forked from len0rd/rockbox
Add rectangle utility functions
Change-Id: Iebcddfc36733aab5131d2fcb9fd8c8a32eff84b8
This commit is contained in:
Aidan MacDonald
parent
52ca658069
commit
7819a06d74
3 changed files with 217 additions and 0 deletions
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@ -234,6 +234,7 @@ common/pathfuncs.c
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common/fdprintf.c
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common/linked_list.c
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common/rb_namespace.c
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common/rectangle.c
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common/strcasecmp.c
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common/strcasestr.c
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common/strnatcmp.c
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141
firmware/common/rectangle.c
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141
firmware/common/rectangle.c
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@ -0,0 +1,141 @@
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/***************************************************************************
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* __________ __ ___.
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* Open \______ \ ____ ____ | | _\_ |__ _______ ___
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* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
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* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
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* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
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* \/ \/ \/ \/ \/
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* $Id$
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*
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* Copyright (C) 2022 Aidan MacDonald
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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* KIND, either express or implied.
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*
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****************************************************************************/
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#include "rectangle.h"
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#include "system.h"
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bool rect_contains(const struct rectangle *ra, const struct rectangle *rb)
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{
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return ra->x <= rb->x && rb->x + rb->w < ra->x + ra->w &&
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ra->y <= rb->y && rb->y + rb->h < ra->y + ra->h;
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}
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bool rect_overlap(const struct rectangle *ra, const struct rectangle *rb)
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{
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return ra->x + ra->w > rb->x && rb->x + rb->w > ra->x &&
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ra->y + ra->h > rb->y && rb->y + rb->h > ra->y;
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}
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bool rect_intersect(const struct rectangle *ra, const struct rectangle *rb,
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struct rectangle *r_out)
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{
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if (!rect_valid(ra) || !rect_valid(rb))
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return false;
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int x = MAX(ra->x, rb->x);
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int y = MAX(ra->y, rb->y);
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int w = MIN(ra->x + ra->w, rb->x + rb->w) - x;
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int h = MIN(ra->y + ra->h, rb->y + rb->h) - y;
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r_out->x = x;
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r_out->y = y;
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r_out->w = w;
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r_out->h = h;
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return w > 0 && h > 0;
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}
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void rect_union(const struct rectangle *ra, const struct rectangle *rb,
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struct rectangle *r_out)
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{
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if (!rect_valid(ra)) {
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*r_out = *rb;
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} else if (!rect_valid(rb)) {
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*r_out = *ra;
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} else {
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int x = MIN(ra->x, rb->x);
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int y = MIN(ra->y, rb->y);
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int w = MAX(ra->x + ra->w, rb->x + rb->w) - x;
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int h = MAX(ra->y + ra->h, rb->y + rb->h) - y;
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r_out->x = x;
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r_out->y = y;
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r_out->w = w;
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r_out->h = h;
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}
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}
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int rect_difference(const struct rectangle *rect,
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const struct rectangle *rsub,
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struct rectangle rects_out[4])
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{
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if (!rect_valid(rect) || !rect_valid(rsub)) {
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rects_out[0] = *rect;
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return 1;
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}
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int x0 = MAX(rect->x, rsub->x);
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int y0 = MAX(rect->y, rsub->y);
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int x1 = MIN(rect->x + rect->w, rsub->x + rsub->w);
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int y1 = MIN(rect->y + rect->h, rsub->y + rsub->h);
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/* no intersection */
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if (x1 - x0 <= 0 || y1 - y0 <= 0) {
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rects_out[0] = *rect;
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return 1;
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}
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/* rect
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* +-------------+
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* | . 2 . |
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* | +-----+ |
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* | 0 |rsub | 1 |
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* | +-----+ |
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* | . 3 . |
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* +-------------+
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*/
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int n = 0;
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if (rect->x < x0) {
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rects_out[n].x = rect->x;
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rects_out[n].y = rect->y;
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rects_out[n].w = x0 - rect->x;
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rects_out[n].h = rect->h;
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n++;
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}
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if (x1 < rect->x + rect->w) {
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rects_out[n].x = x1;
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rects_out[n].y = rect->y;
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rects_out[n].w = rect->x + rect->w - x1;
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rects_out[n].h = rect->h;
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n++;
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}
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if (rect->y < y0) {
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rects_out[n].x = x0;
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rects_out[n].y = rect->y;
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rects_out[n].w = x1 - x0;
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rects_out[n].h = y0 - rect->y;
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n++;
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}
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if (y1 < rect->y + rect->h) {
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rects_out[n].x = x0;
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rects_out[n].y = y1;
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rects_out[n].w = x1 - x0;
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rects_out[n].h = rect->y + rect->h - y1;
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n++;
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}
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return n;
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}
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75
firmware/export/rectangle.h
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75
firmware/export/rectangle.h
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@ -0,0 +1,75 @@
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/***************************************************************************
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* __________ __ ___.
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* Open \______ \ ____ ____ | | _\_ |__ _______ ___
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* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
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* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
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* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
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* \/ \/ \/ \/ \/
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* $Id$
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*
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* Copyright (C) 2022 Aidan MacDonald
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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* KIND, either express or implied.
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*
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****************************************************************************/
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#ifndef _RECTANGLE_H_
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#define _RECTANGLE_H_
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#include <stdbool.h>
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struct rectangle
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{
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int x, y, w, h;
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};
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/** Returns true if the rectangle is non-degenerate (positive width/height). */
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static inline bool rect_valid(const struct rectangle *r)
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{
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return r->w > 0 && r->h > 0;
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}
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/** Returns true if ra contains rb. */
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bool rect_contains(const struct rectangle *ra, const struct rectangle *rb);
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/** Returns true if ra and rb overlap. */
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bool rect_overlap(const struct rectangle *ra, const struct rectangle *rb);
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/**
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* Computes the biggest rectangle contained in ra and rb.
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* Returns true if the intersection exists, and writes it to r_out.
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*
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* Returns false if there is no intersection, or either input
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* rectangle is degenerate. In this case r_out may be uninitialized.
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*/
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bool rect_intersect(const struct rectangle *ra, const struct rectangle *rb,
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struct rectangle *r_out);
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/**
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* Computes the smallest rectangle containing both ra and rb.
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*
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* If one input is degenerate, and the other is not, the output is a
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* copy of the non-degenerate input. If both inputs are degenerate,
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* then the output is degenerate but is otherwise unspecified.
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*/
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void rect_union(const struct rectangle *ra, const struct rectangle *rb,
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struct rectangle *r_out);
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/**
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* Computes the result of subtracting 'rsub' from 'rect'. Up to four
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* non-overlapping output rectangles will written to 'rects_out'; the
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* return value is the number of rectangles written.
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*
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* If 'rsub' does not overlap 'rect', or if either of the inputs are
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* degenerate, the output is a single rectangle: a copy of 'rect'.
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*/
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int rect_difference(const struct rectangle *rect,
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const struct rectangle *rsub,
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struct rectangle rects_out[4]);
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#endif /* _RECTANGLE_H_ */
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