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Here you can Sed posuere consectetur est at lobortis. Donec ullamcorper nulla non metus auctor fringilla. Maecenas sed diam eget risus varius blandit sit amet non magna. Donec id elit non mi porta gravida at eget metus. Praesent commodo cursus magna, vel scelerisque nisl consectetur et.

            
              <canvas id="cvs" width="680px" height="500px" style="background-color:#000;"></canvas>
            
          
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              var canvas = document.getElementById("cvs");
var ctx = canvas.getContext("2d");
var imgCnt = 25;          // 描画する画像の数
var aryImg = [];          // 画像の情報を格納
var cvsw = 680;           // canvasタグに指定したwidth
var cvsh = 500;           // canvasタグに指定したheight
var imgBaseSizeW = 15;    // 画像の基本サイズ横幅
var imgBaseSizeH = 18.5;  // 画像の基本サイズ立幅
var aspectMax = 1.5;      // アスペクト比計算時の最大値
var aspectMin = 0.5;      // アスペクト比計算時の最小値
var speedMax = 2;         // 落下速度の最大値
var speedMin = 0.5;       // 落下速度の最小値

// 画像の読み込み
var img = new Image();
img.src = "http://www.otwo.jp/blog/demo/canvas/images/sakura.png";
img.onload = flow_start;

// 画像のパラメーターを設定
function setImagas(){
  var aspect = 0;
  for(var i = 0;i < imgCnt;i++){
    // 画像サイズに掛けるアスペクト比を0.5~1.5倍でランダムで生成
    aspect = Math.random()*(aspectMax-aspectMin)+aspectMin;
    aryImg.push({
      "posx": Math.random()*cvsw,   // 初期表示位置x
      "posy": Math.random()*cvsh,   // 初期表示位置y
      "sizew": imgBaseSizeW*aspect, // 画像の幅
      "sizeh": imgBaseSizeH*aspect, // 画像の高さ
      "speedy": Math.random()*(speedMax-speedMin)+speedMin, // 画像が落ちていく速度
    });
  }
}

// 画像のパラメーターを設定
function setImagas(){
  var aspect = 0;
  for(var i = 0;i < imgCnt;i++){
    // 画像サイズに掛けるアスペクト比を0.5~1.5倍でランダムで生成
    aspect = Math.random()*(aspectMax-aspectMin)+aspectMin;
    aryImg.push({
      "posx": Math.random()*cvsw,   // 初期表示位置x
      "posy": Math.random()*cvsh,   // 初期表示位置y
      "sizew": imgBaseSizeW*aspect, // 画像の横幅
      "sizeh": imgBaseSizeH*aspect, // 画像の縦幅
      "speedy": Math.random()*(speedMax-speedMin)+speedMin, // 画像が落ちていく速度
    });
  }
}

// 描画、パラメーターの更新
var idx = 0;
function flow(){
  ctx.clearRect(0,0,cvsw,cvsh);
  for(idx = 0;idx < imgCnt;idx++){
    aryImg[idx].posy += aryImg[idx].speedy;
    ctx.drawImage(img, aryImg[idx].posx, aryImg[idx].posy, aryImg[idx].sizew , aryImg[idx].sizeh);
    // 範囲外に描画された画像を上に戻す
    if(aryImg[idx].posy >= cvsh){
      aryImg[idx].posy = -aryImg[idx].sizeh;
    }
  }
}

function flow_start(){
  setImagas();
  setInterval(flow,10);
}
            
          
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