ref: 88ccea37f65b87312292b2b1a107c39927c6a2c3
dir: /sys/src/cmd/eqn/fromto.c/
# 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); }