1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * v4l2-rect.h - v4l2_rect helper functions
4  *
5  * Copyright 2014 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
6  */
7 
8 #ifndef _V4L2_RECT_H_
9 #define _V4L2_RECT_H_
10 
11 #include <linux/videodev2.h>
12 
13 /**
14  * v4l2_rect_set_size_to() - copy the width/height values.
15  * @r: rect whose width and height fields will be set
16  * @size: rect containing the width and height fields you need.
17  */
v4l2_rect_set_size_to(struct v4l2_rect * r,const struct v4l2_rect * size)18 static inline void v4l2_rect_set_size_to(struct v4l2_rect *r,
19 					 const struct v4l2_rect *size)
20 {
21 	r->width = size->width;
22 	r->height = size->height;
23 }
24 
25 /**
26  * v4l2_rect_set_min_size() - width and height of r should be >= min_size.
27  * @r: rect whose width and height will be modified
28  * @min_size: rect containing the minimal width and height
29  */
v4l2_rect_set_min_size(struct v4l2_rect * r,const struct v4l2_rect * min_size)30 static inline void v4l2_rect_set_min_size(struct v4l2_rect *r,
31 					  const struct v4l2_rect *min_size)
32 {
33 	if (r->width < min_size->width)
34 		r->width = min_size->width;
35 	if (r->height < min_size->height)
36 		r->height = min_size->height;
37 }
38 
39 /**
40  * v4l2_rect_set_max_size() - width and height of r should be <= max_size
41  * @r: rect whose width and height will be modified
42  * @max_size: rect containing the maximum width and height
43  */
v4l2_rect_set_max_size(struct v4l2_rect * r,const struct v4l2_rect * max_size)44 static inline void v4l2_rect_set_max_size(struct v4l2_rect *r,
45 					  const struct v4l2_rect *max_size)
46 {
47 	if (r->width > max_size->width)
48 		r->width = max_size->width;
49 	if (r->height > max_size->height)
50 		r->height = max_size->height;
51 }
52 
53 /**
54  * v4l2_rect_map_inside()- r should be inside boundary.
55  * @r: rect that will be modified
56  * @boundary: rect containing the boundary for @r
57  */
v4l2_rect_map_inside(struct v4l2_rect * r,const struct v4l2_rect * boundary)58 static inline void v4l2_rect_map_inside(struct v4l2_rect *r,
59 					const struct v4l2_rect *boundary)
60 {
61 	v4l2_rect_set_max_size(r, boundary);
62 	if (r->left < boundary->left)
63 		r->left = boundary->left;
64 	if (r->top < boundary->top)
65 		r->top = boundary->top;
66 	if (r->left + r->width > boundary->left + boundary->width)
67 		r->left = boundary->left + boundary->width - r->width;
68 	if (r->top + r->height > boundary->top + boundary->height)
69 		r->top = boundary->top + boundary->height - r->height;
70 }
71 
72 /**
73  * v4l2_rect_same_size() - return true if r1 has the same size as r2
74  * @r1: rectangle.
75  * @r2: rectangle.
76  *
77  * Return true if both rectangles have the same size.
78  */
v4l2_rect_same_size(const struct v4l2_rect * r1,const struct v4l2_rect * r2)79 static inline bool v4l2_rect_same_size(const struct v4l2_rect *r1,
80 				       const struct v4l2_rect *r2)
81 {
82 	return r1->width == r2->width && r1->height == r2->height;
83 }
84 
85 /**
86  * v4l2_rect_intersect() - calculate the intersection of two rects.
87  * @r: intersection of @r1 and @r2.
88  * @r1: rectangle.
89  * @r2: rectangle.
90  */
v4l2_rect_intersect(struct v4l2_rect * r,const struct v4l2_rect * r1,const struct v4l2_rect * r2)91 static inline void v4l2_rect_intersect(struct v4l2_rect *r,
92 				       const struct v4l2_rect *r1,
93 				       const struct v4l2_rect *r2)
94 {
95 	int right, bottom;
96 
97 	r->top = max(r1->top, r2->top);
98 	r->left = max(r1->left, r2->left);
99 	bottom = min(r1->top + r1->height, r2->top + r2->height);
100 	right = min(r1->left + r1->width, r2->left + r2->width);
101 	r->height = max(0, bottom - r->top);
102 	r->width = max(0, right - r->left);
103 }
104 
105 /**
106  * v4l2_rect_scale() - scale rect r by to/from
107  * @r: rect to be scaled.
108  * @from: from rectangle.
109  * @to: to rectangle.
110  *
111  * This scales rectangle @r horizontally by @to->width / @from->width and
112  * vertically by @to->height / @from->height.
113  *
114  * Typically @r is a rectangle inside @from and you want the rectangle as
115  * it would appear after scaling @from to @to. So the resulting @r will
116  * be the scaled rectangle inside @to.
117  */
v4l2_rect_scale(struct v4l2_rect * r,const struct v4l2_rect * from,const struct v4l2_rect * to)118 static inline void v4l2_rect_scale(struct v4l2_rect *r,
119 				   const struct v4l2_rect *from,
120 				   const struct v4l2_rect *to)
121 {
122 	if (from->width == 0 || from->height == 0) {
123 		r->left = r->top = r->width = r->height = 0;
124 		return;
125 	}
126 	r->left = (((r->left - from->left) * to->width) / from->width) & ~1;
127 	r->width = ((r->width * to->width) / from->width) & ~1;
128 	r->top = ((r->top - from->top) * to->height) / from->height;
129 	r->height = (r->height * to->height) / from->height;
130 }
131 
132 /**
133  * v4l2_rect_overlap() - do r1 and r2 overlap?
134  * @r1: rectangle.
135  * @r2: rectangle.
136  *
137  * Returns true if @r1 and @r2 overlap.
138  */
v4l2_rect_overlap(const struct v4l2_rect * r1,const struct v4l2_rect * r2)139 static inline bool v4l2_rect_overlap(const struct v4l2_rect *r1,
140 				     const struct v4l2_rect *r2)
141 {
142 	/*
143 	 * IF the left side of r1 is to the right of the right side of r2 OR
144 	 *    the left side of r2 is to the right of the right side of r1 THEN
145 	 * they do not overlap.
146 	 */
147 	if (r1->left >= r2->left + r2->width ||
148 	    r2->left >= r1->left + r1->width)
149 		return false;
150 	/*
151 	 * IF the top side of r1 is below the bottom of r2 OR
152 	 *    the top side of r2 is below the bottom of r1 THEN
153 	 * they do not overlap.
154 	 */
155 	if (r1->top >= r2->top + r2->height ||
156 	    r2->top >= r1->top + r1->height)
157 		return false;
158 	return true;
159 }
160 
161 #endif
162