void vbo_rebase_prims	(	GLcontext *	ctx,
		const struct gl_client_array *	arrays[],
		const struct _mesa_prim *	prim,
		GLuint	nr_prims,
		const struct _mesa_index_buffer *	ib,
		GLuint	min_index,
		GLuint	max_index,
		vbo_draw_func	draw
	)

Definition at line 107 of file vbo_rebase.c.

Referenced by _tnl_draw_prims().

{
   struct gl_client_array tmp_arrays[VERT_ATTRIB_MAX];
   const struct gl_client_array *tmp_array_pointers[VERT_ATTRIB_MAX];

   struct _mesa_index_buffer tmp_ib;
   struct _mesa_prim *tmp_prims = NULL;
   void *tmp_indices = NULL;
   GLuint i;

   assert(min_index != 0);

   if (0)
      _mesa_printf("%s %d..%d\n", __FUNCTION__, min_index, max_index);

   if (ib) {
      /* Unfortunately need to adjust each index individually.
       */
      GLboolean map_ib = ib->obj->Name && !ib->obj->Pointer;
      void *ptr;

      if (map_ib) 
     ctx->Driver.MapBuffer(ctx, 
                   GL_ELEMENT_ARRAY_BUFFER,
                   GL_READ_ONLY_ARB,
                   ib->obj);


      ptr = ADD_POINTERS(ib->obj->Pointer, ib->ptr);

      /* Some users might prefer it if we translated elements to
       * GLuints here.  Others wouldn't...
       */
      switch (ib->type) {
      case GL_UNSIGNED_INT: 
     tmp_indices = rebase_GLuint( ptr, ib->count, min_index );
     break;
      case GL_UNSIGNED_SHORT: 
     tmp_indices = rebase_GLushort( ptr, ib->count, min_index );
     break;
      case GL_UNSIGNED_BYTE: 
     tmp_indices = rebase_GLubyte( ptr, ib->count, min_index );
     break;
      }      

      if (map_ib) 
     ctx->Driver.UnmapBuffer(ctx, 
                 GL_ELEMENT_ARRAY_BUFFER,
                 ib->obj);

      tmp_ib.obj = ctx->Array.NullBufferObj;
      tmp_ib.ptr = tmp_indices;
      tmp_ib.count = ib->count;
      tmp_ib.type = ib->type;

      ib = &tmp_ib;
   }
   else {
      /* Otherwise the primitives need adjustment.
       */
      tmp_prims = (struct _mesa_prim *)_mesa_malloc(sizeof(*prim) * nr_prims);

      for (i = 0; i < nr_prims; i++) {
     /* If this fails, it could indicate an application error:
      */
     assert(prim[i].start >= min_index);

     tmp_prims[i] = prim[i];
     tmp_prims[i].start -= min_index;
      }

      prim = tmp_prims;
   }

   /* Just need to adjust the pointer values on each incoming array.
    * This works for VBO and non-vbo rendering and shouldn't pesimize
    * VBO-based upload schemes.  However this may still not be a fast
    * path for hardware tnl for VBO based rendering as most machines
    * will be happier if you just specify a starting vertex value in
    * each primitive.
    *
    * For drivers with hardware tnl, you only want to do this if you
    * are forced to, eg non-VBO indexed rendering with start != 0.
    */
   for (i = 0; i < VERT_ATTRIB_MAX; i++) {
      tmp_arrays[i] = *arrays[i];
      tmp_arrays[i].Ptr += min_index * tmp_arrays[i].StrideB;
      tmp_array_pointers[i] = &tmp_arrays[i];
   }
   
   /* Re-issue the draw call.
    */
   draw( ctx, 
     tmp_array_pointers, 
     prim, 
     nr_prims, 
     ib, 
     0, 
     max_index - min_index );
   
   if (tmp_indices)
      _mesa_free(tmp_indices);
   
   if (tmp_prims)
      _mesa_free(tmp_prims);
}

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