root/lib/widget/rect.c

/*   */

DEFINITIONS

1. rect_new
2. rect_init
3. rect_move
4. rect_resize
5. rect_grow
6. rect_intersect
7. rect_union
8. rects_are_overlapped
9. rects_are_equal

   1 /* Rectangular class for Midnight Commander widgets
   2 
   3    Copyright (C) 2020-2025
   4    The Free Software Foundation, Inc.
   5 
   6    Written by:
   7    Andrew Borodin <aborodin@vmail.ru>, 2020-2022
   8 
   9    This file is part of the Midnight Commander.
  10 
  11    The Midnight Commander is free software: you can redistribute it
  12    and/or modify it under the terms of the GNU General Public License as
  13    published by the Free Software Foundation, either version 3 of the License,
  14    or (at your option) any later version.
  15 
  16    The Midnight Commander is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19    GNU General Public License for more details.
  20 
  21    You should have received a copy of the GNU General Public License
  22    along with this program.  If not, see <https://www.gnu.org/licenses/>.
  23  */
  24 
  25 /** \file widget-common.c
  26  *  \brief Source: shared stuff of widgets
  27  */
  28 
  29 #include <config.h>
  30 
  31 #include <stdlib.h>
  32 
  33 #include "lib/global.h"
  34 
  35 #include "rect.h"
  36 
  37 /*** global variables ****************************************************************************/
  38 
  39 /*** file scope macro definitions ****************************************************************/
  40 
  41 /*** file scope type declarations ****************************************************************/
  42 
  43 /*** file scope variables ************************************************************************/
  44 
  45 /*** file scope functions ************************************************************************/
  46 
  47 /* --------------------------------------------------------------------------------------------- */
  48 /*** public functions ****************************************************************************/
  49 /* --------------------------------------------------------------------------------------------- */
  50 /**
  51  * Create new WRect object.
  52  *
  53  * @param y y-coordinate of left-up corner
  54  * @param x x-coordinate of left-up corner
  55  * @param lines height
  56  * @param cols width
  57  *
  58  * @return newly allocated WRect object.
  59  */
  60 
  61 WRect *
  62 rect_new (int y, int x, int lines, int cols)
     /*   */
  63 {
  64     WRect *r;
  65 
  66     r = g_try_new (WRect, 1);
  67 
  68     if (r != NULL)
  69         rect_init (r, y, x, lines, cols);
  70 
  71     return r;
  72 }
  73 
  74 /* --------------------------------------------------------------------------------------------- */
  75 /**
  76  * Initialize WRect object.
  77  *
  78  * @param r WRect object
  79  * @param y y-coordinate of left-up corner
  80  * @param x x-coordinate of left-up corner
  81  * @param lines height
  82  * @param cols width
  83  */
  84 
  85 void
  86 rect_init (WRect *r, int y, int x, int lines, int cols)
     /*   */
  87 {
  88     r->y = y;
  89     r->x = x;
  90     r->lines = lines;
  91     r->cols = cols;
  92 }
  93 
  94 /* --------------------------------------------------------------------------------------------- */
  95 /**
  96  * Change position of rectangle area.
  97  *
  98  * @param r WRect object
  99  * @param dy y-shift of left-up corner
 100  * @param dx x-shift of left-up corner
 101  */
 102 
 103 void
 104 rect_move (WRect *r, int dy, int dx)
     /*   */
 105 {
 106     r->y += dy;
 107     r->x += dx;
 108 }
 109 
 110 /* --------------------------------------------------------------------------------------------- */
 111 /**
 112  * Change size of rectangle area keeping it's position.
 113  *
 114  * @param r WRect object
 115  * @param dl change size value of height
 116  * @param dc change size value of width
 117  */
 118 
 119 void
 120 rect_resize (WRect *r, int dl, int dc)
     /*   */
 121 {
 122     r->lines += dl;
 123     r->cols += dc;
 124 }
 125 
 126 /* --------------------------------------------------------------------------------------------- */
 127 /**
 128  * Change size of rectangle area keeping it's center.
 129  *
 130  * @param r WRect object
 131  * @param dl change size value of y-coordinate and height
 132  *           Positive value means move up and increase height.
 133  *           Negative value means move down and decrease height.
 134  * @param dc change size value of x-coordinate and width
 135  *           Positive value means move left and increase width.
 136  *           Negative value means move right and decrease width.
 137  */
 138 
 139 void
 140 rect_grow (WRect *r, int dl, int dc)
     /*   */
 141 {
 142     r->y -= dl;
 143     r->x -= dc;
 144     r->lines += dl * 2;
 145     r->cols += dc * 2;
 146 }
 147 
 148 /* --------------------------------------------------------------------------------------------- */
 149 /**
 150  * Calculates the intersection of two rectangle areas.
 151  * The resulting rectangle is the largest rectangle which contains intersection of rectangle areas.
 152  *
 153  * @param r first WRect object
 154  * @param r1 second WRect object
 155  *
 156  * The resulting rectangle is stored in r.
 157  */
 158 
 159 void
 160 rect_intersect (WRect *r, const WRect *r1)
     /*   */
 161 {
 162     int y, x;
 163     int y1, x1;
 164 
 165     // right-down corners
 166     y = r->y + r->lines;
 167     x = r->x + r->cols;
 168     y1 = r1->y + r1->lines;
 169     x1 = r1->x + r1->cols;
 170 
 171     // right-down corner of intersection
 172     y = MIN (y, y1);
 173     x = MIN (x, x1);
 174 
 175     // left-up corner of intersection
 176     r->y = MAX (r->y, r1->y);
 177     r->x = MAX (r->x, r1->x);
 178 
 179     // intersection sizes
 180     r->lines = y - r->y;
 181     r->cols = x - r->x;
 182 }
 183 
 184 /* --------------------------------------------------------------------------------------------- */
 185 /**
 186  * Calculates the union of two rectangle areas.
 187  * The resulting rectangle is the largest rectangle which contains both rectangle areas.
 188  *
 189  * @param r first WRect object
 190  * @param r1 second WRect object
 191  *
 192  * The resulting rectangle is stored in r.
 193  */
 194 
 195 void
 196 rect_union (WRect *r, const WRect *r1)
     /*   */
 197 {
 198     int x, y;
 199     int x1, y1;
 200 
 201     // right-down corners
 202     y = r->y + r->lines;
 203     x = r->x + r->cols;
 204     y1 = r1->y + r1->lines;
 205     x1 = r1->x + r1->cols;
 206 
 207     // right-down corner of union
 208     y = MAX (y, y1);
 209     x = MAX (x, x1);
 210 
 211     // left-up corner of union
 212     r->y = MIN (r->y, r1->y);
 213     r->x = MIN (r->x, r1->x);
 214 
 215     // union sizes
 216     r->lines = y - r->y;
 217     r->cols = x - r->x;
 218 }
 219 
 220 /* --------------------------------------------------------------------------------------------- */
 221 /**
 222  * Check whether two rectangle areas are overlapped or not.
 223  *
 224  * @param r1 WRect object
 225  * @param r2 WRect object
 226  *
 227  * @return TRUE if rectangle areas are overlapped, FALSE otherwise.
 228  */
 229 
 230 gboolean
 231 rects_are_overlapped (const WRect *r1, const WRect *r2)
     /*   */
 232 {
 233     return !((r2->x >= r1->x + r1->cols) || (r1->x >= r2->x + r2->cols)
 234              || (r2->y >= r1->y + r1->lines) || (r1->y >= r2->y + r2->lines));
 235 }
 236 
 237 /* --------------------------------------------------------------------------------------------- */
 238 /**
 239  * Check whether two rectangle areas are equal or not.
 240  *
 241  * @param r1 WRect object
 242  * @param r2 WRect object
 243  *
 244  * @return TRUE if rectangle areas are equal, FALSE otherwise.
 245  */
 246 
 247 gboolean
 248 rects_are_equal (const WRect *r1, const WRect *r2)
     /*   */
 249 {
 250     return (r1->y == r2->y && r1->x == r2->x && r1->lines == r2->lines && r1->cols == r2->cols);
 251 }
 252 
 253 /* --------------------------------------------------------------------------------------------- */

/*   */