nuttx-apps/graphics/traveler/tools/libwld/wld_addplane.c
2016-11-10 12:21:47 -06:00

120 lines
4.1 KiB
C

/****************************************************************************
* apps/graphics/traveler/tools/libwld/wld_addplane.c
* This file contains the logic to add a plane to a 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 "trv_types.h"
#include "wld_plane.h"
/*************************************************************************
* Public Functions
*************************************************************************/
/*************************************************************************
* Name: wld_add_plane
* Description:
* This function adds a plane to a world plane list
************************************************************************/
void wld_add_plane(rect_list_t * newRect, rect_head_t * list)
{
rect_list_t *nextRect, *prevRect;
/* Search the list to find the location to insert the new rectangle. Each
* list is maintained in ascending plane order.
*/
for (nextRect = list->head;
((nextRect) && (nextRect->d.plane < newRect->d.plane));
nextRect = nextRect->flink);
/* Add the newRect to the spot found in the list. Check if the newRect goes
* at the end of the list.
*/
if (!nextRect)
{
/* No rectangle with plane larger than the one to be added was found in
* the list. The newRect goes at the end of the list.
*/
prevRect = list->tail;
if (!prevRect)
{
/* Special case: The list is empty */
newRect->flink = NULL;
newRect->blink = NULL;
list->head = newRect;
list->tail = newRect;
}
else
{
newRect->flink = NULL;
newRect->blink = prevRect;
prevRect->flink = newRect;
list->tail = newRect;
}
}
else
{
/* The newRect goes just before nextRect */
prevRect = nextRect->blink;
if (!prevRect)
{
/* Special case: Insert at the head of the list */
newRect->flink = nextRect;
newRect->blink = NULL;
nextRect->blink = newRect;
list->head = newRect;
}
else
{
/* Insert in the middle of the list */
newRect->flink = nextRect;
newRect->blink = prevRect;
prevRect->flink = newRect;
nextRect->blink = newRect;
}
}
}