usr.bin/window/wwupdate.c

   1 /*
   2  * Copyright (c) 1983, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * Edward Wang at The University of California, Berkeley.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by the University of
  19  *      California, Berkeley and its contributors.
  20  * 4. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  */
  36
  37 #ifndef lint
  38 static char sccsid[] = "@(#)wwupdate.c  8.1 (Berkeley) 6/6/93";
  39 static char rcsid[] =
  40   "$FreeBSD: src/usr.bin/window/wwupdate.c,v 1.1.1.1.14.1 2001/05/17 09:45:02 obrien Exp $";
  41 #endif /* not lint */
  42
  43 #include "ww.h"
  44 #include "tt.h"
  45
  46 wwupdate1(top, bot)
  47 {
  48         int i;
  49         register j;
  50         char *touched;
  51         struct ww_update *upd;
  52         char check_clreos = 0;
  53         int scan_top, scan_bot;
  54
  55         wwnupdate++;
  56         {
  57                 register char *t1 = wwtouched + top, *t2 = wwtouched + bot;
  58                 register n;
  59
  60                 while (!*t1++)
  61                         if (t1 == t2)
  62                                 return;
  63                 while (!*--t2)
  64                         ;
  65                 scan_top = top = t1 - wwtouched - 1;
  66                 scan_bot = bot = t2 - wwtouched + 1;
  67                 if (scan_bot - scan_top > 1 &&
  68                     (tt.tt_clreos != 0 || tt.tt_clear != 0)) {
  69                         int st = tt.tt_clreos != 0 ? scan_top : 0;
  70
  71                         /*
  72                          * t1 is one past the first touched row,
  73                          * t2 is on the last touched row.
  74                          */
  75                         for (t1--, n = 1; t1 < t2;)
  76                                 if (*t1++)
  77                                         n++;
  78                         /*
  79                          * If we can't clreos then we try for clearing
  80                          * the whole screen.
  81                          */
  82                         if (check_clreos = n * 10 > (wwnrow - st) * 9) {
  83                                 scan_top = st;
  84                                 scan_bot = wwnrow;
  85                         }
  86                 }
  87         }
  88         if (tt.tt_clreol == 0 && !check_clreos)
  89                 goto simple;
  90         for (i = scan_top, touched = &wwtouched[i], upd = &wwupd[i];
  91              i < scan_bot;
  92              i++, touched++, upd++) {
  93                 register gain = 0;
  94                 register best_gain = 0;
  95                 register best_col;
  96                 register union ww_char *ns, *os;
  97
  98                 if (wwinterrupt())
  99                         return;
 100                 if (!check_clreos && !*touched)
 101                         continue;
 102                 wwnupdscan++;
 103                 j = wwncol;
 104                 ns = &wwns[i][j];
 105                 os = &wwos[i][j];
 106                 while (--j >= 0) {
 107                         /*
 108                          * The cost of clearing is:
 109                          *      ncol - nblank + X
 110                          * The cost of straight update is, more or less:
 111                          *      ncol - nsame
 112                          * We clear if  nblank - nsame > X
 113                          * X is the clreol overhead.
 114                          * So we make gain = nblank - nsame.
 115                          */
 116                         if ((--ns)->c_w == (--os)->c_w)
 117                                 gain--;
 118                         else
 119                                 best_gain--;
 120                         if (ns->c_w == ' ')
 121                                 gain++;
 122                         if (gain > best_gain) {
 123                                 best_col = j;
 124                                 best_gain = gain;
 125                         }
 126                 }
 127                 upd->best_gain = best_gain;
 128                 upd->best_col = best_col;
 129                 upd->gain = gain;
 130         }
 131         if (check_clreos) {
 132                 register struct ww_update *u;
 133                 register gain = 0;
 134                 register best_gain = 0;
 135                 int best_row;
 136                 register simple_gain = 0;
 137                 char didit = 0;
 138
 139                 /*
 140                  * gain is the advantage of clearing all the lines.
 141                  * best_gain is the advantage of clearing to eos
 142                  * at best_row and u->best_col.
 143                  * simple_gain is the advantage of using only clreol.
 144                  * We use g > best_gain because u->best_col can be
 145                  * undefined when u->best_gain is 0 so we can't use it.
 146                  */
 147                 for (j = scan_bot - 1, u = wwupd + j; j >= top; j--, u--) {
 148                         register g = gain + u->best_gain;
 149
 150                         if (g > best_gain) {
 151                                 best_gain = g;
 152                                 best_row = j;
 153                         }
 154                         gain += u->gain;
 155                         if (tt.tt_clreol != 0 && u->best_gain > 4)
 156                                 simple_gain += u->best_gain - 4;
 157                 }
 158                 if (tt.tt_clreos == 0) {
 159                         if (gain > simple_gain && gain > 4) {
 160                                 xxclear();
 161                                 i = top = scan_top;
 162                                 bot = scan_bot;
 163                                 j = 0;
 164                                 didit = 1;
 165                         }
 166                 } else
 167                         if (best_gain > simple_gain && best_gain > 4) {
 168                                 i = best_row;
 169                                 xxclreos(i, j = wwupd[i].best_col);
 170                                 bot = scan_bot;
 171                                 didit = 1;
 172                         }
 173                 if (didit) {
 174                         wwnupdclreos++;
 175                         wwnupdclreosline += wwnrow - i;
 176                         u = wwupd + i;
 177                         while (i < scan_bot) {
 178                                 register union ww_char *os = &wwos[i][j];
 179
 180                                 for (j = wwncol - j; --j >= 0;)
 181                                         os++->c_w = ' ';
 182                                 wwtouched[i++] |= WWU_TOUCHED;
 183                                 u++->best_gain = 0;
 184                                 j = 0;
 185                         }
 186                 } else
 187                         wwnupdclreosmiss++;
 188         }
 189 simple:
 190         for (i = top, touched = &wwtouched[i], upd = &wwupd[i]; i < bot;
 191              i++, touched++, upd++) {
 192                 register union ww_char *os, *ns;
 193                 char didit;
 194
 195                 if (!*touched)
 196                         continue;
 197                 *touched = 0;
 198                 wwnupdline++;
 199                 didit = 0;
 200                 if (tt.tt_clreol != 0 && upd->best_gain > 4) {
 201                         wwnupdclreol++;
 202                         xxclreol(i, j = upd->best_col);
 203                         for (os = &wwos[i][j], j = wwncol - j; --j >= 0;)
 204                                 os++->c_w = ' ';
 205                         didit = 1;
 206                 }
 207                 ns = wwns[i];
 208                 os = wwos[i];
 209                 for (j = 0; j < wwncol;) {
 210                         register char *p, *q;
 211                         char m;
 212                         int c;
 213                         register n;
 214                         char buf[512];                  /* > wwncol */
 215                         union ww_char lastc;
 216
 217                         for (; j++ < wwncol && ns++->c_w == os++->c_w;)
 218                                 ;
 219                         if (j > wwncol)
 220                                 break;
 221                         p = buf;
 222                         m = ns[-1].c_m;
 223                         c = j - 1;
 224                         os[-1] = ns[-1];
 225                         *p++ = ns[-1].c_c;
 226                         n = 5;
 227                         q = p;
 228                         while (j < wwncol && ns->c_m == m) {
 229                                 *p++ = ns->c_c;
 230                                 if (ns->c_w == os->c_w) {
 231                                         if (--n <= 0)
 232                                                 break;
 233                                         os++;
 234                                         ns++;
 235                                 } else {
 236                                         n = 5;
 237                                         q = p;
 238                                         lastc = *os;
 239                                         *os++ = *ns++;
 240                                 }
 241                                 j++;
 242                         }
 243                         n = q - buf;
 244                         if (!wwwrap || i != wwnrow - 1 || c + n != wwncol)
 245                                 xxwrite(i, c, buf, n, m);
 246                         else if (tt.tt_inschar || tt.tt_insspace) {
 247                                 if (n > 1) {
 248                                         q[-2] = q[-1];
 249                                         n--;
 250                                 } else
 251                                         c--;
 252                                 xxwrite(i, c, buf, n, m);
 253                                 c += n - 1;
 254                                 if (tt.tt_inschar)
 255                                         xxinschar(i, c, ns[-2].c_c,
 256                                                 ns[-2].c_m);
 257                                 else {
 258                                         xxinsspace(i, c);
 259                                         xxwrite(i, c, &ns[-2].c_c, 1,
 260                                                 ns[-2].c_m);
 261                                 }
 262                         } else {
 263                                 if (--n)
 264                                         xxwrite(i, c, buf, n, m);
 265                                 os[-1] = lastc;
 266                                 *touched = WWU_TOUCHED;
 267                         }
 268                         didit = 1;
 269                 }
 270                 if (!didit)
 271                         wwnupdmiss++;
 272         }
 273 }