The last time I checked ( years ago ) a texture applied to several entities would be a single surface, provided they used compatible texture flags.
I remember testing this with the castle demo. I added some code to load one of the textures used in the castle. Then I wrote some new data to the texture buffer of my loaded texture. This also changed the appearance of the castle, so it was using the same texture, not a separate copy.
I remember testing this with the castle demo. I added some code to load one of the textures used in the castle. Then I wrote some new data to the texture buffer of my loaded texture. This also changed the appearance of the castle, so it was using the same texture, not a separate copy.