/*
 * (c) Copyright 1993, Silicon Graphics, Inc.
 *               1993, 1994 Microsoft Corporation
 *
 * ALL RIGHTS RESERVED
 *
 * Please refer to OpenGL/readme.txt for additional information
 *
 */

#include "glos.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <time.h>
#include <gl\glaux.h>



#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];

extern void FillTorus(float rc,int numc,float rt,int numt);
extern float Clamp(int iters_left,float t);
extern void CALLBACK DrawScene(void );
extern float MyRand(void );
extern void ReInit(void );
extern void Init(void );
extern void CALLBACK Reshape(int width,int height);
static void CALLBACK Key_SPACE(void );
extern unsigned long Args(int argc,char **argv );

GLenum rgb, doubleBuffer;

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 CALLBACK 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) {
    auxSwapBuffers();
    }
}

float MyRand(void)
{
    return 10.0 * ( ((float) rand())/((float) RAND_MAX) - 0.5);
}

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)
{
    float base, height;
    float aspect, x, y;
    int i;
    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};

    srand(time(NULL));
    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 CALLBACK Reshape(int width, int height)
{

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

static void CALLBACK Key_SPACE(void)
{
    ReInit();
}

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

    rgb = GL_TRUE;
    doubleBuffer = GL_TRUE;


    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 {
        return GL_FALSE;
    }
    }
    return GL_TRUE;
}

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

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

    auxInitPosition(0, 0, 400, 300);

    type = (rgb) ? AUX_RGB : AUX_INDEX;
    type |= (doubleBuffer) ? AUX_DOUBLE : AUX_SINGLE;

    auxInitDisplayMode(type);

    if (auxInitWindow("Olympic") == GL_FALSE) {
        auxQuit();
    }

    Init();

    auxExposeFunc((AUXEXPOSEPROC)Reshape);
    auxReshapeFunc((AUXRESHAPEPROC)Reshape);
    auxKeyFunc(AUX_SPACE, Key_SPACE);
    auxIdleFunc(DrawScene);

    auxMainLoop(NULL);
}
