OpenGL - Vector Data

#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glut.h>



void setup(){
    glClearColor(1.0, 1.0, 1.0, 1.0);
    gluOrtho2D(-01.0, 10.0, -01.01, 10.0);
}

void display(){
    glClear(GL_COLOR_BUFFER_BIT);
    glColor3f(1.0, 0.0, 0.0);

    // vector defining
    GLfloat one[] = {0.5, 0.5};
    GLfloat two[] = {0.5, 5.0};
    GLfloat three[] = {5.0, 5.0};

    glBegin(GL_POLYGON);
        glVertex2fv(one);
        glVertex2fv(two);
        glVertex2fv(three);
    glEnd();


    glBegin(GL_LINES);
        // horizontal lines
        glVertex2f(-10.0, 0.0);
        glVertex2f(10.0, 0.0);

        // vertical lines
        glVertex2f(0.0, -10.00);
        glVertex2f(0.0, 10.0);
    glEnd();

    glFlush();
}

int main(int argc, char *argv[]){
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
    glutInitWindowPosition(200, 100);
    glutInitWindowSize(400, 300);
    glutCreateWindow("Hello World");
    glutDisplayFunc(display);

    setup();
    glutMainLoop();

    return 0;

}

OpenGL - Vector Data