gui__intersectrects.c

uc-gui.rar

/*********************************************************************
*                SEGGER MICROCONTROLLER SYSTEME GmbH                 *
*        Solutions for real time microcontroller applications        *
**********************************************************************
*                                                                    *
*        (c) 2002         SEGGER Microcontroller Systeme GmbH        *
*                                                                    *
*        Internet: www.segger.com    Support:  [e-mail]    *
*                                                                    *
**********************************************************************

**** emWin/GSC Grafical user interface for embedded applications ****
emWin is protected by international copyright laws. Knowledge of the
source code may not be used to write a similar product. This file may
only be used in accordance with a license and should not be re-
distributed in any way. We appreciate your understanding and fairness.
----------------------------------------------------------------------
File        : GUI_IntersectRects.c
Purpose     : Implementation of GUI_IntersectRects
---------------------------END-OF-HEADER------------------------------
*/


#include "GUI_Protected.h"

/*********************************************************************
*
*             Macros
*
********************************************************************
*/

#define MIN(v0,v1) ((v0>v1) ? v1 : v0)
#define MAX(v0,v1) ((v0>v1) ? v0 : v1)

/*********************************************************************
*
*             GUI__IntersectRects
*
**********************************************************************
Purpose:
  Calc intersection of rectangles
Return value:
  1 if they do intersect,
  0 if there is no intersection
Add. info:
  Rectangles are passed as pointers. These pointers need to be valid;
  a NULL pointer may not be passed. There is no check for NULL pointers
  implemented in order to avoid avoid performance penalty.
*/

int GUI__IntersectRects(GUI_RECT* pDest, const GUI_RECT* pr0, const GUI_RECT* pr1) {
  pDest->x0 = MAX (pr0->x0, pr1->x0);
  pDest->y0 = MAX (pr0->y0, pr1->y0);
  pDest->x1 = MIN (pr0->x1, pr1->x1);
  pDest->y1 = MIN (pr0->y1, pr1->y1);
  if (pDest->x1 < pDest->x0)
    return 0;
  if (pDest->y1 < pDest->y0)
    return 0;
  return 1;
}