incubator-nuttx/libs/libnx/nxglib/nxglib_nonintersecting.c

117 lines
4.6 KiB
C

/****************************************************************************
* libs/libnx/nxglib/nxglib_nonintersecting.c
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/nx/nxglib.h>
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nxgl_nonintersecting
*
* Description:
* Return the regions of rectangle rect 1 that do not intersect with
* rect2. This may be up to founr rectangles some of which may be
* degenerate (and can be picked off with nxgl_nullrect)
*
****************************************************************************/
void nxgl_nonintersecting(FAR struct nxgl_rect_s result[4],
FAR const struct nxgl_rect_s *rect1,
FAR const struct nxgl_rect_s *rect2)
{
struct nxgl_rect_s intersection;
/* Get the intersection of the two rectangles */
nxgl_rectintersect(&intersection, rect1, rect2);
/* Then return the four rectangles representing the regions NON included
* in the intersection. Some of these rectangles may be invalid (zero
* area), but those can be picked off using nxgl_nullrect()
*
* rect1.pt1
* +-------------------------+
* | rect2.pt1 |
* | int.pt1 |
* | +-------------------------+
* | | | |
* | | | |
* +-------------------------+ |
* | rect1.pt2 |
* | int.pt2 |
* +-------------------------+
* rect2.pt2
* rect1.pt1
* +-------------------------+
* rect2.pt1 |int.pt1 |
* +---------+---------------+ |
* | | | |
* | | | |
* | | |int.pt2 |
* | +---------------+---------+
* | | rect1.pt2
* +-------------------------+
* rect2.pt2
* rect2.pt1
* +-------------------------+
* | rect1.pt1 |
* | int.pt1 |
* | +-------------------------+
* | | | |
* | | | |
* | | | |
* +---------+---------------+ |
* | rect2.pt2 |
* | int.pt2 |
* +-------------------------+
* rect1.pt2
*/
result[NX_TOP_NDX].pt1.x = rect1->pt1.x;
result[NX_TOP_NDX].pt1.y = rect1->pt1.y;
result[NX_TOP_NDX].pt2.x = rect1->pt2.x;
result[NX_TOP_NDX].pt2.y = intersection.pt1.y - 1;
result[NX_BOTTOM_NDX].pt1.x = rect1->pt1.x;
result[NX_BOTTOM_NDX].pt1.y = intersection.pt2.y + 1;
result[NX_BOTTOM_NDX].pt2.x = rect1->pt2.x;
result[NX_BOTTOM_NDX].pt2.y = rect1->pt2.y;
result[NX_LEFT_NDX].pt1.x = rect1->pt1.x;
result[NX_LEFT_NDX].pt1.y = intersection.pt1.y;
result[NX_LEFT_NDX].pt2.x = intersection.pt1.x - 1;
result[NX_LEFT_NDX].pt2.y = intersection.pt2.y;
result[NX_RIGHT_NDX].pt1.x = intersection.pt2.x + 1;
result[NX_RIGHT_NDX].pt1.y = intersection.pt1.y;
result[NX_RIGHT_NDX].pt2.x = rect1->pt2.x;
result[NX_RIGHT_NDX].pt2.y = intersection.pt2.y;
}