#include <GL/glut.h>
#include <stdlib.h>
#include <stdio.h>
static int leftFirst = GL_TRUE;

/*  Initialize alpha blending function.
 */

static void init(void)
{
   glClearColor(0.93f, 0.93f, 0.93f, 0.0f);
	glColor3f(0.0f, 0.0f, 0.0f);

    
}


// ekrana alıştığımız (classworkte olan) şekli çizen program
void objeciz(){
      float x1=-1.0 , y1=1.0 ;
   float x2=0.0 , y2=0.0;
        int line_sayisi=20;
      for(int i = 1;i<=line_sayisi;i++){
          glBegin(GL_LINES);
          glVertex3f(x1,y1,0.0);
          glVertex3f(x2,y2,0.0);
          glEnd();
          printf("x1 : %f y1: %f , x2 : %f y2: %f\n",x1,y1,x2,y2);
          x1+=1.0f/line_sayisi;
          
          x2+=1.0f/line_sayisi;
          y2+=1.0f/line_sayisi;
   }
 x1=1.0 , y1=1.0 ;
 x2=0.0 , y2=0.0;
      for(int i = 1;i<=line_sayisi;i++){
          glBegin(GL_LINES);
          glVertex3f(x1,y1,0.0);
          glVertex3f(x2,y2,0.0);
          glEnd();
          printf("x1 : %f y1: %f , x2 : %f y2: %f\n",x1,y1,x2,y2);
          x1-=1.0f/line_sayisi;
          
          x2-=1.0f/line_sayisi;
          y2+=1.0f/line_sayisi;
   }
     }

void display(void)
{
     
   glClear(GL_COLOR_BUFFER_BIT);
  
   glColor3f(0.0,1.0,0.0);
   objeciz();
   glPushMatrix();
   glRotatef(90,0,0,1); // 30 derece döndüren transformation (X ekseni etrafinda)
   objeciz();
   glPushMatrix(); // stage koyduk
   glRotatef(90,0,0,1);
   objeciz();  // buraya kadar yesil cizdik ayni sekli
   // buradan sonra kirmizi olarak aynı şekli aynı 
   // transformation ile üzerine çiziyoruz
   // dolayısıyla sonuçta yeşil şekil görülmüyor 
   glPopMatrix();
   glColor3f(1.0,0.0,0.0);
   objeciz();
   glPopMatrix();
   glColor3f(1.0,0.0,0.0);
   objeciz();
   glFlush();
}

void reshape(int w, int h)
{
   
}

/*  Main Loop
 *  Open window with initial window size, title bar, 
 *  RGBA display mode, and handle input events.
 */
int main(int argc, char** argv)
{
   glutInit(&argc, argv);
   glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
   glutInitWindowSize (200, 200);
   glutCreateWindow (argv[0]);
   init();
   glutReshapeFunc (reshape);
   glutDisplayFunc (display);
   glutMainLoop();
   return 0;
}