And the problem is?
Well you can see in the first picture that the faces are not sorted correctly. ( some faces far are rendered after faces near )
Here is my opengl configuration ( same for 2 pictures ):
glEnable(GL_CULL_FACE);
glEnable(GL_DEPTH_TEST);
glCullFace(GL_BACK);
glFrontFace(GL_CCW);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
and before rendering:
glClearColor(63.0f / 255.0f, 203 / 255.0f, 213.0f / 255.0f, 1.0f);
glClearDepth(1.0f);
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);