public static SCNMatrix4 Normalize(this SCNMatrix4 matrix)
{
// for row-major matrixes only
var normalized = matrix;
var row0 = SCNVector4.Normalize(matrix.Row0);
var row1 = SCNVector4.Normalize(matrix.Row1);
var row2 = SCNVector4.Normalize(matrix.Row2);
normalized.Row0 = row0;
normalized.Row1 = row1;
normalized.Row2 = row2;
return(normalized);
}
private void UpdateCatapultStable()
{
if (!this.Disabled)
{
// Catapult will be unstable when the physics settles, therefore we do not update catapult's stability status
if (GameTime.TimeSinceLevelStart > CatapultPhysicsSettleTime)
{
// Cannot use simdVelocity on client since simdVelocity could be high from physicsSync interacting with local physics engine
if (!this.lastPosition.HasValue)
{
this.lastPosition = this.Base.PresentationNode.WorldPosition;
return;
}
var position = this.Base.PresentationNode.WorldPosition;
var speed = ((position - this.lastPosition.Value) / (float)GameTime.DeltaTime).Length;
this.lastPosition = position;
// Base below table?
// Base tilted? base's up vector must maintain some amount of y to be determined as stable
var transform = this.Base.PresentationNode.Transform;
transform.Transpose();
var baseUp = SCNVector4.Normalize(transform.Column1);
if (position.Y < -1f || Math.Abs(baseUp.Y) < MinStableTiltBaseUpY)
{
// Switch to knocked mode
if (!this.isCatapultKnocked)
{
this.catapultKnockedStartTime = GameTime.Time;
}
this.isCatapultKnocked = true;
this.isCatapultStable = false;
return;
}
this.isCatapultKnocked = false;
// Base could be moving although the catapult is not knocked
this.isCatapultStable = speed < MaxSpeedToCountAsStable;
}
}
}
private SCNVector3 ComputeBallPosition(CameraInfo cameraInfo)
{
var cameraRay = cameraInfo.Ray;
// These should be based on the projectile radius.
// This affects centering of ball, and can hit near plane of camera
// This is always centering to one edge of screen independent of screen orient
// We always want the ball at the bottom of the screen.
var distancePullToCamera = 0.21f;
var ballShiftDown = 0.2f;
var targetBallPosition = cameraRay.Position + cameraRay.Direction * distancePullToCamera;
var cameraDown = -SCNVector4.Normalize(cameraInfo.Transform.Column1).Xyz;
targetBallPosition += cameraDown * ballShiftDown;
// Clamp to only the valid side
var pullWorldPosition = this.pullOrigin.WorldPosition;
if (pullWorldPosition.Z < 0f)
{
targetBallPosition.Z = Math.Min(targetBallPosition.Z, pullWorldPosition.Z);
}
else
{
targetBallPosition.Z = Math.Max(targetBallPosition.Z, pullWorldPosition.Z);
}
// Clamp to cone/circular core
var yDistanceFromPull = Math.Max(0f, pullWorldPosition.Y - targetBallPosition.Y);
var minBallDistanceFromPull = 0.5f;
var pullBlockConeSlope = 1.0f;
var pullBlockConeRadius = yDistanceFromPull / pullBlockConeSlope;
var pullBlockCoreRadius = Math.Max(minBallDistanceFromPull, pullBlockConeRadius);
// if pull is in the core, move it out.
var pullWorldPositionGrounded = new SCNVector3(pullWorldPosition.X, 0f, pullWorldPosition.Z);
var targetPullPositionGrounded = new SCNVector3(targetBallPosition.X, 0f, targetBallPosition.Z);
var targetInitialToTargetPull = targetPullPositionGrounded - pullWorldPositionGrounded;
if (pullBlockCoreRadius > targetInitialToTargetPull.Length)
{
var moveOutDirection = SCNVector3.Normalize(targetInitialToTargetPull);
var newTargetPullPositionGrounded = pullWorldPositionGrounded + moveOutDirection * pullBlockCoreRadius;
targetBallPosition = new SCNVector3(newTargetPullPositionGrounded.X, targetBallPosition.Y, newTargetPullPositionGrounded.Z);
}
// only use the 2d distance, so that user can gauage stretch indepdent of mtch
var distance2D = targetBallPosition - pullWorldPosition;
var stretchY = Math.Abs(distance2D.Y);
distance2D.Y = 0f;
var stretchDistance = distance2D.Length;
this.stretch = DigitExtensions.Clamp((double)stretchDistance, this.properties.MinStretch, this.properties.MaxStretch);
// clamp a little bit farther than maxStretch
// can't let the strap move back too far right now
var clampedStretchDistance = (float)(1.1d * this.properties.MaxStretch);
if (stretchDistance > clampedStretchDistance)
{
targetBallPosition = (clampedStretchDistance / stretchDistance) * (targetBallPosition - pullWorldPosition) + pullWorldPosition;
stretchDistance = clampedStretchDistance;
}
// Make this optional, not required. You're often at max stretch.
// Also have a timer for auto-launch. This makes it very difficuilt to test
// storing state in member data
this.IsPulledTooFar = stretchDistance > (float)(this.properties.MaxStretch) || stretchY > (float)(this.properties.MaxStretch);
return(targetBallPosition);
}
