DirectX9 - Efficiently Drawing Sprites

I'm trying to create a platformer game, and I am taking various sprite blocks, and piecing them together in order to draw the level. This requires drawing a large number of sprites on the screen every single frame. A good computer has no problem handling drawing all the sprites, but it starts to impact performance on older computers. Since this is NOT a big game, I want it to be able to run on almost any computer. Right now, I am using the following DirectX function to draw my sprites:

D3DXVECTOR3 center(0.0f, 0.0f, 0.0f);

D3DXVECTOR3 position(static_cast<float>(x), static_cast<float>(y), z);

(my LPD3DXSPRITE object)->Draw((sprite texture pointer), NULL, &center, &position, D3DCOLOR_ARGB(a, r, g, b));

Is there a more efficient way to draw these pictures on the screen? Is there a way that I can use less complex picture files (I'm using regular png's right now) to speed things up?

To s开发者_JS百科um it up: What is the most performance friendly way to draw sprites in DirectX? thanks!

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The ID3DXSPRITE interface you are using is already pretty efficient. Make sure all your sprite draw calls happen in one batch if possible between the sprite begin and end calls. This allows the sprite interface to arrange the draws in the most efficient way.

For extra performance you can load multiple smaller textures in to one larger texture and use texture coordinates to get them out. This makes it so textures don't have to be swapped as frequently. See:

http://nexe.gamedev.net/directknowledge/default.asp?p=ID3DXSprite

The file type you are using for the textures does not matter as long as they are are preloaded into textures. Make sure you load them all in to textures once when the game/level is loading. Once you have loaded them in to textures it does not matter what format they were originally in.

If you still are not getting the performance you want, try using PIX to profile your application and find where the bottlenecks really are.

Edit:

This is too long to fit in a comment, so I will edit this post.

When I say swapping textures I mean binding them to a texture stage with SetTexture. Each time SetTexture is called there is a small performance hit as it changes the state of the texture stage. Normally this delay is fairly small, but can be bad if DirectX has to pull the texture from system memory to video memory.

ID3DXsprite will reorder the draws that are between begin and end calls for you. This means SetTexture will typically only be called once for each texture regardless of the order you draw them in.

It is often worth loading small textures into a large one. For example if it were possible to fit all small textures in to one large one, then the texture stage could just stay bound to that texture for all draws. Normally this will give a noticeable improvement, but testing is the only way to know for sure how much it will help. It would look terrible, but you could just throw in any large texture and pretend it is the combined one to test what performance difference there would be.

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I agree with dschaeffer, but would like to add that if you are using a large number different textures, it may better to smush them together on a single (or few) larger textures and adjust the texture coordinates for different sprites accordingly. Texturing state changes cost a lot and this may speed things up on older systems.