Databases
StackOverflow2013
Postsdbo
POWebGL is it possible to emulate an asynchronous call to gl.finish()
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POWebGL is it possible to emulate an asynchronous call to gl.finish()
    primarykey
    data
    text
    <p>WebGL is nice and asynchronous in that you can send off a long list of rendering commands without waiting for them to complete. However, if for some reason you do need to wait for the rendering to complete, you have to do it synchronously with <code>gl.finish()</code>. Surely it would be better if <code>gl.finish</code> accepted a callback and returned immediately?</p> <p><strong>Question:</strong> Is there any way to emulate this reliably? </p> <p><strong>Usage case:</strong> I am rendering a large number of vertices to a large off-screen canvas and then using <code>drawImage</code> to copy sections of this large canvas to small canvases on the page. I don't actually use <code>gl.finish()</code> but <code>drawImage()</code> seems to have the same effect. In my application, re-rendering is only triggered when the user performs an action (e.g. clicking a button), and it may take several hundred milliseconds. It would be nice if during rendering the browser was still responsive allowing scrolling etc. I am looking in particular for a Chrome solution, though something that also works in Firefox and Safari would be good.</p> <p><strong>Possible (bad) answer:</strong> You could try and estimate how long rendering is going to take and then set a timeout that begins with the call to <code>gl.finish()</code>. However, reliably doing this estimation for all sizes of vertex buffer and all users is going to be pretty tricky and inaccurate.</p> <p><strong>Possible (non-)answer:</strong> <code>requestAnimationFrame</code> does what I'm looking for...it doesn't though, does it?</p>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USdan-man
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POWebGL is it possible to emulate an asynchronous call to gl.finish()
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POWebGL is it possible to emulate an asynchronous call to gl.finish()
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. POWebGL is it possible to emulate an asynchronous call to gl.finish()
      1. This table or related slice is empty.
      1. VTUpMod
    1. COThere is no way you could render it from same page, with 'async' gl.finish() as there is no async version. If drawing off-screen image is something considered 'heavy' then you could use Web Worker to generate it, and then just postMessage back with such image, and draw it to canvas. That would slightly save performance, still drawing have to be sync. Reducing resolution of canvas might speed up it as well.
      singulars
      1. POWebGL is it possible to emulate an asynchronous call to gl.finish()
      1. USmoka
    2. CO@MaksimsMihejevs - rendering an image from a web worker would be asynchronous but it would be using the CPU not the GPU, so it will be much slower. (You cant access WebGL from WebWorkers.)
      singulars
      1. POWebGL is it possible to emulate an asynchronous call to gl.finish()
      1. USdan-man
    3. COI've been talking more about canvas 2d context, as you mentioned `drawImage`.
      singulars
      1. POWebGL is it possible to emulate an asynchronous call to gl.finish()
      1. USmoka
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload