OpenGL-1

#include<windows.h>
#include <GL/glut.h>
#include <GL/gl.h>
#include <math.h>

#define PI 3.1416
static float	tx	=  0.0;
static float	ty	=  0.0;

void circle(float radius_x, float radius_y)
{
	int i=0;
	float angle = 0.0;

	glBegin(GL_POLYGON);

		for(i = 0; i < 100; i++)
		{
			angle = 2 * PI * i / 100;
			//glVertex2f (cos(angle) * radius_x, sin(angle) * radius_y);
			glVertex2f (cos(angle) * radius_x+0.8, sin(angle) * radius_y+0.8);
		}

	glEnd();
}


void initGL() {

   glClearColor(0.0f, 0.0f, 0.0f, 0.0f); //background clear
   glOrtho(-1,1,-1,1,-1,1);


}
/*
void triangle()
{
       glBegin(GL_TRIANGLES);

      glVertex2f(0.3f, 0.5f);
      glVertex2f(0.5f, 0.7f);
      glVertex2f(0.7f, 0.5f);
   glEnd();
}
*/
void display() {

   glClear(GL_COLOR_BUFFER_BIT);// Buffer CLear

   glBegin(GL_LINES);
        glColor3f(1.0,1.0,1.0);
        glVertex2f(-100,0);
        glVertex2f(100,0);

        glVertex2f(0,-100);
        glVertex2f(0,100);
   glEnd();
//triangle
   glColor3f(1.0f, 0.0f, 0.0f);
    glBegin(GL_TRIANGLES);

      glVertex2f(0.3f, 0.5f);
      glVertex2f(0.5f, 0.7f);
      glVertex2f(0.7f, 0.5f);
   glEnd();
//square
   glBegin(GL_QUADS);
      glColor3f(0.0f, 0.5f, 1.0f);
      glVertex2f(0.7f, 0.2f);
      glVertex2f(0.3f, 0.2f);
      glVertex2f(0.3f, 0.5f);
      glVertex2f(0.7f, 0.5f);
  glEnd();

     glBegin(GL_QUADS);
      glColor3f(0.0f, 0.5f, 0.5f);
      glVertex2f(0.35f, 0.35f);
      glVertex2f(0.45f, 0.35f);
      glVertex2f(0.45f, 0.45f);
      glVertex2f(0.35f, 0.45f);
  glEnd();

     glBegin(GL_QUADS);
      glColor3f(0.0f, 0.5f, 0.5f);
      glVertex2f(0.55f, 0.35f);
      glVertex2f(0.65f, 0.35f);
      glVertex2f(0.65f, 0.45f);
      glVertex2f(0.55f, 0.45f);
  glEnd();

      glBegin(GL_QUADS);
      glColor3f(0.2f, 0.2f, 0.0f);
      glVertex2f(0.45f, 0.2f);
      glVertex2f(0.55f, 0.2f);
      glVertex2f(0.55f, 0.33f);
      glVertex2f(0.45f, 0.33f);
  glEnd();
//circle
   glColor3f(1.0f, 0.5f, 0.0f);
   circle(0.1,0.1);




   glFlush(); //render
}

void spe_key(int key, int x, int y)
{

	switch (key) {

		case GLUT_KEY_LEFT:
				tx -=5;
				glutPostRedisplay();
				break;

		case GLUT_KEY_RIGHT:
				tx +=5;
				glutPostRedisplay();
				break;

        case GLUT_KEY_DOWN:
				ty -=5;
				glutPostRedisplay();
				break;

		case GLUT_KEY_UP:
				ty +=5;
				glutPostRedisplay();
				break;
	  default:
			break;
	}
}

int main()
{
    glutInitWindowSize(600,600);
    glutInitWindowPosition(0,0);
    glutCreateWindow("CGLAB_TEST_1");
    initGL();
    glutDisplayFunc(display);
    glutMainLoop();

    return 0;
}