classify/fpoint.h

/******************************************************************************
 **	Filename:    fpoint.h
 **	Purpose:     Abstract data type for 2D points (floating point coords)
 **	Author:      Dan Johnson
 **	History:     Thu Apr 12 10:50:01 1990, DSJ, Created.
 **
 **	(c) Copyright Hewlett-Packard Company, 1988.
 ** Licensed under the Apache License, Version 2.0 (the "License");
 ** you may not use this file except in compliance with the License.
 ** You may obtain a copy of the License at
 ** http://www.apache.org/licenses/LICENSE-2.0
 ** Unless required by applicable law or agreed to in writing, software
 ** distributed under the License is distributed on an "AS IS" BASIS,
 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 ** See the License for the specific language governing permissions and
 ** limitations under the License.
 ******************************************************************************/
#ifndef   FPOINT_H
#define   FPOINT_H

/**----------------------------------------------------------------------------
          Include Files and Type Defines
----------------------------------------------------------------------------**/
#include "general.h"
#include <stdio.h>
#include <math.h>

/* define data structure to hold 2D points or vectors using floating point */
typedef struct
{
  FLOAT32 x, y;
} FPOINT;
typedef FPOINT FVECTOR;

/**----------------------------------------------------------------------------
            Macros
----------------------------------------------------------------------------**/
/* macros for manipulating simple point data structures */
#define Xof(P)      ( (P).x )
#define Yof(P)      ( (P).y )
#define XofP(P)     ((P)->x)
#define YofP(P)     ((P)->y)
#define FillPoint(P,X,Y)  ( Xof(P) = (X), Yof(P) = (Y) )
#define CopyPoint(A,B)    ( Xof(B) = Xof(A), Yof(B) = Yof(A) )

/* macros for computing miscellaneous functions of 2 points */
#define XDelta(A,B)   ( Xof(B) - Xof(A) )
#define YDelta(A,B)   ( Yof(B) - Yof(A) )
#define DistanceBetween(A,B)						\
(sqrt ((double) (XDelta(A,B) * XDelta(A,B) + YDelta(A,B) * YDelta(A,B))))

#define SlopeFrom(A,B)    ( YDelta(A,B) / XDelta(A,B) )
#define AngleFrom(A,B)		( atan2((double) YDelta(A,B),		\
					(double) XDelta(A,B) ) )

#define XIntersectionOf(A,B,X)  ( SlopeFrom(A,B) * ((X) - Xof(A)) + Yof(A))

/*-------------------------------------------------------------------------
        Public Function Prototypes
---------------------------------------------------------------------------*/
FLOAT32 NormalizedAngleFrom(FPOINT *Point1, FPOINT *Point2, FLOAT32 FullScale); 
#endif