PImage Simg;  //Pimage constructor

void setup() {
  Simg = loadImage("./img/tower.jpg"); // load image file
  //Simg = loadImage("./img/cube.png");

  size( 400, 300 );  //fixed size window 
  //surface.setResizable(true);  //image size window
  //surface.setSize(Simg.width, Simg.height);
}
void draw() {
  //image( Simg, 0, 0 );
  image( Simg, 0, 0, 400, 300 ); //limit display area
}