syndicate-js/packages/flappy-bird-demo/src/index.js

"use strict";
//---------------------------------------------------------------------------
// @syndicate-lang/flappy-bird-demo
// Copyright (C) 2016-2018 Tony Garnock-Jones <tonyg@leastfixedpoint.com>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.
//---------------------------------------------------------------------------

import { bootModule, $QuitDataspace, Inbound, Outbound, Dataspace, Double } from "@syndicate-lang/core";

let UI = activate require("@syndicate-lang/driver-browser-ui");
// @jsx UI.html
// @jsxFrag UI.htmlFragment

let { PeriodicTick } = activate require("@syndicate-lang/driver-timer");

assertion type Position(x, y);
assertion type GameOver();
assertion type Score(count);
message type IncreaseScore();
message type Reset();

const BOARD_HEIGHT = 567;
const FLAPPY_WIDTH = 57;
const FLAPPY_HEIGHT = 41;
const FLAPPY_XPOS = 212;
const PILLAR_WIDTH = 86;
const PILLAR_GAP = 158;
const FIELD_HEIGHT = 561;
const PILLAR_HEAD_HEIGHT = 40;

spawn named 'game-factory' {
  on start spawnGame();
  during GameOver() {
    on stop spawnGame();
    on message UI.WindowEvent('+keypress', $e) send Reset();
    on message UI.WindowEvent('+click', $e) send Reset();
  }
}

function spawnGame() {
  spawn dataspace named 'GameInstance' {
    spawn named 'game-instance-control' {
      during GameOver() assert Outbound(GameOver());
      on message Inbound(Reset()) send $QuitDataspace;
    }

    spawn named 'score' {
      let ui = new UI.Anchor();
      field this.score = 0;

      assert Score(this.score);

      on start react {
        assert Outbound(ui.html('#board-area', <h1 class="score">{this.score}</h1>));
        stop on asserted GameOver() react {
          assert Outbound(ui.html('#board-area', <h1 class="score">{this.score}<br/>GAME OVER</h1>));
        }
      }

      on message IncreaseScore() {
        this.score++;
      }
    }

    spawn named 'flappy' {
      let ui = new UI.Anchor();
      field this.xpos = 0;
      field this.ypos = 312;
      field this.yvel = 0;

      assert Position(Double(this.xpos), Double(this.ypos));

      assert Outbound(ui.html('#board-area', <div class="flappy"
                                                  style={`transform: rotate(${2 * this.yvel}deg);
                                                          top: ${this.ypos}px`}></div>));

      on (this.ypos > BOARD_HEIGHT - FLAPPY_HEIGHT) {
        this.ypos = BOARD_HEIGHT - FLAPPY_HEIGHT;
        react {
          assert GameOver();
        }
      }

      on start react {
        stop on asserted GameOver();

        on message Inbound(UI.WindowEvent('+keypress', $e)) this.yvel = -10;
        on message Inbound(UI.WindowEvent('+click', $e)) this.yvel = -10;

        const ms_per_tick = 1000.0 / 60;
        on message Inbound(PeriodicTick(Double(ms_per_tick))) {
          this.xpos += 0.15 * ms_per_tick;
          this.ypos = (this.ypos + this.yvel);
          this.yvel += ms_per_tick * 0.05;
        }
      }
    }

    spawn named 'border-scroll' {
      let ui = new UI.Anchor();
      field this.pos = 0;
      on asserted Position($xpos, _) this.pos = xpos.value % 23;
      assert Outbound(ui.html(
        '#board-area',
          <div class="scrolling-border" style={`background-position-x: ${-this.pos}px`}></div>, 0));
    }

    spawn named 'pipe-factory' {
      field this.nextPipe = 0;
      on asserted Score(this.nextPipe) {
        spawnPipe(this.nextPipe++);
      }
    }

    function spawnPipe(i) {
      spawn named ['pipe', i] {
        let ui = new UI.Anchor();

        const xlocation = (i + 1) * 324;

        const upperHeight =
              Math.random() * (FIELD_HEIGHT - PILLAR_GAP - PILLAR_HEAD_HEIGHT * 6)
              + PILLAR_HEAD_HEIGHT * 3;
        const lowerHeight = FIELD_HEIGHT - upperHeight - PILLAR_GAP;

        stop on (this.xpos < -(PILLAR_WIDTH + FLAPPY_XPOS));

        on start react stop on (this.xpos <= 0) send IncreaseScore();

        field this.xpos = xlocation;
        on asserted Position($xpos, _) this.xpos = xlocation - xpos.value;

        on asserted Position($xpos, $ypos) {
          if (touchingPillar(xpos.value, ypos.value)) {
            react {
              assert GameOver();
            }
          }
        }

        assert Outbound(ui.html(
          '#board-area',
            <div class="pillars">
            <div class="pillar pillar-upper"
          style={`left: ${this.xpos + FLAPPY_XPOS}px; height: ${upperHeight}px;`}></div>
            <div class="pillar pillar-lower"
          style={`left: ${this.xpos + FLAPPY_XPOS}px; height: ${lowerHeight}px;`}></div>
            </div>));

        function touchingPillar(xpos, ypos) {
          const inHorizontalRange =
                (xpos + FLAPPY_WIDTH >= xlocation) && (xpos <= xlocation + PILLAR_WIDTH);
          const aboveGapTop = (ypos <= upperHeight);
          const belowGapBottom = (ypos + FLAPPY_HEIGHT >= upperHeight + PILLAR_GAP);
          return inHorizontalRange && (aboveGapTop || belowGapBottom);
        }
      }
    }
  }
}

// Running Syndicate programs in node.js doesn't require this -- it
// automatically detects the "main" module -- but in the browser, when
// using rollup, the mechanism doesn't work properly so we explicitly
// activate *ourselves* here.
bootModule(module);