//polyhedron
//  Demonstration of shading and lighting with moving dodecahedron and icosahedron
//  flat shading
// T. Kosaka CS TNCT 16Aug2002

#include <stdio.h>
#include <math.h>
#include <GL/glut.h>
#include "GLDrawingtool3D.h"
#ifndef M_PI
#define M_PI 3.141592653589793
#endif

GLfloat light0pos[] = { 500.0, 500.0, 1500.0, 0.0 }; // x,y,z,d
GLfloat White[] = { 1.0, 1.0, 1.0, 1.0 }; // R,G,B,A
GLfloat Cyan[] = { 0.0, 1.0, 1.0, 1.0 }; // R,G,B,A
GLfloat Gray[] = { 0.15, 0.15, 0.15, 1.0 }; // R,G,B,A
GLfloat Red[] = { 1.0, 0.0, 0.0, 1.0 }; // R,G,B,A
GLfloat Shine[] = { 100.0}; //0.0(large highlight) ... 128.0(small highlight)

void userdraw(void);

void display(void)
{
    glClear( GL_COLOR_BUFFER_BIT);
    glClear(GL_DEPTH_BUFFER_BIT); // depth check
    userdraw();
    glutSwapBuffers();
}

static void makeDodecahedron(polyhedron_t &dodecahedron,float size)
{
    // size : an edge length of the dodecahedron
    float theta=2.0/5.0*M_PI;// 2 Pi/5 a central angle of the pentagon
    float alpha=3.0/5.0*M_PI;// an interior angle of the pentagon
    float r0;                // a radius of an inscribed circle
    float r1;                // a radius of a circumscribed circle
    float s1;                // a length of a diagonal line of the pentagon
    float r2;                // a radius of a circumscribed circle of the pentagon whose edge length is equal to s1
    float h1,h2,h;           // heights of the dodecahedron

    float r[4],th0[4],ha[4];
    int i,j,k;
    float th;
    face_t face[]={
        {5,{0,1,2,3,4}},{5,{0,5,10,6,1}},{5,{1,6,11,7,2}},
        {5,{2,7,12,8,3}},{5,{3,8,13,9,4}},{5,{4,9,14,5,0}},
        {5,{10,15,16,11,6}},{5,{11,16,17,12,7}},{5,{12,17,18,13,8}},
        {5,{13,18,19,14,9}},{5,{14,19,15,10,5}},{5,{15,19,18,17,16}}
    }; // every face has five vertices and showing vertex numbers
    vector3D_t vecbuff[4];

    dodecahedron.NumberofVertices=20;

    r1=size/(2.0*sin(theta/2.0));
    r0=r1*cos(theta/2.0);
    s1=2.0*size*sin(alpha/2.0);
    r2=s1/(2.0*sin(theta/2.0));
    h1=sqrt(size*size-(r2-r1)*(r2-r1));
    h2=sqrt((r0+r1)*(r0+r1)-(r2-r0)*(r2-r0));
    h=h1+h2;
    r[0]=r1; th0[0]=0.0; ha[0]=h-0.5*h;
    r[1]=r2; th0[1]=0.0; ha[1]=h2-0.5*h;
    r[2]=r2; th0[2]=0.2*M_PI; ha[2]=h1-0.5*h;
    r[3]=r1; th0[3]=0.2*M_PI; ha[3]=0.0-0.5*h;
    for (i = 0; i<4; i++){
        for (j = 0; j<5; j++){
            th=0.4*M_PI*(float)j+th0[i];
            k=5*i+j;
            dodecahedron.pnt[k].z=-r[i]*sin(th);
            dodecahedron.pnt[k].x=r[i]*cos(th);
            dodecahedron.pnt[k].y=ha[i];
        }
    }

    dodecahedron.NumberofFaces=12;

    for (i = 0; i<dodecahedron.NumberofFaces; i++){
        dodecahedron.fc[i]=face[i];
        for (j=0;j<3;j++) {
            vecbuff[j]=Point2Vector(dodecahedron.pnt[dodecahedron.fc[i].pnt[j]]);
        }
        dodecahedron.fc[i].NormalVector=(vecbuff[1]-vecbuff[0])^(vecbuff[2]-vecbuff[0]);
    }
}

static void makeIcosahedron(polyhedron_t &icosahedron,float size)
{
    // size : an edge length of the icosahedron
    float r1,r2,h1,h2,h3;
    float th0[2],h[2];
    int i,j,k;
    float th;
    face_t face[]={
        {3,{0,1,2}},{3,{0,2,3}},{3,{0,3,4}},{3,{0,4,5}},{3,{0,5,1}},
        {3,{1,6,2}},{3,{2,7,3}},{3,{3,8,4}},{3,{4,9,5}},{3,{5,10,1}},
        {3,{2,6,7}},{3,{3,7,8}},{3,{4,8,9}},{3,{5,9,10}},{3,{1,10,6}},
        {3,{6,11,7}},{3,{7,11,8}},{3,{8,11,9}},{3,{9,11,10}},{3,{10,11,6}}
    }; // every face has five vertices and showing vertex numbers
    vector3D_t vecbuff[4];

    icosahedron.NumberofVertices=12;

    r1=size*0.5/tan(0.2*M_PI); // a radius of an inscribed circle of the triangle
    r2=size*0.5/sin(0.2*M_PI); // a radius of a circumscribed circle of the triangle
    h1=sqrt(size*size-r2*r2);                     // height of vertex 1
    h2=h1+sqrt(3.0/4.0*size*size-(r2-r1)*(r2-r1));// height of vertex 1
    h3=h1+h2;                               // height of the icosahedron
    icosahedron.pnt[0].z=0.0;
    icosahedron.pnt[0].x=0.0;
    icosahedron.pnt[0].y=h3-h3/2;
    icosahedron.pnt[11].z=0.0;
    icosahedron.pnt[11].x=0.0;
    icosahedron.pnt[11].y=0.0-h3/2;
    th0[0]=0.0; h[0]=h2;
    th0[1]=0.2*M_PI; h[1]=h1;
    for (i = 0; i<2; i++){
        for (j = 0; j<5; j++){
            th=0.4*M_PI*(float)j+th0[i];
            k=5*i+j+1;
            icosahedron.pnt[k].z=-r2*sin(th);
            icosahedron.pnt[k].x=r2*cos(th);
            icosahedron.pnt[k].y=h[i]-h3/2;
        }
    }

    icosahedron.NumberofFaces=20;

    for (i = 0; i<icosahedron.NumberofFaces; i++){
        icosahedron.fc[i]=face[i];
        for (j=0;j<3;j++) {
            vecbuff[j]=Point2Vector(icosahedron.pnt[icosahedron.fc[i].pnt[j]]);
        }
        icosahedron.fc[i].NormalVector=(vecbuff[1]-vecbuff[0])^(vecbuff[2]-vecbuff[0]);
    }
}

void userdraw(void)
{
    static int tick=0;
    float k1=tick/200.;
    static polyhedron_t dodecahedron;
    static polyhedron_t icosahedron;

    if (tick==0) {
        makeDodecahedron(dodecahedron,60);
        makeIcosahedron(icosahedron,90);
    }

    myInitView(1);

    glRotatef(k1*180.0, 0.0, 1.0, 0.0); // Matrix A
    glTranslatef(150.0, 0.0, 0.0); // Matrix B
    glRotatef(-k1*500.0, 0.0, 0.0, 1.0); // Matrix C
    glRotatef(k1*520.0, 1.0, 0.0, 0.0); // Matrix D

    glMaterialfv(GL_FRONT, GL_AMBIENT, Gray); //Attribute of the object
    glMaterialfv(GL_FRONT, GL_DIFFUSE, Cyan);
    glMaterialfv(GL_FRONT, GL_SPECULAR, White);
    glMaterialfv(GL_FRONT, GL_SHININESS, Shine);

    glEnable(GL_CULL_FACE); // Cull back face
    glCullFace(GL_BACK);    // Cull back face
    glShadeModel(GL_FLAT);

    glPushMatrix(); // save Matrix to a matrix buffer
    glTranslatef(90.0, 0.0, 0.0); // Matrix E
    glRotatef(k1*120.0, 1.0, 0.0, 0.0); // Matrix F
    // Then Transformation Matrix for the dodecahedron is A*B*C*D*E*F
    putFlatPolyhedron(dodecahedron);

    glPopMatrix(); // load Matrix from the matrix buffer
    glTranslatef(-90.0, 0.0, 0.0); // Matrix G
    glRotatef(-k1*120.0, 0.0, 1.0, 0.0); // Matrix H
    // Then Transformation Matrix for the icosahedron is A*B*C*D*G*H
    glMaterialfv(GL_FRONT, GL_DIFFUSE, Red); //Attribute of the object
    putFlatPolyhedron(icosahedron);

    tick++;
}

int main(int argc, char **argv)
{
    glutInit(&argc,argv);
    glutInitDisplayMode ( GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH); // depth check
    glutInitWindowPosition(100,100);
    glutInitWindowSize(640,480);
    glutCreateWindow ("polyhedrons");
    glClearColor(0.0, 0.0, 0.0, 0.0);
    glViewport(0,0,640,480);               
    glutIdleFunc(display); // idle event call back
    glutDisplayFunc(display);
    glEnable(GL_DEPTH_TEST); // depth check (OpenGL inner Z-Buffer)
    glutMainLoop();
    return 0;
}