/*

Copyright (C) 2016 Apple Inc. All Rights Reserved.

See LICENSE.txt for this sample’s licensing information

Abstract:

The view controller class for the Game of Life sample. Manages an MTKView for displaying graphics rendered by Metal

    and mediates touch and mouse interactions.

*/

#import "AAPLViewController.h"

#import "AAPLRenderer.h"

@import Metal;

@import simd;

@import MetalKit;

@interface AAPLViewController ()

@property (nonatomic, weak) MTKView *metalView;

@property (nonatomic, strong) AAPLRenderer * renderer;

@end

@implementation AAPLViewController

#pragma mark - View Controller Methods

- (void)viewDidLoad

{

    [super viewDidLoad];

    self.metalView = (MTKView *)self.view;

    [self setupView];

#if TARGET_OS_IOS || TARGET_OS_TV

    // On iOS and tvOS, we need to expressly enable multitouch on our view and

    // request to be made first responder so we can listen for touches

    self.metalView.userInteractionEnabled = YES;

#if !TARGET_OS_TV

    // On iPhone and iPad, we go further and track multiple touches at once

    self.metalView.multipleTouchEnabled = YES;

#endif

    [self becomeFirstResponder];

#endif

}

#if TARGET_OS_IPHONE

- (BOOL)prefersStatusBarHidden {

    return YES;

}

- (BOOL)canBecomeFirstResponder {

    return YES;

}

#endif

#pragma mark - Setup Methods

- (void)setupView

{

    self.metalView.device = MTLCreateSystemDefaultDevice();

    self.metalView.colorPixelFormat = MTLPixelFormatBGRA8Unorm;

    self.metalView.clearColor = MTLClearColorMake(0, 0, 0, 1);

    self.metalView.drawableSize = self.metalView.bounds.size;

    // Create renderer and make it the delegate of our MTKView

    self.renderer = [[AAPLRenderer alloc] initWithView:self.metalView];

}

#pragma mark - Interaction (Touch / Mouse) Handling

- (CGPoint)locationInGridForLocationInView:(CGPoint)point

{

    CGSize viewSize = self.view.frame.size;

    CGFloat normalizedWidth = point.x / viewSize.width;

    CGFloat normalizedHeight = point.y / viewSize.height;

    CGFloat gridX = round(normalizedWidth * self.renderer.gridSize.width);

    CGFloat gridY = round(normalizedHeight * self.renderer.gridSize.height);

    return CGPointMake(gridX, gridY);

}

- (void)activateRandomCellsForPoint:(CGPoint)point

{

    // Translate between the coordinate space of the view and the game grid,

    // then forward the request to the compute phase to do the real work

    CGPoint gridLocation = [self locationInGridForLocationInView:point];

    [self.renderer activateRandomCellsInNeighborhoodOfCell:gridLocation];

}

#if TARGET_OS_IPHONE

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event

{

    for (UITouch *touch in touches)

    {

        // Turn on random cells in the vicinity of the touched location

        CGPoint location = [touch locationInView:self.view];

        [self activateRandomCellsForPoint:location];

    }

}

- (void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event

{

    for (UITouch *touch in touches)

    {

        // Turn on random cells in the vicinity of the touched location

        CGPoint location = [touch locationInView:self.view];

        [self activateRandomCellsForPoint:location];

    }

}

#else

- (void)mouseDown:(NSEvent *)event {

    // Translate the cursor position into view coordinates, accounting for the fact that

    // App Kit's default window coordinate space has its origin in the bottom left

    CGPoint location = [self.view convertPoint:[event locationInWindow] fromView:nil];

    location.y = self.view.bounds.size.height - location.y;

    // Turn on random cells in the vicinity of the clicked location

    [self activateRandomCellsForPoint:location];

}

- (void)mouseDragged:(NSEvent *)event {

    // Translate the cursor position into view coordinates, accounting for the fact that

    // App Kit's default window coordinate space has its origin in the bottom left

    CGPoint location = [self.view convertPoint:[event locationInWindow] fromView:nil];

    location.y = self.view.bounds.size.height - location.y;

    // Turn on random cells in the vicinity of the clicked location

    [self activateRandomCellsForPoint:location];

}

#endif

@end