LNXSDK/leenkx/Sources/leenkx/logicnode/SetLookAtRotationNode.hx

package leenkx.logicnode;

import iron.math.Vec4;
import iron.math.Quat;
import iron.math.Mat4;
import iron.object.Object;

class SetLookAtRotationNode extends LogicNode {

	public var property0: String; // Axis to align
	public var property1: String; // Use vector for target (true/false)
	public var property2: String; // Use vector for source (true/false)
	public var property3: String; // Damping value (backward compatibility, now input socket)
	public var property4: String; // Disable rotation on aligning axis (true/false)
	public var property5: String; // Use local space (true/false)
	
	// Store the calculated rotation for output
	var calculatedRotation: Quat = null;
	// Store the previous rotation for smooth interpolation
	var previousRotation: Quat = null;

	public function new(tree: LogicTree) {
		super(tree);
		previousRotation = new Quat();
	}

	override function run(from: Int): Void {
		// Determine if we're using a vector or an object as source
		var useSourceVector: Bool = property2 == "true";
		var objectToUse: Object = null;
		var objectLoc: Vec4 = null;

		if (useSourceVector) {
			// Use tree.object as the object to rotate
			objectToUse = tree.object;
			if (objectToUse == null) {
				runOutput(0);
				return;
			}

			// Get the source location directly
			objectLoc = inputs[1].get();
			if (objectLoc == null) {
				runOutput(0);
				return;
			}
		} else {
			// Get the source object (or fallback to tree.object)
			objectToUse = (inputs.length > 1 && inputs[1] != null) ? inputs[1].get() : tree.object;
			if (objectToUse == null) {
				runOutput(0);
				return;
			}

			// Get source object's WORLD position (important for child objects)
			objectLoc = new Vec4(objectToUse.transform.worldx(), objectToUse.transform.worldy(), objectToUse.transform.worldz());
		}

		// Determine if we're using a vector or an object as target
		var useTargetVector: Bool = property1 == "true";
		var targetLoc: Vec4 = null;

		if (useTargetVector) {
			// Get the target location directly
			targetLoc = inputs[2].get();
			if (targetLoc == null) {
				runOutput(0);
				return;
			}
		} else {
			// Get the target object
			var targetObject: Object = inputs[2].get();
			if (targetObject == null) {
				runOutput(0);
				return;
			}
			
			// Get target object's WORLD position (important for child objects)
			targetLoc = new Vec4(targetObject.transform.worldx(), targetObject.transform.worldy(), targetObject.transform.worldz());
		}
		
		// Calculate direction to target
		var direction = new Vec4(
			targetLoc.x - objectLoc.x,
			targetLoc.y - objectLoc.y,
			targetLoc.z - objectLoc.z
		);
		direction.normalize();
		
		// Calculate target rotation based on selected axis
		calculatedRotation = new Quat();
		switch (property0) {
			case "X":
				calculatedRotation.fromTo(new Vec4(1, 0, 0), direction);
			case "-X":
				calculatedRotation.fromTo(new Vec4(-1, 0, 0), direction);
			case "Y":
				calculatedRotation.fromTo(new Vec4(0, 1, 0), direction);
			case "-Y":
				calculatedRotation.fromTo(new Vec4(0, -1, 0), direction);
			case "Z":
				calculatedRotation.fromTo(new Vec4(0, 0, 1), direction);
			case "-Z":
				calculatedRotation.fromTo(new Vec4(0, 0, -1), direction);
		}
		
		// If disable rotation on aligning axis is enabled, constrain the target rotation
		if (property4 == "true") {
			// Apply constraint to the target rotation BEFORE damping to avoid jiggling
			var eulerAngles = calculatedRotation.toEulerOrdered("XYZ");
			
			// Set the rotation around the selected axis to 0
			switch (property0) {
				case "X", "-X":
					eulerAngles.x = 0.0;
				case "Y", "-Y":
					eulerAngles.y = 0.0;
				case "Z", "-Z":
					eulerAngles.z = 0.0;
			}
			
			// Convert back to quaternion
			calculatedRotation.fromEulerOrdered(eulerAngles, "XYZ");
		}
		
		// Convert world rotation to local rotation if local space is enabled and object has a parent
		var targetRotation = new Quat();
		if (property5 == "true" && objectToUse.parent != null) {
			// Get parent's world rotation
			var parentWorldLoc = new Vec4();
			var parentWorldRot = new Quat();
			var parentWorldScale = new Vec4();
			objectToUse.parent.transform.world.decompose(parentWorldLoc, parentWorldRot, parentWorldScale);
			
			// Convert world rotation to local space by removing parent's rotation influence
			// local_rotation = inverse(parent_world_rotation) * world_rotation
			var invParentRot = new Quat().setFrom(parentWorldRot);
			invParentRot.x = -invParentRot.x;
			invParentRot.y = -invParentRot.y;
			invParentRot.z = -invParentRot.z;
			
			targetRotation.multquats(invParentRot, calculatedRotation);
		} else {
			// No local space conversion needed, use world rotation directly
			targetRotation.setFrom(calculatedRotation);
		}
		
		// Apply rotation with damping
		var dampingValue: Float = 0.0;
		
		// Try to get damping from input socket first (index 3), fallback to property
		if (inputs.length > 3 && inputs[3] != null) {
			var dampingInput: Dynamic = inputs[3].get();
			if (dampingInput != null) {
				dampingValue = dampingInput;
			}
		} else {
			// Fallback to property for backward compatibility
			dampingValue = Std.parseFloat(property3);
		}
		
		if (dampingValue > 0.0) {
			// Create a fixed interpolation rate that never reaches exactly 1.0
			// Higher damping = slower rotation (smaller step)
			var step = Math.max(0.001, (1.0 - dampingValue) * 0.2); // 0.001 to 0.2 range
			
			// Get current local rotation as quaternion
			var currentLocalRot = new Quat().setFrom(objectToUse.transform.rot);
			
			// Calculate the difference between current and target rotation
			var diffQuat = new Quat();
			// q1 * inverse(q2) gives the rotation from q2 to q1
			var invCurrent = new Quat().setFrom(currentLocalRot);
			invCurrent.x = -invCurrent.x;
			invCurrent.y = -invCurrent.y;
			invCurrent.z = -invCurrent.z;
			diffQuat.multquats(targetRotation, invCurrent);
			
			// Convert to axis-angle representation
			var axis = new Vec4();
			var angle = diffQuat.toAxisAngle(axis);
			
			// Apply only a portion of this rotation (step)
			var partialAngle = angle * step;
			
			// Create partial rotation quaternion
			var partialRot = new Quat().fromAxisAngle(axis, partialAngle);
			
			// Apply this partial rotation to current local rotation
			var newLocalRot = new Quat();
			newLocalRot.multquats(partialRot, currentLocalRot);
			
			// Apply the new local rotation
			objectToUse.transform.rot.setFrom(newLocalRot);
		} else {
			// No damping, apply instant rotation
			objectToUse.transform.rot.setFrom(targetRotation);
		}
		
		objectToUse.transform.buildMatrix();
		
		runOutput(0);
	}

	// No output sockets needed - this node only performs actions
}