Texture question

[asantiago]

Hi all,

I'm working on a better version of remote loading in SurfaceImage and I have a question about texture loading.

In SurfaceImage the textures are loaded in the renderer thread with a sentence like:
<code>t = TextureIO.newTexture(iconStream, true, null);</code>

The data read process generates a pause in the rendering loop and I want to avoid it.

My question is: how does the loading data process work in TiledLayers so that it doesn't happens?

Thanks a lot.

[fabrizio.giudici]

Same for me - BTW, I think I'm showing a deep ignorance about JOGL, but what are the multi-threading issues when dealing with Textures?

[asantiago]

Hi, Fabrizzio

as JOGL doc says:
"OpenGL rendering semantics specify that only one context may be current on the current thread at any given time, and also that a given context may be current on only one thread at any given time."

In the modified version of SurfaceImage, the remote image is downloaded and putted in a buffer in a separate thread, but the texture must be created in the rendering thread. At this point when the sentence to create the new texture :

t = TextureIO.newTexture(this.stream, true, null);

the rendering thread needs to read the data from file, and produces a freeze "moment" in the animation of the globe.

[asantiago]

Ok I'm here again.

I continue working on SurfaceImage class. Now (in the initializeTexture method), when the texture must be loaded, I create a RequestTask and queue it in the 'WorldWind.getTaskService()'.

This RequestTask checks if the texture is local or remote. If local then load it (in this separate thread) and if not creates a task, that is queue in the 'WorldWind.getRetrievalService()', to download the image.

All work generates a TextureData object that finally is passes to the Texture object used by the SurfaceImage.

Now there are two problems:

1- There is my imagination or when is TextureData the freeze problem seems not a problem. It seems all is more smooth.

2- When load images (local or remotly) I get a white texture. This is strange because I amb rendering the BMNGOneImage object, that is based on SurfaceImage and it is ok.

Any ideas.
Thanks a lot.

[asantiago]

Ok, problem solved. I don't know if it is a JOGL bug or a misunderstand of OpenGL.

I have changed the line:
SurfaceImage.this.textureData = TextureIO.newTextureData(iconStream, false, null);

by:
SurfaceImage.this.textureData = TextureIO.newTextureData(iconStream, true, null);

the only change is putting mipmap to true and all images loads ok. Really I don't understand because with the first form only some images are loaded right and some not.