GameField/game-field.html at master · jscud/GameField · GitHub

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<!doctype html>
<html>
  <head>
    <title>Game Field</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
  </head>
  <body>
    <div>
      <button onclick="GameField.displayRun_()">Run</button>
      <button onclick="GameField.displayCode_()">Code</button>
      <button onclick="GameField.displayMyPrograms_()">My Programs</button>
    </div>
    <div id="game-field">
    </div>
    <div id="code-editor" style="display:none">
      Program Name: <input id="program-name" value="first example"></input><br>
      <span id="code-area" contenteditable="true" style="font-family:monospace">
// Your code here :-)<br>
GameField.eachTick = function() {<br>
&nbsp;&nbsp;var click = checkclick();<br>
&nbsp;&nbsp;if (click) {<br>
&nbsp;&nbsp;&nbsp;&nbsp;setpixel(click.x, click.y, randomcolor());<br>
&nbsp;&nbsp;}<br>
};
      </span>
    </div>
    <div id="my-programs" style="display:none">
      Programs:<br>
    </div>
    <script>
// Unnamed closure to avoid polluting the global namespace.
(function() {
var publicGameField = {};

// Constructor for a game field state container.
function GameEngine() {
  this.numRows = 0;
  this.numCols = 0;
  this.tileSize = 1;
  this.eventLoopDelay = 100;
  this.reset_();
  this.eventLoopInterval = null;
}

// Called before creating a new canvas to remove internal state associated
// with a run on a GameField program.
GameEngine.prototype.reset_ = function() {
  this.clickQueue = [];
  this.eventListenerStarted = false;
};

// Starts an event loop to call GameField.eachTick at the interval specified
// by the stored event loop internal.
GameEngine.prototype.resetEventLoop_ = function() {
  if (this.eventLoopInterval) {
    clearInterval(this.eventLoopInterval);
  }
  this.eventLoopInterval = setInterval(function() {
    if (publicGameField.eachTick) {
      publicGameField.eachTick();
    }
  }, this.eventLoopDelay);
};

// Starts recording clicks on the canvas, saving them in the GameField click
// queue.
GameEngine.prototype.listenForEvents_ = function() {
  var field = document.getElementById('field');
  var thisGameEngine = this;
  field.addEventListener('click', function(e) {
    var x;
    var y;
    if (e.pageX || e.pageY) {
      x = e.pageX;
      y = e.pageY;
    } else {
      x = e.clientX + document.body.scrollLeft +
          document.documentElement.scrollLeft;
      y = e.clientY + document.body.scrollTop +
          document.documentElement.scrollTop;
    }
    var fieldCanvas = document.getElementById('field');
    x -= fieldCanvas.offsetLeft;
    y -= fieldCanvas.offsetTop;

    thisGameEngine.clickQueue.push(
        [Math.floor(x / thisGameEngine.tileSize),
         Math.floor(y / thisGameEngine.tileSize)]);
  }, true);
};

// Creates a blank game field canvas prepared to start running a
// GameField program.
GameEngine.prototype.resetCanvas = function(numPixelsWide, numPixelsHigh) {
  this.reset_();
  // Wipe out old canvas.
  var gameFieldDiv = document.getElementById('game-field');
  gameFieldDiv.innerHTML = '';
  // Determine new game fild pixel size.
  var maxPixelSizeBasedOnWidth = Math.floor(
      (document.documentElement.clientWidth - 20) / numPixelsWide);
  var maxPixelSizeBasedOnHeight = Math.floor(
      (document.documentElement.clientHeight - 30) / numPixelsHigh);
  var pixelSize = Math.min(
      maxPixelSizeBasedOnWidth, maxPixelSizeBasedOnHeight);
  // Create new game field.
  var gameFieldCanvas = document.createElement('canvas');
  gameFieldCanvas.id = 'field';
  gameFieldCanvas.width = pixelSize * numPixelsWide;
  gameFieldCanvas.height = pixelSize * numPixelsHigh;
  gameFieldCanvas.style.border = '1px solid #000000';
  gameFieldDiv.appendChild(gameFieldCanvas);

  this.numRows = numPixelsHigh;
  this.numCols = numPixelsWide;
  this.tileSize = pixelSize;
  this.listenForEvents_();
  this.resetEventLoop_();
};

GameEngine.prototype.setPixel = function(x, y, color) {
  var field = document.getElementById('field');
  var fieldContext = field.getContext('2d');
  fieldContext.fillStyle = color;
  fieldContext.fillRect(
      x * this.tileSize, y * this.tileSize, this.tileSize, this.tileSize);
};

// Gets the next stored click if there is one.
GameEngine.prototype.checkClick = function() {
  if (this.clickQueue.length > 0) {
    var click = this.clickQueue[0];
    this.clickQueue = this.clickQueue.slice(1);
    return {x: click[0], y: click[1]};
  }
  return null;
};

function randomNumber(low, high) {
  return Math.floor(Math.random() * ((high - low + 1))) + low;
}

var hexDigits_ = ['0', '1', '2', '3', '4', '5', '6', '7',
                  '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'];

function randomColor() {
  var digits = ['#'];
  for (var i = 0; i < 6; i++) {
    digits.push(hexDigits_[randomNumber(0, 15)]);
  }
  return digits.join('');
}

function randomColor() {
  var digits = ['#'];
  for (var i = 0; i < 6; i++) {
    digits.push(hexDigits_[randomNumber(0, 15)]);
  }
  return digits.join('');
}

// Singleton GameEngine used by functions exposed for users.
var gameField = new GameEngine();

var PROGRAM_PREFIX = 'gameField-program-';

function saveProgram_() {
  var programName = document.getElementById('program-name').value;
  if (!programName) {
    console.log('no file name given, not saving program');
    return;
  }
  localStorage[PROGRAM_PREFIX + programName] = document.getElementById(
      'code-area').innerHTML;
}

function loadProgram_(programName) {
  document.getElementById('program-name').value = programName;
  var code = localStorage[PROGRAM_PREFIX + programName]
  if (code) {
    document.getElementById('code-area').innerHTML = code;
  } else {
    document.getElementById('code-area').innerHTML = '// Your code here :-)';
  }
}

// Functions exposed to that button click handlers can load, save, and run
// programs.
publicGameField.displayRun_ = function() {
  saveProgram_();
  document.getElementById('code-editor').style.display = 'none';
  document.getElementById('my-programs').style.display = 'none';
  var gameFieldDiv = document.getElementById('game-field');
  gameFieldDiv.style.display = '';
  gameField.resetCanvas(16, 16);

  var code = document.getElementById('code-area').innerText;
  eval(code);
};

publicGameField.displayCode_ = function() {
  document.getElementById('game-field').style.display = 'none';
  document.getElementById('my-programs').style.display = 'none';
  document.getElementById('code-editor').style.display = '';
};

function generateProgramOpener_(programName) {
  return function() {
    loadProgram_(programName);
    publicGameField.displayCode_();
  }
}

publicGameField.displayMyPrograms_ = function() {
  saveProgram_();
  document.getElementById('game-field').style.display = 'none';
  document.getElementById('code-editor').style.display = 'none';
  var programsDiv = document.getElementById('my-programs');
  programsDiv.style.display = '';
  programsDiv.innerHTML = 'Programs:<br>';

  // Find everything in local storage that starts with the
  // 'gameField-program-' prefix.
  for (var programKey in localStorage) {
    if (programKey.indexOf(PROGRAM_PREFIX) == 0) {
      var programName = programKey.substr(PROGRAM_PREFIX.length);
      var a = document.createElement('a');
      a.onclick = generateProgramOpener_(programName);
      a.innerText = programName;
      programsDiv.appendChild(a);
      programsDiv.appendChild(document.createElement('br'));
    }
  }
};

// Adds a function to the public name space to allow users to call it. Exposes
// both the name given and an all lowercase name to allow users to skip having
// to shift to uppercase.
function addPublicFunction(name, f) {
  publicGameField[name] = f;
  window[name.toLowerCase()] = f;
}

addPublicFunction('setPixel', function(x, y, color) {
  gameField.setPixel(x, y, color);
});

addPublicFunction('checkClick', function() {
  return gameField.checkClick();
});

addPublicFunction('randomNumber', function(low, high) {
  return randomNumber(low, high);
});

addPublicFunction('randomColor', function() {
  return randomColor();
});

// Expose the GameField namespace.
window['GameField'] = publicGameField;

// Run the example program at the start.
publicGameField.displayRun_();
})();
    </script>
  </body>
</html>