BSD 4.4 Lite Usr.bin Sources

1 files changed, 271 insertions, 0 deletions

diff --git a/usr.bin/window/wwupdate.c b/usr.bin/window/wwupdate.c
new file mode 100644
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--- /dev/null
+++ b/usr.bin/window/wwupdate.c
@@ -0,0 +1,271 @@
+/*
+ * Copyright (c) 1983, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Edward Wang at The University of California, Berkeley.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef lint
+static char sccsid[] = "@(#)wwupdate.c	8.1 (Berkeley) 6/6/93";
+#endif /* not lint */
+
+#include "ww.h"
+#include "tt.h"
+
+wwupdate1(top, bot)
+{
+	int i;
+	register j;
+	char *touched;
+	struct ww_update *upd;
+	char check_clreos = 0;
+	int scan_top, scan_bot;
+
+	wwnupdate++;
+	{
+		register char *t1 = wwtouched + top, *t2 = wwtouched + bot;
+		register n;
+
+		while (!*t1++)
+			if (t1 == t2)
+				return;
+		while (!*--t2)
+			;
+		scan_top = top = t1 - wwtouched - 1;
+		scan_bot = bot = t2 - wwtouched + 1;
+		if (scan_bot - scan_top > 1 &&
+		    (tt.tt_clreos != 0 || tt.tt_clear != 0)) {
+			int st = tt.tt_clreos != 0 ? scan_top : 0;
+
+			/*
+			 * t1 is one past the first touched row,
+			 * t2 is on the last touched row.
+			 */
+			for (t1--, n = 1; t1 < t2;)
+				if (*t1++)
+					n++;
+			/*
+			 * If we can't clreos then we try for clearing
+			 * the whole screen.
+			 */
+			if (check_clreos = n * 10 > (wwnrow - st) * 9) {
+				scan_top = st;
+				scan_bot = wwnrow;
+			}
+		}
+	}
+	if (tt.tt_clreol == 0 && !check_clreos)
+		goto simple;
+	for (i = scan_top, touched = &wwtouched[i], upd = &wwupd[i];
+	     i < scan_bot;
+	     i++, touched++, upd++) {
+		register gain = 0;
+		register best_gain = 0;
+		register best_col;
+		register union ww_char *ns, *os;
+
+		if (wwinterrupt())
+			return;
+		if (!check_clreos && !*touched)
+			continue;
+		wwnupdscan++;
+		j = wwncol;
+		ns = &wwns[i][j];
+		os = &wwos[i][j];
+		while (--j >= 0) {
+			/*
+			 * The cost of clearing is:
+			 *	ncol - nblank + X
+			 * The cost of straight update is, more or less:
+			 *	ncol - nsame
+			 * We clear if  nblank - nsame > X
+			 * X is the clreol overhead.
+			 * So we make gain = nblank - nsame.
+			 */
+			if ((--ns)->c_w == (--os)->c_w)
+				gain--;
+			else
+				best_gain--;
+			if (ns->c_w == ' ')
+				gain++;
+			if (gain > best_gain) {
+				best_col = j;
+				best_gain = gain;
+			}
+		}
+		upd->best_gain = best_gain;
+		upd->best_col = best_col;
+		upd->gain = gain;
+	}
+	if (check_clreos) {
+		register struct ww_update *u;
+		register gain = 0;
+		register best_gain = 0;
+		int best_row;
+		register simple_gain = 0;
+		char didit = 0;
+
+		/*
+		 * gain is the advantage of clearing all the lines.
+		 * best_gain is the advantage of clearing to eos
+		 * at best_row and u->best_col.
+		 * simple_gain is the advantage of using only clreol.
+		 * We use g > best_gain because u->best_col can be
+		 * undefined when u->best_gain is 0 so we can't use it.
+		 */
+		for (j = scan_bot - 1, u = wwupd + j; j >= top; j--, u--) {
+			register g = gain + u->best_gain;
+
+			if (g > best_gain) {
+				best_gain = g;
+				best_row = j;
+			}
+			gain += u->gain;
+			if (tt.tt_clreol != 0 && u->best_gain > 4)
+				simple_gain += u->best_gain - 4;
+		}
+		if (tt.tt_clreos == 0) {
+			if (gain > simple_gain && gain > 4) {
+				xxclear();
+				i = top = scan_top;
+				bot = scan_bot;
+				j = 0;
+				didit = 1;
+			}
+		} else
+			if (best_gain > simple_gain && best_gain > 4) {
+				i = best_row;
+				xxclreos(i, j = wwupd[i].best_col);
+				bot = scan_bot;
+				didit = 1;
+			}
+		if (didit) {
+			wwnupdclreos++;
+			wwnupdclreosline += wwnrow - i;
+			u = wwupd + i;
+			while (i < scan_bot) {
+				register union ww_char *os = &wwos[i][j];
+
+				for (j = wwncol - j; --j >= 0;)
+					os++->c_w = ' ';
+				wwtouched[i++] |= WWU_TOUCHED;
+				u++->best_gain = 0;
+				j = 0;
+			}
+		} else
+			wwnupdclreosmiss++;
+	}
+simple:
+	for (i = top, touched = &wwtouched[i], upd = &wwupd[i]; i < bot;
+	     i++, touched++, upd++) {
+		register union ww_char *os, *ns;
+		char didit;
+
+		if (!*touched)
+			continue;
+		*touched = 0;
+		wwnupdline++;
+		didit = 0;
+		if (tt.tt_clreol != 0 && upd->best_gain > 4) {
+			wwnupdclreol++;
+			xxclreol(i, j = upd->best_col);
+			for (os = &wwos[i][j], j = wwncol - j; --j >= 0;)
+				os++->c_w = ' ';
+			didit = 1;
+		}
+		ns = wwns[i];
+		os = wwos[i];
+		for (j = 0; j < wwncol;) {
+			register char *p, *q;
+			char m;
+			int c;
+			register n;
+			char buf[512];			/* > wwncol */
+			union ww_char lastc;
+
+			for (; j++ < wwncol && ns++->c_w == os++->c_w;)
+				;
+			if (j > wwncol)
+				break;
+			p = buf;
+			m = ns[-1].c_m;
+			c = j - 1;
+			os[-1] = ns[-1];
+			*p++ = ns[-1].c_c;
+			n = 5;
+			q = p;
+			while (j < wwncol && ns->c_m == m) {
+				*p++ = ns->c_c;
+				if (ns->c_w == os->c_w) {
+					if (--n <= 0)
+						break;
+					os++;
+					ns++;
+				} else {
+					n = 5;
+					q = p;
+					lastc = *os;
+					*os++ = *ns++;
+				}
+				j++;
+			}
+			n = q - buf;
+			if (!wwwrap || i != wwnrow - 1 || c + n != wwncol)
+				xxwrite(i, c, buf, n, m);
+			else if (tt.tt_inschar || tt.tt_insspace) {
+				if (n > 1) {
+					q[-2] = q[-1];
+					n--;
+				} else
+					c--;
+				xxwrite(i, c, buf, n, m);
+				c += n - 1;
+				if (tt.tt_inschar)
+					xxinschar(i, c, ns[-2].c_c,
+						ns[-2].c_m);
+				else {
+					xxinsspace(i, c);
+					xxwrite(i, c, &ns[-2].c_c, 1,
+						ns[-2].c_m);
+				}
+			} else {
+				if (--n)
+					xxwrite(i, c, buf, n, m);
+				os[-1] = lastc;
+				*touched = WWU_TOUCHED;
+			}
+			didit = 1;
+		}
+		if (!didit)
+			wwnupdmiss++;
+	}
+}