/// <summary>
/// Doubles the no. of points in the snake
/// </summary>
public void doublePoints()
{
// Create copy
SnakePoint[] snakepointsCopy = new SnakePoint[m_points.Count];
m_points.CopyTo(snakepointsCopy);
m_points.Clear();
// Refill points with middle points
for (int i = 0; i < snakepointsCopy.Length; ++i)
{
SnakePoint p = snakepointsCopy[i];
SnakePoint p_next;
if (i < snakepointsCopy.Length - 1)
{
p_next = snakepointsCopy[i + 1];
}
else
{
p_next = snakepointsCopy[0];
}
addPoint(p.pos);
Vec2F midPoint = new Vec2F((p.pos + p_next.pos) * 0.5f);
addPoint(midPoint);
}
}
/// <summary>
/// Cuts the no. of points of the snake in half
/// </summary>
public void halfPoints()
{
if (m_points.Count > 4)
{
// Create copy
SnakePoint[] snakepointsCopy = new SnakePoint[m_points.Count];
m_points.CopyTo(snakepointsCopy);
m_points.Clear();
// Add every second point
for (int i = 0; i < snakepointsCopy.Length; i += 2)
{
addPoint(snakepointsCopy[i].pos);
}
}
else
{
m_points.Clear();
m_center = Vec2F.Zero;
m_F_elasSum = Vec2F.Zero;
m_F_curvSum = Vec2F.Zero;
m_F_imgSum = Vec2F.Zero;
frm.btnDeleteSnake.Enabled = false;
frm.btnDoublePoints.Enabled = false;
frm.btnHalfPoints.Enabled = false;
}
}
private void Disp_Tick(object sender, object e)
{
List <SnakePoint> tmpPoints = player;
player = new List <SnakePoint>();
if (food.X == tmpPoints[0].X && food.Y == tmpPoints[0].Y)
{
Windows.UI.ViewManagement.ApplicationView.GetForCurrentView().Title = "!!!";
}
player.Add(Direction(dir, tmpPoints));
if (food.X == player[0].Y && food.Y == player[0].X)
{
state = 0;
}
for (int i = 0; i < tmpPoints.Count - state; i++)
{
player.Add(tmpPoints[i]);
}
//if (food.X == player[0].Y && food.Y == player[0].X) Windows.UI.ViewManagement.ApplicationView.GetForCurrentView().Title = "!!!";
//Windows.UI.ViewManagement.ApplicationView.GetForCurrentView().Title = "food: " + food.X + " " + food.Y + " plr: " + player[0].X + " " + player[0].Y;
board = new int[10, 20];
Array.Clear(board, 0, board.Length);
foreach (SnakePoint i in player)
{
if (i.Y > board.GetLength(0) - 1 || i.Y < 0 || i.X > board.GetLength(1) - 1 || i.X < 0 || board[i.Y, i.X] == 1)
{
disp.Stop();
return;
}
board[i.Y, i.X] = 1;
}
if (state == 0)
{
food = new SnakePoint {
X = rnd.Next(board.GetLength(0) - 1), Y = rnd.Next(board.GetLength(1) - 1)
};
state = 1;
}
board[food.X, food.Y] = 2;
//textBlock.Text ="\n\n\n\n\n";
//for (int i = 0; i < board.GetLength(0); i++)
//{
// for (int j = 0; j < board.GetLength(1); j++)
// {
// textBlock.Text += board[i, j] + " ";
// }
// textBlock.Text += "\n";
//}
drawBoard();
Windows.UI.ViewManagement.ApplicationView.GetForCurrentView().Title = player.Count.ToString();
}
/// <summary>
/// Adds a new point to the snake at the currente mousPos
/// </summary>
/// <param name="mousePos">Mouse down point</param>
public void addPoint(Vec2F mousePos)
{
SnakePoint p = new SnakePoint();
p.pos = mousePos;
p.F_elas = new Vec2F(0, 0);
p.F_curv = new Vec2F(0, 0);
p.F_ball = new Vec2F(0, 0);
p.F_img = new Vec2F(0, 0);
m_points.Add(p);
}
public Snake()
{//蛇的构造函数
//初始化蛇头的位置为左上角,并额外生成一个蛇身到后面
Gm.Point p;
p.X = 2;
p.Y = 1;
SnakePoint.Add(p);
p.X--;
SnakePoint.Add(p);
SnakeHaed = SnakePoint[0];
SnakeBack.X = 0;
SnakeBack.Y = 0;
}
/// <summary>
/// Updates all points by summing up all point forces
/// </summary>
public void update()
{
if (m_points.Count < 3)
{
return;
}
for (int i = 0; i < m_points.Count; ++i)
{
SnakePoint p = (SnakePoint)m_points[i];
// Update position by summing up force vectors
//////////////////////////////////////////////////
p.pos += p.F_elas + p.F_curv + p.F_ball + p.F_img;
//////////////////////////////////////////////////
}
frm.Invalidate();
}
private void InitGame()
{
player = new List <SnakePoint>();
player.Add(new SnakePoint(5, 2));
player.Add(new SnakePoint(4, 2));
player.Add(new SnakePoint(3, 2));
player.Add(new SnakePoint(2, 2));
head = player[0];
dir = 2;
disp = new DispatcherTimer();
disp.Tick += Disp_Tick;
disp.Interval = new TimeSpan(0, 0, 0, 1);
disp.Start();
rnd = new Random();
state = 0;
}
/// <summary>
/// Calculates all the forces of all snake points
/// </summary>
/// <param name="bmp">bitmap from witch the image force is taken</param>
public void calculateFroces(Bitmap bmp)
{
if (m_points.Count < 3)
{
return;
}
const float C_ELAS = 0.1f; // constant to scale elastic force vector
const float C_CURV = 0.5f; // constant to scale curvature force vector
const float C_BALL = 0.5f; // constant to scale balloon force vector
const float C_IMG = 0.1f; // constant to scale image force
// Caluclate center of mass first
m_center = Vec2F.Zero;
for (int i = 0; i < m_points.Count; ++i)
{
m_center += ((SnakePoint)m_points[i]).pos;
}
m_center /= m_points.Count;
// Clear the sum vectors
m_F_elasSum = Vec2F.Zero;
m_F_curvSum = Vec2F.Zero;
m_F_ballSum = Vec2F.Zero;
m_F_imgSum = Vec2F.Zero;
for (int i = 0; i < m_points.Count; ++i)
{
SnakePoint p = m_points[i];
// Get the neighbours
SnakePoint p_next, p_prev;
if (i == 0)
{
p_next = m_points[i + 1];
p_prev = m_points[m_points.Count - 1];
}
else if (i == m_points.Count - 1)
{
p_next = m_points[0];
p_prev = m_points[i - 1];
}
else
{
p_next = m_points[i + 1];
p_prev = m_points[i - 1];
}
///////////////////////
// Elasticity Force //
///////////////////////
// Build the elasticity force vector
Vec2F vNext = p_next.pos - p.pos;
Vec2F vPrev = p_prev.pos - p.pos;
p.F_elas = vNext + vPrev;
// Scale the force components
p.F_elas *= (float)frm.numAlpha.Value * C_ELAS;
// Sum up
m_F_elasSum += p.F_elas;
///////////////////
// Curve Force //
///////////////////
// Calculate the curvature equalization force vector
vNext.Normalize();
vPrev.Normalize();
Vec2F vCurv = vNext + vPrev;
vCurv.Normalize();
p.F_curv = vCurv;
// Scale the force vector
p.F_curv *= (float)frm.numBeta.Value * C_CURV;
// Sum up
m_F_curvSum += p.F_curv;
/////////////////////
// Balloon Force //
/////////////////////
// Calculate the outward pointing balloon expansion force vector
p.F_ball = -(vNext + vPrev);
// Scale the force vector
p.F_ball *= (float)frm.numDelta.Value * C_BALL;
// Sum up
m_F_ballSum += p.F_ball;
///////////////////
// Image Force //
///////////////////
// Check first the boundries of the lookup coordinates
int x = (int)p.pos.x;
int y = (int)p.pos.y;
x = Math.Min(x, bmp.Width - 2); x = Math.Max(x, 1);
y = Math.Min(y, bmp.Height - 2); y = Math.Max(y, 1);
// Build the image force vector
// bmp.GetPixel(x, y).R retrieves the gray value (0-255) at pos. x,y
// TODO: Is it really the gray value? Documentation notes: Gets the red component value
p.F_img.x = bmp.GetPixel(x + 1, y).R - bmp.GetPixel(x - 1, y).R;
p.F_img.y = bmp.GetPixel(x, y + 1).R - bmp.GetPixel(x, y - 1).R;
// Scale the force components
p.F_img *= (float)frm.numGamma.Value * C_IMG;
// Sum up
m_F_imgSum += p.F_img;
}
}
/// <summary>
/// Draws the snake
/// </summary>
/// <param name="g">graphics context for drawing</param>
/// <param name="bmp">bitmap from witch the image forces are calculated</param>
public void draw(Graphics g, Bitmap bmp)
{
if (m_points.Count == 0)
{
return;
}
calculateFroces(bmp);
const float C = 50.0f; // Constant scale factor for the vector visualization
for (int i = 0; i < m_points.Count; ++i)
{
SnakePoint p = m_points[i];
SnakePoint p_next;
if (i < m_points.Count - 1)
{
p_next = m_points[i + 1];
}
else
{
p_next = m_points[0];
}
// Draw outgoing line and circle around p1.pos
g.DrawLine(Pens.Red, p.pos.x, p.pos.y, p_next.pos.x, p_next.pos.y);
g.DrawEllipse(Pens.Yellow, p.pos.x - 1.0f, p.pos.y - 1.0f, 2.0f, 2.0f);
if (frm.chkShowForces.Checked)
{
// Draw elastic force vector
Vec2F eF = p.pos + p.F_elas * C;
g.DrawLine(Pens.Blue, p.pos.x, p.pos.y, eF.x, eF.y);
// Draw curvature force vector
Vec2F cF = p.pos + p.F_curv * C;
g.DrawLine(Pens.Cyan, p.pos.x, p.pos.y, cF.x, cF.y);
// Draw balloon force vector
Vec2F bF = p.pos + p.F_ball * C;
g.DrawLine(Pens.Magenta, p.pos.x, p.pos.y, bF.x, bF.y);
// Draw image force vector
Vec2F iF = p.pos + p.F_img * C;
g.DrawLine(Pens.Green, p.pos.x, p.pos.y, iF.x, iF.y);
}
}
if (frm.chkShowForces.Checked)
{
// Draw summed up forces
g.DrawEllipse(Pens.White, m_center.x - 1.0f, m_center.y - 1.0f, 2.0f, 2.0f);
Vec2F sum_eF = m_center + m_F_elasSum * C;
Vec2F sum_cF = m_center + m_F_curvSum * C;
Vec2F sum_bF = m_center + m_F_ballSum * C;
Vec2F sum_iF = m_center + m_F_imgSum * C;
g.DrawLine(Pens.Blue, m_center.x, m_center.y, sum_eF.x, sum_eF.y);
g.DrawLine(Pens.Cyan, m_center.x, m_center.y, sum_cF.x, sum_cF.y);
g.DrawLine(Pens.Magenta, m_center.x, m_center.y, sum_bF.x, sum_bF.y);
g.DrawLine(Pens.Green, m_center.x, m_center.y, sum_iF.x, sum_iF.y);
}
}
