public static void UpdateEnemyPositions(
List <EnemyObject> enemyObjects,
long elapsedMillisecondsPerIteration)
{
foreach (EnemyObject enemyObject in enemyObjects)
{
if (enemyObject.IsDestroyed)
{
continue;
}
DTDanmakuMath.Offset offset = DTDanmakuMath.GetOffset(
speedInMillipixelsPerMillisecond: enemyObject.SpeedInMillipixelsPerMillisecond,
movementDirectionInMillidegrees: enemyObject.MovementDirectionInMillidegrees,
elapsedMillisecondsPerIteration: elapsedMillisecondsPerIteration);
enemyObject.XMillis += offset.DeltaXInMillipixels;
enemyObject.YMillis += offset.DeltaYInMillipixels;
}
}
private static Tuple <ObjectAction, BooleanExpression> MoveToSpecifiedLocations_Helper(
long startingXMillis,
long startingYMillis,
long endingXMillis,
long endingYMillis,
long speedInPixelsPerSecond,
bool shouldStrafe,
GuidGenerator guidGenerator)
{
string variableName = guidGenerator.NextGuid();
string variableName2 = guidGenerator.NextGuid();
long?direction = DTDanmakuMath.GetMovementDirectionInMillidegrees(
currentX: startingXMillis,
currentY: startingYMillis,
desiredX: endingXMillis,
desiredY: endingYMillis);
if (direction == null)
{
throw new Exception();
}
DTDanmakuMath.Offset offset = DTDanmakuMath.GetOffset(
speedInMillipixelsPerMillisecond: speedInPixelsPerSecond, // millipixels/millisecond is equivalent to pixels/second
movementDirectionInMillidegrees: direction.Value,
elapsedMillisecondsPerIteration: 1000); // Use the 1000 to help prevent rounding issues
ObjectAction moveAction = ObjectAction.SetPosition(
xMillis: MathExpression.Add(MathExpression.XMillis(), MathExpression.Divide(MathExpression.Multiply(MathExpression.Constant(offset.DeltaXInMillipixels), MathExpression.ElapsedMillisecondsPerIteration()), MathExpression.Constant(1000))),
yMillis: MathExpression.Add(MathExpression.YMillis(), MathExpression.Divide(MathExpression.Multiply(MathExpression.Constant(offset.DeltaYInMillipixels), MathExpression.ElapsedMillisecondsPerIteration()), MathExpression.Constant(1000))));
ObjectAction setDirectionAction = shouldStrafe
? ObjectAction.SetFacingDirection(facingDirectionInMillidegrees: MathExpression.Constant(180 * 1000))
: ObjectAction.SetFacingDirection(facingDirectionInMillidegrees: MathExpression.Constant(direction.Value));
IMathExpression deltaX = MathExpression.AbsoluteValue(MathExpression.Subtract(MathExpression.XMillis(), MathExpression.Constant(endingXMillis)));
IMathExpression deltaY = MathExpression.AbsoluteValue(MathExpression.Subtract(MathExpression.YMillis(), MathExpression.Constant(endingYMillis)));
IMathExpression totalDelta = MathExpression.Add(deltaX, deltaY);
ObjectAction setDeltaToVariable = ObjectAction.Union(
ObjectAction.SetNumericVariable(variableName: variableName2, variableValue: MathExpression.Variable(variableName)),
ObjectAction.SetNumericVariable(variableName: variableName, variableValue: totalDelta));
BooleanExpression reachedDestination = BooleanExpression.And(
BooleanExpression.LessThanOrEqualTo(
MathExpression.Variable(variableName2),
MathExpression.Variable(variableName)),
BooleanExpression.And(
BooleanExpression.GreaterThanOrEqualTo(MathExpression.Variable(variableName), MathExpression.Constant(0)),
BooleanExpression.GreaterThanOrEqualTo(MathExpression.Variable(variableName2), MathExpression.Constant(0))
));
ObjectAction initializeVariables = ObjectAction.Union(
ObjectAction.SetNumericVariable(variableName: variableName, variableValue: MathExpression.Constant(-1)),
ObjectAction.SetNumericVariable(variableName: variableName2, variableValue: MathExpression.Constant(-1)));
return(new Tuple <ObjectAction, BooleanExpression>(
ObjectAction.Union(
moveAction,
setDirectionAction,
ObjectAction.ConditionalNextAction(
currentAction: initializeVariables,
condition: BooleanExpression.True(),
nextAction: setDeltaToVariable)),
reachedDestination));
}