bezr0.c

nucleus 文件系统,内核和彩色图形系统,在小系统上非常好用

/*************************************************************************/
/*                                                                       */
/*         Copyright (c) 1997 - 1999 Accelerated Technology, Inc.        */
/*                                                                       */
/* PROPRIETARY RIGHTS of Accelerated Technology are involved in the      */
/* subject matter of this material.  All manufacturing, reproduction,    */
/* use, and sales rights pertaining to this subject matter are governed  */
/* by the license agreement.  The recipient of this software implicitly  */
/* accepts the terms of the license.                                     */
/*                                                                       */
/*************************************************************************/

/*************************************************************************/
/*                                                                       */
/* FILE NAME                                            VERSION          */
/*                                                                       */
/*      BEZR0.c                                          1.9             */
/*                                                                       */
/* COMPONENT                                                             */
/*                                                                       */
/*      All                                                              */
/*                                                                       */
/* DESCRIPTION                                                           */
/*                                                                       */
/*      This file contains the FrameBezier function.                     */
/*                                                                       */
/* AUTHOR                                                                */
/*                                                                       */
/*      Robert G. Burrill, Accelerated Technology, Inc.                  */
/*                                                                       */
/* DATA STRUCTURES                                                       */
/*                                                                       */
/*      None                                                             */
/*                                                                       */
/* FUNCTIONS                                                             */
/*                                                                       */
/*      None                                                             */
/*                                                                       */
/* DEPENDENCIES                                                          */
/*                                                                       */
/*      None                                                             */
/*                                                                       */
/* HISTORY                                                               */
/*                                                                       */
/*         NAME            DATE                    REMARKS               */
/*                                                                       */
/*                                                                       */
/*************************************************************************/

#include "meta_wnd.h"
#include "metconst.h"    /* MetaWINDOW Constant & Stucture Definitions */
#include "metports.h"    /* MetaWINDOW Port & Bitmap Definitions */
#include "grafdata.h"
#include "metmacs3.h"


/* Function FrameBezier draws a frame around a series of Bezier curves
(closing the last point to the first if necessary). */

void FrameBezier(point *PTS, int PTCNT)
{
	void mwBezier(point *PTS, int PTCNT, point *BEZPTS);
	void PolyLine(short PTCNT, point *PTS);
	void GrafFree(void *freePtr);
	int mwBezCount(point *PTS, int PTCNT);
	point *GrafAlloc(int memSize);
	int numBzPts;	/* number of interpolation points */
	point *ptrBzPts;	/* pointer for interpolated point array */

	if (grafPort.pnLevel < 0) return;	/* is pnLevel visible? */

	/* Compute the number of points for approximation */
	numBzPts = mwBezCount(PTS, PTCNT);

	/* Allocate memory to point approximation array (add space for one
	additional point in case we need to close) */
	ptrBzPts = (point *) GrafAlloc(((numBzPts + 1) << 2));

	/* Compute the bezier approximation and draw */
	if (ptrBzPts != NULL)
	{
		mwBezier(PTS, PTCNT, ptrBzPts);	;

		/* Does the last point close to the first? */
		if ((ptrBzPts[0].X != ptrBzPts[numBzPts-1].X) ||
			(ptrBzPts[0].Y != ptrBzPts[numBzPts-1].Y))
		{	/* no, add final point to close to first */
			ptrBzPts[numBzPts].X = ptrBzPts[0].X;
			ptrBzPts[numBzPts].Y = ptrBzPts[0].Y;
			numBzPts++;
		}

		globalLevel--;
		PolyLine((short)numBzPts, (point *)ptrBzPts);	/* Draw the bezier curve(s) */
		globalLevel++;

		GrafFree(ptrBzPts);	/* Free the point array */
	}

	return;
}