include/media/v4l2-rect.h

   1 /*
   2  * v4l2-rect.h - v4l2_rect helper functions
   3  *
   4  * Copyright 2014 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
   5  *
   6  * This program is free software; you may redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2 of the License.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  11  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  12  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  13  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  14  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  15  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  16  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  17  * SOFTWARE.
  18  */
  19
  20 #ifndef _V4L2_RECT_H_
  21 #define _V4L2_RECT_H_
  22
  23 #include <linux/videodev2.h>
  24
  25 /**
  26  * v4l2_rect_set_size_to() - copy the width/height values.
  27  * @r: rect whose width and height fields will be set
  28  * @size: rect containing the width and height fields you need.
  29  */
  30 static inline void v4l2_rect_set_size_to(struct v4l2_rect *r,
  31                                          const struct v4l2_rect *size)
  32 {
  33         r->width = size->width;
  34         r->height = size->height;
  35 }
  36
  37 /**
  38  * v4l2_rect_set_min_size() - width and height of r should be >= min_size.
  39  * @r: rect whose width and height will be modified
  40  * @min_size: rect containing the minimal width and height
  41  */
  42 static inline void v4l2_rect_set_min_size(struct v4l2_rect *r,
  43                                           const struct v4l2_rect *min_size)
  44 {
  45         if (r->width < min_size->width)
  46                 r->width = min_size->width;
  47         if (r->height < min_size->height)
  48                 r->height = min_size->height;
  49 }
  50
  51 /**
  52  * v4l2_rect_set_max_size() - width and height of r should be <= max_size
  53  * @r: rect whose width and height will be modified
  54  * @max_size: rect containing the maximum width and height
  55  */
  56 static inline void v4l2_rect_set_max_size(struct v4l2_rect *r,
  57                                           const struct v4l2_rect *max_size)
  58 {
  59         if (r->width > max_size->width)
  60                 r->width = max_size->width;
  61         if (r->height > max_size->height)
  62                 r->height = max_size->height;
  63 }
  64
  65 /**
  66  * v4l2_rect_map_inside()- r should be inside boundary.
  67  * @r: rect that will be modified
  68  * @boundary: rect containing the boundary for @r
  69  */
  70 static inline void v4l2_rect_map_inside(struct v4l2_rect *r,
  71                                         const struct v4l2_rect *boundary)
  72 {
  73         v4l2_rect_set_max_size(r, boundary);
  74         if (r->left < boundary->left)
  75                 r->left = boundary->left;
  76         if (r->top < boundary->top)
  77                 r->top = boundary->top;
  78         if (r->left + r->width > boundary->width)
  79                 r->left = boundary->width - r->width;
  80         if (r->top + r->height > boundary->height)
  81                 r->top = boundary->height - r->height;
  82 }
  83
  84 /**
  85  * v4l2_rect_same_size() - return true if r1 has the same size as r2
  86  * @r1: rectangle.
  87  * @r2: rectangle.
  88  *
  89  * Return true if both rectangles have the same size.
  90  */
  91 static inline bool v4l2_rect_same_size(const struct v4l2_rect *r1,
  92                                        const struct v4l2_rect *r2)
  93 {
  94         return r1->width == r2->width && r1->height == r2->height;
  95 }
  96
  97 /**
  98  * v4l2_rect_intersect() - calculate the intersection of two rects.
  99  * @r: intersection of @r1 and @r2.
 100  * @r1: rectangle.
 101  * @r2: rectangle.
 102  */
 103 static inline void v4l2_rect_intersect(struct v4l2_rect *r,
 104                                        const struct v4l2_rect *r1,
 105                                        const struct v4l2_rect *r2)
 106 {
 107         int right, bottom;
 108
 109         r->top = max(r1->top, r2->top);
 110         r->left = max(r1->left, r2->left);
 111         bottom = min(r1->top + r1->height, r2->top + r2->height);
 112         right = min(r1->left + r1->width, r2->left + r2->width);
 113         r->height = max(0, bottom - r->top);
 114         r->width = max(0, right - r->left);
 115 }
 116
 117 /**
 118  * v4l2_rect_scale() - scale rect r by to/from
 119  * @r: rect to be scaled.
 120  * @from: from rectangle.
 121  * @to: to rectangle.
 122  *
 123  * This scales rectangle @r horizontally by @to->width / @from->width and
 124  * vertically by @to->height / @from->height.
 125  *
 126  * Typically @r is a rectangle inside @from and you want the rectangle as
 127  * it would appear after scaling @from to @to. So the resulting @r will
 128  * be the scaled rectangle inside @to.
 129  */
 130 static inline void v4l2_rect_scale(struct v4l2_rect *r,
 131                                    const struct v4l2_rect *from,
 132                                    const struct v4l2_rect *to)
 133 {
 134         if (from->width == 0 || from->height == 0) {
 135                 r->left = r->top = r->width = r->height = 0;
 136                 return;
 137         }
 138         r->left = (((r->left - from->left) * to->width) / from->width) & ~1;
 139         r->width = ((r->width * to->width) / from->width) & ~1;
 140         r->top = ((r->top - from->top) * to->height) / from->height;
 141         r->height = (r->height * to->height) / from->height;
 142 }
 143
 144 /**
 145  * v4l2_rect_overlap() - do r1 and r2 overlap?
 146  * @r1: rectangle.
 147  * @r2: rectangle.
 148  *
 149  * Returns true if @r1 and @r2 overlap.
 150  */
 151 static inline bool v4l2_rect_overlap(const struct v4l2_rect *r1,
 152                                      const struct v4l2_rect *r2)
 153 {
 154         /*
 155          * IF the left side of r1 is to the right of the right side of r2 OR
 156          *    the left side of r2 is to the right of the right side of r1 THEN
 157          * they do not overlap.
 158          */
 159         if (r1->left >= r2->left + r2->width ||
 160             r2->left >= r1->left + r1->width)
 161                 return false;
 162         /*
 163          * IF the top side of r1 is below the bottom of r2 OR
 164          *    the top side of r2 is below the bottom of r1 THEN
 165          * they do not overlap.
 166          */
 167         if (r1->top >= r2->top + r2->height ||
 168             r2->top >= r1->top + r1->height)
 169                 return false;
 170         return true;
 171 }
 172
 173 #endif