javascript - 突破代码不起作用。不知道怎么做数组

Question

我不明白如何将多个彩色积木组成一个数组。每行都有不同的颜色，我只出现一 block 砖，我不确定如何获得 8x4 的砖阵列。

我不知道该怎么做。

//Tracy Miles
//N220
//4.29.2019

var screenW = 800;
var screenH = 600;

var objects = [];

//setup for the canvas
function setup() {
createCanvas(screenW, screenH);
var paddle = new Paddle();
var ball = new Ball(paddle);
objects.push(paddle);
objects.push(ball);
objects.push(new Block(screenH/2, screenW/2, ball));
}

function draw() {
    background(0);
    for (var i = 0; i < objects.length; i++)
    {
        objects[i].update();
    }
}

function Paddle() {
    this.x = 0; this.y = screenH - 35;
    this.width = 100; this.height = 20;
    this.update = function() {
        this.x = mouseX;
        rect(this.x, this.y, this.width, this.height);
    }
}

function Ball(paddle) {
    this.paddle = paddle;
    this.x = screenW/2; this.y = screenH - 40;
    this.rad = 10;
    this.speedX = 3; this.speedY = -3;
    this.update = function() {
        this.x += this.speedX;
        this.y += this.speedY;

        if (this.x < 0 || this.x > screenW) {
            this.speedX *= -1;
        }

        if (this.y < 0 || this.y > screenH) {
            this.speedY *= -1;
        }

        if (this.y > this.paddle.y && this.y < this.paddle.y + this.paddle.height) {
            if (this.x > this.paddle.x && this.x < this.paddle.x + this.paddle.width) {
                this.speedY *= -1;
            }
        }
        rect(this.x, this.y, this.rad, this.rad, 90);
    }
}



////////This is where the main problem arises.//////////////

function Block(x, y, ball) {
    this.ball = ball;
    this.x = x; this.y = x;
    this.width= 100; this.height= 20;
    this.broken = false;
    this.update = function() {
        if (!this.broken) {
            rect(this.x, this.y, this.width, this.height);

            if (this.ball.y > this.y && this.ball.y < this.y + this.height) {
                if (this.ball.x > this.x && this.ball.x < this.x + this.width) {
                    this.broken = true;
                    ball.speedY *= -1;
                }
            }
        }
    }

}

我想要一个 8x4 的 block 阵列，每​​一行都是不同的颜色。

Answer 1

将颜色的属性添加到 Ball 的颜色。填充对象的颜色可以通过 stroke() 设置。 :

function Block(x, y, color, ball) {
    this.ball = ball;
    this.x = x; this.y = y;
    this.width = 100; this.height= 20;
    this.color = color;
    this.broken = false;
    this.update = function() {
        if (!this.broken) {

            fill(this.color); // set current color
            rect(this.x, this.y, this.width, this.height);
            fill(255);        // switch back to "white" color 

            if (this.ball.y > this.y && this.ball.y < this.y + this.height) {
                if (this.ball.x > this.x && this.ball.x < this.x + this.width) {
                    this.broken = true;
                    ball.speedY *= -1;
                }
            }
        }
    }
}

block 可以在 2 个嵌套循环中创建。 RGB 颜色可以由 [color()`] ( https://p5js.org/reference/#/p5/color ) 生成。在以下示例中，生成了从蓝色到红色的渐变颜色:

for (let i=0; i < 4; ++i) {
    for (let j=0; j < 8; ++j) {
        let red = 70+(8-j)*20;
        let blue = 90+j*20;
        objects.push(new Block(50 + i*200, 20 + j*40, color(red, 0, blue), ball));
    }
}

查看示例，其中我将建议应用到您的代码中:

var screenW = 800;
var screenH = 600;

var objects = [];

//setup for the canvas
function setup() {
createCanvas(screenW, screenH);

    var paddle = new Paddle();
    var ball = new Ball(paddle);
    objects.push(paddle);
    objects.push(ball);

    for (let i=0; i < 4; ++i) {
        for (let j=0; j < 8; ++j) {
            let red = 70+(8-j)*20;
            let blue = 90+j*20;
            objects.push(new Block(50 + i*200, 20 + j*40, color(red, 0, blue), ball));
        }
    }
}

function draw() {
    background(0);
    for (var i = 0; i < objects.length; i++)
    {
        objects[i].update();
    }
}

function Paddle() {
    this.x = 0; this.y = screenH - 35;
    this.width = 100; this.height = 20;
    this.update = function() {
        this.x = mouseX;
        rect(this.x, this.y, this.width, this.height);
    }
}

function Ball(paddle) {
    this.paddle = paddle;
    this.x = screenW/2; this.y = screenH - 40;
    this.rad = 10;
    this.speedX = 3; this.speedY = -3;
    this.update = function() {
        this.x += this.speedX;
        this.y += this.speedY;

        if (this.x < 0 || this.x > screenW) {
            this.speedX *= -1;
        }

        if (this.y < 0 || this.y > screenH) {
            this.speedY *= -1;
        }

        if (this.y > this.paddle.y && this.y < this.paddle.y + this.paddle.height) {
            if (this.x > this.paddle.x && this.x < this.paddle.x + this.paddle.width) {
                this.speedY *= -1;
            }
        }
        rect(this.x, this.y, this.rad, this.rad, 90);
    }
}



////////This is where the main problem arises.//////////////

function Block(x, y, color, ball) {
    this.ball = ball;
    this.x = x; this.y = y;
    this.width = 100; this.height= 20;
    this.color = color;
    this.broken = false;
    this.update = function() {
        if (!this.broken) {
            fill(this.color);
            rect(this.x, this.y, this.width, this.height);
            fill(255);
            if (this.ball.y > this.y && this.ball.y < this.y + this.height) {
                if (this.ball.x > this.x && this.ball.x < this.x + this.width) {
                    this.broken = true;
                    ball.speedY *= -1;
                }
            }
        }
    }
}

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