In XNA 3.1, is it possible to disable texture filtering?

Question

I want to disable texture filtering (since I'm making a retro-style game where it looks bad if a texture gets filtered like that), but since I'm on XNA 3.1 there seems to be no option to set a SamplerState with SpriteBatch.Begin or anything. Is it possible to do this?

Answer 1

The behaviour of SpriteBatch in XNA before 4.0 is rather ugly. Note that this answer only applies to XNA pre-4.0.

This is a list of render states that SpriteBatch controls (pre-4.0).

When SpriteBatch applies those settings depends on the SpriteSortMode parameter. The only reliable way to modify those settings is with SpriteSortMode.Immediate.

The way this works that, in immediate mode, SpriteBatch will set its render state when you call Begin. Immediately after calling Begin you can set your own render state, before you call SpriteBatch.Draw.

(States that SpriteBatch does not control can be set outside of the Begin/End block.)

The states you want to change (as r2d2rigo mentioned) are:

GraphicsDevice.SamplerStates[0].MagFilter = TextureFilter.Point;
GraphicsDevice.SamplerStates[0].MinFilter = TextureFilter.Point;
GraphicsDevice.SamplerStates[0].MipFilter = TextureFilter.Point;

Answer 2

Call

GraphicsDevice.SamplerStates[0].MagFilter = TextureFilter.Point;
GraphicsDevice.SamplerStates[0].MinFilter = TextureFilter.Point;
GraphicsDevice.SamplerStates[0].MipFilter = TextureFilter.Point;

before using SpriteBatch.Begin. And remember to restore the values after SpriteBatch.End.

Answer 3

This is very possible. You can use a custom shader with spritebatch. The source to the default spritebatch shader is available from the XNA 'education catalog'. What you will need to do is get this shader and change the texture filtering in the shader from linear to point filtering, and then use your new version of the shader with spritebatch. To use it with spritebatch, call spritebatch.Begin, but set the sprite sort mode to immediate (This effectively means no batching). Then, apply the correct technique on your new effect. Then draw your sprites. Spritebatch will draw them immediately with whatever effect is currently applied.

IIRC using a custom shader with spritebatch is far simpler in XNA 4.0.