问使用箭头关键点的基本动画

EN

0-3 when DOWN key is pressed |
4-7 when LEFT key is pressed |
8-11 when RIGHT key is pressed |
12-15 when UP key is pressed |

PImage[] p = new PImage[16];
int frameCounter = 0;
int current;
int walkTo = 15;
int walkFrom;

void setup(){
frameRate(60);
size(200,200);
imageMode(CENTER);
ashWalk();
}

void draw() {
background(255);
image(p[current], width/2, height/2);
if(frameCounter % 8 == 0) { 
  if (current > walkTo-1)current = walkFrom;
  current++;
}
  frameCounter++;
}

void ashWalk(){
 for(int i = 0; i < walkTo+1; i++){
  p[i] = loadImage("Pokemon"+i+".png");
  } 
}

void keyPressed() {
ashWalk();
if (key == CODED) {
  if (keyCode == DOWN){
    walkFrom = 0;
    walkTo = 3;
  }  
  else if(keyCode == LEFT){
    walkFrom = 4; //what I would possibly want is to start looping in this number
    walkTo = 7;
  }
  else if(keyCode == RIGHT){
    walkFrom = 8;
    walkTo = 11;
  }
  else if(keyCode == UP){
    walkFrom = 12;
    walkTo = 15;
  }
 }
}