shellquest/src/screens/game/Camera.ts

Terminal-based procedurally generated dungeon crawler

import type {ZombieAttackGame} from './ZombieAttackGame.ts';
import {TILE_SIZE} from './TileMap.ts';
import {MAP_HEIGHT, MAP_WIDTH} from './constants.ts';

export class Camera {
  constructor(private game: ZombieAttackGame) {}

  // Camera position in pixels
  x: number = 0;
  y: number = 0;

  // Target positions for smooth interpolation
  targetX: number = 0;
  targetY: number = 0;

  get viewportWidth(): number {
    return this.game.width;
  }
  get viewportHeight(): number {
    return this.game.height;
  }

  update(playerPixelX: number, playerPixelY: number): void {
    // Calculate ideal camera position to center player
    const centerX = this.viewportWidth / 2;
    const centerY = this.viewportHeight / 2;

    // Calculate ideal camera position in pixels
    this.targetX = playerPixelX - centerX + TILE_SIZE / 2;
    this.targetY = playerPixelY - centerY + TILE_SIZE / 2;

    // Clamp to map bounds in pixels
    const maxX = MAP_WIDTH * TILE_SIZE - this.viewportWidth;
    const maxY = MAP_HEIGHT * TILE_SIZE - this.viewportHeight;

    if (this.targetX < 0) {
      this.targetX = 0;
    } else if (this.targetX > maxX) {
      this.targetX = maxX;
    }

    if (this.targetY < 0) {
      this.targetY = 0;
    } else if (this.targetY > maxY) {
      this.targetY = maxY;
    }

    // Smooth interpolation (instant for now, can be smoothed later)
    this.x = this.targetX;
    this.y = this.targetY;
  }
}