Hello, I am trying to make a game for a school project using DirectX 9. It is a 2 dimensional game. However, I want to make it in a 3 dimensional space in order to be able to use the camera ( zoom, pan, etc ). Now, the way I'm planning on doing this is by drawing rectangles and drawing a different frame from each texture ( all frames of the texture are in the same file, one after another ) by moving a sort of clipping rectangle across the texture, where it only gets the part of the texture that the rectangle "sees". This is easy to do with the Draw() function, if I was to be using sprites, but because sprites do not resize( without my own calculations ), I need to use my d3dDevice to grab each frame. Is there any way to do this? BTW, if what I want seems confusing please ask for clarification. Regards, Serge

This sounds like what I need to do. Can you please show me how I would render to the texture? Thanks a lot.

Regards,
Serge

I'm not exactly sure what DesignerX was getting at but...

You sound like you are trying to do a project like I did not too long ago. Basically I made a 2d fighter in a 3d world. The way I did it was to create a 3d Qaud (or two triangles that make a quad). Since it is in 3d space you can obviously zoom in and out on the quad and it looks 3d... just flat :).

To make the animation properly "animate" on the quad, modify the UV coordinates for the 4 vertices to move across the texture (if the texture has many animation frames) or just change which texture your using when you render the quad if they are all on different images.

Hope this helps,
Stephen Timothy Cooney

I'll be watching for a reply to help...

That's exactly what I needed to know. Thanks :)

The answer to your question is just to dynamically update the UV coordinate pairs to render each frame of animation in succession, as others have pointed out. There are a couple things you need to consider with regard to performance, though, because there's a lot of ways to get the same result in D3D and most of them are slow.

First, you want to combine as many textures as is reasonable into one file just so you can batch your quads more efficiently. All sprites/quads that use this texture should be rendered with one DrawPrimitive (unless there are layering considerations), because you don't have to interrupt the batch to 'device.SetTexture'. It sounds like you're already set up to do this...

Second, you have to be careful how you implement dynamic data when you're using the GPU and CPU together. Make sure your vertex buffers are set up for dynamic use, and try to avoid locking the VB with any flags besides DISCARD and NOOVERWRITE (there are places that explain this better than I can). Get this right and your fps will skyrocket over the naive implementations that seem natural to those of us who migrated from DirectDraw and other 2D APIs.