// Determines and sets the center of gravity for a planet. If no center of gravity is in range, the planet will not move.
public void DetermineCOG(CenterOfGravity possibleCOG)
{
//Determine the distance between the point of gravity and the planet
var d = Math.Sqrt(Math.Pow(m_location.X - possibleCOG.Location.X, 2) + Math.Pow(m_location.Y - possibleCOG.Location.Y, 2));
var dist = Math.Abs(d);
// Verify that the planet is within the radius of the center of gravity
if (dist <= possibleCOG.Radius)
{
if (dist < m_distanceFromCOG)
{
m_distanceFromCOG = dist;
//Set the center of gravity
m_centerOfGravity = possibleCOG;
}
}
}
private void pictureBox1_Click(object sender, EventArgs e)
{
MouseEventArgs click = e as MouseEventArgs;
Point newPoint = new Point(click.X, click.Y);
if (centerOfGravityButton.Checked)
{
int radius = (int)numericUpDown1.Value;
//Add a new CenterOfGravity to the list
CenterOfGravity newCOG = new CenterOfGravity(newPoint, radius);
COG.Add(newCOG);
Bitmap bmp = new Bitmap(pictureBox1.Width, pictureBox1.Height);
Graphics circle = Graphics.FromImage(bmp);
int index = 0;
//display all centers of gravity
foreach (CenterOfGravity cog in COG)
{
int diameter = cog.Radius * 2;
circle.FillEllipse(grayBrush, cog.Location.X - cog.Radius, cog.Location.Y - cog.Radius, diameter, diameter);
circle.FillEllipse(blackBrush, cog.Location.X - 3, cog.Location.Y - 3, 6, 6);
index++;
}
//display any planets
foreach (Planet planet in Planets)
{
circle.FillEllipse(redBrush, planet.Location.X - 5, planet.Location.Y - 5, 10, 10);
}
pictureBox1.Image = bmp;
}
else if (planetButton.Checked)
{
bool inPull = false;
CenterOfGravity gravity = new CenterOfGravity();
double closestDist = 100000.00;
//only add the point if it is within the area of the center of gravity
//Determine the distance between the point of gravity and the planet
foreach (CenterOfGravity cog in COG)
{
var d = Math.Sqrt(Math.Pow(newPoint.X - cog.Location.X, 2) + Math.Pow(newPoint.Y - cog.Location.Y, 2));
var dist = Math.Abs(d);
if (dist <= cog.Radius)
{
inPull = true;
if (dist < closestDist)
{
closestDist = dist;
gravity.Location = cog.Location;
gravity.Radius = cog.Radius;
}
break;
}
else
{
inPull = false;
}
}
if (inPull == true)
{
//add the planet to our list
Planet newPlanet = new Planet(newPoint);
newPlanet.DetermineCOG(gravity);
Planets.Add(newPlanet);
Bitmap bmp = new Bitmap(pictureBox1.Width, pictureBox1.Height);
Graphics planet = Graphics.FromImage(bmp);
//first redraw any centers of gravity
int index = 0;
foreach (CenterOfGravity cog in COG)
{
int diameter = cog.Radius * 2;
planet.FillEllipse(grayBrush, cog.Location.X - cog.Radius, cog.Location.Y - cog.Radius, diameter, diameter);
planet.FillEllipse(blackBrush, cog.Location.X - 3, cog.Location.Y - 3, 6, 6);
index++;
}
//then draw planets on top.
foreach (Planet pt in Planets)
{
planet.FillEllipse(redBrush, pt.Location.X - 5, pt.Location.Y - 5, 10, 10);
}
pictureBox1.Image = bmp;
}
else
{
MessageBox.Show("Please place the planet in a center of gravity");
}
}
else // neither is checked and that's an issue
{
MessageBox.Show("Please select an option: create a center of gravity or a planet.");
}
}