diff options
| -rw-r--r-- | term_ps.c | 76 |
1 files changed, 61 insertions, 15 deletions
@@ -59,12 +59,13 @@ struct termp_ps { #define PS_INLINE (1 << 0) /* we're in a word */ #define PS_MARGINS (1 << 1) /* we're in the margins */ #define PS_NEWPAGE (1 << 2) /* new page, no words yet */ +#define PS_BACKSP (1 << 3) /* last character was backspace */ size_t pscol; /* visible column (AFM units) */ size_t psrow; /* visible row (AFM units) */ char *psmarg; /* margin buf */ size_t psmargsz; /* margin buf size */ size_t psmargcur; /* cur index in margin buf */ - char last; /* character buffer */ + char last; /* last non-backspace seen */ enum termfont lastf; /* last set font */ enum termfont nextf; /* building next font here */ size_t scale; /* font scaling factor */ @@ -1047,7 +1048,7 @@ ps_fclose(struct termp *p) */ if (p->ps->last != '\0') { - assert(p->ps->last != 8); + assert( ! (p->ps->flags & PS_BACKSP)); if (p->ps->nextf != p->ps->lastf) { ps_pclose(p); ps_setfont(p, p->ps->nextf); @@ -1066,25 +1067,30 @@ ps_fclose(struct termp *p) static void ps_letter(struct termp *p, int arg) { + size_t savecol; char c; c = arg >= 128 || arg <= 0 ? '?' : arg; /* - * When receiving an initial character, merely buffer it, - * because a backspace might follow to specify formatting. - * When receiving a backspace, use the buffered character - * to build the font instruction and clear the buffer. - * Only when there are two non-backspace characters in a row, - * activate the font built so far and print the first of them; - * the second, again, merely gets buffered. - * The final character will get printed from ps_fclose(). + * When receiving a backspace, merely flag it. + * We don't know yet whether it is + * a font instruction or an overstrike. */ - if (c == 8) { + if (c == '\b') { assert(p->ps->last != '\0'); - assert(p->ps->last != 8); - if ('_' == p->ps->last) { + assert( ! (p->ps->flags & PS_BACKSP)); + p->ps->flags |= PS_BACKSP; + return; + } + + /* + * Decode font instructions. + */ + + if (p->ps->flags & PS_BACKSP) { + if (p->ps->last == '_') { switch (p->ps->nextf) { case TERMFONT_BI: break; @@ -1094,7 +1100,11 @@ ps_letter(struct termp *p, int arg) default: p->ps->nextf = TERMFONT_UNDER; } - } else { + p->ps->last = c; + p->ps->flags &= ~PS_BACKSP; + return; + } + if (p->ps->last == c) { switch (p->ps->nextf) { case TERMFONT_BI: break; @@ -1104,8 +1114,26 @@ ps_letter(struct termp *p, int arg) default: p->ps->nextf = TERMFONT_BOLD; } + p->ps->flags &= ~PS_BACKSP; + return; } - } else if (p->ps->last != '\0' && p->ps->last != 8) { + + /* + * This is not a font instruction, but rather + * the next character. Prepare for overstrike. + */ + + savecol = p->ps->pscol; + } else + savecol = SIZE_MAX; + + /* + * We found the next character, so the font instructions + * for the previous one are complete. + * Use them and print it. + */ + + if (p->ps->last != '\0') { if (p->ps->nextf != p->ps->lastf) { ps_pclose(p); ps_setfont(p, p->ps->nextf); @@ -1113,7 +1141,25 @@ ps_letter(struct termp *p, int arg) p->ps->nextf = TERMFONT_NONE; ps_pletter(p, p->ps->last); } + + /* + * Do not print the current character yet because font + * instructions might follow; only remember it. + * For the first character, nothing else is done. + * The final character will get printed from ps_fclose(). + */ + p->ps->last = c; + + /* + * For an overstrike, back up to the previous position. + */ + + if (savecol != SIZE_MAX) { + ps_pclose(p); + p->ps->pscol = savecol; + p->ps->flags &= ~PS_BACKSP; + } } static void |