/// <summary>
/// See if a move is allowed by a figure.
/// </summary>
/// <param name="figure">The figure to move.</param>
/// <param name="move">The desired move amount.</param>
/// <returns>Whether the move is valid.</returns>
public static bool IsMoveAllowed(Figure figure, Vector2 move, List<Block> blocks)
{
//Set some startup variables.
bool valid = false;
//Project the current figure to the new position and see whether the move was valid.
figure.Move(move);
valid = !blocks.Exists(block => figure.Intersects(block));
figure.Move(-move);
//Return the result.
return valid;
}
/// <summary>
/// See if a rotation is allowed by a figure.
/// </summary>
/// <returns>Whether the rotation is valid.</returns>
public static bool IsRotationAllowed(Figure figure, List<Block> blocks)
{
//Project the current figure to the new position.
var proj = new Figure(figure) { Left = figure.Left, Bottom = figure.Bottom };
proj.Rotate();
//Return whether the movement is valid.
return !blocks.Exists(block => !figure.Blocks.Contains(block) && proj.Intersects(block));
}
/// <summary>
/// See if a move is allowed by a figure.
/// </summary>
/// <param name="figure">The figure to move.</param>
/// <param name="move">The desired move amount.</param>
/// <param name="assist">The move assist.</param>
/// <param name="allowNegativeY">Whether to allow the figure to find a position above the current one.</param>
/// <returns>Whether the move is valid.</returns>
public static bool IsMoveAllowed(Figure figure, Vector2 move, List<Block> blocks, out Vector2 assist, bool allowNegativeY)
{
//Set some startup variables.
bool valid = false;
assist = move;
//Try to find an acceptable position by granting the figure some leeway.
for (int x = 0; x <= WIDTH / 2; x++)
{
for (int y = 0; y <= HEIGHT / 2; y++)
{
//Do four tests; (x, y), (x, -y), (-x, y), (-x, -y).
for (int n = 0; n < 4; n++)
{
//Decide upon the x, y configuration.
Vector2 config = Vector2.Zero;
switch (n)
{
case 0: { config = new Vector2(x, y); break; }
case 1: { config = allowNegativeY ? new Vector2(x, -y) : new Vector2(x, y); break; }
case 2: { config = new Vector2(-x, y); break; }
case 3: { config = allowNegativeY ? new Vector2(-x, -y) : new Vector2(-x, y); break; }
}
//Project the current figure to the new position and see whether the move was valid.
figure.Move(move + config);
valid = !blocks.Exists(block => figure.Intersects(block));
figure.Move(-(move + config));
//If the move was valid, stop here.
if (valid) { assist = move + config; return valid; }
}
}
}
//Return the result (Hint: fail).
return valid;
}