/*

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

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 Create a fireworks simulation using particles, respond to user actions

 */

#import "AppController.h"

@implementation AppController

- (void)awakeFromNib {

    //Create the root layer

    rootLayer = [CALayer layer];

    //Set the root layer's attributes

    rootLayer.bounds = CGRectMake(0, 0, 640, 480);

    CGColorRef color = CGColorCreateGenericRGB(0.0, 0.0, 0.0, 1);

    rootLayer.backgroundColor = color;

    CGColorRelease(color);

    //Load the spark image for the particle

    NSImage *image = [NSImage imageNamed:@"tspark"];

    CGImageRef img = [image CGImageForProposedRect:nil context:nil hints:nil];

    mortor = [CAEmitterLayer layer];

    mortor.emitterPosition = CGPointMake(320, 0);

    mortor.renderMode = kCAEmitterLayerAdditive;

    //Invisible particle representing the rocket before the explosion

    CAEmitterCell *rocket = [CAEmitterCell emitterCell];

    rocket.emissionLongitude = M_PI / 2;

    rocket.emissionLatitude = 0;

    rocket.lifetime = 1.6;

    rocket.birthRate = 1;

    rocket.velocity = 400;

    rocket.velocityRange = 100;

    rocket.yAcceleration = -250;

    rocket.emissionRange = M_PI / 4;

    color = CGColorCreateGenericRGB(0.5, 0.5, 0.5, 0.5);

    rocket.color = color;

    CGColorRelease(color);

    rocket.redRange = 0.5;

    rocket.greenRange = 0.5;

    rocket.blueRange = 0.5;

    //Name the cell so that it can be animated later using keypath

    rocket.name = @"rocket";

    //Flare particles emitted from the rocket as it flys

    CAEmitterCell *flare = [CAEmitterCell emitterCell];

    flare.contents = (__bridge id)img;

    flare.emissionLongitude = (4 * M_PI) / 2;

    flare.scale = 0.4;

    flare.velocity = 100;

    flare.birthRate = 45;

    flare.lifetime = 1.5;

    flare.yAcceleration = -350;

    flare.emissionRange = M_PI / 7;

    flare.alphaSpeed = -0.7;

    flare.scaleSpeed = -0.1;

    flare.scaleRange = 0.1;

    flare.beginTime = 0.01;

    flare.duration = 0.7;

    //The particles that make up the explosion

    CAEmitterCell *firework = [CAEmitterCell emitterCell];

    firework.contents = (__bridge id)img;

    firework.birthRate = 9999;

    firework.scale = 0.6;

    firework.velocity = 130;

    firework.lifetime = 2;

    firework.alphaSpeed = -0.2;

    firework.yAcceleration = -80;

    firework.beginTime = 1.5;

    firework.duration = 0.1;

    firework.emissionRange = 2 * M_PI;

    firework.scaleSpeed = -0.1;

    firework.spin = 2;

    //Name the cell so that it can be animated later using keypath

    firework.name = @"firework";

    //preSpark is an invisible particle used to later emit the spark

    CAEmitterCell *preSpark = [CAEmitterCell emitterCell];

    preSpark.birthRate = 80;

    preSpark.velocity = firework.velocity * 0.70;

    preSpark.lifetime = 1.7;

    preSpark.yAcceleration = firework.yAcceleration * 0.85;

    preSpark.beginTime = firework.beginTime - 0.2;

    preSpark.emissionRange = firework.emissionRange;

    preSpark.greenSpeed = 100;

    preSpark.blueSpeed = 100;

    preSpark.redSpeed = 100;

    //Name the cell so that it can be animated later using keypath

    preSpark.name = @"preSpark";

    //The 'sparkle' at the end of a firework

    CAEmitterCell *spark = [CAEmitterCell emitterCell];

    spark.contents = (__bridge id)img;

    spark.lifetime = 0.05;

    spark.yAcceleration = -250;

    spark.beginTime = 0.8;

    spark.scale = 0.4;

    spark.birthRate = 10;

    preSpark.emitterCells = @[spark];

    rocket.emitterCells = @[flare, firework, preSpark];

    mortor.emitterCells = @[rocket];

    [rootLayer addSublayer:mortor];

    //Set the view's layer to the base layer

    theView.layer = rootLayer;

    [theView setWantsLayer:YES];

    //Force the view to update

    [theView setNeedsDisplay:YES];

}

// Update particle properites based on the slider values

- (IBAction)slidersMoved:(id)sender {

    [mortor setValue:[NSNumber numberWithFloat:rocketRange.floatValue * M_PI / 4] 

          forKeyPath:@"emitterCells.rocket.emissionRange"]; 

    [mortor setValue:@(rocketVelocity.floatValue)

          forKeyPath:@"emitterCells.rocket.velocity"];

    [mortor setValue:@(rocketVelocityRange.floatValue)

          forKeyPath:@"emitterCells.rocket.velocityRange"];

    [mortor setValue:@(-1 * rocketGravity.floatValue)

          forKeyPath:@"emitterCells.rocket.yAcceleration"];

    [mortor setValue:[NSNumber numberWithFloat:fireworkRange.floatValue * M_PI / 4]

          forKeyPath:@"emitterCells.rocket.emitterCells.firework.emissionRange"]; 

    [mortor setValue:@(fireworkVelocity.floatValue)

          forKeyPath:@"emitterCells.rocket.emitterCells.firework.velocity"];

    [mortor setValue:@(fireworkVelocityRange.floatValue)

          forKeyPath:@"emitterCells.rocket.emitterCells.firework.velocityRange"];

    [mortor setValue:@(-1 * fireworkGravity.floatValue)

          forKeyPath:@"emitterCells.rocket.emitterCells.firework.yAcceleration"];

    [mortor setValue:[NSNumber numberWithFloat:fireworkVelocity.floatValue * 0.70]

          forKeyPath:@"emitterCells.rocket.emitterCells.preSpark.velocity"];

    [mortor setValue:[NSNumber numberWithFloat:fireworkGravity.floatValue * -0.85]

          forKeyPath:@"emitterCells.rocket.emitterCells.preSpark.yAcceleration"];

    [mortor setValue:[NSNumber numberWithFloat:fireworkRange.floatValue * M_PI / 4]

          forKeyPath:@"emitterCells.rocket.emitterCells.preSpark.emissionRange"];

    mortor.speed = animationSpeed.floatValue / 100.0;

}

// Reset the slider positions to the default values

- (IBAction)resetSliders:(id)sender {

    rocketRange.intValue = 1;

    rocketVelocity.intValue = 400;

    rocketVelocityRange.intValue = 100;

    rocketGravity.intValue = 250;

    fireworkRange.intValue = 8;

    fireworkVelocity.intValue = 130;

    fireworkVelocityRange.intValue = 0;

    fireworkGravity.intValue = 80;

    animationSpeed.intValue = 100;

    [self slidersMoved:self]; 

}

@end