shithub: neatroff

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ref: 1c6ab0f6ebf582dd22f9057662e8ac366b7e5c25
parent: 7d5b285d8bbd4b8e90fce45260455a75e1ce463e
author: Ali Gholami Rudi <[email protected]>
date: Tue Sep 13 18:45:05 EDT 2016

fmt: support stretchable no-break space (\~)

Suggested and tested by aksr <[email protected]>.

--- a/fmt.c
+++ b/fmt.c
@@ -271,14 +271,14 @@
 	word->wid = wb_wid(wb);
 	word->elsn = wb->els_neg;
 	word->elsp = wb->els_pos;
-	word->cost = cost ? wb_cost(wb) : 0;
 	word->hy = hy ? wb_hywid(wb) : 0;
 	word->str = str;
 	word->gap = gap;
+	word->cost = cost;
 }
 
-/* find explicit hyphenation positions: dashes, \: and \% */
-static int fmt_hyphmarks(char *word, int *hyidx, int *hyins)
+/* find explicit break positions: dashes, \:, \%, and \~ */
+static int fmt_hyphmarks(char *word, int *hyidx, int *hyins, int *hygap)
 {
 	char *s = word;
 	char *d = NULL;
@@ -296,6 +296,10 @@
 			hyins[n] = 0;
 			hyidx[n++] = s - word;
 		}
+		if (!c && !strcmp(c_nb, d)) {
+			hygap[n] = 1;
+			hyidx[n++] = s - word;
+		}
 	}
 	return n;
 }
@@ -312,8 +316,9 @@
 
 static void fmt_insertword(struct fmt *f, struct wb *wb, int gap)
 {
-	int hyidx[NHYPHSWORD];
-	int hyins[NHYPHSWORD] = {0};
+	int hyidx[NHYPHSWORD];		/* sub-word boundaries */
+	int hyins[NHYPHSWORD] = {0};	/* insert dash */
+	int hygap[NHYPHSWORD] = {0};	/* stretchable no-break space */
 	char *src = wb_buf(wb);
 	struct wb wbc;
 	char *beg;
@@ -320,9 +325,9 @@
 	char *end;
 	int n, i;
 	int cf, cs, cm;
-	n = fmt_hyphmarks(src, hyidx, hyins);
+	n = fmt_hyphmarks(src, hyidx, hyins, hygap);
 	if (n <= 0) {
-		fmt_wb2word(f, fmt_mkword(f), wb, 0, 1, gap, 1);
+		fmt_wb2word(f, fmt_mkword(f), wb, 0, 1, gap, wb_cost(wb));
 		return;
 	}
 	/* update f->fillreq considering the new sub-words */
@@ -329,16 +334,23 @@
 	if (f->fillreq == f->words_n + 1)
 		f->fillreq += n;
 	wb_init(&wbc);
+	/* add sub-words */
 	for (i = 0; i <= n; i++) {
+		int ihy = i < n && hyins[i];		/* dash width */
+		int istr = i == 0 || hygap[i - 1];	/* stretchable */
+		int igap;				/* gap width */
+		int icost;				/* hyphenation cost */
 		beg = src + (i > 0 ? hyidx[i - 1] : 0);
 		end = src + (i < n ? hyidx[i] : strlen(src));
+		if (i < n && hygap[i])			/* remove \~ */
+			end -= strlen(c_nb);
 		wb_catstr(&wbc, beg, end);
-		fmt_wb2word(f, fmt_mkword(f), &wbc,
-			i < n && hyins[i], i == 0, i == 0 ? gap : 0, i == n);
-		/* restoring wbc */
-		wb_fnszget(&wbc, &cs, &cf, &cm);
+		wb_fnszget(&wbc, &cf, &cs, &cm);
+		icost = i == n ? wb_cost(&wbc) : hygap[i] * 10000000;
+		igap = i == 0 ? gap : hygap[i - 1] * font_swid(dev_font(cf), cs, n_ss);
+		fmt_wb2word(f, fmt_mkword(f), &wbc, ihy, istr, igap, icost);
 		wb_reset(&wbc);
-		wb_fnszset(&wbc, cs, cf, cm);
+		wb_fnszset(&wbc, cf, cs, cm);		/* restoring wbc */
 	}
 	wb_done(&wbc);
 }
--- a/roff.h
+++ b/roff.h
@@ -73,6 +73,7 @@
 #define c_tc	env_tc()
 #define c_lc	env_lc()
 #define c_bp	"\\:"	/* zero-width word break point */
+#define c_nb	"\\~"	/* stretchable no-break space */
 
 /* number registers */
 #define num_get(id)	(*nreg(id))
--- a/wb.c
+++ b/wb.c
@@ -251,6 +251,12 @@
 		wb_hmov(wb, font_swid(dev_font(R_F(wb)), R_S(wb), n_ss));
 		return;
 	}
+	if (!strcmp(c_nb, c)) {
+		wb_flushsub(wb);
+		sbuf_append(&wb->sbuf, c);
+		wb->h += font_swid(dev_font(R_F(wb)), R_S(wb), n_ss);
+		return;
+	}
 	if (wb_pendingfont(wb) || wb->sub_n == LEN(wb->sub_c))
 		wb_flush(wb);
 	if (wb->sub_collect) {