How do I get the sampling rate of a canvas element? -


i investigating preprocessing on-line handwriting recognition (see http://write-math.com). 1 interesting property of input devices sampling rate, means rate @ onmousemove , similar events.

i can record them , see time delta between 2 events varies 1.00 ms - 700.00 ms, in average 27.34 ms for recording.

(sampling rate measured in points / second. sampling rate enter image description here or average case enter image description here)

is there possibility information client directly? there devices sampling rate known? how javascript internally decide how fire events? can "event firing rate" increased / decreased?

mousemove firing rates particular browser stable on sufficient sample size, firing rate of individual mouse event affected non-canvas activities (garbage collection, background tasks, etc).

i don't know of browser allows adjustment of mousemove timing--all internally defined.

interesting project!


Comments

Post a Comment

Popular posts from this blog

javascript - RequestAnimationFrame not working when exiting fullscreen switching space on Safari -

request animation frame stops working when exiting fullscreen clicking on original space's safari window. fine if fullscreen mode canceled escape key or calling cancelfullscreen(). steps reproduce: open https://dl.dropboxusercontent.com/u/769042/prezi/safari-fullscreen.html click "draw raf", kittie appears click "fullscreen", go fullscreen click "draw raf", kittie appears go space original safari was, showing "click exit fullscreen mode", click anywhere, out fullscreen click "draw raf", nothing happens what handling click calling: window.requestanimationframe(draw); which draws on canvas context: function draw() { ctx.drawimage(img, math.random()*500|0, math.random()*400|0, 100, 100); } i checked .hidden , .visibilitystate, updated correctly. tested on osx 10.9.3, safari 7.0.4 (9537.76.4). has workaround/solution other switching old settimeout? this sounds webkit bug 88940 : using reque
Read more

Python ctypes access violation with const pointer arguments -

i have api i'm trying wrap in python (2.7.6 on win7) code using ctypes. here's api: client_dllfunc bool clientapi search_exporttoclipcopy(clienthsearch handle, int channel, lpctstr filename, const time_t& from, const time_t& to, const bool* cameras, int length, bool usepassword, lpctstr password, bool includetextin = false, bool excludeplayer = false); the issue i'm having cameras argument; , i've had issue other const pointer arguments well. here's how i'm wrapping api: def search_exporttoclipcopy(self, hsearch, csearch, filename, tfrom, tto, cameras, length, usepassword, password, includetextin=true, excludeplayer=false): exporttoclipcopy = self.sdkdll.search_exporttoclipcopy exporttoclipcopy.argtypes = [c_int, c_int, c_wchar_p, c_long, c_long, pointer(c_bool), c_int, c_bool, c_wchar_p, c_bool, c_bool] exporttoclipcopy.restype = c_bool exporttoclipcopy(hsearch, csearch, filename, tfrom, tto, cameras, length, usepassword, pass
Read more