window(1): Remove __RCSID & friends.
[dragonfly.git] / usr.bin / window / wwupdate.c
1 /*      @(#)wwupdate.c  8.1 (Berkeley) 6/6/93   */
2 /*      $NetBSD: wwupdate.c,v 1.6 2003/08/07 11:17:46 agc Exp $ */
3
4 /*
5  * Copyright (c) 1983, 1993
6  *      The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Edward Wang at The University of California, Berkeley.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35
36 #include "ww.h"
37 #include "tt.h"
38 #include "xx.h"
39
40 void
41 wwupdate1(int top, int bot)
42 {
43         int i;
44         int j;
45         char *touched;
46         struct ww_update *upd;
47         char check_clreos = 0;
48         int scan_top, scan_bot;
49
50         wwnupdate++;
51         {
52                 char *t1 = wwtouched + top, *t2 = wwtouched + bot;
53                 int n;
54
55                 while (!*t1++)
56                         if (t1 == t2)
57                                 return;
58                 while (!*--t2)
59                         ;
60                 scan_top = top = t1 - wwtouched - 1;
61                 scan_bot = bot = t2 - wwtouched + 1;
62                 if (scan_bot - scan_top > 1 &&
63                     (tt.tt_clreos != 0 || tt.tt_clear != 0)) {
64                         int st = tt.tt_clreos != 0 ? scan_top : 0;
65
66                         /*
67                          * t1 is one past the first touched row,
68                          * t2 is on the last touched row.
69                          */
70                         for (t1--, n = 1; t1 < t2;)
71                                 if (*t1++)
72                                         n++;
73                         /*
74                          * If we can't clreos then we try for clearing
75                          * the whole screen.
76                          */
77                         if ((check_clreos = n * 10 > (wwnrow - st) * 9)) {
78                                 scan_top = st;
79                                 scan_bot = wwnrow;
80                         }
81                 }
82         }
83         if (tt.tt_clreol == 0 && !check_clreos)
84                 goto simple;
85         for (i = scan_top, touched = &wwtouched[i], upd = &wwupd[i];
86              i < scan_bot;
87              i++, touched++, upd++) {
88                 int gain = 0;
89                 int best_gain = 0;
90                 int best_col = 0;
91                 union ww_char *ns, *os;
92
93                 if (wwinterrupt())
94                         return;
95                 if (!check_clreos && !*touched)
96                         continue;
97                 wwnupdscan++;
98                 j = wwncol;
99                 ns = &wwns[i][j];
100                 os = &wwos[i][j];
101                 while (--j >= 0) {
102                         /*
103                          * The cost of clearing is:
104                          *      ncol - nblank + X
105                          * The cost of straight update is, more or less:
106                          *      ncol - nsame
107                          * We clear if  nblank - nsame > X
108                          * X is the clreol overhead.
109                          * So we make gain = nblank - nsame.
110                          */
111                         if ((--ns)->c_w == (--os)->c_w)
112                                 gain--;
113                         else
114                                 best_gain--;
115                         if (ns->c_w == ' ')
116                                 gain++;
117                         if (gain > best_gain) {
118                                 best_col = j;
119                                 best_gain = gain;
120                         }
121                 }
122                 upd->best_gain = best_gain;
123                 upd->best_col = best_col;
124                 upd->gain = gain;
125         }
126         if (check_clreos) {
127                 struct ww_update *u;
128                 int gain = 0;
129                 int best_gain = 0;
130                 int best_row = 0;
131                 int simple_gain = 0;
132                 char didit = 0;
133
134                 /*
135                  * gain is the advantage of clearing all the lines.
136                  * best_gain is the advantage of clearing to eos
137                  * at best_row and u->best_col.
138                  * simple_gain is the advantage of using only clreol.
139                  * We use g > best_gain because u->best_col can be
140                  * undefined when u->best_gain is 0 so we can't use it.
141                  */
142                 for (j = scan_bot - 1, u = wwupd + j; j >= top; j--, u--) {
143                         int g = gain + u->best_gain;
144
145                         if (g > best_gain) {
146                                 best_gain = g;
147                                 best_row = j;
148                         }
149                         gain += u->gain;
150                         if (tt.tt_clreol != 0 && u->best_gain > 4)
151                                 simple_gain += u->best_gain - 4;
152                 }
153                 if (tt.tt_clreos == 0) {
154                         if (gain > simple_gain && gain > 4) {
155                                 xxclear();
156                                 i = top = scan_top;
157                                 bot = scan_bot;
158                                 j = 0;
159                                 didit = 1;
160                         }
161                 } else
162                         if (best_gain > simple_gain && best_gain > 4) {
163                                 i = best_row;
164                                 xxclreos(i, j = wwupd[i].best_col);
165                                 bot = scan_bot;
166                                 didit = 1;
167                         }
168                 if (didit) {
169                         wwnupdclreos++;
170                         wwnupdclreosline += wwnrow - i;
171                         u = wwupd + i;
172                         while (i < scan_bot) {
173                                 union ww_char *os = &wwos[i][j];
174
175                                 for (j = wwncol - j; --j >= 0;)
176                                         os++->c_w = ' ';
177                                 wwtouched[i++] |= WWU_TOUCHED;
178                                 u++->best_gain = 0;
179                                 j = 0;
180                         }
181                 } else
182                         wwnupdclreosmiss++;
183         }
184 simple:
185         for (i = top, touched = &wwtouched[i], upd = &wwupd[i]; i < bot;
186              i++, touched++, upd++) {
187                 union ww_char *os, *ns;
188                 char didit;
189
190                 if (!*touched)
191                         continue;
192                 *touched = 0;
193                 wwnupdline++;
194                 didit = 0;
195                 if (tt.tt_clreol != 0 && upd->best_gain > 4) {
196                         wwnupdclreol++;
197                         xxclreol(i, j = upd->best_col);
198                         for (os = &wwos[i][j], j = wwncol - j; --j >= 0;)
199                                 os++->c_w = ' ';
200                         didit = 1;
201                 }
202                 ns = wwns[i];
203                 os = wwos[i];
204                 for (j = 0; j < wwncol;) {
205                         char *p, *q;
206                         char m;
207                         int c;
208                         int n;
209                         char buf[512];                  /* > wwncol */
210                         union ww_char lastc;
211
212                         for (; j++ < wwncol && ns++->c_w == os++->c_w;)
213                                 ;
214                         if (j > wwncol)
215                                 break;
216                         p = buf;
217                         m = ns[-1].c_m;
218                         c = j - 1;
219                         os[-1] = ns[-1];
220                         *p++ = ns[-1].c_c;
221                         n = 5;
222                         q = p;
223                         while (j < wwncol && ns->c_m == m) {
224                                 *p++ = ns->c_c;
225                                 if (ns->c_w == os->c_w) {
226                                         if (--n <= 0)
227                                                 break;
228                                         os++;
229                                         ns++;
230                                 } else {
231                                         n = 5;
232                                         q = p;
233                                         lastc = *os;
234                                         *os++ = *ns++;
235                                 }
236                                 j++;
237                         }
238                         n = q - buf;
239                         if (!wwwrap || i != wwnrow - 1 || c + n != wwncol)
240                                 xxwrite(i, c, buf, n, m);
241                         else if (tt.tt_inschar || tt.tt_insspace) {
242                                 if (n > 1) {
243                                         q[-2] = q[-1];
244                                         n--;
245                                 } else
246                                         c--;
247                                 xxwrite(i, c, buf, n, m);
248                                 c += n - 1;
249                                 if (tt.tt_inschar)
250                                         xxinschar(i, c, ns[-2].c_c,
251                                                 ns[-2].c_m);
252                                 else {
253                                         xxinsspace(i, c);
254                                         xxwrite(i, c, &ns[-2].c_c, 1,
255                                                 ns[-2].c_m);
256                                 }
257                         } else {
258                                 if (--n)
259                                         xxwrite(i, c, buf, n, m);
260                                 os[-1] = lastc;
261                                 *touched = WWU_TOUCHED;
262                         }
263                         didit = 1;
264                 }
265                 if (!didit)
266                         wwnupdmiss++;
267         }
268 }