audventure/scripts/game.js

function createSound(name, url) {
  var deferred = Q.defer();
  soundManager.createSound({
    id: name,
    url: url,
    autoLoad: true,
    onload: function() {
      deferred.resolve(this);
    }
  });
  return deferred.promise;
}

function sign(x) { return x > 0 ? 1 : x < 0 ? -1 : 0; }

function lerp(from, to, p) {
  return to * p + from * (1 - p);
}

function ease(v) { return v * v * (3 - 2 * v); }

function easeOutExpo(t, b, c, d) {
  return (t==d) ? b+c : c * (-Math.pow(2, -10 * t/d) + 1) + b;
}

function color(r,g,b,a) {
  return 'rgba('+r+','+g+','+b+','+a.toFixed(5)+')';
}

var SoundSafari = function(canvas, beatInfo, pSoundManager) {
  var ctx = canvas.getContext('2d');

  // Constants
  var RADIUS = 8;
  var LEAF_SIZE = 8;
  var LEVEL_SIZE = 800;
  var ALLOWANCE = (LEVEL_SIZE - canvas.width)/2;
  var METER_WIDTH = 120;
  var METER_HEIGHT = 40;
  var METER_SPEED = 10;
  var PLAYER_SPEED = 50;
  var STAGE_SPEED = 25;
  var RIPPLE_SIZE = 10;
  var RIPPLE_SPEED = 10;
  var DOT_SIZE = 3;
  var DOT_DISTANCE = 4 * 5;

  var starColors = [
    'maroon',
    'red',
    'orange',
    'yellow',
    'olive',
    'green',
    'teal',
    'blue',
    'navy',
    'purple'
  ];

  var paused = false;
  var debug = false;

  var beats = [];
  var gameTime = 0;
  var currentBeats = [];
  var gotPoint = false;

  var switchBeat = function(index) {
    var currentBeat = beats[index];
    currentBeats.push(currentBeat);
    if(currentBeats.length > 4) {
      currentBeats.splice(0, 1);
    }

    activeTarget = new Target(currentBeat);
    entities.push(activeTarget);
  };

  var soundPromise = pSoundManager.then(function() {
    var soundPromises = beatInfo.map(function(elem, index) {
      var beat = { info: elem, rounds: 0 };
      var promise = createSound('beat'+index, elem.url).then(function(sound) {
        beat.sound = sound;
      });
      beats.push(beat);
      return promise;
    });
    soundPromises.push(createSound('get', 'sound/get.mp3'));

    return Q.all(soundPromises);
  });

  // Input handling
  var keysDown = {};

  addEventListener('keydown', function(e) {
    keysDown[e.keyCode] = true;
  }, false);

  addEventListener('keyup', function(e) {
    if(e.keyCode == 68) {
      debug = !debug;
    }
    if(e.keyCode == 80) {
      pause();
    }
    delete keysDown[e.keyCode];
  }, false);

  addEventListener('blur', function() {
    if(!paused) pause();
  });

  // Drawing functions
  function drawCircle(point, r, w, color) {
    ctx.beginPath();
    ctx.arc(point.x, point.y, r, 0, 2*Math.PI, false);
    ctx.lineWidth = w;
    ctx.strokeStyle = color;
    ctx.stroke();
  }

  function drawLeafV(point, h, w) {
    ctx.beginPath();
    ctx.moveTo(point.x, point.y);
    ctx.quadraticCurveTo(point.x + w, point.y + h/2, point.x, point.y + h);
    ctx.quadraticCurveTo(point.x - w, point.y + h/2, point.x, point.y);
    ctx.fill();
  }

  function drawLeafH(point, w, h) {
    ctx.beginPath();
    ctx.moveTo(point.x, point.y);
    ctx.quadraticCurveTo(point.x + w/2, point.y + h, point.x + w, point.y);
    ctx.quadraticCurveTo(point.x + w/2, point.y - h, point.x, point.y);
    ctx.fill();
  }

  function drawPlayer(point) {
    drawCircle(point, RADIUS, 5, "#FFFFFF");
  }

  function drawSpectrum() {
    var barHeight = 30;
    var barWidth = 6;
    var barSpacing = 2;
    var margin = 5;
    ctx.strokeStyle = 'white';
    ctx.lineWidth = 2;
    ctx.beginPath();
    ctx.rect(
      margin - ctx.lineWidth,
      canvas.height - barHeight - ctx.lineWidth - margin,
      activeTarget.spectrum.length * (barWidth+barSpacing) + 2 * ctx.lineWidth - barSpacing,
      barHeight + 2 * ctx.lineWidth
    );
    ctx.stroke();
    for(var i = 0; i < activeTarget.spectrum.length; ++i) {
      var height = activeTarget.spectrum[i]*20;
      ctx.fillStyle = starColors[i];
      ctx.fillRect(i * (barWidth + barSpacing) + margin, canvas.height - height - margin, barWidth, height);
    }
  }

  function distX(a, b) {
    var dx = a.x - b.x;
    if(dx > LEVEL_SIZE / 2) dx -= LEVEL_SIZE;
    if(dx < -LEVEL_SIZE / 2) dx += LEVEL_SIZE;
    return dx;
  }

  function distSq(a, b) {
    var c = distX(a, b);
    var d = a.y - b.y;
    return c * c + d * d;
  }

  function colliding(a, b) {
    return distSq(a, b) <= 4 * RADIUS * RADIUS;
  }

  // "Entities"
  function Meter() {
    this.offset = 10;
    this.amp = 0;
    this.percentage = 0;
    this.direction = METER_SPEED;
  }

  Meter.prototype.draw = function() {
    var left = (canvas.width - METER_WIDTH) / 2;
    var vmid = this.offset + METER_HEIGHT / 2;
    var third = METER_WIDTH / 3;
    var peak = METER_HEIGHT / 2;

    ctx.fillStyle = 'black';
    ctx.rect(left, this.offset, METER_WIDTH, METER_HEIGHT);
    ctx.fill();

    var cpUp = lerp(vmid, vmid + peak * this.amp, this.percentage);
    var cpDown = lerp(vmid, vmid - peak * this.amp, this.percentage);

    ctx.lineWidth = 2;
    ctx.strokeStyle = 'red';
    ctx.beginPath();
    var pos = left;
    ctx.moveTo(left, vmid);
    ctx.quadraticCurveTo(pos+third/2, cpUp, pos+third, vmid);
    pos += third;
    ctx.quadraticCurveTo(pos+third/2, cpDown, pos+third, vmid);
    pos += third;
    ctx.quadraticCurveTo(pos+third/2, cpUp, pos+third, vmid);
    ctx.stroke();

    ctx.lineWidth = 3;
    ctx.strokeStyle = 'white';
    ctx.beginPath();
    ctx.rect(left, this.offset, METER_WIDTH, METER_HEIGHT);
    ctx.stroke();
  };

  Meter.prototype.onUpdate = function(dt) {
    if(this.percentage > 1) {
      this.direction = -METER_SPEED;
    }
    if(this.percentage < -1) {
      this.direction = METER_SPEED;
    }
    this.percentage += this.direction * dt;
    this.amp = 0.5 + lerp(0, 1, activeTarget.shimmerFactor);
  };

  function Star(x, y) {
    this.x = x;
    this.y = y;
    this.alpha = 0;
    this.randomize();
  }

  Star.prototype.randomize = function() {
    this.type = Math.floor(Math.random()*starColors.length);
    this.color = starColors[this.type];
  };

  Star.prototype.draw = function() {
    ctx.fillStyle = this.color;
    ctx.globalAlpha = this.alpha;
    var adjPosition = translatePoints(this);
    ctx.fillRect(adjPosition.x, adjPosition.y, DOT_SIZE, DOT_SIZE);

    var top    = {x: adjPosition.x + DOT_SIZE/2,   y: adjPosition.y - DOT_SIZE/2  };
    var bottom = {x: adjPosition.x + DOT_SIZE/2,   y: adjPosition.y + DOT_SIZE/2*3};
    var left   = {x: adjPosition.x - DOT_SIZE/2,   y: adjPosition.y + DOT_SIZE/2  };
    var right  = {x: adjPosition.x + DOT_SIZE/2*3, y: adjPosition.y + DOT_SIZE/2  };

    drawLeafH(left, -LEAF_SIZE, LEAF_SIZE/2);
    drawLeafH(right, LEAF_SIZE, LEAF_SIZE/2);
    drawLeafV(top, -LEAF_SIZE, LEAF_SIZE/2);
    drawLeafV(bottom, LEAF_SIZE, LEAF_SIZE/2);
    ctx.globalAlpha = 1;
  };

  Star.prototype.onUpdate = function() {
    if(gotPoint) {
      this.randomize();
    }
    if(this.y > canvas.height + DOT_DISTANCE * 2) {
      this.y -= canvas.height + DOT_DISTANCE * 4;
    }
    var newAlpha = 1.5 * activeTarget.spectrum[this.type];
    var a = 0.001;
    if(newAlpha > this.alpha) {
      a = 0.9;
    }
    this.alpha = Math.min(1, activeTarget.shimmerFactor * (this.alpha * (1-a) + newAlpha * a));
  };

  function Dot(x, y) {
    this.x = x;
    this.y = y;
  }

  Dot.prototype.draw = function() {
    ctx.fillStyle = 'gray';
    var adjPosition = translatePoints(this);
    ctx.fillRect(adjPosition.x, adjPosition.y, DOT_SIZE, DOT_SIZE);
  };

  Dot.prototype.onUpdate = function() {
    if(this.y > canvas.height + DOT_DISTANCE * 2) {
      this.y -= canvas.height + DOT_DISTANCE * 4;
    }
  };

  function Target(beat) {
    this.beat = beat;
    this.alpha = 0;
    if(points < 4) {
      this.alpha = ease(1-points/4);
    }
    this.rippleCounter = 0;
    this.reset();
  }

  Target.prototype.reset = function() {
    this.y = -20;
    this.x = Math.random()*LEVEL_SIZE;
  };

  Target.prototype.color = function(p) {
    return color(0, 255, 0, p*this.alpha);
  };

  Target.prototype.draw = function() {
    var adjPosition = translatePoints(this);
    drawCircle(adjPosition, RADIUS, 3, this.color(1));
    drawCircle(adjPosition, 2, 3, this.color(1));

    // ripples
    var p = lerp(1, 0, ease(this.rippleCounter/RIPPLE_SIZE));
    drawCircle(adjPosition, RADIUS+7+this.rippleCounter, 1, this.color(p));
    drawCircle(adjPosition, RADIUS+4+this.rippleCounter, 1, this.color(p*0.8));
    drawCircle(adjPosition, RADIUS+1+this.rippleCounter, 1, this.color(p*0.5));
  };

  Target.prototype.onUpdate = function(dt, t) {
    this.rippleCounter += RIPPLE_SPEED * dt;
    if(this.rippleCounter > RIPPLE_SIZE) {
      this.rippleCounter = 0;
    }

    if(gotPoint) {
      gotPoint = false;
    }

    if(colliding(player, this)) {
      gotPoint = true;
      this.beat.sound.setPan(0);
      this.beat.sound.setVolume(100);
      this.shouldDelete = true;
      return;
    }

    if(this.y > canvas.height + 20) {
      this.reset();
    }

    var xDist = distX(this, player);
    var s = sign(xDist);
    var xDistAbs = easeOutExpo(Math.abs(xDist), 0, 100, LEVEL_SIZE/2);

    var yDist = this.y - player.y;
    var angle = 0;
    if(yDist != 0) {
      angle = easeOutExpo(Math.abs(Math.atan2(Math.abs(yDist), xDist) - Math.PI/2), 0, 100, Math.PI);
    }
    else {
      angle = s * 100;
    }
    this.beat.sound.setPan(Math.max(xDistAbs, angle) * s);

    var rDist = xDist*xDist + yDist*yDist;
    if(rDist >= 250000) {
      rDist = 250000;
    }
    rDist = 250000 - rDist;
    rDist /= 2500;
    this.beat.sound.setVolume(rDist);

    this.shimmerFactor = easeOutExpo(Math.abs(xDist), 1, -1, LEVEL_SIZE/2) * rDist / 100;
    if(isNaN(this.shimmerFactor) || this.shimmerFactor < 0) {
      this.shimmerFactor = 0;
    }

    this.spectrum = this.beat.sound.getSpectrum(t%this.beat.info.duration);
  };

  var player = {
    x: 0,
    y: canvas.height - 20,
    dx: PLAYER_SPEED
  };

  var meter = new Meter();

  var points;
  var entities;
  var activeTarget;

  var reset = function() {
    points = 0;
    entities = [];

    for(var j = 0; j < canvas.height / DOT_DISTANCE + 4; ++j) {
      for(var i = 0; i < LEVEL_SIZE / DOT_DISTANCE; ++i) {
        var x = i * DOT_DISTANCE;
        var y = (j-4) * DOT_DISTANCE;
        if(j % 2 == 0 && i % 2 == 0) {
          entities.push(new Dot(x, y));
        }

        if(j % 4 == 1) {
          if(i % 4 == 0) {
            entities.push(new Star(x, y));
          }
          else {
            entities.push(new Dot(x, y));
          }

        }

        if(j % 4 == 3) {
          if(i % 4 == 2) {
            entities.push(new Star(x, y));
          }
          else {
            entities.push(new Dot(x, y));
          }
        }
      }
    }
  };

  // Update
  var update = function(delta) {
    if(paused) return;
    var dt = delta / 1000;

    currentBeats.map(function(beat) {
      if(beat.repeat) {
        beat.repeat = false;
      }
      else {
        if(gameTime + delta > Math.ceil(gameTime / beat.info.duration) * beat.info.duration) {
          beat.repeat = true;
        }
      }
    });


    currentBeats.map(function(beat) {
      if(beat.repeat) beat.sound.play();
    });

    if(37 in keysDown) {
      player.x -= player.dx * dt;
    }
    if(39 in keysDown) {
      player.x += player.dx * dt;
    }
    player.x = (player.x + LEVEL_SIZE) % LEVEL_SIZE;

    for(var i = entities.length - 1; i >= 0; --i) {
      var entity = entities[i];
      entity.y += STAGE_SPEED * dt;
      entity.onUpdate(dt, gameTime);
      if(entity.shouldDelete) {
        entities.splice(i, 1);
      }
    }
    meter.onUpdate(dt);

    if(gotPoint) {
      ++points;
      soundManager.play('get');
      if(beats.length > 0) {
        switchBeat(points % beats.length);
      }
    }

    gameTime += delta;
  };

  // Render
  var translatePoints = function(point) {
    var x = point.x - player.x + canvas.width/2;
    if(x < -ALLOWANCE) x += LEVEL_SIZE;
    if(x > LEVEL_SIZE - ALLOWANCE) x -= LEVEL_SIZE;
    return {x:x, y:point.y};
  };

  var render = function() {
    ctx.fillStyle = "black";
    ctx.fillRect(0, 0, canvas.width, canvas.height);
    entities.map(function(elem) {
      elem.draw();
    });
    drawPlayer(translatePoints(player));
    meter.draw();
    ctx.fillStyle = "white";
    ctx.fillText(points+"", 5, 15);

    if(debug) {
      drawSpectrum();
    }

    if(paused) {
      ctx.fillStyle = 'white';
      ctx.textAlign = 'center';
      ctx.fillText("Paused (P to unpause)", canvas.width / 2, canvas.height / 2);
      ctx.textAlign = 'start';
    }
  };

  var then;

  var main = function() {
    var now = Date.now();
    var delta = (now - then);
    update(delta);
    render();
    then = now;
  };

  var start = function() {
    reset();
    switchBeat(0);
    then = Date.now();
    setInterval(main, 10);
  };

  var pause = function() {
    paused = !paused;
    if(paused) {
      currentBeats.map(function(beat) {beat.sound.pause()});
    }
    else {
      currentBeats.map(function(beat) {beat.sound.resume()});
    }
  };

  ctx.textAlign = 'center';
  ctx.fillText("Loading...", canvas.width / 2, canvas.height / 2);
  ctx.textAlign = 'start';

  Q.all([soundPromise]).done(function() {
    start();
  });
};

var canvas = document.getElementById('game');

var beats = [
  {url: 'sound/b1.mp3', duration: 4000},
  {url: 'sound/b2.mp3', duration: 4000},
  {url: 'sound/b3.mp3', duration: 4000},
  {url: 'sound/b4.mp3', duration: 4000},
  {url: 'sound/b5.mp3', duration: 4000}
];

var soundDeferred = Q.defer();
var pSoundManager = soundDeferred.promise;
soundManager.setup({
  url: 'swf/',
  flashVersion: 9,
  onready: function() {
    soundDeferred.resolve(this);
  }
});

SoundSafari(canvas, beats, pSoundManager);