从本质上讲,我只需要一些有关如何使圆从活动对象反弹的指导.我遇到了麻烦,已经尝试了三个小时,因此向论坛寻求帮助.我尝试了多个“ if”语句,但显然我无法正确理解,因为没有一个起作用.谢谢 ：)

我已经尝试了3个小时,用不同的if语句弄清楚了这一点.

float x;
float easing = 1;
float circle_x = 1;
float circle_y = 30;
float rad = 12.5;
float gravity = 0.98;
float move_x = 5;
float move_y = 5;

void setup() {
    size(640, 480);
    frameRate(60);
}

void draw() {
    background(#87CEEB);

    fill(#7cfc00);
    rect(0, 430, 640, 80);

    float targetX = mouseX;
    float dx = targetX - x;
    x += dx * easing;

    fill(#000000);
    rect(x, 400, 30, 30);
    rect(x-20, 390, 70, 10);
    rect(x, 430, 5, 20);
    rect(x+25, 430, 5, 20);


    ellipse(circle_x, circle_y, 25, 25);
    circle_x = circle_x + move_x;
    circle_y = circle_y + move_y;

    if (circle_x > width) {
        circle_x = width;
        move_x = -move_x;
    }

    if (circle_y > height) {
        circle_y = height;
        move_y = -move_y;
    }

    if (circle_x < 0) {
        circle_x = 0;
        move_x = -move_x;
    }

    if (circle_y < 0) {
        circle_y = 0;
        move_y= -move_y;
    }
}

将任何变量插入到if语句中,然后只接收回来：我的鼠标光标(不是对象)将球反弹,毛刺的圆圈和模糊的图像.

解决方法:

必须检查球的x坐标是否在对象的范围内(objW是对象的宽度)：

circle_x > x && circle_x < x + objW

并且如果球的y坐标已达到对象的高度(objH是对象的高度,而circleR是球的半径)：

circle_y > objH - circleR

此外,重要的是要先进行命中测试,然后在物体反弹后再进行测试.一个好的样式是在else if语句中执行此操作：

int objX1 = -20;
int objX2 = 70;
int objH = 390;
int circleR = 25/2;
if (circle_x > x + objX1  && circle_x < x + objX2 && circle_y > objH - circleR ) {
    circle_y = objH-circleR;
    move_y = -move_y; 
}
else if (circle_y > height) {
    circle_y = height;
    move_y = -move_y;
}
else if (circle_y < 0) {
    circle_y = 0;
    move_y= -move_y;
}  

此外,我建议先计算球的位置,然后在当前位置绘制球：

float x;
float easing = 1;
float circle_x = 1;
float circle_y = 30;
float rad = 12.5;
float gravity = 0.98;
float move_x = 5;
float move_y = 5;

void setup() {
    size(640, 480);
    frameRate(60);
}

void draw() {
    background(#87CEEB);

    fill(#7cfc00);
    rect(0, 430, 640, 80);

    float targetX = mouseX;
    float dx = targetX - x;
    x += dx * easing;

    circle_x = circle_x + move_x;
    circle_y = circle_y + move_y;
    if (circle_x > width) {
        circle_x = width;
        move_x = -move_x;
    }
    else if (circle_x < 0) {
        circle_x = 0;
        move_x = -move_x;
    }

    int objW = 70;
    int objH = 390;
    int circleR = 25/2;
    if (circle_x > x && circle_x < x + objW && circle_y > objH-circleR ) {
        circle_y = objH-circleR;
        move_y = -move_y; 
    }
    else if (circle_y > height) {
        circle_y = height;
        move_y = -move_y;
    }
    else if (circle_y < 0) {
        circle_y = 0;
        move_y= -move_y;
    }

    fill(#000000);
    rect(x, 400, 30, 30);
    rect(x-20, 390, 70, 10);
    rect(x, 430, 5, 20);
    rect(x+25, 430, 5, 20);

    ellipse(circle_x, circle_y, 25, 25);
}