CODE:

#include
#include
#include

void draw_line( int x1, int y1, int x2, int y2, float r, float g, float b, float w )
{
	glColor3f( r,g,b );
	glLineWidth( w );
	glBegin( GL_LINES );
		glVertex2f( x1, y1 );
		glVertex2f( x2, y2 );
	glEnd();
	glFlush();
}

void display( void )
{
	int i;

	glClear( GL_COLOR_BUFFER_BIT );
	
	for( i = 0;i <= 200;i += 10 )
	{
		draw_line( 100, 250 - i, 100 + i, 50, 1.0, 0.0, 0.0, 1.0 );
	}

	glFlush();

}

void reshape( int w, int h )
{
	glViewport( 0, 0, w, h );
	glLoadIdentity();
	gluOrtho2D( 0, w, 0, h );
}

int main( int argc, char *argv[] )
{
	glutInit( &argc, argv );
	glutInitWindowSize( 400, 300 );
	glutCreateWindow( "Test1-1" );
	glutDisplayFunc( display );
	glutReshapeFunc( reshape );
	glClearColor( 1.0, 1.0, 1.0, 1.0 );
	glutMainLoop();

	return 0;
}