question

Seems like there should be some convenient way to do this?

I couldn’t find one, so I threw together the below algorithm. Is it memory/computationally optimal?

Thanks:

Edit: Original algorithm was stupidly wrong, maybe this is better?

public static float minDistance(RectF rect, PointF point)
{
    if(rect.contains(point.x, point.y))
    {
        //North line 
        float distance = point.y - rect.top;

        //East line
        distance = Math.min(distance, point.x - rect.left);

        //South line
        distance = Math.min(distance, rect.bottom - point.y);

        //West line
        distance = Math.min(distance, rect.right - point.x);

        return distance;
    }
    else
    {
        float minX, minY;

        if (point.x < rect.left) 
        {
            minX = rect.left;
        } 
        else if (point.x > rect.right) 
        {
            minX = rect.right;
        } 
        else 
        {
            minX = point.x;
        }

        if (point.y < rect.top) 
        {
            minY = rect.top;
        } 
        else if (point.y > rect.bottom) 
        {
            minY = rect.bottom;
        } 
        else 
        {
            minY = point.y;
        }

        float vectorX = point.x - minX;
        float vectorY = point.y - minY;

        float distance = (float) Math.sqrt((vectorX * vectorX) + (vectorY * vectorY)); 

        return distance;
    }
}

Answer 1

Just take the closest point and then get the distance to that.
Off the top of my head:

    float closestX, closestY;

    if(point.x >= x1 && point.x <= x2 && point.y >= y1 && point.y <= y2)
    {
         float bestDistance = point.y - y1;
         bestDistance = Math.min(distance, y2 - point.y);
         bestDistance = Math.min(distance, point.x - x1);
         bestDistance = Math.min(distance, x2 - point.x);

         return bestDistance;
    }

    if (point.x < x1) {
        closestX = x1;
    } else if (point.x > x2) {
        closestX = x2;
    } else {
        closestX = point.x;
    }

    if (point.y < x1) {
        closestY = y1;
    } else if (point.y > y2) {
        closestY = y2;
    } else {
        closestY = point.y;
    }

    float vectorY = point.x - closestX;
    float vectorY = point.Y - closestY;

    float distance = sqrtf((vectorX * vectorX) + (vectorY * vectorY));