#include?“Arrow.h“
#include?

//?ArrowTo（）
//
void?ArrowTo（HDC?hDC?int?x?int?y?ARROWSTRUCT?*pA）?{

	POINT?ptTo?=?{x?y};

	ArrowTo（hDC?&ptTo?pA）;
}

//?ArrowTo（）
//
void?ArrowTo（HDC?hDC?const?POINT?*lpTo?ARROWSTRUCT?*pA）?{

	POINT?pFrom;
	POINT?pbase;
	POINT?aptPoly[3];
	float?vecLine[2];
	float?vecLeft[2];
	float?fLength;
	float?th;
	float?ta;

	//?get?from?point
	MoveToEx（hDC?0?0?&pFrom）;

	//?set?to?point
	aptPoly[0].x?=?lpTo->x;
	aptPoly[0].y?=?lpTo->y;

	//?build?the?line?vector
	vecLine[0]?=?（float）?aptPoly[0].x?-?pFrom.x;
	vecLine[1]?=?（float）?aptPoly[0].y?-?pFrom.y;

	//?build?the?arrow?base?vector?-?normal?to?the?line
	vecLeft[0]?=?-vecLine[1];
	vecLeft[1]?=?vecLine[0];

	//?setup?length?parameters
	fLength?=?（float）?sqrt（vecLine[0]?*?vecLine[0]?+?vecLine[1]?*?vecLine[1]）;
	th?=?pA->nWidth?/?（2.0f?*?fLength）;
	ta?=?pA->nWidth?/?（2.0f?*?（tanf（pA->fTheta）?/?2.0f）?*?fLength）;

	//?find?the?base?of?the?arrow
	pbase.x?=?（int）?（aptPoly[0].x?+?-ta?*?vecLine[0]）;
	pbase.y?=?（int）?（aptPoly[0].y?+?-ta?*?vecLine[1]）;

	//?build?the?points?on?the?sides?of?the?arrow
	aptPoly[1].x?=?（int）?（pbase.x?+?th?*?vecLeft[0]）;
	aptPoly[1].y?=?（int）?（pbase.y?+?th?*?vecLeft[1]）;
	aptPoly[2].x?=?（int）?（pbase.x?+?-th?*?vecLeft[0]）;
	aptPoly[2].y?=?（int）?（pbase.y?+?-th?*?vecLeft[1]）;

	MoveToEx（hDC?pFrom.x?pFrom.y?NULL）;

	//?draw?we‘re?fillin‘...
	if（pA->bFill）?{
		LineTo（hDC?aptPoly[0].x?aptPoly[0].y）;
		Polygon（hDC?aptPoly?3）;
	}

	//?...?or?even?jes?chillin‘...
	else?{
		LineTo（hDC?pbase.x?pbase.y）;
		LineTo（hDC?aptPoly[1].x?aptPoly[1].y）;
		LineTo（hDC?aptPoly[0].x?aptPoly[0].y）;
		LineTo（hDC?aptPoly[2].x?aptPoly[2].y）;
		LineTo（hDC?pbase.x?pbase.y）;
		MoveToEx（hDC?aptPoly[0].x?aptPoly[0].y?NULL）;
	}
}

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件????????1831??2002-12-01?14:29??Arrow.cpp
?????文件?????????743??2002-12-01?14:28??Arrow.h
?????文件????????3726??2002-12-01?12:59??ArrowTest.cpp
?????文件????????4664??2002-12-01?14:26??ArrowTest.dsp
?????文件?????????541??2002-12-01?12:59??ArrowTest.dsw
?????文件????????1400??2002-12-01?12:59??ArrowTest.h
?????文件????????8739??2002-12-01?12:59??ArrowTest.rc
?????文件????????1721??2002-12-01?14:29??ChildView.cpp
?????文件????????1267??2002-12-01?12:59??ChildView.h
?????文件????????3286??2002-12-01?12:59??MainFrm.cpp
?????文件????????1744??2002-12-01?12:59??MainFrm.h
?????目錄???????????0??2002-12-01?12:59??res\
?????文件????????1078??2002-12-01?12:59??res\ArrowTest.ico
?????文件?????????401??2002-12-01?12:59??res\ArrowTest.rc2
?????文件?????????718??2002-12-01?12:59??res\Toolbar.bmp
?????文件?????????497??2002-12-01?12:59??Resource.h
?????文件?????????211??2002-12-01?12:59??StdAfx.cpp
?????文件????????1054??2002-12-01?12:59??StdAfx.h