nuttx-apps/graphics/traveler/tools/libwld/wld_findplane.c
2016-11-11 07:04:01 -06:00

85 lines
3.3 KiB
C

/****************************************************************************
* apps/graphics/traveler/tools/libwld/wld_findplane.c
* This file contains the logic to find the plane at the specified location
* in the world plane list
*
* Copyright (C) 2016 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/*************************************************************************
* Included files
*************************************************************************/
#include <stdio.h>
#include "wld_plane.h"
/*************************************************************************
* Public Functions
*************************************************************************/
/*************************************************************************
* Name: wld_find_plane
* Description:
* This function finds the plane at the specified point in the world plane
* list
************************************************************************/
rect_list_t *wld_find_plane(wld_coord_t h, wld_coord_t v, wld_coord_t plane,
rect_head_t * list)
{
rect_list_t *rect;
/* Search until we find the first occurrence of a rectangle in the specified
* plane.
*/
for (rect = list->head;
((rect) && (rect->d.plane < plane)); rect = rect->flink);
/* Then look at every occurrence of rectangles at this plane or until a
* rectangle containing the specified point is found.
*/
for (; ((rect) && (rect->d.plane == plane)); rect = rect->flink)
{
/* There is another rectangle in this plane. Check if the point lies
* within the rectangle.
*/
if ((h >= rect->d.hstart) && (h <= rect->d.hend)
&& (v >= rect->d.vstart) && (v <= rect->d.vend))
return rect;
}
return NULL;
}