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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2022 Aidan MacDonald
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#ifndef _RECTANGLE_H_
#define _RECTANGLE_H_
#include <stdbool.h>
struct rectangle
{
int x, y, w, h;
};
/** Returns true if the rectangle is non-degenerate (positive width/height). */
static inline bool rect_valid(const struct rectangle *r)
{
return r->w > 0 && r->h > 0;
}
/** Returns true if ra contains rb. */
bool rect_contains(const struct rectangle *ra, const struct rectangle *rb);
/** Returns true if ra and rb overlap. */
bool rect_overlap(const struct rectangle *ra, const struct rectangle *rb);
/**
* Computes the biggest rectangle contained in ra and rb.
* Returns true if the intersection exists, and writes it to r_out.
*
* Returns false if there is no intersection, or either input
* rectangle is degenerate. In this case r_out may be uninitialized.
*/
bool rect_intersect(const struct rectangle *ra, const struct rectangle *rb,
struct rectangle *r_out);
/**
* Computes the smallest rectangle containing both ra and rb.
*
* If one input is degenerate, and the other is not, the output is a
* copy of the non-degenerate input. If both inputs are degenerate,
* then the output is degenerate but is otherwise unspecified.
*/
void rect_union(const struct rectangle *ra, const struct rectangle *rb,
struct rectangle *r_out);
/**
* Computes the result of subtracting 'rsub' from 'rect'. Up to four
* non-overlapping output rectangles will written to 'rects_out'; the
* return value is the number of rectangles written.
*
* If 'rsub' does not overlap 'rect', or if either of the inputs are
* degenerate, the output is a single rectangle: a copy of 'rect'.
*/
int rect_difference(const struct rectangle *rect,
const struct rectangle *rsub,
struct rectangle rects_out[4]);
#endif /* _RECTANGLE_H_ */
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