xref: /plan9/sys/src/cmd/eqn/paren.c (revision 3e12c5d1bb89fc02707907988834ef147769ddaf)
1 #include "e.h"
2 
3 #define abs(x) ((x) > 0 ? (x) : (-(x)))
4 
5 extern void brack(int, char *, char *, char *);
6 
paren(int leftc,int p1,int rightc)7 void paren(int leftc, int p1, int rightc)
8 {
9 	int n, m, j;
10 	double h1, b1;
11 	double v, bv;	/* v = shift of inside, bv = shift of brackets */
12 	extern double Parenbase, Parenshift, Parenheight;
13 
14 	bv = ttype == DEVPOST ? Parenshift : 0;	/* move brackets down this much */
15 	h1 = eht[p1];
16 	b1 = ebase[p1];
17 	yyval = p1;
18 	lfont[yyval] = rfont[yyval] = 0;
19 	n = REL(h1,ps) + 0.99;	/* ceiling */
20 	if (n < 2)
21 		n = 1;
22 	m = n - 2;
23 	if (leftc == '{' || rightc == '}') {
24 		n = n%2 ? n : ++n;
25 		if (n < 3)
26 			n = 3;
27 		m = n-3;
28 	}
29 	eht[yyval] = EM((double) n + Parenheight, ps);
30 	ebase[yyval] = eht[yyval]/2 - EM(Parenbase, ps);
31 
32 	/* try to cope with things that are badly centered */
33 	/* (top heavy or bottom heavy) */
34 	if (abs(h1/2 - b1) >= EM(0.5, ps))
35 		v = REL(-ebase[yyval] + (eht[yyval]-h1)/2 + b1, ps);
36 	else
37 		v = 0;	/* don't shift it at all */
38 
39 	printf(".ds %d \\^", yyval);	/* was \| */
40 	if (bv)
41 		printf("\\v'%gm'", bv);
42 	switch (leftc) {
43 	case 'n':	/* nothing */
44 	case '\0':
45 		break;
46 	case 'f':	/* floor */
47 		if (n <= 1)
48 			printf("\\(lf");
49 		else
50 			brack(m, "\\(bv", "\\(bv", "\\(lf");
51 		break;
52 	case 'c':	/* ceiling */
53 		if (n <= 1)
54 			printf("\\(lc");
55 		else
56 			brack(m, "\\(lc", "\\(bv", "\\(bv");
57 		break;
58 	case '{':
59 		printf("\\b'\\(lt");
60 		for(j = 0; j < m; j += 2) printf("\\(bv");
61 		printf("\\(lk");
62 		for(j = 0; j < m; j += 2) printf("\\(bv");
63 		printf("\\(lb'");
64 		break;
65 	case '(':
66 		brack(m, "\\(lt", "\\(bv", "\\(lb");
67 		break;
68 	case '[':
69 		brack(m, "\\(lc", "\\(bv", "\\(lf");
70 		break;
71 	case '|':
72 		brack(m, "|", "|", "|");
73 		break;
74 	default:
75 		brack(m, (char *) &leftc, (char *) &leftc, (char *) &leftc);
76 		break;
77 	}
78 	if (bv)
79 		printf("\\v'%gm'", -bv);
80 	if (v)
81 		printf("\\v'%gm'\\*(%d\\v'%gm'", -v, p1, v);
82 	else
83 		printf("\\*(%d", p1);
84 	if (rightc) {
85 		if (bv)
86 			printf("\\v'%gm'", bv);
87 		switch (rightc) {
88 		case 'f':	/* floor */
89 			if (n <= 1)
90 				printf("\\(rf");
91 			else
92 				brack(m, "\\(bv", "\\(bv", "\\(rf");
93 			break;
94 		case 'c':	/* ceiling */
95 			if (n <= 1)
96 				printf("\\(rc");
97 			else
98 				brack(m, "\\(rc", "\\(bv", "\\(bv");
99 			break;
100 		case '}':
101 			printf("\\b'\\(rt");
102 			for(j = 0; j < m; j += 2) printf("\\(bv");
103 			printf("\\(rk");
104 			for(j = 0; j < m; j += 2) printf("\\(bv");
105 			printf("\\(rb'");
106 			break;
107 		case ']':
108 			brack(m, "\\(rc", "\\(bv", "\\(rf");
109 			break;
110 		case ')':
111 			brack(m, "\\(rt", "\\(bv", "\\(rb");
112 			break;
113 		case '|':
114 			brack(m, "|", "|", "|");
115 			break;
116 		default:
117 			brack(m, (char *) &rightc, (char *) &rightc, (char *) &rightc);
118 			break;
119 		}
120 		if (bv)
121 			printf("\\v'%gm'", -bv);
122 	}
123 	printf("\n");
124 	dprintf(".\tcurly: h=%g b=%g n=%d v=%g l=%c, r=%c\n",
125 		eht[yyval], ebase[yyval], n, v, leftc, rightc);
126 }
127 
brack(int m,char * t,char * c,char * b)128 void brack(int m, char *t, char *c, char *b)
129 {
130 	int j;
131 	printf("\\b'%s", t);
132 	for( j=0; j < m; j++)
133 		printf("%s", c);
134 	printf("%s'", b);
135 }
136