/// <summary>
/// Calls the Tick method of the currently executing nested instruction
/// and if necessary advances the PC.
/// </summary>
/// <param name="critterState">The state of the critter to work on.</param>
/// <returns><code>true</code> if more execution steps must be executed
/// to finish the instruction execution. <code>false</code> if
/// instruction execution has finished.</returns>
protected bool InternalTick(CritterState critterState)
{
if (critterState == null)
{
throw new ArgumentNullException(nameof(critterState));
}
if (this.pc < 0)
{
throw new IndexOutOfRangeException("PC out of range");
}
if (this.pc >= this.instructions.Count)
{
return(false);
}
var instr = this.instructions[this.pc];
if (instr.Tick(critterState) == false)
{
this.pc++;
}
return(this.pc < this.instructions.Count);
}
/// <summary>
/// Advances the critter in direction of the destination by <see cref="StepLength"/>.
/// </summary>
/// <returns><code>false</code> if the critter has arrived at its destination.</returns>
public override bool Tick(CritterState critterState)
{
// calculate difference vector from current pos to dest
var pos = new Vector(critterState.PositionX, critterState.PositionY);
var dest = new Vector(DestX, DestY);
var diff = dest - pos;
if (diff.Length < StepLength)
{
critterState.PositionX = DestX;
critterState.PositionY = DestY;
return(false);
}
// normalize diff vector so that length is 1, then multiply it
// with StepLength to get the increment vector.
var unit = diff.Normalize();
var increment = unit * StepLength;
// add increment vector to current pos to get new pos
var newPos = pos + increment;
critterState.PositionX = newPos.X;
critterState.PositionY = newPos.Y;
return(true);
}
/// <summary>
/// See <see cref="Instruction.Tick(CritterState)"/>.
/// </summary>
public override bool Tick(CritterState critterState)
{
if (base.InternalTick(critterState) == false)
{
base.ResetPC();
this.count++;
if (this.count >= Repetitions)
{
this.count = 0;
return(false);
}
}
return(true);
}
public override bool Tick(CritterState critterState)
{
return(this.tick(critterState));
}
/// <summary> /// When implemented in a derived class, advances to the next step in /// instruction execution, potentially mutating the passed <see cref="CritterState"/>. /// </summary> /// <param name="critterState">The critter state to work on.</param> /// <returns><code>true</code> if more execution steps must be executed /// to finish the instruction execution. <code>false</code> if /// instruction execution has finished.</returns> public abstract bool Tick(CritterState critterState);
public override bool Tick(CritterState critterState)
{
return(base.InternalTick(critterState));
}
/// <summary>
/// Advances the program by one step, potentially mutating the passed
/// <see cref="CritterState"/>.
/// </summary>
/// <param name="critterState">The state of the critter that is controlled by the program.</param>
/// <returns><code>true</code> if the program has more steps to execute.
/// <code>false</code> if the program has finished.</returns>
public bool Tick(CritterState critterState)
{
return(this.root.Tick(critterState));
}
