{

Matrix m = MirrorY();

for ( int i = 0; i < PointNumber; i++ )

Point[i] = m * Point[i];

Center = m * Center;

Normal = m * Normal;

}

void Polygon :: PolyMirrorZ ()

{

Matrix m = MirrorZ();

for ( int i = 0; i < PointNumber; i++ )

Point[i] = m * Point[i];

Center = m * Center;

Normal = m * Normal;

}

void Polygon :: Draw ( const Vector& PrCenter )

{

int VisPoint[MaxPoints * 2], k = 0;

for ( int i = 0; i < PointNumber; i++ ) {

double Coeff = 1 / ( 1 - Point[i].z / PrCenter.z );

VisPoint[k++] = ( int ) Point[i].x * Coeff + 320;

VisPoint[k++] = ( int ) -Point[i].y * Coeff + 175;

}

setcolor ( Color );

setfillstyle ( 1, Color );

fillpoly ( PointNumber, VisPoint );

}

// GrObject's methods

GrObject :: GrObject ( Polygon * FacetArr, int FacetNum, const Vector& Crds )

{

if ( FacetNum <= MaxFacets )

{

FacetNumber = FacetNum;

Facet = FacetArr;

Coords = Crds;

}

}

void GrObject :: Move ( const Vector& v )

{

for ( int i = 0; i < FacetNumber; i++ )

Facet[i].Move ( v );

Coords = Translate ( v ) * Coords;

}

void GrObject :: Rotate ( double Alfa, double Beta, double Gamma )

{

for ( int i = 0; i < FacetNumber; i++ )

Facet[i].Rotate ( Alfa, Beta, Gamma );

Coords = RotateX ( Alfa ) * RotateY ( Beta ) * RotateZ ( Gamma ) * Coords;

}

void GrObject :: ObjScale ( const Vector& v )

{

for ( int i = 0; i < FacetNumber; i++ )

Facet[i].PolyScale ( v );

Coords = Scale ( v ) * Coords;

}

void GrObject :: ObjMirrorX ()

{

Matrix m = MirrorX();

for ( int i = 0; i < FacetNumber; i++ )

Facet[i].PolyMirrorX ();

Coords = m * Coords;

}

void GrObject :: ObjMirrorY ()

{

Matrix m = MirrorY();

for ( int i = 0; i < FacetNumber; i++ )

Facet[i].PolyMirrorY ();

Coords = m * Coords;

}

void GrObject :: ObjMirrorZ ()

{

Matrix m = MirrorZ();

for ( int i = 0; i < FacetNumber; i++ )

Facet[i].PolyMirrorZ ();

Coords = m * Coords;

}

// Space's methods

Space :: Space ( GrObject * Obj, int ObjectNum )

{

if ( ObjectNum <= MaxObjects )

{

ObjectNumber = ObjectNum;

for ( int i = 0; i < ObjectNumber; i++ )

Object[i] = &Obj[i];

};

}

void Space :: Add ( GrObject * Obj )

{

if ( ObjectNumber < MaxObjects ) Object [ObjectNumber++] = Obj;

}

void Space :: Draw ( const Vector& PrCenter )

{

}

// Other functions

int IsVisible ( const Polygon& Poly, const Vector& PrCenter )

{

return ( Poly.Normal & ( PrCenter - Poly.Point[0] )) < 0 || Poly.TwoSides;

}

void DrawBSPTree ( BSPNode * Tree, const Vector& PrCntr )

{

if (( Tree -> Poly -> Normal & PrCntr ) > Tree -> d ) {

if ( Tree -> Right != NULL ) DrawBSPTree ( Tree -> Right, PrCntr );

Tree -> Poly -> Draw ( PrCntr );

if ( Tree -> Left != NULL ) DrawBSPTree ( Tree -> Left, PrCntr );

}

else {

if ( Tree -> Left != NULL ) DrawBSPTree ( Tree -> Left, PrCntr );

Tree -> Poly -> Draw ( PrCntr );

if ( Tree -> Right != NULL ) DrawBSPTree ( Tree -> Right, PrCntr );

}

}

Далее представлена демонстрационная программа, которая выполняет все вышеперечисленные операции с тетраэдром.

//Файл 3dgame.cpp

#include <dos.h>

#include <graphics.h>

#include <math.h>

#include <stdio.h>

#include <conio.h>

#include <stdlib.h>

#include "3dworks.h"

void DrawObject ( GrObject* Obj, const Vector& v )

{

for ( int i = 0; i < Obj->FacetNumber; i++ )

if ( IsVisible ( Obj->Facet[i], v )) Obj->Facet[i].Draw ( v );

}

main ()

{

Vector Poly1[3], Poly2[3], Poly3[3], Poly4[3];

Polygon O[4];

Vector A ( -50, 0, 0 ),

B ( 0, 0, 50 ),

C ( 50, 0, 0 ),

D ( 0, 100, 0 ),

PrCenter ( 0, 0, 1000 );

Poly1[0] = A; Poly2[0] = B;

Poly1[1] = D; Poly2[1] = D;

Poly1[2] = B; Poly2[2] = C;

Poly3[0] = C; Poly4[0] = C;

Poly3[1] = A; Poly4[1] = D;

Poly3[2] = B; Poly4[2] = A;

Polygon * P1 = new Polygon ( Poly1, 3, 11, OneSd );

Polygon * P2 = new Polygon ( Poly2, 3, 12, OneSd );

Polygon * P3 = new Polygon ( Poly3, 3, 13, OneSd );

Polygon * P4 = new Polygon ( Poly4, 3, 14, OneSd );

O[0] = *P1; O[1] = *P2;

O[2] = *P3; O[3] = *P4;

delete P1; delete P2;

delete P3; delete P4;

GrObject * Obj = new GrObject ( O, 4, Vector ( 0 ) );

double fi = 0.1, psi = 0.1, step = 0.1;

int ch = 0, Page = 3;

int driver = DETECT, mode, res;

initgraph ( &driver, &mode, "" );

if ( ( res = graphresult () ) != grOk ) {

printf ( "\nGraphics error: %s\n", grapherrormsg ( res ) );

exit ( 1 );

}

setgraphmode ( 1 );

DrawObject ( Obj, PrCenter );

do {

setactivepage ( Page % 2 );

clearviewport ();

if ( kbhit ())

{

switch ( ch = getch() ) {

case '+': Obj->ObjScale ((1.1,1.1,1.1)); break;

case '-': Obj->ObjScale ((0.9,0.9,0.9)); break;

case 'x': Obj->ObjMirrorX (); break;

case 'y': Obj->ObjMirrorY (); break;

case 'z': Obj->ObjMirrorZ (); break;

};

if ( ch == 0 )

{

switch ( ch = getch () ) {

case 72 : fi -= step; break;

case 80 : fi += step; break;

case 75 : psi += step; break;

case 77 : psi -= step; break;

};

};

};

Obj->Rotate ( fi, psi, 0 );

DrawObject ( Obj, PrCenter );

setvisualpage ( Page++ % 2 );

if ( fi == 0 && psi == 0 ) while ( !kbhit ());

} while ( ch != 27 );

delete Obj;

closegraph ();

}