void setObstacles()
{
obs = new sectList(snakeCoord.count * snakeCoord.count);
Random rnd = new Random();
//using a power function to modulate the logarithmic sense of human
int difficulty = (int)(Math.Pow(1.4, trackBar4.Value) + 5) * trackBar4.Value / (trackBar2.Value + 1);
//Number of obstacle groups is "difficulty"
for (int i = 0; i < difficulty; i++)
{
int x = -1;
int y = -1;
x = rnd.Next(0, snakeCoord.count);
y = rnd.Next(0, snakeCoord.count);
obs.append(new Point(x, y), pictureBox1, Color.Black);
//Each obstacle group has the size of a random number between o and "difficulty * 2"
//but they may overlap with each other, or may round up an extra space, which allows them to occupy a more variable area
int size = rnd.Next(0, difficulty * 2);
for (int j = 0; j < size; j++)
{
int x1, y1;
do
{
x1 = rnd.Next(-1, 2);
y1 = rnd.Next(-1, 2);
} while (x + x1 < 0 || y + y1 < 0 || x + x1 >= snakeCoord.count || y + y1 >= snakeCoord.count); //Only valid inside the drawing area
obs.append(new Point(x + x1, y + y1), pictureBox1, Color.Black);
}
}
}
public void timer1_Tick(object sender, EventArgs e)
{
//Memorizing the last increment, to avoid the situation when pressing opposite arrow keys at the same time kills the snake instantly
if (incre.x == incRec.x && incre.y == -(incRec.y) && incre.y != 0)
{
incre.y = incRec.y;
}
else if (incre.x == -(incRec.x) && incre.y == incRec.y && incre.x != 0)
{
incre.x = incRec.x;
}
incRec.x = incre.x;
incRec.y = incre.y;
Point addPoint = new Point();
addPoint.X = snake.getEnd().point.X + incre.x;
addPoint.Y = snake.getEnd().point.Y + incre.y;
if (checkBox1.Checked)
{
//if crossing the boundries is allowed, when the snake reaches the boundries, set it to appear from the other side
turnAround(ref addPoint);
}
if (addPoint.X > snakeCoord.count - 1 || addPoint.Y > snakeCoord.count - 1 || addPoint.X < 0 || addPoint.Y < 0)
{
//if the snake moves out of the boundries
gameOver();
return;
}
if (snake.overlaps(addPoint) || obs.overlaps(addPoint))
{
//if the snake hits any obstacles
gameOver();
return;
}
if (sectList.collision(apple.point, addPoint))
{
//if the snake swallows an apple, its length will increase by 1, and we need to set a new apple
snake.append(addPoint, pictureBox1, snakeColor);
setApple();
}
else
{
//normal movement of the snake, by adding a new square to the head, as well as removing one from the tail
snake.append(addPoint, pictureBox1, snakeColor);
snake.remove_front();
}
}
void initGame()
{
gameHandler = true; //set game on
label13.Hide(); //"Game over" will be hidden
pictureBox1.Show(); //Main drawing area
int speed = trackBar1.Value + 1; //moving speed of the snake
//using a power function to modulate the logarithmic sense for speed of human
int interval = (int)(500 * Math.Pow(0.6, speed));
timer1.Interval = interval;
//using a static class to record how many grid lines to show
snakeCoord.unit = trackBar2.Value * 4 + 10;
snakeCoord.count = maxSize / snakeCoord.unit; //"maxsize" is the size of the drawing area
Point startPoint = new Point();
//start at about the centre
startPoint.X = snakeCoord.count / 2;
startPoint.Y = snakeCoord.count / 2;
//Establish an instance of the queue recording the snake itself
//Construction the list using the max possible length of the snake, which is the square of the grid size
snake = new sectList(snakeCoord.count * snakeCoord.count);
//The initial snake consists of 2 squares at nearly the centre of the drawing area
snake.append(startPoint, pictureBox1, snakeColor);
incre.x = 1;
incre.y = 0;
incRec.x = incre.x;
incRec.y = incre.y;
startPoint.X += incre.x;
startPoint.Y += incre.y;
//The second square of the initial snake
snake.append(startPoint, pictureBox1, snakeColor);
label7.Hide(); //Hise "Press any key to begin"
setObstacles();
setApple();
this.Refresh();
timer1.Start();
//The obstacles the grids are generated in initGame() above and will be fixed throughout the game; therefore their controls must be locked
trackBar2.Enabled = false;
trackBar4.Enabled = false;
}