texture manager class

Why not have each mesh just cache the textures it needs at load time? Then time to access the texture manager doesn't really matter.

I have my objects include a texture (pointer) member. They only ask the manager for the texture (causing a map lookup and texture load if it is the first request for the texture) once, when the object is first created. Essentially they cache the texture pointer locally for fast access when rendering.

EDIT: ninja'd by steve, so i'll try and add something - Requesting the texture from the manager only once has the benefit of allowing you to easily keep track of how many objects reference each texture

Quote:

Original post by Evil Steve Why not have each mesh just cache the textures it needs at load time? Then time to access the texture manager doesn't really matter.

sorry , but i'm not understand what you intend for cache.
I would share textures between many mesh that have the same texture.
My idea is to sort the meshes for texture id and draw first the mesh that have shared texture.
For not resend disable the texture to the shader.
Is an too heavy?
Thanks

Quote:

Original post by giugio sorry , but i'm not understand what you intend for cache. I would share textures between many mesh that have the same texture. My idea is to sort the meshes for texture id and draw first the mesh that have shared texture. For not resend disable the texture to the shader. Is an too heavy? Thanks

The basic idea (as described by the previous posters) is this:

1. The manager (or cache, or whatever you want to call it - some people don't like the term 'manager') holds (for example) a map whose values are shared pointers to texture objects. This is basically what you described in your original post.

2. The map is *not* queried for every render. Instead, the mesh (or whatever) retrieves a shared pointer to the texture it needs from the manager/cache once only, and then stores it. From then on, it has its own shared pointer that points to the texture.

3. You can then render (and sort by render state, if desired) as usual.

Does that make things more clear?

Quote:

Original post by jyk Quote: Original post by giugio sorry , but i'm not understand what you intend for cache. I would share textures between many mesh that have the same texture. My idea is to sort the meshes for texture id and draw first the mesh that have shared texture. For not resend disable the texture to the shader. Is an too heavy? Thanks The basic idea (as described by the previous posters) is this: 1. The manager (or cache, or whatever you want to call it - some people don't like the term 'manager') holds (for example) a map whose values are shared pointers to texture objects. This is basically what you described in your original post. 2. The map is *not* queried for every render. Instead, the mesh (or whatever) retrieves a shared pointer to the texture it needs from the manager/cache once only, and then stores it. From then on, it has its own shared pointer that points to the texture. 3. You can then render (and sort by render state, if desired) as usual. Does that make things more clear?

To further clarify, the point is that most systems have something like a 'texture' which is applied to a 'sprite'. The point of storing it in a cache/manager map is to assure that you only load the 'texture' content ONCE and then apply that same content to multiple sprites.

This poses an interesting point.

The OP intends to order objects being sent for render so that objects with the same texture are contiguous and will be rendered one after the other so the texture does not have to be re-bound.

In some scenarios it is best to order objects by distance from the camera location, close to far. That poses a choice between one ordering solution or the other - or am I missing something? This is something I am planning on tackling soon, and I wasn't sure what implications changing texture a lot would have. The other option is to map several textures together onto one 4096x4096 texture so that only 1 is bound. But when using shaders to map the textures are there other things to think about? There must be a good solution for the overall problem? I am planning on working on my first renderer for 3D game environment soon and I do not think I will be using shaders for texturing yet, do they solve many issues previously encountered without them? Or only bring better performance and nicer appearance?