Fix Texture rebuild on context lost

[sebavan]

https://forum.babylonjs.com/t/context-restore-for-textures-with-bloburl-not-working/36114

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[Popov72]

See https://forum.babylonjs.com/t/context-restore-for-textures-with-bloburl-not-working/36114, it seems it is not enough, the restored texture is Y inverted...

.

[Popov72]

One way to fix the problem is to remove this (in thinEngine._createTextureBase):

if (fromBlob && !this._doNotHandleContextLost) {
    // We need to store the image if we need to rebuild the texture
    // in case of a webgl context lost
    texture._buffer = img;
}

As _buffer will be null, the original url will be used instead ("blob:...") when recreating the texture after the context lost and it will work. But maybe for some other types of blob urls it would not work...

Without removing this block of code I could not make it work. Currently, _buffer is what is used to recreate the texture after a context lost (when the texture has been created from a blob in the first place) and even by setting invertY=false before calling engine.createTexture the texture is not re-inverted...

[sebavan]

I ll have a look in a bit thanks for the feedback :-)