OpenGL 3 VBO Indexing Multiple figures (glDrawElements) - opengl

Question

I'm working on my first steps with OpenGL (3.x) and I plan to use VAO & VBO's to draw several figures (triangle, cube,...):
Now i got the following setup:
VAO -->
VBO [vertices, colors] + VBO [indices]
Where "vertices" has [3 * 3floats vertices of triangle, 8*3floats of cube],
"colors" has RGB per vertex (no alpha),
"indices" has [ triangle: 0,1,2, square: 0,1,2, 0,2,3, ...]
Now if I draw using "glDrawElements". i only see the first figure on the series drawn correctly (and getting the right color), the second one doesn't works as it should.
So if i render the triangle data first, it goes like:
And if i render the cube first, it goes like:
Note: triangle is red, and cube is colourful, so the first figure is always shown as I expected
This worked ok drawing arrays with "glDrawArrays" (with offset + trianglecount) instead of drawElements but, of course, indexing makes the data arrays muuuuuch smaller. So i wanted to do the move.
How could i draw the same setup but with indexing? should i call another method?
This is the code I use to prepare the VBO's data, in case of doubt.
// VBOS solid
glBindBuffer(GL_ARRAY_BUFFER, vboSolid[0]);
glBufferData(GL_ARRAY_BUFFER, vertices.size()*sizeof(GLfloat),&vertices[0], GL_STATIC_DRAW);
glVertexAttribPointer((GLuint)0, 3, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(0);
glBindBuffer(GL_ARRAY_BUFFER, vboSolid[1]);
glBufferData(GL_ARRAY_BUFFER, colors.size()*sizeof(GLfloat),&colors[0], GL_STATIC_DRAW);
glVertexAttribPointer((GLuint)1, 3, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(1);
glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, vboIndex );
glBufferData( GL_ELEMENT_ARRAY_BUFFER, indices.size()*sizeof(GLuint),&indices[0], GL_STATIC_DRAW);
glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, 0 );
And this is the call I do when rendering.
In this loop, the triangle would have indicesCount=3 & offset=0, while cube would have 24 & 3 respectively.
glDrawElements(
GL_TRIANGLES,
primitives[i]->indicesCount,
GL_UNSIGNED_INT,
(void*) (primitives[i]->offsetIndices*sizeof(GLuint))
);

Answer 1

Since i was still testing after posting, i finally made a working attempt, using:
glDrawElementsBaseVertex(
GL_TRIANGLES.
__INDICES_TO_RENDER__,
GL_UNSIGNED_INT,
(void*) (__INDICES_RENDERED___*sizeof(GLuint)),
_VERTICES_RENDERED_BEFORE_
);
where "INDICES_TO_RENDER" and "INDICES_RENDERED_" are values counting 3f, so for a cube you use 24floats as value "TO_RENDER", and 0 to "_RENDERED".
"_VERTICES_RENDERED_BEFORE_" worked being a human value of vertices rendered, so before cube is rendered, it is 0, after, it should be 8.
Kinda weird (probably i did something wrong), but it worked in my tests:
It was said at Using an offset with VBOs in OpenGL, but i tried several times till i found what to put into the call.
If an expert could verify this, i would be happier :P.