oval1.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          */
/*                                                                       */
/*      OVAL1.c                                          1.9             */
/*                                                                       */
/* COMPONENT                                                             */
/*                                                                       */
/*      All                                                              */
/*                                                                       */
/* DESCRIPTION                                                           */
/*                                                                       */
/*      This file contains the PaintOval 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"
#include "xpol_4.h"


/* Function PaintOval fills the specified elliptical region contained by 
rectangle argR using the current pen pattern (pnPat) and pen rasterOp mode 
(pnMode).  The current "pen" position is not affected by PaintOval.. */

void PaintOval(rect *argR)
{
	void mwSTQA(qarcState *QArcEdge, int QArcA, int QArcB, int QArcCenterX,
			   int QArcCenterY, int QArcDirection, int QArcTToB);
	void AddToGETYXSorted(qarcState *newEdge);
	void mwSBQA(qarcState *QArcEdge, int QArcA, int QArcB, int QArcCenterX,
			int QArcCenterY, int QArcDirection, int QArcTToB);
	void mwScanGET(void **GETPtrPtr, blitRcd *fillRcd, int scanRcdSize, int shape,
			   int fillRule, int allEdgesAreLines);
	short grafErrValue;	/* error value */
	int i;
	qarcState *newEdge;	/* pointer to new edge to add to table */

	for (i = 0; i < 12; i++) qaEdgeBuffer[i].NextEdge = 0;	/* GET is initially empty */
	if (grafPort.pnLevel < 0) return;	/* nothing to do */

	rXmin = *argR;	/* get rectangle */
	if (globalLevel > 0)
	{
		/* convert from user to global */
		U2GR(rXmin, &rXmin, 0);
	}

	rXWidth = rXmin.Xmax - rXmin.Xmin;	/* width */
	if (rXWidth < 0)
	{
		grafErrValue = c_PaintOva +  c_NullRect;	/* bad rectangle */
		nuGrafErr(grafErrValue);	/* report error */
		return;
	}

	rXHeight = rXmin.Ymax - rXmin.Ymin;	/* height */
	if (rXHeight < 0)
	{
		grafErrValue = c_PaintOva +  c_NullRect;	/* bad rectangle */
		nuGrafErr(grafErrValue);	/* report error */
		return;
	}

	xRadius = (rXWidth >> 1);
	yRadius = (rXHeight >> 1);

	thisLeftEdge = rXmin.Xmin + xRadius;	/* left edge + height */
	nextTopEdge = rXmin.Ymin + yRadius;	/* top edge + height */
	thisRightEdge = rXmin.Xmax - xRadius;	/* right edge + height */
	nextBottomEdge = rXmin.Ymax - yRadius - 1;	/* bottom edge - height 
												-1 for filling */

	/* set up the upper left arc */
	GETPtr = &qaEdgeBuffer[0];
	newEdge = GETPtr;
	mwSTQA(newEdge, xRadius, yRadius, thisLeftEdge, nextTopEdge, -1, -1);

	/* set up the upper right arc */
	newEdge = &qaEdgeBuffer[1];
	mwSTQA(newEdge, xRadius, yRadius, thisRightEdge, nextTopEdge, 1, 1);
	AddToGETYXSorted(newEdge);	/* insert the new edge in GET, YX sorted */

	/* now add the bottom arcs, with the top points trimmed off to avoid
	overlap problems */

	if (qaEdgeBuffer[0].Count != 1)	/*are arcs only one scan line high? */
	{	/* no */
		newEdge = &qaEdgeBuffer[2];
		mwSBQA(newEdge, xRadius, yRadius, thisLeftEdge, nextBottomEdge, 1, -1);
		newEdge->StepVector(newEdge);	/* advance Y by 1 (skip first point) */
		newEdge->StartY++;	/* start on the next scan line */
		newEdge->Count--;	/* skip the topmost point */
		AddToGETYXSorted(newEdge);	/* insert the new edge in GET, YX sorted */

		/* advance bottom arcs by one scan line to avoid overlap problems (skip
		the top scan line, which can stick out too far and always overlaps with
		the top quadrant arcs anyway) */

		/* set up the lower right arc */
		newEdge = &qaEdgeBuffer[3];
		mwSBQA(newEdge, xRadius, yRadius, thisRightEdge, nextBottomEdge, -1, 1);
		newEdge->StepVector(newEdge);	/* advance Y by 1 (skip first point) */
		newEdge->StartY++;	/* start on the next scan line */
		newEdge->Count--;	/* skip the topmost point */
		AddToGETYXSorted(newEdge);	/* insert the new edge in GET, YX sorted */
	}	

	/* draw the oval and done! */
	mwScanGET((void **)&GETPtr, (blitRcd *)&rFillRcd[0], fillRcdSize, cmplx, 1, 0);

	return;
}