Tunnel: C++Builder Version

/****************************************************************************\
*                                                                            *
*  Tunnel.cpp                                                                *
*  TunnelU.cpp                                                               *
*                                                                            *
*  This program draws a Gouraud-shaded tunnel and allows the viewer to move  *
*  through the tunnel using keyboard controls.                               *
*                                                                            *
\****************************************************************************/
#include 
#pragma hdrstop
#include "TunnelU.h"
//---------------------------------------------------------------------------
#pragma resource "*.dfm"
TForm1 *Form1;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
   : TForm(Owner)
{
}
//---------------------------------------------------------------------------
void __fastcall TForm1::OnIdle(TObject *Sender, bool &Done)
{
   CheckForMovement();
   Done = False;
}
//---------------------------------------------------------------------------
void __fastcall TForm1::FormActivate(TObject *Sender)
{
   fg_realize(hPal);
   Invalidate();
}
//---------------------------------------------------------------------------
void __fastcall TForm1::FormCreate(TObject *Sender)
{
   int vbDepth;
   hDC = GetDC(Form1->Handle);
   fg_setdc(hDC);
   hPal = fg_defpal();
   fg_realize(hPal);
   fg_vbinit();
   vbDepth = fg_colors();
   if (vbDepth < 16) vbDepth = 16;
   fg_vbdepth(vbDepth);
   hVB = fg_vballoc(vbWidth,vbHeight);
   fg_vbopen(hVB);
   fg_vbcolors();
   hZB = fg_zballoc(vbWidth,vbHeight);
   fg_zbopen(hZB);
   fg_setcolor(-1);
   fg_fillpage();
   fg_3Dviewport(0,vbWidth-1,0,vbHeight-1,1.0);
   fg_3Drenderstate(FG_ZBUFFER | FG_ZCLIP);
   fg_3Dlookat(0.0,10.0,50.0,0.0,10.0,100.0);
   Application->OnActivate = OnActivate;
   Application->OnIdle = OnIdle;
}
//---------------------------------------------------------------------------
void __fastcall TForm1::FormPaint(TObject *Sender)
{
   fg_vbscale(0,vbWidth-1,0,vbHeight-1,0,cxClient-1,0,cyClient-1);
}
//---------------------------------------------------------------------------
void __fastcall TForm1::FormResize(TObject *Sender)
{
   cxClient = ClientWidth;
   cyClient = ClientHeight;
   Invalidate();
}
//---------------------------------------------------------------------------
void __fastcall TForm1::FormDestroy(TObject *Sender)
{
   fg_vbclose();
   fg_zbfree(hZB);
   fg_vbfree(hVB);
   fg_vbfin();
   DeleteObject(hPal);
   ReleaseDC(Form1->Handle,hDC);
}
/****************************************************************************\
*                                                                            *
*  CheckForMovement()                                                        *
*                                                                            *
*  The CheckForMovement() function checks for key presses that control the   *
*  user's movement, and if required redraws the tunnel viewed from the new   *
*  camera position. It is called from the WinMain() message loop when there  *
*  are no messages waiting.                                                  *
*                                                                            *
\****************************************************************************/
void __fastcall TForm1::CheckForMovement()
{
   static bool Redraw = True;
   // up arrow moves viewer forward
   if (fg_kbtest(72))
   {
      fg_3Dmoveforward(2.0);
      Redraw = TRUE;
   }
   // down arrow moves viewer backward
   else if (fg_kbtest(80))
   {
      fg_3Dmoveforward(-2.0);
      Redraw = TRUE;
   }
   // right arrow turns viewer to the right
   else if (fg_kbtest(77))
   {
      fg_3Drotateright(6*10);
      Redraw = TRUE;
   }
   // left arrow turns viewer to the left
   else if (fg_kbtest(75))
   {
      fg_3Drotateright(-6*10);
      Redraw = TRUE;
   }
   // if the viewer's position or rotation changed, redraw the tunnel
   if (Redraw)
   {
      // prepare the z-buffer for the next frame
      fg_zbframe();
      // erase the previous frame from the virtual buffer
      fg_setcolor(-1);
      fg_fillpage();
      // draw the tunnel
      DrawTunnel();
      // display what we just drew
      fg_vbscale(0,vbWidth-1,0,vbHeight-1,0,cxClient-1,0,cyClient-1);
      Redraw = False;
   }
}
/****************************************************************************\
*                                                                            *
*  DrawTunnel()                                                              *
*                                                                            *
*  Draws each of the tunnel's four sides in 3D world space.                  *
*                                                                            *
\****************************************************************************/
void __fastcall TForm1::DrawTunnel()
{
   register int i;
   for (i = 0; i < 4; i++)
   {
      fg_3Dshade((double *)Faces[i],(char *)FacesRGB[i],4);
   }
}