// Program to demonstrate how to open a window size and position it properly
// Animated version of basicwindow.c
// Left mouse button fires the cannonball again
// Q or q or ESC quits the program
// R or C determines whether to use a circle or a rectangle
// This variation by Mr. Latimer
#include <stdlib.h>
#include <GL/glut.h>
int wide=300, high=300;   // Global Variables for Length and Width
int winX=40, winY=40;     // X and Y positions for window

double xPos;
double yPos;
double MinX=-2.0;
double MaxX=2.0;
double MinY=-2.0;
double MaxY=2.0;
double MinZ=-1.0;
double MaxZ=1.0;
double RADIUS=0.1;
int DRAWCIRCLE;

void DrawMyStuff()  // The Drawing Routine
{ 
//    double x,y;
    GLUquadricObj *p;
    
    glPushMatrix();
    p = gluNewQuadric();
    glColor3f(1.0, 1.0, 0.0);           // Set drawing color to yellow
    yPos =  4* xPos -  4* xPos * xPos ;     // Calculate y value of parabola
    glTranslatef(xPos,yPos,0.0);
    gluQuadricDrawStyle(p, GLU_FILL);//Use GLU_SILHOUETTE for a circle outline
    gluDisk(p,0,0.1,20,1);    //gluDisk(p, innerRadius, outerRadius, 
                              //         slices, rings);
    glPopMatrix();
   if (xPos <= 1) xPos += .001;
}

void DrawMyStuffRectangle()
{
    glColor3f(1.0, 1.0, 0.0);
    yPos =  4* xPos -  4* xPos * xPos ;     // Calculate y value of parabola
    glRectf(xPos, yPos, xPos+.4, yPos+.4);
    if (xPos <= 1) xPos += .001;
}

void DrawAxis()
{
    glColor3f(0.0,0.0,0.0);
    glBegin(GL_LINES);
    glVertex2f(MinX, 0);
    glVertex2f(MaxX, 0);
    glVertex2f(0 , MinY);
    glVertex2f(0 , MaxY);
    glEnd();
    glFlush();
}

void display(void)
{ /* clear all pixels */

   glClear(GL_COLOR_BUFFER_BIT);
   DrawAxis();
   if (DRAWCIRCLE == 1)
       DrawMyStuff();              // Call my Drawing Routine
   else DrawMyStuffRectangle();
   glutSwapBuffers();
   glFlush();  // Force writing all pending OpenGL actions to the screen.
   if (xPos <=1)
      glutPostRedisplay();
}

void keyboard(unsigned char key, int x, int y)
{
    printf("Key pressed= %c %d\n", key, key);
    if (key == 'q' || key == 'Q' || key == (unsigned char)  27)
        exit(0);                       // This should work: key == '\27'
    if (key == 'r' || key == 'R')
        DRAWCIRCLE = 0;
    if (key == 'c' || key == 'C')
        DRAWCIRCLE = 1;
}

void mouse(int button, int state, int x, int y)
{
    if (state == GLUT_DOWN && button == GLUT_LEFT_BUTTON)
    {
        xPos = -1.0;
        glutPostRedisplay();
    }
}

void myinit(void)
{
   xPos = -1.0;
   DRAWCIRCLE = 1;
   /* select clearing (background) color   */
   glClearColor(0.5, 0.5, 0.5, 0.0);     // These RGB values make gray
/* initialize viewing values */
   glMatrixMode(GL_PROJECTION);                 // Select Matrix Mode
   glLoadIdentity();                            // Provide Base Matrix 
   glOrtho(MinX, MaxX, MinY, MaxY, MinZ, MaxZ);      // Set window dimensions
   // Parameters:  glOrtho(Left, Right, Bottom, Top, Front, Back)
   DrawAxis();
}

/* Declare initial window size, position, and display mode */

int main(int argc, char* argv[])
{  
   printf("Creating window %d pixels wide and %d pixels high", wide, high);
   printf(" at (%d,%d).\n", winX, winY);
   glutInit(&argc, argv);   // Call glut's initialization routine
   glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB);   // Set Single Buffer, RGB Color
   glutInitWindowSize(wide, high);      // Initialize window size
   glutInitWindowPosition(winX,winY);   // Position window
   glutCreateWindow("My Window");       // Actually create window with title
   myinit();                            // Call my initialization routine

   glutKeyboardFunc(keyboard);
   glutMouseFunc(mouse);
   glutDisplayFunc(display);            // Call my display routine 
   glutMainLoop();                      // Fall into glut's main event loop 
   return 0;
}

/* 
 *  Adapted for use in Supercomputer Applications 
 *  at TJHSST from the OpenGL Tutor by Mahesh Kumar
 *  Parts of this program might have been adopted from or inspired by 
 *  sample programs in 
 *  "OpenGL Programming Guide", 
 *  Copyright (c) 1993-1997, Silicon Graphics, Inc.
 *  "Interactive Computer Graphics"  
 *  Copyright (c) 1997, Addison-Wesley,
 *  and/or those written by Dr. Sumanta Guha guha@cs.uwm.edu
 *  and/or those written by Dr. Ichiro Suzuki suzuki@cs.uwm.edu
 */