javascript - requestAnimationFrame() performance issue -


i experienced performance issues requestanimationframe().

consider following code. it's simple loop prints time since last frame every time time delta larger 20ms.

const glob_time_info = {delta_time: 0.0, last_frame: performance.now()};  var render = function (timestamp) {     glob_time_info.delta_time = timestamp - glob_time_info.last_frame;     glob_time_info.last_frame = timestamp;      if(glob_time_info.delta_time > 20)         console.log(glob_time_info.delta_time);     requestanimationframe(render); }; render(performance.now());

as understood requestanimationframe snippet should never print anything, because tries run 60 times second (60hz monitor). therefore time delta should around 16-17ms.

but prints times around 33ms every few seconds. why?

i experienced on windows 10 chrome 54 , firefox 49. own i5-6600

update here output of nit's script windows , ubuntu. windows, doing? windows 10 (pc): enter image description here windows 8 (same netbook below): enter image description here ubuntu (same netbook above): enter image description here

it's easy test hypothesis issue related platform you're running on - measure performance.

shortly put, run requestanimationframe number of times similar how did , note down timestamp on each run. after visualize results.

var times = [];  var measure = function() {    times.push(new date().gettime());    if (times.length > 100) return draw();    requestanimationframe(measure);  };  var draw = function() {    var dataset = {      x: [],      y: [],      type: 'bar'    };    var layout = {      xaxis: {        title: 'measurement #'      },      yaxis: {        title: 'iteration duration (ms)'      },      height: 250    };    var options = {      displaymodebar: false    };    times.reduce(function(previous, current, i) {      dataset.x.push(i);      dataset.y.push(current - previous);      return current;    }, times.shift());    plotly.newplot('target', [dataset], layout, options);  }  measure();
#target {    margin-top: -50px;  }
<script src="https://cdn.plot.ly/plotly-1.2.0.min.js"></script>  <div id="target"></div>

you can run same simulation on different operating systems , different browsers see if can narrow down issue further.


Comments

Post a Comment

Popular posts from this blog

sql server - Cannot query correctly (MSSQL - PHP - JSON) -

i have little problem on project. , turns out query result returns nothing when value of first name or last name has 'ñ' in it. here's code config.php: <?php ini_set('mssql.charset', 'utf-8'); header('content-type: text/html; charset=utf-8'); $servername = "192.168.1.21"; /* ip add of db server */ $connection = array("database" => "db", "uid" => "?", "pwd" => "***"); $conn = sqlsrv_connect($servername, $connection); if(!$conn){ echo "connection not established."; die(print_r(sqlsrv_errors(), true)); } ?> myquery: $idnumber = $_post["idnum"]; $response = array(); $query2 = "select clname, cfname, cmname, cqualifier student cidno = '$idnumber'"; try{ $stmt2 = sqlsrv_query($conn, $query2); } catch(pdoexeption $ex){ $response["success"] = 0; $response["message"] = "d...
Read more

php - trouble displaying mysqli database results in correct order -

i have table in database stores events , date expire. want display events on website display current events first expired events after? i have tried following sql $sql = "select noticeid, notice, noticedesc, noticeimg, noticedate, expirydate tbl_notices group noticeid ,expired order expirydate asc"; but returns expired results first due expirydate being ordered asc in query. my tbl_notice structure looks this noticeid => int(4) notice => varchar(100) noticedesc => text noticedate => timestamp noticeimg => varchar(40) expirydate => datetime expired => int(1) 0 current or 1 expired my php code is $sql = "select noticeid, notice, noticedesc, noticeimg, noticedate, expirydate tbl_notices group noticeid ,expired order expirydate asc"; $result = mysqli_query($conn,$sql); if ($result->num_rows > 0) { // output data of each row while($row = $result->fetch_assoc()) { ...
Read more

C++ Linked List -

i trying create linked list download txt file , use linked list handle file line line. when handling downloaded linked list operations performed on such text editor would. encountering problems however. seems "node(string value)" section of code has wrong though original node() declaration no arguments passes. unable figure out quite is. node.h class node { public: node(); node(string value); void setnext(node *nextnode); // allows user set "next" pointer of node points friend class linkedlist; private: string data; // data box node* next; // pointer box }; node.cpp # include <string> # include "node.h" using namespace std; node::node() { data = ""; next = null; } node::node(string value) { data = value; next = null; } void node::setnext(node *nextnode) // allows user set "next" pointer of node points { this->next = nextnode; } your #include <string> ...
Read more