如何在Phaser 3中使用冲突检测设置变量的值？

Question

我正在使用Phaser 3框架以JavaScript创建游戏。我使用的是物质物理引擎，我只希望玩家在接触地面时能够跳起来（或像游戏中的奥利一样）。我正在尝试在物质物理学中使用碰撞检测，但似乎什么也无法工作。

此当前代码中的错误是“ Uncaught TypeError: this.matter.world is not a function”，尽管我尝试了其他实现此处使用的冲突检测的方法。

我希望玩家仅在按下向上箭头键并且他们接触地面时才能够跳跃。

//Configurations for the physics engine
var physicsConfig = {
    default: 'matter',
    matter : {
        gravity: {
            x: 0,
            y: 2.5, // <--This is the only way I could get the skater to roll up the ramp.
        },
        debug: false //CHANGE THIS TO TRUE TO SEE LINES
    }   
}

//Variables for height and width
var gameHeight = 750;
var gameWidth = 3000;

/* Declare variable to decide whether the player can ollie or not
Player should be touching the ground or a ramp to be able to ollie */
var canOllie;

//Game configurations
var config = {
    type: Phaser.AUTO,
    width: 1500, //<-- this is the width of what we will see at one time
    height: gameHeight,
    physics: physicsConfig,
    scene: {
        preload: preload,
        create: create,
        update: update
    }   
}

//Start the game
var game = new Phaser.Game(config);

//Declare variables so we can access them in all functions
var skater;

var ground;

//Declare variable for the sky background
var sky;

function preload() {
    //Images
    this.load.image('sky', 'archery_assets/images/sky.png');

    //Load sprites from TexturePacker
    this.load.atlas('sheet', 'skate_assets/sprites.png', 'skate_assets/sprites.json');
    //Load body shapes from PhysicsEditor
    this.load.json('shapes', 'skate_assets/spritesPE.json');
}

function create() {

    //Background
    sky = this.add.image(1500, 325,'sky')
    //Scale the image
    sky.setDisplaySize(gameWidth, gameHeight);

    //Get the hitboxes
    var shapes = this.cache.json.get('shapes');

    //Set world bounds    
    this.matter.world.setBounds(0, 0, gameWidth, gameHeight);

    //Place ground object
    ground = this.matter.add.sprite(0, 0, 'sheet', 'ground', {shape: shapes.ground});
    //Ground is 600x600, so double the x pixels and we get screen width
    ground.setScale(5, 1);
    ground.setPosition(1500, 650);
    //Let the ground detect collisions 
    ground.isSensor(true);

    //Place the ramp
    var ramp = this.matter.add.sprite(0, 0, 'sheet', 'ramp', {shape: shapes.ramp});
    ramp.setPosition(550 + ramp.centerOfMass.x, 250  + ramp.centerOfMass.y);

    //Create the skater
    skater = this.matter.add.sprite(0, 0, 'sheet', 'roll/0001', {shape: shapes.s0001});
    skater.setPosition(100 + skater.centerOfMass.x, 200 + skater.centerOfMass.y);

    //Collision filtering
    var staticCategory = this.matter.world.nextCategory();
    ramp.setCollisionCategory(staticCategory);
    ground.setCollisionCategory(staticCategory);

    var skaterCategory = this.matter.world.nextCategory();
    skater.setCollisionCategory(skaterCategory);

    //Roll animation
    //Generate the frame names
    var rollFrameNames = this.anims.generateFrameNames(
        'sheet', {start: 1, end: 4, zeroPad: 4,
        prefix: 'roll/'}
    );
    //Create the animation
    this.anims.create({
        key: 'roll', frames: rollFrameNames, frameRate: 16, repeat: -1
    });

    //Push animation
    var pushFrameNames = this.anims.generateFrameNames(
        'sheet', {start: 5, end: 8, zeroPad: 4,
        prefix: 'push/'}
    );
    this.anims.create({
        key: 'push', frames: pushFrameNames, frameRate: 16, repeat: 0 
    });

    //Shuvit animation
    var shuvFrameNames = this.anims.generateFrameNames(
        'sheet', {start: 9, end: 12, zeroPad: 4,
        prefix: 'shuv/'}
    );
    this.anims.create({
        key: 'shuv', frames: shuvFrameNames, frameRate: 32, repeat: 0 
    });

    //Ollie animation
    var ollieFrameNames = this.anims.generateFrameNames(
        'sheet', {start: 13, end: 20, zeroPad: 4,
        prefix: 'ollie/'}
    );
    this.anims.create({
        key: 'ollie', frames: ollieFrameNames, frameRate: 24, repeat: 0
    });

    //Kickflip animation
    var kfFrameNames = this.anims.generateFrameNames(
        'sheet', {start: 21, end: 33, zeroPad: 4,
        prefix: 'kickflip/'}
    );
    this.anims.create({
        key: 'kickflip', frames: kfFrameNames, frameRate: 24, repeat: 0
    });

    //This keeps the rolling animation going once the push animation is done
    skater.on('animationcomplete', () => {
        skater.anims.play('roll');
    });

    //Input for arrowkeys
    this.arrowKeys = this.input.keyboard.addKeys({
        up: 'up',
        down: 'down',
        left: 'left',
        right: 'right'
    }); 

    //Input for WASD keys
    this.WASDkeys = this.input.keyboard.addKeys({
        W: 'W',
        A: 'A',
        S: 'S',
        D: 'D'
    });

    //Spacebar
    this.spacebar = this.input.keyboard.addKey(Phaser.Input.Keyboard.KeyCodes.SPACE);

    //Camera to follow the skater
    this.cameras.main.setBounds(0, 0, 3000, gameHeight);
    this.cameras.main.startFollow(skater);


    //Detect collision with ground
    this.matter.world('collisionactive', (skater, ground) => {
        if (this) {
            canOllie = true;
        }
        else {
            canOllie = false;
        }
    });

}

function update() {
    //Set variable for player movement
    var pushSpeed = 0;
    var ollie = 0;

    //Push
    if (this.spacebar.isDown && skater.angle > -60 && skater.angle < 60) {
        //Increase speed
        pushSpeed = 10;

        //Move player
        skater.setVelocityX(pushSpeed);

        //Play push animation
        skater.anims.play('push');
    }

    //Ollie
    if (Phaser.Input.Keyboard.JustDown(this.arrowKeys.up) && canOllie == true) {
        //Set ollie power
        ollie = -12;

        //Set skate velocity
        skater.setVelocityY(ollie);

        //Play the ollie animation
        skater.anims.play('ollie');

    }

    //Shuvit
    if (this.arrowKeys.down.isDown) {
        //Play the shuvit animation
        skater.anims.play('shuv');
    }

    //Kickflip
    if (this.WASDkeys.W.isDown) {
        //Set jump height
        ollie = -8

        //Move the player
        skater.setVelocityY(ollie);

        //Play animation
        skater.anims.play('kickflip');
    }

    //Tilting backwards in the air
    if (this.arrowKeys.left.isDown && skater.y < 470) {
        //Be able to turn backwards so you don't flip
        skater.angle -= 3 ;
    }
    //Tilting forwards in the air
    if (this.arrowKeys.right.isDown && skater.y < 470) {
        //Be able to turn forwards so you don't flip
        skater.angle += 3 ;
    }


}   

Answer 1

我终于找到了解决此问题的方法：

• First，在skaterTouchingGround对象之后声明一个名为config的变量，如下所示：

let skaterTouchingGround;

• Second，在create()函数中添加碰撞检测器事件并将变量skaterTouchingGround设置为true，如下所示：

//Detect collision with ground
this.matter.world.on("collisionactive", (skater, ground) => {
   skaterTouchingGround = true;
});

• Third，在update()函数＆if语句中，添加skaterTouchingGround变量作为触发跳转的条件，并且一旦跳转完成将变量skaterTouchingGround设置为false，如下所示：

//Ollie
if (Phaser.Input.Keyboard.JustDown(this.arrowKeys.up) && skaterTouchingGround) {
    skaterTouchingGround = false;
    //Set ollie power
    ollie = -12;

    //Set skate velocity
    skater.setVelocityY(ollie);

    //Play the ollie animation
    skater.anims.play('ollie');

}

如果遵循这些步骤，则滑冰者将无法跳到空中。