offscrn.c

nucleus 文件系统,内核和彩色图形系统,在小系统上非常好用

#define byte unsigned char
#define word unsigned short
#include "metawndo.h"      /* master MetaWINDOW include file */

void Waiting(int a);

void offscreen( )
{
	void quit(void);
   int       scrnHeight;   // screen height
   int       scrnWidth;    // screen width
   rect      sR, fR;       // temp working rects
   grafPort *thePort;      // pointer to the screen port(/bitmap)
   grafPort *offscrPort;   // pointer to the offscreen port(/bitmap)
   int   GrafixCard = 2;
	mwEvent waitEvent;

   /* init the system */
//   i = InitGraphics( GrafixCard );

   GetPort( &thePort );                // get pointer to the screen port
   scrnWidth  = thePort->portMap->pixWidth;
   scrnHeight = thePort->portMap->pixHeight;

   // *** create a memory bitmap and port matching the screen ***
   // (we could create any size bitmap if we wanted)
   offscrPort = CreateBitmap( cMEMORY, scrnWidth, scrnHeight );

   if ( offscrPort == 0 ) {
      printf("ERROR: Unable to allocate offscreen bitmap\n");
      Waiting(150);
	  return; // abort if CreateBitmap() fails
   }


   sR = offscrPort->portRect;
   PenNormal();
   PenColor( LtRed );
   BackColor( LtGray );
   FillRect( &sR, 30 );

   fR = sR;
   fR.Xmax--;
   fR.Ymax--;
   PenColor( LtGreen );
   FrameRect( &fR );

   PenColor( Blue );
   MoveTo( fR.Xmin, fR.Ymin );
   LineTo( fR.Xmax, fR.Ymax );
   MoveTo( fR.Xmax, fR.Ymin );
   LineTo( fR.Xmin, fR.Ymax );

   PenColor( Black );
   MoveTo( 20,40 );           
   DrawString("Offscreen bitmaps are easy with CreateBitmap()!");

   SetPort( thePort );     // switch back to the screen
   PaintRect( &sR );       // fill screen with a different color

   // copy the memory bitmap to the screen bitmap
   CopyBlit( offscrPort, thePort,
            &offscrPort->portRect, &thePort->portRect );

   // free the offscreen bitmap
   DestroyBitmap( offscrPort );

#ifndef CYCLE
	MoveTo( 0,sR.Ymax - 20 );
	DrawString( "Press 'x' to exit" );
	MoveTo( 0,sR.Ymax - 10 );
	DrawString( "any other key to continue" );
	  while(!KeyEvent(1, &waitEvent));
	  if((waitEvent.eventChar == 'x') || (waitEvent.eventChar == 'X')) quit();
#else
#ifdef _MNT_
	  KeyEvent(0, &waitEvent);
	  if((waitEvent.eventChar == 'x') || (waitEvent.eventChar == 'X')) quit();
#endif
   Waiting(150);
#endif

	return;
}