| 1 | /* |
| 2 | * Copyright (c) 1983 Regents of the University of California. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms are permitted |
| 6 | * provided that the above copyright notice and this paragraph are |
| 7 | * duplicated in all such forms and that any documentation, |
| 8 | * advertising materials, and other materials related to such |
| 9 | * distribution and use acknowledge that the software was developed |
| 10 | * by the University of California, Berkeley. The name of the |
| 11 | * University may not be used to endorse or promote products derived |
| 12 | * from this software without specific prior written permission. |
| 13 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR |
| 14 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED |
| 15 | * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. |
| 16 | */ |
| 17 | |
| 18 | #ifndef lint |
| 19 | static char sccsid[] = "@(#)wwupdate.c 3.26 (Berkeley) %G%"; |
| 20 | #endif /* not lint */ |
| 21 | |
| 22 | #include "ww.h" |
| 23 | #include "tt.h" |
| 24 | |
| 25 | wwupdate1(top, bot) |
| 26 | { |
| 27 | int i; |
| 28 | register j; |
| 29 | char *touched; |
| 30 | struct ww_update *upd; |
| 31 | char check_clreos = 0; |
| 32 | int scan_top, scan_bot; |
| 33 | |
| 34 | wwnupdate++; |
| 35 | { |
| 36 | register char *t1 = wwtouched + top, *t2 = wwtouched + bot; |
| 37 | register n; |
| 38 | |
| 39 | while (!*t1++) |
| 40 | if (t1 == t2) |
| 41 | return; |
| 42 | while (!*--t2) |
| 43 | ; |
| 44 | scan_top = top = t1 - wwtouched - 1; |
| 45 | scan_bot = bot = t2 - wwtouched + 1; |
| 46 | if (scan_bot - scan_top > 1 && |
| 47 | (tt.tt_clreos != 0 || tt.tt_clear != 0)) { |
| 48 | int st = tt.tt_clreos != 0 ? scan_top : 0; |
| 49 | |
| 50 | /* |
| 51 | * t1 is one past the first touched row, |
| 52 | * t2 is on the last touched row. |
| 53 | */ |
| 54 | for (t1--, n = 1; t1 < t2;) |
| 55 | if (*t1++) |
| 56 | n++; |
| 57 | /* |
| 58 | * If we can't clreos then we try for clearing |
| 59 | * the whole screen. |
| 60 | */ |
| 61 | if (check_clreos = n * 10 > (wwnrow - st) * 9) { |
| 62 | scan_top = st; |
| 63 | scan_bot = wwnrow; |
| 64 | } |
| 65 | } |
| 66 | } |
| 67 | if (tt.tt_clreol == 0 && !check_clreos) |
| 68 | goto simple; |
| 69 | for (i = scan_top, touched = &wwtouched[i], upd = &wwupd[i]; |
| 70 | i < scan_bot; |
| 71 | i++, touched++, upd++) { |
| 72 | register gain = 0; |
| 73 | register best_gain = 0; |
| 74 | register best_col; |
| 75 | register union ww_char *ns, *os; |
| 76 | |
| 77 | if (wwinterrupt()) |
| 78 | return; |
| 79 | if (!check_clreos && !*touched) |
| 80 | continue; |
| 81 | wwnupdscan++; |
| 82 | j = wwncol; |
| 83 | ns = &wwns[i][j]; |
| 84 | os = &wwos[i][j]; |
| 85 | while (--j >= 0) { |
| 86 | /* |
| 87 | * The cost of clearing is: |
| 88 | * ncol - nblank + X |
| 89 | * The cost of straight update is, more or less: |
| 90 | * ncol - nsame |
| 91 | * We clear if nblank - nsame > X |
| 92 | * X is the clreol overhead. |
| 93 | * So we make gain = nblank - nsame. |
| 94 | */ |
| 95 | if ((--ns)->c_w == (--os)->c_w) |
| 96 | gain--; |
| 97 | else |
| 98 | best_gain--; |
| 99 | if (ns->c_w == ' ') |
| 100 | gain++; |
| 101 | if (gain > best_gain) { |
| 102 | best_col = j; |
| 103 | best_gain = gain; |
| 104 | } |
| 105 | } |
| 106 | upd->best_gain = best_gain; |
| 107 | upd->best_col = best_col; |
| 108 | upd->gain = gain; |
| 109 | } |
| 110 | if (check_clreos) { |
| 111 | register struct ww_update *u; |
| 112 | register gain = 0; |
| 113 | register best_gain = 0; |
| 114 | int best_row; |
| 115 | register simple_gain = 0; |
| 116 | char didit = 0; |
| 117 | |
| 118 | /* |
| 119 | * gain is the advantage of clearing all the lines. |
| 120 | * best_gain is the advantage of clearing to eos |
| 121 | * at best_row and u->best_col. |
| 122 | * simple_gain is the advantage of using only clreol. |
| 123 | * We use g > best_gain because u->best_col can be |
| 124 | * undefined when u->best_gain is 0 so we can't use it. |
| 125 | */ |
| 126 | for (j = scan_bot - 1, u = wwupd + j; j >= top; j--, u--) { |
| 127 | register g = gain + u->best_gain; |
| 128 | |
| 129 | if (g > best_gain) { |
| 130 | best_gain = g; |
| 131 | best_row = j; |
| 132 | } |
| 133 | gain += u->gain; |
| 134 | if (tt.tt_clreol != 0 && u->best_gain > 4) |
| 135 | simple_gain += u->best_gain - 4; |
| 136 | } |
| 137 | if (tt.tt_clreos == 0) { |
| 138 | if (gain > simple_gain && gain > 4) { |
| 139 | xxclear(); |
| 140 | i = top = scan_top; |
| 141 | bot = scan_bot; |
| 142 | j = 0; |
| 143 | didit = 1; |
| 144 | } |
| 145 | } else |
| 146 | if (best_gain > simple_gain && best_gain > 4) { |
| 147 | i = best_row; |
| 148 | xxclreos(i, j = wwupd[i].best_col); |
| 149 | bot = scan_bot; |
| 150 | didit = 1; |
| 151 | } |
| 152 | if (didit) { |
| 153 | wwnupdclreos++; |
| 154 | wwnupdclreosline += wwnrow - i; |
| 155 | u = wwupd + i; |
| 156 | while (i < scan_bot) { |
| 157 | register union ww_char *os = &wwos[i][j]; |
| 158 | |
| 159 | for (j = wwncol - j; --j >= 0;) |
| 160 | os++->c_w = ' '; |
| 161 | wwtouched[i++] |= WWU_TOUCHED; |
| 162 | u++->best_gain = 0; |
| 163 | j = 0; |
| 164 | } |
| 165 | } else |
| 166 | wwnupdclreosmiss++; |
| 167 | } |
| 168 | simple: |
| 169 | for (i = top, touched = &wwtouched[i], upd = &wwupd[i]; i < bot; |
| 170 | i++, touched++, upd++) { |
| 171 | register union ww_char *os, *ns; |
| 172 | char didit; |
| 173 | |
| 174 | if (!*touched) |
| 175 | continue; |
| 176 | *touched = 0; |
| 177 | wwnupdline++; |
| 178 | didit = 0; |
| 179 | if (tt.tt_clreol != 0 && upd->best_gain > 4) { |
| 180 | wwnupdclreol++; |
| 181 | xxclreol(i, j = upd->best_col); |
| 182 | for (os = &wwos[i][j], j = wwncol - j; --j >= 0;) |
| 183 | os++->c_w = ' '; |
| 184 | didit = 1; |
| 185 | } |
| 186 | ns = wwns[i]; |
| 187 | os = wwos[i]; |
| 188 | for (j = 0; j < wwncol;) { |
| 189 | register char *p, *q; |
| 190 | char m; |
| 191 | int c; |
| 192 | register n; |
| 193 | char buf[512]; /* > wwncol */ |
| 194 | union ww_char lastc; |
| 195 | |
| 196 | for (; j++ < wwncol && ns++->c_w == os++->c_w;) |
| 197 | ; |
| 198 | if (j > wwncol) |
| 199 | break; |
| 200 | p = buf; |
| 201 | m = ns[-1].c_m; |
| 202 | c = j - 1; |
| 203 | os[-1] = ns[-1]; |
| 204 | *p++ = ns[-1].c_c; |
| 205 | n = 5; |
| 206 | q = p; |
| 207 | while (j < wwncol && ns->c_m == m) { |
| 208 | *p++ = ns->c_c; |
| 209 | if (ns->c_w == os->c_w) { |
| 210 | if (--n <= 0) |
| 211 | break; |
| 212 | os++; |
| 213 | ns++; |
| 214 | } else { |
| 215 | n = 5; |
| 216 | q = p; |
| 217 | lastc = *os; |
| 218 | *os++ = *ns++; |
| 219 | } |
| 220 | j++; |
| 221 | } |
| 222 | if (wwwrap |
| 223 | && i == wwnrow - 1 && q - buf + c == wwncol) { |
| 224 | if (tt.tt_inschar) { |
| 225 | if (q - buf != 1) { |
| 226 | xxwrite(i, c, buf + 1, |
| 227 | q - buf - 1, m); |
| 228 | xxinschar(i, c, *buf, m); |
| 229 | } else { |
| 230 | xxwrite(i, c - 1, buf, 1, m); |
| 231 | xxinschar(i, c - 1, |
| 232 | ns[-2].c_c, ns[-2].c_m); |
| 233 | } |
| 234 | } else if (tt.tt_insspace) { |
| 235 | if (q - buf != 1) { |
| 236 | xxwrite(i, c, buf + 1, |
| 237 | q - buf - 1, m); |
| 238 | xxinsspace(i, c); |
| 239 | xxwrite(i, c, buf, 1, m); |
| 240 | } else { |
| 241 | xxwrite(i, c - 1, buf, 1, m); |
| 242 | xxinsspace(i, c - 1); |
| 243 | xxwrite(i, c - 1, &ns[-2].c_c, |
| 244 | 1, ns[-2].c_m); |
| 245 | } |
| 246 | } else { |
| 247 | if (q - buf > 1) |
| 248 | xxwrite(i, c, buf, |
| 249 | q - buf - 1, m); |
| 250 | os[-1] = lastc; |
| 251 | *touched = WWU_TOUCHED; |
| 252 | } |
| 253 | } else |
| 254 | xxwrite(i, c, buf, q - buf, m); |
| 255 | didit = 1; |
| 256 | } |
| 257 | if (!didit) |
| 258 | wwnupdmiss++; |
| 259 | } |
| 260 | } |