/*
 * (c) Copyright 1993, Silicon Graphics, Inc.
 * ALL RIGHTS RESERVED 
 * Permission to use, copy, modify, and distribute this software for 
 * any purpose and without fee is hereby granted, provided that the above
 * copyright notice appear in all copies and that both the copyright notice
 * and this permission notice appear in supporting documentation, and that 
 * the name of Silicon Graphics, Inc. not be used in advertising
 * or publicity pertaining to distribution of the software without specific,
 * written prior permission. 
 *
 * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
 * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
 * FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SILICON
 * GRAPHICS, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
 * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
 * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
 * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
 * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN
 * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
 * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
 * 
 * US Government Users Restricted Rights 
 * Use, duplication, or disclosure by the Government is subject to
 * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
 * (c)(1)(ii) of the Rights in Technical Data and Computer Software
 * clause at DFARS 252.227-7013 and/or in similar or successor
 * clauses in the FAR or the DOD or NASA FAR Supplement.
 * Unpublished-- rights reserved under the copyright laws of the
 * United States.  Contractor/manufacturer is Silicon Graphics,
 * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311.
 *
 * OpenGL(TM) is a trademark of Silicon Graphics, Inc.
 */
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <sys/types.h>
#ifdef __unix 
#include <sys/time.h>
#else
#include <stdlib.h>
#include <time.h>
#endif
#include "tk.h"


#ifdef __unix
extern double drand48(void);
extern void srand48(long seedval);
#endif


#define XSIZE	100
#define YSIZE	75

#define RINGS 5
#define BLUERING 0
#define BLACKRING 1
#define REDRING 2
#define YELLOWRING 3
#define GREENRING 4

#define BACKGROUND 8

enum {
    BLACK = 0,
    RED,
    GREEN,
    YELLOW,
    BLUE,
    MAGENTA,
    CYAN,
    WHITE
};


typedef short Point[2];


GLenum rgb, doubleBuffer, directRender;

unsigned char rgb_colors[RINGS][3];
int mapped_colors[RINGS];
float dests[RINGS][3];
float offsets[RINGS][3];
float angs[RINGS];
float rotAxis[RINGS][3];
int iters[RINGS];
GLuint theTorus;


void FillTorus(float rc, int numc, float rt, int numt)
{
    int i, j, k;
    double s, t;
    double x, y, z;
    double pi, twopi;

    pi = 3.14159265358979323846;
    twopi = 2 * pi;
 
    for (i = 0; i < numc; i++) {
	glBegin(GL_QUAD_STRIP);
        for (j = 0; j <= numt; j++) {
	    for (k = 1; k >= 0; k--) {
		s = (i + k) % numc + 0.5;
		t = j % numt;

		x = cos(t*twopi/numt) * cos(s*twopi/numc);
		y = sin(t*twopi/numt) * cos(s*twopi/numc);
		z = sin(s*twopi/numc);
		glNormal3f(x, y, z);

		x = (rt + rc * cos(s*twopi/numc)) * cos(t*twopi/numt);
		y = (rt + rc * cos(s*twopi/numc)) * sin(t*twopi/numt);
		z = rc * sin(s*twopi/numc);
		glVertex3f(x, y, z);
	    }
        }
	glEnd();
    }
}

float Clamp(int iters_left, float t)
{

    if (iters_left < 3) {
	return 0.0;
    }
    return (iters_left-2)*t/iters_left;
}

void DrawScene(void)
{
    int i, j;

    for (i = 0; i < RINGS; i++) {
	if (iters[i]) {
	    for (j = 0; j < 3; j++) {
		offsets[i][j] = Clamp(iters[i], offsets[i][j]);
	    }
	    angs[i] = Clamp(iters[i], angs[i]);
	    iters[i]--;
	}
    }

    glPushMatrix();
    
    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
    gluLookAt(0,0,10, 0,0,0, 0,1,0);

    for (i = 0; i < RINGS; i++) {
	if (rgb) {
	    glColor3ubv(rgb_colors[i]);
	} else {
	    glIndexi(mapped_colors[i]);
	}
	glPushMatrix();
	glTranslatef(dests[i][0]+offsets[i][0], dests[i][1]+offsets[i][1],
		     dests[i][2]+offsets[i][2]);
	glRotatef(angs[i], rotAxis[i][0], rotAxis[i][1], rotAxis[i][2]);
	glCallList(theTorus);
	glPopMatrix();
    }

    glPopMatrix();

    glFlush();

    if (doubleBuffer) {
	tkSwapBuffers();
    }
}

float MyRand(void)
{
#ifdef __unix
    return 10.0 * (drand48() - 0.5);
#else
    return 10.0 * ( ((float) rand())/((float) RAND_MAX) - 0.5);
#endif
}

void ReInit(void)
{
    int i;
    float deviation;

    deviation = MyRand() / 2;
    deviation = deviation * deviation;
    for (i = 0; i < RINGS; i++) {
	offsets[i][0] = MyRand();
	offsets[i][1] = MyRand();
	offsets[i][2] = MyRand();
	angs[i] = 260.0 * MyRand();
	rotAxis[i][0] = MyRand();
	rotAxis[i][1] = MyRand();
	rotAxis[i][2] = MyRand();
	iters[i] = (deviation * MyRand() + 60.0);
    }
}

void Init(void)
{
    int gid;
    float base, height;
    float aspect, x, y;
    int i;
#ifdef __unix 
    struct timeval t;
    struct timezone tz;
#else
    time_t timer, timerr;
#endif
    float sc = 10;
    float top_y = 1.0;
    float bottom_y = 0.0;
    float top_z = 0.15;
    float bottom_z = 0.69;
    float spacing = 2.5;
    static float lmodel_ambient[] = {0.0, 0.0, 0.0, 0.0};
    static float lmodel_twoside[] = {GL_FALSE};
    static float lmodel_local[] = {GL_FALSE};
    static float light0_ambient[] = {0.1, 0.1, 0.1, 1.0};
    static float light0_diffuse[] = {1.0, 1.0, 1.0, 0.0};
    static float light0_position[] = {0.8660254, 0.5, 1, 0};
    static float light0_specular[] = {1.0, 1.0, 1.0, 0.0};
    static float bevel_mat_ambient[] = {0.0, 0.0, 0.0, 1.0};
    static float bevel_mat_shininess[] = {40.0};
    static float bevel_mat_specular[] = {1.0, 1.0, 1.0, 0.0};
    static float bevel_mat_diffuse[] = {1.0, 0.0, 0.0, 0.0};

#ifdef __unix 
    gettimeofday(&t, &tz);
    srand48(t.tv_usec);
#else
    time( &timer );
    srand( timer );
#endif
    ReInit();
    for (i = 0; i < RINGS; i++) {
	rgb_colors[i][0] = rgb_colors[i][1] = rgb_colors[i][2] = 0;
    }
    rgb_colors[BLUERING][2] = 255;
    rgb_colors[REDRING][0] = 255;
    rgb_colors[GREENRING][1] = 255;
    rgb_colors[YELLOWRING][0] = 255;
    rgb_colors[YELLOWRING][1] = 255;
    mapped_colors[BLUERING] = BLUE;
    mapped_colors[REDRING] = RED;
    mapped_colors[GREENRING] = GREEN;
    mapped_colors[YELLOWRING] = YELLOW;
    mapped_colors[BLACKRING] = BLACK;

    dests[BLUERING][0] = -spacing;
    dests[BLUERING][1] = top_y;
    dests[BLUERING][2] = top_z;

    dests[BLACKRING][0] = 0.0;
    dests[BLACKRING][1] = top_y;
    dests[BLACKRING][2] = top_z;

    dests[REDRING][0] = spacing;
    dests[REDRING][1] = top_y;
    dests[REDRING][2] = top_z;

    dests[YELLOWRING][0] = -spacing / 2.0;
    dests[YELLOWRING][1] = bottom_y;
    dests[YELLOWRING][2] = bottom_z;

    dests[GREENRING][0] = spacing / 2.0;
    dests[GREENRING][1] = bottom_y;
    dests[GREENRING][2] = bottom_z;

    base = 2.0; 
    height = 2.0;
    theTorus = glGenLists(1);
    glNewList(theTorus, GL_COMPILE);
    FillTorus(0.1, 8, 1.0, 25);
    glEndList();

    x = (float)XSIZE;
    y = (float)YSIZE;
    aspect = x / y;
    glEnable(GL_CULL_FACE);
    glCullFace(GL_BACK);
    glEnable(GL_DEPTH_TEST);
    glClearDepth(1.0);

    if (rgb) {
	glClearColor(0.5, 0.5, 0.5, 0.0);
	glLightfv(GL_LIGHT0, GL_AMBIENT, light0_ambient);
	glLightfv(GL_LIGHT0, GL_DIFFUSE, light0_diffuse);
	glLightfv(GL_LIGHT0, GL_SPECULAR, light0_specular);
	glLightfv(GL_LIGHT0, GL_POSITION, light0_position);
	glEnable(GL_LIGHT0);

	glLightModelfv(GL_LIGHT_MODEL_LOCAL_VIEWER, lmodel_local);
	glLightModelfv(GL_LIGHT_MODEL_TWO_SIDE, lmodel_twoside);
	glLightModelfv(GL_LIGHT_MODEL_AMBIENT, lmodel_ambient);
	glEnable(GL_LIGHTING);

	glMaterialfv(GL_FRONT, GL_AMBIENT, bevel_mat_ambient);
	glMaterialfv(GL_FRONT, GL_SHININESS, bevel_mat_shininess);
	glMaterialfv(GL_FRONT, GL_SPECULAR, bevel_mat_specular);
	glMaterialfv(GL_FRONT, GL_DIFFUSE, bevel_mat_diffuse);

	glColorMaterial(GL_FRONT_AND_BACK, GL_DIFFUSE);
	glEnable(GL_COLOR_MATERIAL);
	glShadeModel(GL_SMOOTH);
    } else {
	glClearIndex(BACKGROUND);
	glShadeModel(GL_FLAT);
    }

    glMatrixMode(GL_PROJECTION);
    gluPerspective(45, 1.33, 0.1, 100.0);
    glMatrixMode(GL_MODELVIEW);
}

void Reshape(int width, int height)
{

    glViewport(0, 0, width, height);
}

GLenum Key(int key, GLenum mask)
{

    switch (key) {
      case TK_ESCAPE:
	tkQuit();
      case TK_SPACE:
	ReInit();
	break;
      default:
	return GL_FALSE;
    }
    return GL_TRUE;
}

GLenum Args(int argc, char **argv)
{
    GLint i;

    rgb = GL_TRUE;
    doubleBuffer = GL_TRUE;
    directRender = 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 if (strcmp(argv[i], "-dr") == 0) {
	    directRender = GL_TRUE;
	} else if (strcmp(argv[i], "-ir") == 0) {
	    directRender = GL_FALSE;
	} else {
	    printf("%s (Bad option).\n", argv[i]);
	    return GL_FALSE;
	}
    }
    return GL_TRUE;
}

void main(int argc, char **argv)
{
    GLenum type;

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

    tkInitPosition(10, 30, 400, 300);

    type = (rgb) ? TK_RGB : TK_INDEX;
    type |= (doubleBuffer) ? TK_DOUBLE : TK_SINGLE;
    type |= (directRender) ? TK_DIRECT : TK_INDIRECT;
    type |= TK_DEPTH16;
    tkInitDisplayMode(type);

    if (tkInitWindow("Olympic") == GL_FALSE) {
        tkQuit();
    }

    Init();

    tkExposeFunc(Reshape);
    tkReshapeFunc(Reshape);
    tkKeyDownFunc(Key);
    tkIdleFunc(DrawScene);

    tkExec();
}