I am trying to create a textured hexagonal tile map in opengl. I have the VBO and respective index buffer. Additionally I have a texture atlas for texturing individual tiles. I'm attempting to create a distinct texture for each hex without mixing the textures.
I understood that one should use a pair of (U,V) texture coordinates for each vertex. Now if the tile map would not be indexed and have the overlapping vertices, I could just set the texture coordinates for each vertex and get each hex rendering the correct texture. However, with indexing the overlapping vertices are gone and I can only set single pair of texture coordinates for each vertex which results in the textures mixing inside the hexes. Is there a way to texture tiles with indexing or another alternative approach to creating hex maps with different textures?