lib/widget/rect.c

   1 /* Rectangular class for Midnight Commander widgets
   2
   3    Copyright (C) 2020-2024
   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 <http://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 /* --------------------------------------------------------------------------------------------- */