/*
 * Smiley.c
 *
 * A first attempt at OpenGL programming
 *
 */

/*
#include <windows.h> // needed for Windows programming only
*/

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

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

// Global variables representing state of the graphics window
int rgb, doubleBuffer; 
GLenum windType;
GLint windW, windH;

// Values & functions for setting colors
#include "tkmap.c"

// Used to draw circles
GLUquadricObj *face;

// Initialize variables that do not change
static void Init(void)
{
    glClearColor(0.0, 0.0, 0.0, 0.0); // black background

/* Create quadric object for Smiley's face */

    face = gluNewQuadric();
    gluQuadricDrawStyle(face, GLU_FILL);
    gluQuadricNormals(face, GLU_FLAT);
}

//This is called when the window appears or changes shape
static void Reshape(int width, int height)
{
    windW = (GLint)width;
    windH = (GLint)height;

	// Draw in all of the screen window
    glViewport(0, 0, width, height);

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(-1, 1, -1, 1); // Range of coordinates in the viewport
    glMatrixMode(GL_MODELVIEW);
}

// Respond to special keys
static void Key2(int key, int x, int y)
{
    switch (key) {
      case GLUT_KEY_LEFT: // left arrow
	break;
      case GLUT_KEY_RIGHT: // right arrow
	break;
      case GLUT_KEY_UP: // up arrow
	break;
      case GLUT_KEY_DOWN: // down arrow
	break;
      default:
	return;
    }

    glutPostRedisplay();
}

// Respond to regular keys
static void Key(unsigned char key, int x, int y)
{
    switch (key) {
      case 27: // ESC key
	    exit(1);
      default:
	    return;
    }

    glutPostRedisplay();
}

// Draw the smiley face: called whenever the screen window changes
static void Draw(void)
{
    float one_eighth, one_sixteenth, one_third;

    one_eighth = 2.0/8.0;		// one eighth of the visible area
    one_sixteenth = 2.0/16.0;	// one sixteenth of the visible area
	one_third = 2.0/3.0;		// one third of the visible area

/* Clear the screen */
    glClear(GL_COLOR_BUFFER_BIT);

/* Draw a yellow face */
    SetColor(COLOR_YELLOW);
    gluDisk(face, 0.0, one_third, 20, 1); 

/* Draw black eyes */
    SetColor(COLOR_BLACK);
    glBegin(GL_POLYGON);        /* right eye */
	glVertex2f(one_eighth, one_eighth);
	glVertex2f(one_eighth,one_sixteenth);
	glVertex2f(one_sixteenth, one_sixteenth);
	glVertex2f(one_sixteenth, one_eighth);
    glEnd();
    glBegin(GL_POLYGON);        /* left eye */
	glVertex2f(-one_eighth, one_eighth);
	glVertex2f(-one_eighth,one_sixteenth);
	glVertex2f(-one_sixteenth, one_sixteenth);
	glVertex2f(-one_sixteenth, one_eighth);
    glEnd();

/* Draw the mouth */
    glLineWidth(5);
    glBegin(GL_LINE_STRIP);
	glVertex2f(-one_eighth, -one_eighth);
	glVertex2f(one_eighth,-one_eighth);
    glEnd();

    glFlush();

    if (doubleBuffer) {
	  glutSwapBuffers();
    }
}

static GLenum Args(int argc, char **argv)  // command line arguments
{
    GLint i;

    rgb = GL_TRUE;
    doubleBuffer = GL_FALSE;

    for (i = 1; i < argc; i++) {
	if (strcmp(argv[i], "-ci") == 0) {
	    rgb = GL_FALSE;
	} else if (strcmp(argv[i], "-rgb") == 0) {
	    rgb = GL_TRUE;
	} else if (strcmp(argv[i], "-sb") == 0) {
	    doubleBuffer = GL_FALSE;
	} else if (strcmp(argv[i], "-db") == 0) {
	    doubleBuffer = GL_TRUE;
	} else {
	    printf("%s (Bad option).\n", argv[i]);
	    return GL_FALSE;
	}
    }
    return GL_TRUE;
}

int main(int argc, char **argv)
{
    glutInit(&argc, argv);

    if (Args(argc, argv) == GL_FALSE) {
		exit(1);
    }

    windW = 300;
    windH = 300;
    glutInitWindowPosition(0, 0); 
	glutInitWindowSize( windW, windH);

    windType = (rgb) ? GLUT_RGB : GLUT_INDEX;
    windType |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
    glutInitDisplayMode(windType);

    if (glutCreateWindow("Smiley Face") == GL_FALSE) {
		exit(1);
    }

    InitMap(rgb);

    Init();

    glutReshapeFunc(Reshape);
    glutKeyboardFunc(Key);
    glutSpecialFunc(Key2);
    glutDisplayFunc(Draw);
    glutMainLoop();
}