glVertex3f ( (x+1)*squareSize, 0.0, z*squareSize );
glTexCoord2f( 0.0, 0.0 );
glVertex3f ( x*squareSize, 0.0, z*squareSize );
glVertex3f ( (x+1)*squareSize, 0.0, z*squareSize );
glTexCoord2f( 0.0, 0.0 );
glVertex3f ( x*squareSize, 0.0, z*squareSize );