Texture Filtering and Blending

After a texture has been mapped to a surface, the texture elements (texels) of the texture rarely correspond to individual pixels in the final image. A pixel in the final image can correspond to a large collection of texels or to a small piece of a single texel. You can use texture filtering to specify how to interpolate texel values to pixels.

You can use the D3DRENDERSTATE_TEXTUREMAG and D3DRENDERSTATE_TEXTUREMIN render states (from the D3DRENDERSTATETYPE enumerated type) to specify the type of texture filtering to use.

The D3DRENDERSTATE_TEXTUREMAPBLEND render state allows you to specify the type of texture blending. Texture blending combines the colors of the texture with the color of the surface to which the texture is being applied. This can be an effective way to achieve a translucent appearance. Texture blending can produce unexpected colors; the best way to avoid this is to ensure that the color of the material is white. The texture-blending options are specified in the D3DTEXTUREBLEND enumerated type.

You can use the D3DRENDERSTATE_SRCBLEND and D3DRENDERSTATE_DESTBLEND render states to specify how colors in the source and destination are combined. The combination options (called blend factors) are specified in the D3DBLEND enumerated type.