1 files changed, 52 insertions, 0 deletions
diff --git a/src/cmd/eqn/fromto.c b/src/cmd/eqn/fromto.c
new file mode 100644
index 00000000..2d4d7f74
--- /dev/null
+++ b/src/cmd/eqn/fromto.c
@@ -0,0 +1,52 @@
+# include "e.h"
+
+void fromto(int p1, int p2, int p3)
+{
+	double b, h1, b1, t;
+	int subps;
+
+	yyval = salloc();
+	lfont[yyval] = rfont[yyval] = 0;
+	h1 = eht[yyval] = eht[p1];
+	b1 = ebase[p1];
+	b = 0;
+	subps = ps;
+	ps += deltaps;
+	nrwid(p1, ps, p1);
+	printf(".nr %d \\n(%d\n", yyval, p1);
+	if (p2 > 0) {
+		nrwid(p2, subps, p2);
+		printf(".if \\n(%d>\\n(%d .nr %d \\n(%d\n", p2, yyval, yyval, p2);
+		eht[yyval] += eht[p2];
+		b = eht[p2];
+	}
+	if (p3 > 0) {
+		nrwid(p3, subps, p3);
+		printf(".if \\n(%d>\\n(%d .nr %d \\n(%d\n", p3, yyval, yyval, p3);
+		eht[yyval] += eht[p3];
+	}
+	printf(".ds %d ", yyval);	/* bottom of middle box */
+	if (p2 > 0) {
+		t = eht[p2]-ebase[p2]+b1;
+		printf("\\v'%gm'\\h'\\n(%du-\\n(%du/2u'%s\\*(%d%s", 
+			REL(t,ps), yyval, p2, DPS(ps,subps), p2, DPS(subps,ps));
+		printf("\\h'-\\n(%du-\\n(%du/2u'\\v'%gm'\\\n", 
+			yyval, p2, REL(-t,ps));
+	}
+	printf("\\h'\\n(%du-\\n(%du/2u'\\*(%d\\h'\\n(%du-\\n(%du/2u'\\\n", 
+		yyval, p1, p1, yyval, p1);
+	if (p3  >0) {
+		t = h1-b1+ebase[p3];
+		printf("\\v'%gm'\\h'-\\n(%du-\\n(%du/2u'%s\\*(%d%s\\h'\\n(%du-\\n(%du/2u'\\v'%gm'\\\n", 
+			REL(-t,ps), yyval, p3, DPS(ps,subps), p3, DPS(subps,ps), yyval, p3, REL(t,ps));
+	}
+	printf("\n");
+	ebase[yyval] = b + b1;
+	dprintf(".\tS%d <- %d from %d to %d; h=%g b=%g\n", 
+		yyval, p1, p2, p3, eht[yyval], ebase[yyval]);
+	sfree(p1);
+	if (p2 > 0)
+		sfree(p2);
+	if (p3 > 0)
+		sfree(p3);
+}