<#include <GL/glut.h>
void display(void) { glClear(GL_COLOR_BUFFER_BIT);

glPointSize(3.0);
glBegin(GL_POINTS);
 	glColor3f(1.0,1.0,0.0);
	glVertex2f(-0.5, -0.5);
 	
	glColor3f(1.0,0.0,0.0);
	glVertex2f(-0.5, 0.5);
	
	glColor3f(0.0,0.0,1.0);
 	glVertex2f(0.5, 0.5);
	
	glColor3f(0.0,1.0,0.0);
 	glVertex2f(0.5, -0.5);
glEnd();

glFlush(); 

} void init(){}

int main(int argc, char** argv) { glutCreateWindow("simple"); glutDisplayFunc(display); init(); glutMainLoop(); }