private bool AreAllSnakePartsInTheHamiltonianCycle(ReturnData returnDatas, HamiltonianCycleData HamiltonianCycleData)
{
// Check whether all snake parts are in the Hamiltonia Cycle.
for (int i = 0; i < returnDatas.SnakePositions.Count - 1; i++)
{
var pointA = returnDatas.SnakePositions[i];
var pointB = returnDatas.SnakePositions[i + 1];
if (HamiltonianCycleData.Data.PointToSequenceNumber[pointA.X, pointA.Y] == 0)
{
if (HamiltonianCycleData.Data.PointToSequenceNumber[pointB.X, pointB.Y] != HamiltonianCycleData.Data.PointToSequenceNumber.Length - 1)
{
return(false);
}
}
else if (HamiltonianCycleData.Data.PointToSequenceNumber[pointA.X, pointA.Y] - 1 != HamiltonianCycleData.Data.PointToSequenceNumber[pointB.X, pointB.Y])
{
return(false);
}
}
// All snake parts are in the Hamiltonian Cycle.
return(true);
}
public GameLogic(int playFieldWidth, int playFieldHeight)
{
_PlayFieldWidth = playFieldWidth;
_PlayFieldHeight = playFieldHeight;
HamiltonianCycle = new HamiltonianCycle();
HamiltonianCycleData = HamiltonianCycle.GetHamiltonianCycleData(_PlayFieldWidth, _PlayFieldHeight);
ShortCut = new ShortCut();
ReturnDatas = new ReturnData
{
ShotCutMoveDirections = new List <MoveDirection>(),
ResetThesePositions = new List <Point>(),
SnakePositions = new List <Point>
{
// new Point(0,0)
GetRandomPosition()
},
ApplePosition = new Point(-1, -1), // Init values
DrawApple = true,
IslogicalEndReached = false
};
}
// NOTICE:
// The here used terms "above", "left", "right" and "under/below" are "seen visually".
// Example:
// Snakehead.Y should be equal to 5
// while apple.Y should be equal to 10
// a) seen visually:
// The snakehaed is ABOVE the apple.
// b) seen mathimatically:
// For sure snakehead.Y is less than apple.Y. So it is "under/ lower".
//
// Keep this in mind when reading the following comments.
public void CalcShortCutForCase1And3(ReturnData returnDatas, HamiltonianCycleData HamiltonianCycleData)
{
var snakesHeadPosition = returnDatas.SnakePositions[0];
var applePosition = returnDatas.ApplePosition;
if (snakesHeadPosition.X < 1 || snakesHeadPosition.Y < 1)
{
// No need to calculate a shortcut because snakes head is already in
// .X == 0 -> ... the column 0
// .Y == 0 -> ... the first row that leads the snake to column 0
return;
}
if (snakesHeadPosition.Y == applePosition.Y &&
(
(snakesHeadPosition.X < applePosition.X && HamiltonianCycleData.Data.MoveDirections[snakesHeadPosition.X, snakesHeadPosition.Y] == MoveDirection.Right)
||
(snakesHeadPosition.X > applePosition.X && HamiltonianCycleData.Data.MoveDirections[snakesHeadPosition.X, snakesHeadPosition.Y] == MoveDirection.Left)
)
)
{
// No need to calculate a shortcut because snakes head is
// already in the row that contains the apple
// and
// ( snakes head is left from the apple and the snake movedirection is right towards the apple
// or
// snakes head is right from the apple and the snake movedirection is left towards the apple
// )
return;
}
// Check whether all snake parts are in the Hamiltonia Cycle. Leave if not.
if (!AreAllSnakePartsInTheHamiltonianCycle(returnDatas, HamiltonianCycleData))
{
return;
}
if (snakesHeadPosition.Y > applePosition.Y)
{
// The snake is below the apple.
// The shortcut path to be calculated here should lead the snake one row below the row that contains the apple.
for (int y = snakesHeadPosition.Y - 1; applePosition.Y < y; y--)
{
returnDatas.ShotCutMoveDirections.Add(MoveDirection.Up);
}
// The short cut path ends here exact below the row with the apple. Check whether the apple is up next to the snakehead.
if (snakesHeadPosition.X == applePosition.X)
{
// The apple is up next to the snakehead.
returnDatas.ShotCutMoveDirections.Add(MoveDirection.Up);
}
else if (snakesHeadPosition.X < applePosition.X && !Common.IsValueEven(applePosition.Y))
{
// Snakes head is left from the apple
// AND
// the apple is in a row with an odd number like 1, 3, 5, 7, ...
// The direction in "odd rows" in right, so we can additionally lead the snake into the row with the apple
// because the then following non-shortcut path (aka "normal" Hamiltonian Cylce) is going to lead the snake into the apple.
returnDatas.ShotCutMoveDirections.Add(MoveDirection.Up);
}
else if (snakesHeadPosition.X > applePosition.X && Common.IsValueEven(applePosition.Y))
{
// Snakes head is right from the apple ... -> See previous comment.
returnDatas.ShotCutMoveDirections.Add(MoveDirection.Up);
}
}
else
{
// The snake is above the apple.
// The snake should be lead to column 0.
if (!Common.IsValueEven(snakesHeadPosition.Y))
{
// Do not use:
// if (HamiltonianCycleData.Data.MoveDirections[snakesHeadPosition.X, snakesHeadPosition.Y] == MoveDirection.Right)
// because the snake head can be in an odd row while its move direction is ".Up"!
// Do also not use:
// if (HamiltonianCycleData.Data.MoveDirections[2, snakesHeadPosition.Y] == MoveDirection.Right)
// becasue the minimum square size is 2-by-2.
// But this would work:
// if (HamiltonianCycleData.Data.MoveDirections[1, snakesHeadPosition.Y] == MoveDirection.Right)
returnDatas.ShotCutMoveDirections.Add(MoveDirection.Up);
}
for (int x = snakesHeadPosition.X; x > 0; x--)
{
returnDatas.ShotCutMoveDirections.Add(MoveDirection.Left);
}
}
}
public void CalcShortCutForCase2(ReturnData returnDatas, HamiltonianCycleData HamiltonianCycleData)
{
var snakesHeadPosition = returnDatas.SnakePositions[0];
var applePosition = returnDatas.ApplePosition;
if (snakesHeadPosition.X < 1 || snakesHeadPosition.Y < 1)
{
// No need to calculate a shortcut because snakes head is already in
// .X == 0 -> ... the column 0
// .Y == 0 -> ... the first row that leads the snake to column 0
return;
}
if (snakesHeadPosition.X == applePosition.X &&
(
(snakesHeadPosition.Y < applePosition.Y && HamiltonianCycleData.Data.MoveDirections[snakesHeadPosition.X, snakesHeadPosition.Y] == MoveDirection.Down)
||
(snakesHeadPosition.Y > applePosition.Y && HamiltonianCycleData.Data.MoveDirections[snakesHeadPosition.X, snakesHeadPosition.Y] == MoveDirection.Up)
)
)
{
// No need to calculate a shortcut because snakes head is
// already in the column that contains the apple
// and
// ( snakes head is above the apple and the snake movedirection is down towards the apple
// or
// snakes head is under the apple and the snake movedirection is up towards the apple
// )
return;
}
if (!AreAllSnakePartsInTheHamiltonianCycle(returnDatas, HamiltonianCycleData))
{
return;
}
if (snakesHeadPosition.X < applePosition.X)
{
// The snake is to the left of the apple.
// The shortcut path to be calculated here should lead the snake one column before the column that contains the apple.
for (int x = snakesHeadPosition.X; x < applePosition.X - 1; x++)
{
returnDatas.ShotCutMoveDirections.Add(MoveDirection.Right);
}
// The short cut path ends here exact one column before the row with the apple. Check whether the apple is right next to the snake head.
if (snakesHeadPosition.Y == applePosition.Y)
{
// The apple is right next to the snake head.
returnDatas.ShotCutMoveDirections.Add(MoveDirection.Right);
}
else if (snakesHeadPosition.Y < applePosition.Y && Common.IsValueEven(applePosition.X))
{
// Snakes head is above the apple
// AND
// the apple is in a column with an even number like 2, 4, 6, 8, ...
// The direction in "even columns" in down, so we can additionally lead the snake into this apple containing column
// because the then following non-shortcut path (aka "normal" Hamiltonian Cylce) is going to lead the snake into the apple.
returnDatas.ShotCutMoveDirections.Add(MoveDirection.Right);
}
else if (snakesHeadPosition.Y > applePosition.Y && !Common.IsValueEven(applePosition.X))
{
// Snakes head is below the apple ... -> See previous comment.
returnDatas.ShotCutMoveDirections.Add(MoveDirection.Right);
}
else if (applePosition.Y == 0)
{
returnDatas.ShotCutMoveDirections.Add(MoveDirection.Right);
// snake head is no in the same column as the apple.
// Lead the snake up into the apple.
for (int y = snakesHeadPosition.Y; y > 0; y--)
{
returnDatas.ShotCutMoveDirections.Add(MoveDirection.Up);
}
}
}
else
{
// The snake is to the right of the apple.
// The snake should be lead to row 0.
if (Common.IsValueEven(snakesHeadPosition.X))
{
// Snake head is a "even column".
// The move direction of "even columns" is down, so go one step to the right, to a "odd column.
// The move direction of "odd columns" is up.
returnDatas.ShotCutMoveDirections.Add(MoveDirection.Right);
}
for (int y = snakesHeadPosition.Y; y > 0; y--)
{
returnDatas.ShotCutMoveDirections.Add(MoveDirection.Up);
}
}
}
