I can't repeat the texture using GL_TEXTURE_CUBE_MAP and GL_REPEAT - opengl

Question

After two days of reading and trying, I was able to texture a cube with GL_TEXTURE_CUBE_MAP:
Textured Cube
Then I decided to make a parallelepiped from the cube, in which the corresponding texture is repeated on the long side. I get similar or worse results:
Poorly stretched texture
And I want to get such a result:
Repeated texture
Is it even possible?
Here is the essential part of the code:
void Create( void ) {
glGenTextures( 1, &id );
glBindTexture( GL_TEXTURE_CUBE_MAP, id );
glPixelStorei( GL_UNPACK_ALIGNMENT, 1 );
const RGB bk_cols[ ] = { {207,193,0}, {133,96,169}, {0,166,81}, {0,84,166}, {158,11,15}, {137,137,137} };
const char letters[ ] = { 'x', 'y', 'z' };
RGB* rgb = new RGB[ 16 * 16 + 16 ];
for( unsigned int i = 0; i < 6; i++ ) {
glTexImage2D( GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, GL_RGB, 16, 16, 0, GL_RGB, GL_UNSIGNED_BYTE,
CreateLetter16x16( rgb, {0,250,0}, bk_cols[i], {0,0,0}, letters[ i >> 1 ], (i & 1 ? false : true) ) );
}
delete [ ] rgb;
glTexParameteri( GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
glTexParameteri( GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
glTexParameteri( GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_REPEAT/*GL_CLAMP_TO_EDGE*/ );
glTexParameteri( GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_REPEAT/*GL_CLAMP_TO_EDGE*/ );
glTexParameteri( GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE );
}
void DrawTexturedCube( void ) {
float v = 2.0;
float p = 6.0;
// All the faces that are not front-faces are discarded.
// This is a good test of vertex sequence.
glEnable( GL_CULL_FACE );
// Of course a depth test is needed here.
glEnable( GL_DEPTH_TEST );
// Must be enabled, else textures doesn't work
glEnable( GL_TEXTURE_CUBE_MAP );
// If you want your image to be unaffected by the current color,
// you must change the texture environment parameter to decal
glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL );
// Select texture
glBindTexture( GL_TEXTURE_CUBE_MAP, sq_txt.id );
glBegin( GL_QUADS );
// Right
glTexCoord3f( 1,-1,-1); glVertex3f( p,-v,-v);
glTexCoord3f( 1, 1,-1); glVertex3f( p, v,-v);
glTexCoord3f( 1, 1, 1); glVertex3f( p, v, v);
glTexCoord3f( 1,-1, 1); glVertex3f( p,-v, v);
// Left
glTexCoord3f(-1,-1,-1); glVertex3f(-p,-v,-v);
glTexCoord3f(-1,-1, 1); glVertex3f(-p,-v, v);
glTexCoord3f(-1, 1, 1); glVertex3f(-p, v, v);
glTexCoord3f(-1, 1,-1); glVertex3f(-p, v,-v);
// Top
glTexCoord3f(-1, 1, 1); glVertex3f(-p, v, v);
glTexCoord3f( 1, 1, 1); glVertex3f( p, v, v);
glTexCoord3f( 1, 1,-1); glVertex3f( p, v,-v);
glTexCoord3f(-1, 1,-1); glVertex3f(-p, v,-v);
// Bottom
glTexCoord3f(-1,-1,-1); glVertex3f(-p,-v,-v);
glTexCoord3f( 1,-1,-1); glVertex3f( p,-v,-v);
glTexCoord3f( 1,-1, 1); glVertex3f( p,-v, v);
glTexCoord3f(-1,-1, 1); glVertex3f(-p,-v, v);
// Front
float xn = -3.0;
float xp = 3.0;
float yn = -1.0;
float yp = 1.0;
float zz = 1.0;
glTexCoord3f(xn,yn,zz); glVertex3f(-p,-v, v);
glTexCoord3f(xp,yn,zz); glVertex3f( p,-v, v);
glTexCoord3f(xp,yp,zz); glVertex3f( p, v, v);
glTexCoord3f(xn,yp,zz); glVertex3f(-p, v, v);
// Back
glTexCoord3f( 1,-1,-1); glVertex3f( p,-v,-v);
glTexCoord3f(-1,-1,-1); glVertex3f(-p,-v,-v);
glTexCoord3f(-1, 1,-1); glVertex3f(-p, v,-v);
glTexCoord3f( 1, 1,-1); glVertex3f( p, v,-v);
glEnd();
// Restore default parameters
glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE );
// Must be disabled, else colors doesn't work ( Everything will be textured ).
glDisable( GL_TEXTURE_CUBE_MAP );
// --------------------------------------------------------------------
float k = v+.01f;
// Disable fill
glPolygonMode( GL_FRONT_AND_BACK, GL_LINE );
// Set line width
glLineWidth( 3 );
glBegin( GL_QUADS );
glColor3f( .9f, 0, 0 );
glVertex3f( k,-k,-k); glVertex3f( k, k,-k); glVertex3f( k, k, k); glVertex3f( k,-k, k); // Right
glVertex3f(-k,-k,-k); glVertex3f(-k,-k, k); glVertex3f(-k, k, k); glVertex3f(-k, k,-k); // Left
glVertex3f(-k, k, k); glVertex3f( k, k, k); glVertex3f( k, k,-k); glVertex3f(-k, k,-k); // Top
glVertex3f(-k,-k,-k); glVertex3f( k,-k,-k); glVertex3f( k,-k, k); glVertex3f(-k,-k, k); // Bottom
glVertex3f(-k,-k, k); glVertex3f( k,-k, k); glVertex3f( k, k, k); glVertex3f(-k, k, k); // Front
glVertex3f( k,-k,-k); glVertex3f(-k,-k,-k); glVertex3f(-k, k,-k); glVertex3f( k, k,-k); // Back
glEnd();
// Restore fill
glPolygonMode( GL_FRONT_AND_BACK, GL_FILL );
// Restore default line width
glLineWidth( 1 );
// Restore default state
glDisable( GL_DEPTH_TEST );
// Restore default state
glDisable( GL_CULL_FACE );
}

Answer 1

Repeat filtering is a texture sampling wrap mode. And wrap modes explain how texture coordinates outside of the space of the texture work.
But the way cubemap texture coordinates are defined (they are vectors from the center of a cube pointing to a location inside that cube), they basically never fall outside of the size of a face of the cubemap. So repeat filtering is a no-op, functionally identical to clamp-to-edge.