/*

 Copyright (C) 2018 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 GKComponent subclass that encapsulates code shared by other custom components.

 */

#import "AAPLBaseComponent.h"

#define EnemyAltitude -0.46

@implementation GKAgent2D (AAPL_Scenekit)

- (matrix_float4x4) transform {

    simd_quatf quat = simd_quaternion(-(float)(self.rotation - (M_PI/2)), simd_make_float3(0, 1, 0));

    matrix_float4x4 transform = simd_matrix4x4(quat);

    transform.columns[3] = simd_make_float4(self.position.x, EnemyAltitude, self.position.y , 1);

    return transform;

}

- (void) setTransform:(matrix_float4x4)transform {

    simd_quatf quatf = simd_quaternion(transform);

    self.rotation = - (simd_angle(quatf) + (M_PI/2));

    self.position = transform.columns[3].xz;

}

@end

@implementation AAPLBaseComponent

- (instancetype)init{

    if (self = [super init]) {

        _agent = [[GKAgent2D alloc] init];

        _autoMoveNode = YES;

    }

    return self;

}

- (BOOL)isDead

{

    return NO;

}

- (void)positionAgentFromNode

{

    GKSCNNodeComponent *nodeComponent = (GKSCNNodeComponent *)[self.entity componentForClass:GKSCNNodeComponent.class];

    SCNNode *node = nodeComponent.node;

    self.agent.transform = node.simdTransform;

}

- (void)positionNodeFromAgent

{

    GKSCNNodeComponent *nodeComponent = (GKSCNNodeComponent *)[self.entity componentForClass:GKSCNNodeComponent.class];

    SCNNode *node = nodeComponent.node;

    node.simdTransform = self.agent.transform;

}

- (void)constrainPosition

{

    simd_float2 position = self.agent.position;

    if (position.x > 2)

        position.x = 2;

    if (position.x < -2)

        position.x = -2;

    if (position.y > 12.5)

        position.y = 12.5;

    if (position.y < 8.5)

        position.y = 8.5;

    self.agent.position = position;

}

- (void)updateWithDeltaTime:(NSTimeInterval)seconds

{

    if ([self isDead]) {

        return;

    }

    [self.agent updateWithDeltaTime:seconds];

    [self constrainPosition];

    if (self.autoMoveNode)

        [self positionNodeFromAgent];

    [super updateWithDeltaTime:seconds];

}

@end