sys/src/cmd/eqn/paren.c

   1 #include "e.h"
   2
   3 #define abs(x) ((x) > 0 ? (x) : (-(x)))
   4
   5 extern void brack(int, char *, char *, char *);
   6
   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
 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 }