eraser shot

ViewController.m

//
//  ViewController.m
//  EraserShot
//
//  Created by MizushimaYusuke on 9/2/15.
//  Copyright (c) 2015 MizushimaYusuke. All rights reserved.
//

#import "ViewController.h"
@import SceneKit;

@interface ViewController ()
@property (nonatomic, weak) SCNView *sceneView;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    [self setupScene];
    [self createDesk];
    [self createEraser];
    [self createPurpleShot];
    [self createCamera];
}

- (void)setupScene {
    SCNView *sv = [[SCNView alloc] initWithFrame:self.view.bounds];
    sv.scene = [SCNScene scene];
    sv.autoenablesDefaultLighting = YES;
    sv.allowsCameraControl = YES;
    [self.view addSubview:sv];
    
    self.sceneView = sv;
}

- (void)createDesk {
    SCNBox *desk = [SCNBox boxWithWidth:20 height:0.1 length:20 chamferRadius:0];
    desk.firstMaterial.diffuse.contents = [self color:1];
    SCNNode *deskNode = [SCNNode nodeWithGeometry:desk];
    deskNode.name = @"desk";
    deskNode.physicsBody = [SCNPhysicsBody staticBody];
    [self.sceneView.scene.rootNode addChildNode:deskNode];
}

- (void)createEraser {
    SCNNode *eraser = [SCNNode node];
    eraser.name = @"eraser";
    
    SCNBox *partA = [SCNBox boxWithWidth:0.5 height:0.5 length:2 chamferRadius:0];
    partA.firstMaterial.diffuse.contents = [self color:0];
    SCNNode *partANode = [SCNNode nodeWithGeometry:partA];
    partANode.position = SCNVector3Make(0.5, 0, 0);
    [eraser addChildNode:partANode];
    
    SCNBox *partB = [SCNBox boxWithWidth:1.45 height:0.49 length:2.6 chamferRadius:0];
    partB.firstMaterial.diffuse.contents = [self color:2];
    SCNNode *partBNode = [SCNNode nodeWithGeometry:partB];
    partBNode.position = SCNVector3Make(0, 0, 0.31);
    [eraser addChildNode:partBNode];
    
    SCNBox *partC = [SCNBox boxWithWidth:0.5 height:0.5 length:2 chamferRadius:0];
    partC.firstMaterial.diffuse.contents = [self color:3];
    SCNNode *partCNode = [SCNNode nodeWithGeometry:partC];
    partCNode.position = SCNVector3Make(-0.5, 0, 0);
    [eraser addChildNode:partCNode];
    
    eraser.position = SCNVector3Make(0, 1, 0);
    eraser.physicsBody = [SCNPhysicsBody dynamicBody];
    [self.sceneView.scene.rootNode addChildNode:eraser];
}

- (void)createPurpleShot {
    SCNNode *shot = [SCNNode node];
    shot.name = @"shot";
    
    SCNBox *partA = [SCNBox boxWithWidth:1 height:0.4 length:0.6 chamferRadius:0];
    partA.firstMaterial.diffuse.contents = [self color:4];
    SCNNode *partANode = [SCNNode nodeWithGeometry:partA];
    partANode.position = SCNVector3Make(0, 0, 0.2);
    partANode.name = @"shotbody";
    [shot addChildNode:partANode];
    
    SCNBox *partB = [SCNBox boxWithWidth:0.4 height:0.4 length:1 chamferRadius:0];
    partB.firstMaterial.diffuse.contents = [self color:4];
    SCNNode *partBNode = [SCNNode nodeWithGeometry:partB];
    partBNode.name = @"shotbody";
    [shot addChildNode:partBNode];
    
    shot.position = SCNVector3Make(0, 0.3, 3);
    [self.sceneView.scene.rootNode addChildNode:shot];
    
    SCNNode *eraser = [self.sceneView.scene.rootNode childNodeWithName:@"eraser" recursively:NO];
    SCNLookAtConstraint *lc = [SCNLookAtConstraint lookAtConstraintWithTarget:eraser];
    lc.gimbalLockEnabled = YES;
    shot.constraints = @[lc];
}

- (void)createCamera {
    SCNNode *camera = [SCNNode node];
    camera.camera = [SCNCamera camera];
    camera.position = SCNVector3Make(0, 10, 20);
    camera.rotation = SCNVector4Make(1, 0, 0, -0.5);
    [self.sceneView.scene.rootNode addChildNode:camera];
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    CGPoint p = [[touches anyObject] locationInView:self.sceneView];
    SCNHitTestResult *hit = [self.sceneView hitTest:p options:@{SCNHitTestSortResultsKey : @YES}].firstObject;
    if (hit) {
        SCNNode *shot = [self.sceneView.scene.rootNode childNodeWithName:@"shot" recursively:NO];
        if ([hit.node.name isEqual:@"desk"]) {
            shot.position = SCNVector3Make(hit.worldCoordinates.x, hit.worldCoordinates.y + 0.25, hit.worldCoordinates.z);
        } else if ([hit.node.name isEqual:@"shotbody"]) {
            
            
            SCNNode *eraser = [self.sceneView.scene.rootNode childNodeWithName:@"eraser" recursively:NO];
            
            SCNBox *b = [SCNBox boxWithWidth:0.5 height:0.5 length:0.5 chamferRadius:0.1];
            b.firstMaterial.diffuse.contents = [self color:2];
            SCNNode *bNode = [SCNNode nodeWithGeometry:b];
            bNode.position = shot.position;
            bNode.physicsBody = [SCNPhysicsBody dynamicBody];
            [self.sceneView.scene.rootNode addChildNode:bNode];
            
            float dx = eraser.presentationNode.position.x - shot.presentationNode.position.x;
            float dz = eraser.presentationNode.position.z - shot.presentationNode.position.z;
            float u = sqrt(pow(dx, 2) + pow(dz, 2));
            [bNode.physicsBody applyForce:SCNVector3Make(10 * dx / u, 0, 10 * dz / u) impulse:YES];
        }
    }

}

#define ColorHex(rgb) [UIColor colorWithRed:((rgb & 0xFF0000) >> 16) / 255.0 green:((rgb & 0xFF00) >> 8) / 255.0 blue:(rgb & 0xFF) / 255.0 alpha:1.0]
- (UIColor *)color:(int)i {
    if (i > 4) return nil;
    int code[] = {0x0F0F0D, 0xA3969D, 0xFEFEFE, 0x1B286C, 0x8E1E9C};
    return ColorHex(code[i]);
}

@end