Using Index vertex arrays with Tex Coords

OpenGL OpenGL: Basic Coding
1

Hey,
just trying to teach myself how to use indexed vertex arrays but im encountering problems assigning tex coords to each vertex when using indexes and a vertex array …a coord is applied to each vertex…but not for each face…only the base vertices before they are run through by the indexing.

2

i think i know where your problem is, but if you use indexed vertexarray you only get one texcoordpair (using glTexCoordPointer and enabling GL_TEXTURE_COORD_ARRAY), per vertex, so you cannot use different texcoords per face, by using glDrawElements! To get independent texcoords, you should draw like(disable texcoord_array):

per vertex in face(3 times):

  1. set texcoords by yourself
  2. call glArrayElement(index);
3

that defeats the purpose of using the vertex array i think.