CODEWITHSUNDEEP
webglangle
Kos
Kos

Reputation: 1778

WebGL: Asynchronous texImage2D?

I am updating some textures of the scene all the time by new images. Problem is uploading is synchronous and texImage2D takes ~100ms. It takes so long time even if texture is not used during rendering of the next frame or rendering is switched off.

I am wondering, is there any way to upload texture data asynchronously?

Additional conditions:

I had mention there is old texture which could stay active until uploading of new one to GPU will be finished.

Upvotes: 1

Views: 2046

Answers (2)

Kos
Kos

Reputation: 1778

Solution is to use texSubImage2D and upload image to GPU by small portions. Once uploading will be finished activate your new texture and delete old one.

Upvotes: 4

user128511
user128511

Reputation:

is there any way to upload texture data asynchronously?

no, not in WebGL 1.0. There might be in WebGL 2.0 but that's not out yet.

Somethings you might try.

  • make it smaller

    What are you uploading? Video? Can you make it smaller?

  • Have you tried different formats?

    WebGL converts from whatever format the image is stored in to the format you request. So for example if you load a .JPG the browser might make an RGB image. If you then upload it with gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE it has to convert the image to RGBA before uploading (more time).

  • Do you have UNPACK_FLIP_Y set to true?

    If so WebGL has to flip your image before uploading it.

  • Do you have UNPACK_COLORSPACE_CONVERSION_WEBGL set to BROWSER_DEFAULT_WEBGL?

    If not WebGL may have to re-decompress your image

  • Do you have UNPACK_PREMULTIPLY_ALPHA_WEBGL set to false or true?

    Depending on how the browser normally stores images it might have to convert the image to the format your requesting

  • Images have to be decompressed

    are you sure your time is in "uploading" vs "decompressing"? If you switch to uploading a TypedArray of the same dimensions does it speed up?

Upvotes: 4

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