//  sphere with class
//  mesh modeling
//  Gouraud shading
// T. Kosaka CS TNCT 8Aug2002

#include <stdio.h>
#include <math.h>
#include <GL/glut.h>
#include "CGCore3D.h"
#ifndef M_PI
#define M_PI 3.141592653589793
#endif

void userdraw(void);

void display(void)
{
    glClear( GL_COLOR_BUFFER_BIT);
    userdraw();
    glutSwapBuffers();
}

//////////////////////////////////////////////////////////////////
static void makeSphere(C_Smoothpolyhedron &sphere,float r,int NumLatEdge,int NumLngEdge,C_Color color,opticalAttribute_t attr)
{
    // r : radius of the sphere
    // NumLatEdge : number of segments along the longitude at Latitude 0
    // NumLngEdge : number of segments along the equator
    int NumberVertices;      //多面体を構成する頂点の数
    C_Vertex *Vertex;        //多面体を構成する頂点の座標
    C_Vector *NormalVector;  //各擬似頂点位置の法線ベクトル
    int NumberFaces;         //多面体を構成する面の数
    C_Face *Face;            //多面体を構成する面の定義
    float latitude;
    float longitude;
    int i,j,k;
    C_Vector unitz(0,0,1);
    C_Vector unityn(0,1,0);
    C_Vector unitys(0,-1,0);
    C_Matrix mat1,mat2;
    
    NumberVertices=1+(NumLatEdge-1)*NumLngEdge+1;
    Vertex = new C_Vertex[NumberVertices];
    NormalVector = new C_Vector[NumberVertices];

    NormalVector[0]=unityn;
    Vertex[0]=r*NormalVector[0];
    for(i=1;i<NumLatEdge;i++) {
        latitude=(NumLatEdge/2.-i)/(float)NumLatEdge*M_PI;
        mat1.setRotationX(-latitude);
        for(j=0;j<NumLngEdge;j++) {
            k=NumLngEdge*(i-1)+j+1;
            longitude=(float)j/NumLngEdge*2.*M_PI;
            mat2.setRotationY(longitude);
            NormalVector[k]=mat2*mat1*unitz;
            Vertex[k]=r*NormalVector[k];
        }
    }
    k=(NumLatEdge-1)*NumLngEdge+1;
    NormalVector[k]=unitys;
    Vertex[k]=r*NormalVector[k];

    NumberFaces=NumLatEdge*NumLngEdge;
    Face = new C_Face[NumberFaces];

    for(i=0;i<NumLatEdge;i++) {
        if (i==0) {
            for(j=0;j<NumLngEdge;j++) {
                k=j;
                Face[k].numberVertices=3;
                Face[k].VertexNumber = new int[3];
                Face[k].VertexNumber[0]=0;
                Face[k].VertexNumber[1]=k+1;
                if (j!=NumLngEdge-1) {
                    Face[k].VertexNumber[2]=k+2;
                } else {
                    Face[k].VertexNumber[2]=1;
                }
            }
        } else if (i<NumLatEdge-1) {
            for(j=0;j<NumLngEdge;j++) {
                k=NumLngEdge*i+j;
                Face[k].numberVertices=4;
                Face[k].VertexNumber = new int[4];
                Face[k].VertexNumber[0]=k+1-NumLngEdge;
                Face[k].VertexNumber[1]=k+1;
                if (j!=NumLngEdge-1) {
                    Face[k].VertexNumber[2]=k+2;
                    Face[k].VertexNumber[3]=k+2-NumLngEdge;
                } else {
                    Face[k].VertexNumber[2]=NumLngEdge*i+1;
                    Face[k].VertexNumber[3]=NumLngEdge*i+1-NumLngEdge;
                }
            }
        } else {
            for(j=0;j<NumLngEdge;j++) {
                k=NumLngEdge*i+j;
                Face[k].numberVertices=3;
                Face[k].VertexNumber = new int[3];
                Face[k].VertexNumber[0]=k+1-NumLngEdge;
                Face[k].VertexNumber[1]=(NumLatEdge-1)*NumLngEdge+1;
                if (j!=NumLngEdge-1) {
                    Face[k].VertexNumber[2]=k+2-NumLngEdge;
                } else {
                    Face[k].VertexNumber[2]=NumLngEdge*i+1-NumLngEdge;
                }
            }
        }
    }
    sphere.createSmoothPolyhedron(Vertex,NormalVector,NumberVertices,Face,NumberFaces,color,attr);
    delete[] Vertex;
    delete[] NormalVector;
    for (i=0;i<NumberFaces;i++) Face[i].~C_Face();
    delete[] Face;
}

void userdraw(void)
{
    static int tick=0;
    int disp=(tick/200)%3;
    static C_Smoothpolyhedron sphere;
    float phi=0.5;    // for tilting
    float theta=-0.5; // for tilting
    C_Vector ViewVector(0,0,1);
    C_Vector LightVector(0,1,0);
    C_Scene myScene;

    if (tick==0) {
        opticalAttribute_t attr;
        C_Color Cyan(0,1,1);
        attr.kspe=0.7; // specular reflection coefficient
        attr.kdif=0.6; // diffuse reflection coefficient
        attr.kamb=0.4; // ambient light coefficient
        makeSphere(sphere,150,18,32,Cyan,attr);
    }
    myScene.drawAxes();

    myScene.initializeTMatrix();
    myScene.setRotationY(0.02*tick);
    myScene.setScale(1,0.8+0.2*sin(0.05*tick),1);
    switch (disp) {
    case 0:
        myScene.drawPolyhedronWire(sphere);
        break;
    case 1:
        myScene.drawPolyhedronSurface(sphere);
        break;
    case 2:
        myScene.drawPolyhedronSmoothSurface(sphere);
        break;
    default:
        break;
    }

    tick++;
}

int main(int argc, char **argv)
{
    glutInit(&argc,argv);
    glutInitDisplayMode ( GLUT_DOUBLE | GLUT_RGB );
    glutInitWindowPosition(100,100);
    glutInitWindowSize(640,480);
    glutCreateWindow ("sphere");
    glClearColor(0.0, 0.0, 0.0, 0.0);
    gluOrtho2D(-320., 320., -240.0, 240.0);
      // Define the dimensions of the Orthographic Viewing Volume
    glutIdleFunc(display); // idle event call back
    glutDisplayFunc(display);
    glutMainLoop();
    return 0;
}