绘制火箭，跟随鼠标

  1. //9:24
  2. PImage rocket;
  4. void setup(){
  5.  size(600,500);
  6.  rocket = loadImage("🚀.png");
  7.  pixelDensity(2);
  9.  imageMode(CENTER);
  10. }
  12. void draw(){
  13.   image(rocket,mouseX,mouseY,68/2,132/2);
  15. }

image.png

绘制子弹，触壁反弹

  1. //9:24
  2. PImage rocket;
  3. float x, y, r;
  4. float spx, spy;
  6. void setup() {
  7.   size(800, 600);
  8.   rocket = loadImage("🚀.png");
  9.   pixelDensity(2);
  11.   imageMode(CENTER);
  13.   //variable of bullet
  14.   r=10;
  15.   x=width/2;
  16.   y=r;  
  17.   spx = 2;
  18.   spy=2;
  19. }
  21. void draw() {
  22.   background(#132638);
  24.   //rocket
  25.   image(rocket, mouseX, mouseY, 34, 66);
  27.   //bullet
  28.   noStroke();
  29.   fill(220, 220, 30);
  30.   ellipse(x, y, 2*r, 2*r);
  32.   //update bullet position
  33.   x+=spx;
  34.   y+=spy;
  36.   //checkEdge
  37.   if(x>=width-r || x<r){
  38.     spx = -spx;
  39.   }else if(y>=height-r || y<r ){
  40.     spy = -spy;
  41.   }
  43.   if(x<mouseX+34/2 && x>mouseX-34 && y>mouseY-66/2 && y<mouseY+66/2){
  44.     background(255,100,100);
  45.     noLoop();
  46.   }
  47. }

image.png

模块化

  1. //9:24
  2. PImage rocket;
  3. float x, y, r;
  4. float spx, spy;
  6. void setup() {
  7.   size(800, 600);
  8.   rocket = loadImage("🚀.png");
  9.   pixelDensity(2);
  11.   imageMode(CENTER);
  13.   //variable of bullet
  14.   r=10;
  15.   x=width/2;
  16.   y=r;  
  17.   spx = 2;
  18.   spy=2;
  19. }
  21. void draw() {
  22.   background(#132638);
  24.   //rocket
  25.   image(rocket, mouseX, mouseY, 34, 66);
  27.   display();
  28.   update();
  29.   checkEdge();
  31.   if (x<mouseX+34/2 && x>mouseX-34 && y>mouseY-66/2 && y<mouseY+66/2) {
  32.     background(255, 100, 100);
  33.     noLoop();
  34.   }
  35. }
  37. void display() {
  38.   //display bullet
  40.   noStroke();
  41.   fill(220, 220, 30);
  42.   ellipse(x, y, 2*r, 2*r);
  43. }
  45. void update() {
  46.   //update bullet position
  47.   x+=spx;
  48.   y+=spy;
  49. }
  51. void checkEdge() {
  53.   //check edge
  54.   if (x>=width-r || x<r) {
  55.     spx = -spx;
  56.   } else if (y>=height-r || y<r ) {
  57.     spy = -spy;
  58.   }
  59. }

面向对象编程

  1. //9:24
  2. PImage rocket;
  4. Bullet [] bullets= new Bullet[10];
  6. void setup() {
  7.   size(800, 600);
  8.   rocket = loadImage("🚀.png");
  9.   pixelDensity(2);
  11.   imageMode(CENTER);
  12.   for (int i=0; i<bullets.length; i++) {
  13.     bullets[i] = new Bullet();
  14.   }
  15. }
  17. void draw() {
  18.   background(#132638);
  20.   //rocket
  21.   image(rocket, mouseX, mouseY, 34, 66);
  23.   //操作子弹
  24.   for (int i=0; i<bullets.length; i++) {
  25.     bullets[i].display();
  26.     bullets[i].update();
  27.     bullets[i].checkEdge();
  28.     bullets[i].checkJoin();
  29.   }
  30. }
  1. class Bullet {
  2.   //子弹的变量
  3.   float x, y, r;
  4.   float spx, spy;
  6.   Bullet() {
  7.     //初始化子弹
  8.     r=10;
  9.     x=random(0,width);
  10.     y=r;
  11.     spx = 2;
  12.     spy=2;
  13.   }
  15.   void display() {
  16.     //display bullet
  18.     noStroke();
  19.     fill(220, 220, 30);
  20.     ellipse(x, y, 2*r, 2*r);
  21.   }
  23.   void update() {
  24.     //update bullet position
  25.     x+=spx;
  26.     y+=spy;
  27.   }
  29.   void checkEdge() {
  31.     //check edge
  32.     if (x>=width-r || x<r) {
  33.       spx = -spx;
  34.     } else if (y>=height-r || y<r ) {
  35.       spy = -spy;
  36.     }
  37.   }
  39.   void checkJoin() {
  40.     if (x<mouseX+34/2 && x>mouseX-34 && y>mouseY-66/2 && y<mouseY+66/2) {
  41.       background(255, 100, 100);
  42.       noLoop();
  43.     }
  44.   }
  45. }

优化

  1. ...
  3. void draw() {
  4.   ...
  6.   //操作子弹
  7.   for (int i=0; i<bullets.length; i++) {
  8.     bullets[i].display();
  9.     bullets[i].update();
  10.     bullets[i].checkEdge();
  11.   }
  13.   for (int i=0; i<bullets.length; i++) {
  14.     bullets[i].checkJoin();
  15.   }
  16. }

加入声音

  1. import processing.sound.*;
  3. PImage rocket;
  4. SoundFile explode;
  6. ...
  8. void setup() {
  9.   ...
  10.   for (int i=0; i<bullets.length; i++) {
  11.     bullets[i] = new Bullet(random(r, width), random(r, height), random(-2, 2), random(-2, 2));
  12.   }
  14.   explode = new SoundFile(this,"explode.wav");
  15. }
  16. ...
  1. class Bullet {
  2.   ...
  3.   void checkJoin() {
  4.     if (x<mouseX+34/2 && x>mouseX-34 && y>mouseY-66/2 && y<mouseY+66/2) {
  5.       background(255, 100, 100);
  6.       explode.play();
  7.       noLoop();
  8.     }
  9.   }
  10. }