ref: fe5d1976a0b4376c955ca8423eb9005f5d035403
dir: /sys/src/libttf/cmap.c/
#include <u.h> #include <libc.h> #include <bio.h> #include <ttf.h> #include "impl.h" int ttffindchar(TTFont *fx, Rune r) { int i, j, k, rv; TTChMap *p; TTFontU *f; f = fx->u; i = 0; j = f->ncmap - 1; if(r < f->cmap[0].start || r > f->cmap[j].end) return 0; while(i < j){ k = (i + j) / 2; if(f->cmap[k].end < r) i = k+1; else if(f->cmap[k].start > r) j = k-1; else i = j = k; } if(i > j) return 0; p = &f->cmap[i]; if(r < p->start || r > p->end) return 0; if((p->flags & TTCINVALID) != 0) return 0; if(p->tab != nil) return p->tab[r - p->start]; rv = r + p->delta; if((p->flags & TTCDELTA16) != 0) rv = (u16int)rv; return rv; } int ttfenumchar(TTFont *fx, Rune r, Rune *rp) { int i, j, k, rv; TTChMap *p; TTFontU *f; f = fx->u; i = 0; j = f->ncmap - 1; if(r > f->cmap[j].end) return 0; while(i < j){ k = (i + j) / 2; if(f->cmap[k].end < r) i = k+1; else if(f->cmap[k].start > r) j = k-1; else i = j = k; } if(j < 0) j = 0; for(p = &f->cmap[j]; p < &f->cmap[f->ncmap]; p++){ if((p->flags & TTCINVALID) != 0) continue; if(r < p->start) r = p->start; if(p->tab != nil){ SET(rv); while(r <= p->end && (rv = p->tab[r - p->start], rv == 0)) r++; if(r > p->end) continue; if(rp != nil) *rp = r; return rv; } while(r < p->end){ rv = r + p->delta; if((p->flags & TTCDELTA16) != 0) rv = (u16int) rv; if(rv != 0){ if(rp != nil) *rp = r; return rv; } } } return 0; } static int ttfgotosub(TTFontU *f) { int i; u16int nsub, id, sid; int rank, maxrank; u32int maxoff, off; #define SUBID(a,b) ((a)<<16|(b)) if(ttfgototable(f, "cmap") < 0) return -1; ttfunpack(f, ".. w", &nsub); maxrank = 0; maxoff = 0; for(i = 0; i < nsub; i++){ ttfunpack(f, "wwl", &id, &sid, &off); switch(id << 16 | sid){ case SUBID(0, 4): /* Unicode 2.0 or later (BMP and non-BMP) */ rank = 100; break; case SUBID(3, 10): /* Windows, UCS-4 */ rank = 80; break; case SUBID(0, 0): /* Unicode default */ case SUBID(0, 1): /* Unicode 1.1 */ case SUBID(0, 2): /* ISO 10646 */ case SUBID(0, 3): /* Unicode 2.0 (BMP) */ rank = 60; break; case SUBID(3, 1): /* Windows, UCS-2 */ rank = 40; break; case SUBID(3, 0): /* Windows, Symbol */ rank = 20; break; default: rank = 0; break; } if(rank > maxrank){ maxrank = rank; maxoff = off; } } if(maxrank == 0){ werrstr("no suitable character table"); return -1; } if(ttfgototable(f, "cmap") < 0) return -1; Bseek(f->bin, maxoff, 1); return 0; } static int cmap0(TTFontU *f) { u16int len; int i; u8int *p; int *q; ttfunpack(f, "w2", &len); if(len < 262){ werrstr("character table too short"); return -1; } f->cmap = mallocz(sizeof(TTChMap), 1); if(f->cmap == nil) return -1; f->ncmap = 1; f->cmap->start = 0; f->cmap->end = 0xff; f->cmap->tab = mallocz(256 * sizeof(int), 1); if(f->cmap->tab == nil) return -1; Bread(f->bin, f->cmap->tab, 256 * sizeof(int)); p = (u8int*)f->cmap->tab + 256; q = f->cmap->tab + 256; for(i = 255; i >= 0; i--) *--q = *--p; return 0; } static int cmap4(TTFontU *f) { u16int len, ncmap; int i, j, n, n0, off; u16int v; u8int *buf; ttfunpack(f, "w2", &len); if(len < 16){ werrstr("character table too short"); return -1; } ttfunpack(f, "w6", &ncmap); ncmap /= 2; if(len < 16 + 8 * ncmap){ werrstr("character table too short"); return -1; } f->cmap = mallocz(sizeof(TTChMap) * ncmap, 1); if(f->cmap == nil) return -1; f->ncmap = ncmap; for(i = 0; i < ncmap; i++) f->cmap[i].flags = TTCDELTA16; for(i = 0; i < ncmap; i++) ttfunpack(f, "W", &f->cmap[i].end); ttfunpack(f, ".."); for(i = 0; i < ncmap; i++) ttfunpack(f, "W", &f->cmap[i].start); for(i = 0; i < ncmap; i++) ttfunpack(f, "W", &f->cmap[i].delta); for(i = 0; i < ncmap; i++) ttfunpack(f, "W", &f->cmap[i].temp); len -= 10 + 8 * ncmap; buf = malloc(len); if(buf == nil) return -1; Bread(f->bin, buf, len); for(i = 0; i < ncmap; i++){ if(f->cmap[i].temp == 0) continue; n0 = f->cmap[i].end - f->cmap[i].start + 1; n = n0; off = f->cmap[i].temp - (ncmap - i) * 2; if(off + 2 * n > len) n = (len - off) / 2; if(off < 0 || n <= 0){ f->cmap[i].flags |= TTCINVALID; continue; } f->cmap[i].tab = mallocz(n0 * sizeof(int), 1); if(f->cmap[i].tab == nil) return -1; for(j = 0; j < n; j++){ v = buf[off + 2*j] << 8 | buf[off + 2*j + 1]; if(v != 0) v += f->cmap[i].delta; f->cmap[i].tab[j] = v; } } free(buf); return 0; } static int cmap6(TTFontU *f) { u16int len, first, cnt, v; int *p; u8int *q; ttfunpack(f, "w2", &len); if(len < 12){ werrstr("character table too short"); return -1; } ttfunpack(f, "ww", &first, &cnt); f->cmap = mallocz(sizeof(TTChMap), 1); if(f->cmap == nil) return -1; f->ncmap = 1; f->cmap->start = first; f->cmap->end = first + len - 1; f->cmap->tab = mallocz(cnt * sizeof(int), 1); if(f->cmap->tab == nil) return -1; if(len < 10 + 2 * cnt){ werrstr("character table too short"); return -1; } Bread(f->bin, f->cmap->tab, 2 * cnt); p = f->cmap->tab + cnt; q = (u8int*) f->cmap->tab + 2 * cnt; while(p > f->cmap->tab){ v = *--q; v |= *--q << 8; *--p = v; } return 0; } static int cmap12(TTFontU *f) { u32int len; u32int ncmap; int i; ttfunpack(f, "2l4", &len); if(len < 16){ werrstr("character table too short"); return -1; } ttfunpack(f, "l", &ncmap); if(len < 16 + 12 * ncmap){ werrstr("character table too short"); return -1; } f->cmap = mallocz(sizeof(TTChMap) * ncmap, 1); if(f->cmap == nil) return -1; f->ncmap = ncmap; for(i = 0; i < ncmap; i++){ ttfunpack(f, "lll", &f->cmap[i].start, &f->cmap[i].end, &f->cmap[i].delta); f->cmap[i].delta -= f->cmap[i].start; } return 0; } int (*cmaphand[])(TTFontU *) = { [0] cmap0, [4] cmap4, [6] cmap6, [12] cmap12, }; int ttfparsecmap(TTFontU *f) { u16int format; if(ttfgotosub(f) < 0) return -1; ttfunpack(f, "w", &format); if(format >= nelem(cmaphand) || cmaphand[format] == nil){ werrstr("character table in unknown format %d", format); return -1; } if(cmaphand[format](f) < 0) return -1; return 0; }