JavaScriptでオタマジャクシが集団で泳ぐアニメーション効果を実現-jsチュートリアル-php.cn

この記事では主に、Sketch.js に基づいて集団で泳ぐオタマジャクシの動きをシミュレートするアニメーション効果の JS 実装を紹介します。これには、Sketch.js プラグインの使用と HTML5 要素の応用スキルも含まれます。読者が参照用にダウンロードできるソースコードです。必要な友人は以下を参照してください

この記事では、オタマジャクシが群れで泳ぐモーションアニメーション効果をシミュレートするための Sketch.js に基づく JS 実装の例について説明します。参考までに皆さんと共有してください。詳細は次のとおりです:

Sketch.js に基づいて、オブジェクトのタッチ検出 (オタマジャクシが障害物に遭遇し、マウスのクリックを巧みに回避します)、ランダムな動き、集計アルゴリズムなどを実装します。

ゲームの基本要素がすでに備わっており、それを拡張することで優れた HTML5 ゲームに変えることができます。

デモの効果は次のとおりです:

完全なコードは次のとおりです:

<!DOCTYPE html>
<html class=" -webkit- js flexbox canvas canvastext webgl no-touch geolocation postmessage websqldatabase indexeddb hashchange history draganddrop websockets rgba hsla multiplebgs backgroundsize borderimage borderradius boxshadow textshadow opacity cssanimations csscolumns cssgradients cssreflections csstransforms csstransforms3d csstransitions fontface generatedcontent video audio localstorage sessionstorage webworkers applicationcache svg inlinesvg smil svgclippaths">
<head>
<meta charset="UTF-8">
<title>HTML5 Preview Panel</title>
<script src="prefixfree.min.js"></script>
<script src="modernizr.js"></script>
<style>
body {
  background-color: #222;
}
</style>
</head>
<body>
<script src="sketch.min.js"></script>
<p id="container">
<canvas class="sketch" id="sketch-0" height="208" width="607"></canvas>
</p>
<script>
var calculateDistance = function(object1, object2) {
  x = Math.abs(object1.x - object2.x);
  y = Math.abs(object1.y - object2.y);
  return Math.sqrt((x * x) + (y * y));
};
var calcMagnitude = function(x, y) {
  return Math.sqrt((x * x) + (y * y));
};
var calcVectorAdd = function(v1, v2) {
  return {
    x: v1.x + v2.x,
    y: v1.y + v2.y
  };
};
var random = function(min, max) {
  return min + Math.random() * (max - min);
};
var getRandomItem = function(list, weight) {
  var total_weight = weight.reduce(function(prev, cur, i, arr) {
    return prev + cur;
  });
  var random_num = random(0, total_weight);
  var weight_sum = 0;
  //console.log(random_num)
  for (var i = 0; i < list.length; i++) {
    weight_sum += weight[i];
    weight_sum = +weight_sum.toFixed(2);
    if (random_num <= weight_sum) {
      return list[i];
    }
  }
  // end of function
};
/***********************
BOID
***********************/
function Boid(x, y) {
  this.init(x, y);
}
Boid.prototype = {
  init: function(x, y) {
    //body
    this.type = "boid";
    this.alive = true;
    this.health = 1;
    this.maturity = 4;
    this.speed = 6;
    this.size = 5;
    this.hungerLimit = 12000;
    this.hunger = 0;
    this.isFull = false;
    this.digestTime = 400;
    this.color = &#39;rgb(&#39; + ~~random(0, 100) + &#39;,&#39; + ~~random(50, 220) + &#39;,&#39; + ~~random(50, 220) + &#39;)&#39;;
    //brains
    this.eyesight = 100; //range for object dectection
    this.personalSpace = 20; //distance to avoid safe objects
    this.flightDistance = 60; //distance to avoid scary objects
    this.flockDistance = 100; //factor that determines how attracted the boid is to the center of the flock
    this.matchVelFactor = 6; //factor that determines how much the flock velocity affects the boid. less = more matching
    this.x = x || 0.0;
    this.y = y || 0.0;
    this.v = {
      x: random(-1, 1),
      y: random(-1, 1),
      mag: 0
    };
    this.unitV = {
      x: 0,
      y: 0,
    };
    this.v.mag = calcMagnitude(this.v.x, this.v.y);
    this.unitV.x = (this.v.x / this.v.mag);
    this.unitV.y = (this.v.y / this.v.mag);
  },
  wallAvoid: function(ctx) {
    var wallPad = 10;
    if (this.x < wallPad) {
      this.v.x = this.speed;
    } else if (this.x > ctx.width - wallPad) {
      this.v.x = -this.speed;
    }
    if (this.y < wallPad) {
      this.v.y = this.speed;
    } else if (this.y > ctx.height - wallPad) {
      this.v.y = -this.speed;
    }
  },
  ai: function(boids, index, ctx) {
    percievedCenter = {
      x: 0,
      y: 0,
      count: 0
    };
    percievedVelocity = {
      x: 0,
      y: 0,
      count: 0
    };
    mousePredator = {
      x: ((typeof ctx.touches[0] === "undefined") ? 0 : ctx.touches[0].x),
      y: ((typeof ctx.touches[0] === "undefined") ? 0 : ctx.touches[0].y)
    };
    for (var i = 0; i < boids.length; i++) {
      if (i != index) {
        dist = calculateDistance(this, boids[i]);
        //Find all other boids close to it
        if (dist < this.eyesight) {
          //if the same species then flock
          if (boids[i].type == this.type) {
            //Alignment
            percievedCenter.x += boids[i].x;
            percievedCenter.y += boids[i].y;
            percievedCenter.count++;
            //Cohesion
            percievedVelocity.x += boids[i].v.x;
            percievedVelocity.y += boids[i].v.y;
            percievedVelocity.count++;
            //Separation
            if (dist < this.personalSpace + this.size + this.health) {
              this.avoidOrAttract("avoid", boids[i]);
            }
          } else {
            //if other species fight or flight
            if (dist < this.size + this.health + boids[i].size + boids[i].health) {
              this.eat(boids[i]);
            } else {
              this.handleOther(boids[i]);
            }
          }
        } //if close enough
      } //dont check itself
    } //Loop through boids
    //Get the average for all near boids
    if (percievedCenter.count > 0) {
      percievedCenter.x = ((percievedCenter.x / percievedCenter.count) - this.x) / this.flockDistance;
      percievedCenter.y = ((percievedCenter.y / percievedCenter.count) - this.y) / this.flockDistance;
      this.v = calcVectorAdd(this.v, percievedCenter);
    }
    if (percievedVelocity.count > 0) {
      percievedVelocity.x = ((percievedVelocity.x / percievedVelocity.count) - this.v.x) / this.matchVelFactor;
      percievedVelocity.y = ((percievedVelocity.y / percievedVelocity.count) - this.v.y) / this.matchVelFactor;
      this.v = calcVectorAdd(this.v, percievedVelocity);
    }
    //Avoid Mouse
    if (calculateDistance(mousePredator, this) < this.eyesight) {
      var mouseModifier = 20;
      this.avoidOrAttract("avoid", mousePredator, mouseModifier);
    }
    this.wallAvoid(ctx);
    this.limitVelocity();
  },
  setUnitVector: function() {
    var magnitude = calcMagnitude(this.v.x, this.v.y);
    this.v.x = this.v.x / magnitude;
    this.v.y = this.v.y / magnitude;
  },
  limitVelocity: function() {
    this.v.mag = calcMagnitude(this.v.x, this.v.y);
    this.unitV.x = (this.v.x / this.v.mag);
    this.unitV.y = (this.v.y / this.v.mag);
    if (this.v.mag > this.speed) {
      this.v.x = this.unitV.x * this.speed;
      this.v.y = this.unitV.y * this.speed;
    }
  },
  avoidOrAttract: function(action, other, modifier) {
    var newVector = {
      x: 0,
      y: 0
    };
    var direction = ((action === "avoid") ? -1 : 1);
    var vModifier = modifier || 1;
    newVector.x += ((other.x - this.x) * vModifier) * direction;
    newVector.y += ((other.y - this.y) * vModifier) * direction;
    this.v = calcVectorAdd(this.v, newVector);
  },
  move: function() {
    this.x += this.v.x;
    this.y += this.v.y;
    if (this.v.mag > this.speed) {
      this.hunger += this.speed;
    } else {
      this.hunger += this.v.mag;
    }
  },
  eat: function(other) {
    if (!this.isFull) {
      if (other.type === "plant") {
        other.health--;
        this.health++;
        this.isFull = true;
        this.hunger = 0;
      }
    }
  },
  handleOther: function(other) {
    if (other.type === "predator") {
      this.avoidOrAttract("avoid", other);
    }
  },
  metabolism: function() {
    if (this.hunger >= this.hungerLimit) {
      this.health--;
      this.hunger = 0;
    }
    if (this.hunger >= this.digestTime) {
      this.isFull = false;
    }
    if (this.health <= 0) {
      this.alive = false;
    }
  },
  mitosis: function(boids) {
    if (this.health >= this.maturity) {
      //reset old boid
      this.health = 1;
      birthedBoid = new Boid(
        this.x + random(-this.personalSpace, this.personalSpace),
        this.y + random(-this.personalSpace, this.personalSpace)
      );
      birthedBoid.color = this.color;
      boids.push(birthedBoid);
    }
  },
  draw: function(ctx) {
    drawSize = this.size + this.health;
    ctx.beginPath();
    ctx.moveTo(this.x + (this.unitV.x * drawSize), this.y + (this.unitV.y * drawSize));
    ctx.lineTo(this.x + (this.unitV.y * drawSize), this.y - (this.unitV.x * drawSize));
    ctx.lineTo(this.x - (this.unitV.x * drawSize * 2), this.y - (this.unitV.y * drawSize * 2));
    ctx.lineTo(this.x - (this.unitV.y * drawSize), this.y + (this.unitV.x * drawSize));
    ctx.lineTo(this.x + (this.unitV.x * drawSize), this.y + (this.unitV.y * drawSize));
    ctx.fillStyle = this.color;
    ctx.shadowBlur = 20;
    ctx.shadowColor = this.color;
    ctx.fill();
  }
};
Predator.prototype = new Boid();
Predator.prototype.constructor = Predator;
Predator.constructor = Boid.prototype.constructor;
function Predator(x, y) {
  this.init(x, y);
  this.type = "predator";
  //body
  this.maturity = 6;
  this.speed = 6;
  this.hungerLimit = 25000;
  this.color = &#39;rgb(&#39; + ~~random(100, 250) + &#39;,&#39; + ~~random(10, 30) + &#39;,&#39; + ~~random(10, 30) + &#39;)&#39;;
  //brains
  this.eyesight = 150;
  this.flockDistance = 300;
}
Predator.prototype.eat = function(other) {
  if (!this.isFull) {
    if (other.type === "boid") {
      other.health--;
      this.health++;
      this.isFull = true;
      this.hunger = 0;
    }
  }
};
Predator.prototype.handleOther = function(other) {
  if (other.type === "boid") {
    if (!this.isFull) {
      this.avoidOrAttract("attract", other);
    }
  }
};
Predator.prototype.mitosis = function(boids) {
  if (this.health >= this.maturity) {
    //reset old boid
    this.health = 1;
    birthedBoid = new Predator(
      this.x + random(-this.personalSpace, this.personalSpace),
      this.y + random(-this.personalSpace, this.personalSpace)
    );
    birthedBoid.color = this.color;
    boids.push(birthedBoid);
  }
};
Plant.prototype = new Boid();
Plant.prototype.constructor = Plant;
Plant.constructor = Boid.prototype.constructor;
function Plant(x, y) {
  this.init(x, y);
  this.type = "plant";
  //body
  this.speed = 0;
  this.size = 10;
  this.health = ~~random(1, 10);
  this.color = &#39;rgb(&#39; + ~~random(130, 210) + &#39;,&#39; + ~~random(40, 140) + &#39;,&#39; + ~~random(160, 220) + &#39;)&#39;;
  //brains
  this.eyesight = 0;
  this.flockDistance = 0;
  this.eyesight = 0; //range for object dectection
  this.personalSpace = 100; //distance to avoid safe objects
  this.flightDistance = 0; //distance to avoid scary objects
  this.flockDistance = 0; //factor that determines how attracted the boid is to the center of the flock
  this.matchVelFactor = 0; //factor that determines how much the flock velocity affects the boid
}
Plant.prototype.ai = function(boids, index, ctx) {};
Plant.prototype.move = function() {};
Plant.prototype.mitosis = function(boids) {
  var growProbability = 1,
    maxPlants = 40,
    plantCount = 0;
  for (m = boids.length - 1; m >= 0; m--) {
    if (boids[m].type === "plant") {
      plantCount++;
    }
  }
  if (plantCount <= maxPlants) {
    if (random(0, 100) <= growProbability) {
      birthedBoid = new Plant(
        this.x + random(-this.personalSpace, this.personalSpace),
        this.y + random(-this.personalSpace, this.personalSpace)
      );
      birthedBoid.color = this.color;
      boids.push(birthedBoid);
    }
  }
};
Plant.prototype.draw = function(ctx) {
  var drawSize = this.size + this.health;
  ctx.fillStyle = this.color;
  ctx.shadowBlur = 40;
  ctx.shadowColor = this.color;
  ctx.fillRect(this.x - drawSize, this.y + drawSize, drawSize, drawSize);
};
/***********************
SIM
***********************/
var boids = [];
var sim = Sketch.create({
  container: document.getElementById(&#39;container&#39;)
});
sim.setup = function() {
  for (i = 0; i < 50; i++) {
    x = random(0, sim.width);
    y = random(0, sim.height);
    sim.spawn(x, y);
  }
};
sim.spawn = function(x, y) {
  var predatorProbability = 0.1,
    plantProbability = 0.3;
  switch (getRandomItem([&#39;boid&#39;, &#39;predator&#39;, &#39;plant&#39;], [1 - predatorProbability - plantProbability, predatorProbability, plantProbability])) {
    case &#39;predator&#39;:
      boid = new Predator(x, y);
      break;
    case &#39;plant&#39;:
      boid = new Plant(x, y);
      break;
    default:
      boid = new Boid(x, y);
      break;
  }
  boids.push(boid);
};
sim.update = function() {
  for (i = boids.length - 1; i >= 0; i--) {
    if (boids[i].alive) {
      boids[i].ai(boids, i, sim);
      boids[i].move();
      boids[i].metabolism();
      boids[i].mitosis(boids);
    } else {
      //remove dead boid
      boids.splice(i, 1);
    }
  }
};
sim.draw = function() {
  sim.globalCompositeOperation = &#39;lighter&#39;;
  for (i = boids.length - 1; i >= 0; i--) {
    boids[i].draw(sim);
  }
  sim.fillText(boids.length, 20, 20);
};
</script>
</body>
</html>

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以上がJavaScriptでオタマジャクシが集団で泳ぐアニメーション効果を実現の詳細内容です。詳細については、PHP 中国語 Web サイトの他の関連記事を参照してください。