Pobtastic / Goldfish Game / Chaining Scenes

Created Sun, 21 Apr 2024 09:45:03 +0100 Modified Sat, 04 May 2024 21:31:28 +0000

Introduction

So you don’t miss it and have to reload the page, here’s the transition between the scenes first … and showing everything combined.

To achieve this, we just have to tell Phaser we’re using two scenes:

  const config = {
    type: Phaser.AUTO,
    width: 1024,
    height: 768,
    scene: [SplashScreen, MainScene],
    backgroundColor: '#CDC6CD',
    physics: {
      default: 'arcade',
      arcade: {
        debug: false
      }
    },
    scale: {
      mode: Phaser.Scale.FIT,
      parent: 'gameContainer',
      autoCenter: Phaser.Scale.CENTER_BOTH,
      zoom: 0.5
    }
  };
  const game = new Phaser.Game(config);

And tell Phaser how we shift between the scenes. The game itself just uses a long pause, so we can do the same:

  class SplashScreen extends BaseScene {
    constructor() {
      super('SplashScreen');
    }
    create() {
      this.cameras.main.setBackgroundColor('#000000');
      this.printAt("   BOOTY BY JOHN F CAIN   ", 2, 4);
      this.printAt("CATCH 20 GOLDFISH", 7, 12);
      this.printAt("BUT DONT RUN OUT OF AIR", 4, 14);
      this.printAt("OR GET TOO CLOSE TO THE BIG FISH", 0, 16);
      this.time.delayedCall(3000, () => {
        this.scene.start('MainScene');
      });
    }
  }

This is the equivalent z80 assembly code:

; Hidden Goldfish Game
@label=GoldfishGame
c$CE41 CALL $D4BE      ; Call ClearScreen.

; Print the playing instructions.
 $CE44 LD DE,$DD9A     ; DE=Messaging_GoldfishGame.
 $CE47 CALL $D60E      ; Call PrintString.

; Pause to let the message sink in...
 $CE4A LD BC,$012C     ; BC=$012C (pause loops).
@label=GoldfishGame_PauseLoop
*$CE4D PUSH BC         ; Stash the pause loop counter on the stack.
 $CE4E CALL $D3A6      ; Call SmallPause.
 $CE51 POP BC          ; Restore the pause loop counter from the stack.
 $CE52 DEC BC          ; Decrease the pause loop counter by one.
 $CE53 LD A,B          ; {Jump to GoldfishGame_PauseLoop until the pause loop counter is zero.
 $CE54 OR C            ;
 $CE55 JR NZ,$CE4D     ; }
We could measure in time how long this actually is … but this isn’t an emulation, so 3 seconds is fine.

The only other thing I’ve added, is the status bar text, which is easy now we have the “PRINT AT” method to call:

// Add the status text.
this.printAt("FISH ", 0, 22, "32px", "#000000");
this.printAt("AIR", 8, 22, "32px", "#000000");

Booty Disassembly