/******************************************
* Пример программы вращения куба
* 
*     FILE : rcube.c
*  CREATED : 10.03.1997
*  
*  (c) Evgeny S. Borisov 
*  
*        OS : MS DOS 6.22
*  COMPILER : TopSpeed C
******************************************/

#include <stdio.h>
#include <graph.h>
#include <conio.h>
#include <math.h>

float v11, v12, v13, v21, v22, v23, v31, v32, v33, v43, horfact, vertfact;
float d=15, c1=4.5, c2=3.5,x_max=10.0, y_max=7.0;
int X__max, Y__max;

/*----------------------------------------------------*/
void initgr(void) {
   _setvideomode( _VRES16COLOR );
   X__max = 640; 
   Y__max = 480;
   horfact = X__max / x_max; 
   vertfact = Y__max / y_max;
}

/*-------------------------------------------------------*/
void endgr() {
    getch(); 
    _setvideomode( _DEFAULTMODE );
}

/*-------------------------------------------------------*/
int IX(float x) {
    return (int) (x * horfact + 0.5);
}

/*-------------------------------------------------------*/
int IY(float y) {
    return (int) Y__max - (int)(y * vertfact + 0.5);
}

/*-------------------------------------------------------*/
void coeff( float rho, float theta, float phi ,float alpha) {
   float th, ph, c1, s1, c2, s2, s3, c3, factor;

   factor=atan(1.0)/45.0; 
   th=theta*factor;   
   ph=phi*factor;  
   alpha=alpha*factor;
    
   c1=cos(th);    s1=sin(th);
   c2=cos(ph);    s2=sin(ph);
   c3=cos(alpha); s3=sin(alpha);

   /* матрица V  */
   v11=c1*c3+s1*s2*s3;   v12=-c1*s3+c3*s1*s2;  v13=c2*s1;
   v21=c2*s3;            v22=c2*c3;            v23=-s2;
   v31=-c3*s1+c1*s2*s3;  v32=s1*s3+c1*c3*s2;   v33=c1*c2;
                                               v43=rho;             
}

/*------------------------------------------*/
void perspective(float x, float y, float z, float *pX, float *pY) {
   float xe, ye, ze;
   
   /* видовое преобразование */
   xe = v11*x + v21*y + v31*z;
   ye = v12*x + v22*y + v32*z;
   ze = v13*x + v23*y + v33*z + v43;
   
   /* перспективное преобразование */
   *pX = screen_dist*xe/ze + c1;
   *pY = screen_dist*ye/ze + c2;  
}

/*------------------------------------*/
/* lineto для 3D */
void dw(float x, float y, float z) {
   float X, Y;
   perspective(x, y, z, &X, &Y);
   _lineto(IX(X), IY(Y));
}

/*-------------------------------------------------*/
/* Прорисовка куба  */
void drawcube() {
   float h=50.0;
    
   mv(h, -h, -h); dw(h, h, -h);    /* AB */
   dw(-h, h, -h);                  /* BC */
   dw(-h, h, h);                   /* CG */
   dw(-h, -h, h);                  /* GH */
   dw(h, -h, h);                   /* HE */
   dw(h, -h, -h);                  /* EA */
   mv(h, h, -h); dw(h, h, h);      /* BF */
   dw(-h, h, h);                   /* FG */
   mv(h, h, h); dw(h, -h, h);      /* FE */
   mv(h, -h, -h); dw(-h, -h, -h);  /* AD */
   dw(-h, h, -h);                  /* DC */
   mv(-h, -h, -h); dw(-h, -h, h);  /* DH */ 
}

/*--------------------------------------------------*/
int main() {
    float rho=500,theta=0, phi=0 ,psi=0;
    
    printf("Угол  phi: ");  scanf("%f", &phi);
    printf("Угол  psi: ");  scanf("%f", &psi);
    printf("Угол theta: "); scanf("%f", &theta); 
    coeff(rho, phi, psi, theta);
    initgr();
    drawcube();
    endgr(); 
    
    return 0;
}