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

139 lines
4.7 KiB
C

/****************************************************************************
* apps/graphics/traveler/tools/libwld/wld_mergeplanelists.c
* This file contains the logic that concatenates two world plane lists.
*
* 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_merge_planelists
* Description:
* This function concatenates two world plane lists
************************************************************************/
void wld_merge_planelists(rect_head_t * outList, rect_head_t * inList)
{
rect_list_t *inRect, *nextInRect;
rect_list_t *outRect, *prevRect;
/* Initialize the inner plane search loop */
outRect = outList->head;
/* Process every plane in the input plane list */
for (inRect = inList->head; (inRect); inRect = nextInRect)
{
nextInRect = inRect->flink;
/* Search the output plane list to find the location to insert the input
* rectangle. Each is list is maintained in ascending plane order.
*/
for (;
((outRect) && (outRect->d.plane < inRect->d.plane));
outRect = outRect->flink);
/* Add the inRect to the spot found in the list. Check if the inRect
* goes at the one of the ends of the list. */
if (!outRect)
{
/* No rectangle with plane larger than the one to be added was found
* in the list. The inRect goes at the end of the list.
*/
prevRect = outList->tail;
if (!prevRect)
{
/* Special case: The list is empty */
inRect->flink = NULL;
inRect->blink = NULL;
outList->head = inRect;
outList->tail = inRect;
}
else
{
inRect->flink = NULL;
inRect->blink = prevRect;
prevRect->flink = inRect;
outList->tail = inRect;
}
}
else
{
/* The inRect goes just before outRect */
prevRect = outRect->blink;
if (!prevRect)
{
/* Special case: Insert at the head of the list */
inRect->flink = outRect;
inRect->blink = NULL;
outRect->blink = inRect;
outList->head = inRect;
}
else
{
/* Insert in the middle of the list */
inRect->flink = outRect;
inRect->blink = prevRect;
prevRect->flink = inRect;
outRect->blink = inRect;
}
}
/* Set up for the next time through */
outRect = inRect;
}
/* Mark the input list empty */
inList->head = NULL;
inList->tail = NULL;
}