#include <GL/glut.h>

#include <iostream>

#include <cstdio>

#include <cmath>

using namespace std;

void draw()
{
    glClearColor(1.0,1.0,1.0,0);
	
	/*void draw()
{
	glClearColor(1.0,1.0,1.0,0);
	
	glClear(GL_COLOR_BUFFER_BIT);

	rectangle(0.0,0.4,0.75,0.75);

	glFlush();
}*/
	glClear(GL_COLOR_BUFFER_BIT);
	
	line(0.0,0.4,0.75,0.75, 10000);
	
	glFlush();
}

void line(float a11, float b11, float a12, float b12, int ss)
{
	int ik;
	
	float ttt, da, dy;
	
	float a, y;

	da = a12-a11;
	
	dy = b12-b11;
	
	float m = dy/da;
	
	ttt = (da/float(ss));
	
	/*void draw()
{
	glClearColor(1.0,1.0,1.0,0);
	
	glClear(GL_COLOR_BUFFER_BIT);

	rectangle(0.0,0.4,0.75,0.75);

	glFlush();
}*/
	glColor3f(1.0,0.0,0.0);
	
	glPointSize(2.0);
	
	glBegin(GL_POINTS);
	
	glVertex3f(a11,b11,0.0);

	a = a11;
	
	y = b11;
	
	for (ik = 1; ik <= ss; ik++) {
	
		a = a + ttt;
	
		y = b11 + m*(a-a11);

		glVertex3f(a,y,0.0);
	}

	glEnd();
}

int main(int abcd, char **xyz)
{
	glutInit(&abcd, xyz);

	glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);
	
	/*void draw()
{
	glClearColor(1.0,1.0,1.0,0);
	
	glClear(GL_COLOR_BUFFER_BIT);

	rectangle(0.0,0.4,0.75,0.75);

	glFlush();
}*/

	glutInitWindowSize(500,500);
	
	glutInitWindowPosition(0, 0);
	
	glutCreateWindow("line using closely spaced points");
	
	glutDisplayFunc(draw);
	
	glutMainLoop();

	return 0;
}