ref: 99db038e2825266e84ddb381718f3d047dc6d733
dir: /sys/src/libttf/head.c/
#include <u.h> #include <libc.h> #include <bio.h> #include <draw.h> #include <ctype.h> #include <ttf.h> #include "impl.h" void ttfunpack(TTFontU *f, char *p, ...) { va_list va; int n; uchar *p1; u16int *p2; u32int *p4; va_start(va, p); for(; *p != 0; p++) switch(*p){ case 'b': p1 = va_arg(va, u8int *); *p1 = Bgetc(f->bin); break; case 'B': p4 = va_arg(va, u32int *); *p4 = Bgetc(f->bin); break; case 'w': p2 = va_arg(va, u16int *); *p2 = Bgetc(f->bin) << 8; *p2 |= Bgetc(f->bin); break; case 'W': p4 = va_arg(va, u32int *); *p4 = Bgetc(f->bin) << 8; *p4 |= Bgetc(f->bin); break; case 'S': p4 = va_arg(va, u32int *); *p4 = (char)Bgetc(f->bin) << 8; *p4 |= Bgetc(f->bin); break; case 'l': p4 = va_arg(va, u32int *); *p4 = Bgetc(f->bin) << 24; *p4 |= Bgetc(f->bin) << 16; *p4 |= Bgetc(f->bin) << 8; *p4 |= Bgetc(f->bin); break; case '.': Bgetc(f->bin); break; case ' ': break; default: if(isdigit(*p)){ n = strtol(p, &p, 10); p--; Bseek(f->bin, n, 1); }else abort(); break; } } static int directory(TTFontU *f) { u32int scaler; int i; ttfunpack(f, "lw .. .. ..", &scaler, &f->ntab); if(scaler != 0x74727565 && scaler != 0x10000){ werrstr("unknown scaler type %#ux", scaler); return -1; } f->tab = mallocz(sizeof(TTTable) * f->ntab, 1); if(f->tab == nil) return -1; for(i = 0; i < f->ntab; i++) ttfunpack(f, "llll", &f->tab[i].tag, &f->tab[i].csum, &f->tab[i].offset, &f->tab[i].len); return 0; } int ttfgototable(TTFontU *f, char *str) { TTTable *t; u32int tag; tag = (u8int)str[0] << 24 | (u8int)str[1] << 16 | (u8int)str[2] << 8 | (u8int)str[3]; for(t = f->tab; t < f->tab + f->ntab; t++) if(t->tag == tag){ Bseek(f->bin, t->offset, 0); return t->len; } werrstr("no such table '%s'", str); return -1; } static int ttfparseloca(TTFontU *f) { int len, i; u32int x; len = ttfgototable(f, "loca"); if(len < 0) return -1; x = 0; if(f->longloca){ if(len > (f->numGlyphs + 1) * 4) len = (f->numGlyphs + 1) * 4; for(i = 0; i < len/4; i++){ x = Bgetc(f->bin) << 24; x |= Bgetc(f->bin) << 16; x |= Bgetc(f->bin) << 8; x |= Bgetc(f->bin); f->ginfo[i].loca = x; } }else{ if(len > (f->numGlyphs + 1) * 2) len = (f->numGlyphs + 1) * 2; for(i = 0; i < len/2; i++){ x = Bgetc(f->bin) << 8; x |= Bgetc(f->bin); f->ginfo[i].loca = x * 2; } } for(; i < f->numGlyphs; i++) f->ginfo[i].loca = x; return 0; } static int ttfparsehmtx(TTFontU *f) { int i; u16int x, y; int len; int maxlsb; len = ttfgototable(f, "hmtx"); if(len < 0) return -1; if(f->numOfLongHorMetrics > f->numGlyphs){ werrstr("nonsensical header: numOfLongHorMetrics > numGlyphs"); return -1; } for(i = 0; i < f->numOfLongHorMetrics; i++){ ttfunpack(f, "ww", &x, &y); f->ginfo[i].advanceWidth = x; f->ginfo[i].lsb = y; } maxlsb = (len - 2 * f->numOfLongHorMetrics) / 2; if(maxlsb > f->numGlyphs){ werrstr("nonsensical header: maxlsb > f->numGlyphs"); return -1; } for(; i < maxlsb; i++){ ttfunpack(f, "w", &y); f->ginfo[i].advanceWidth = x; f->ginfo[i].lsb = y; } for(; i < f->numGlyphs; i++){ f->ginfo[i].advanceWidth = x; f->ginfo[i].lsb = y; } return 0; } int ttfparsecvt(TTFontU *f) { int len; int i; int x; u8int *p; short *w; len = ttfgototable(f, "cvt "); if(len <= 0) return 0; f->cvtu = mallocz(len, 1); if(f->cvtu == 0) return -1; Bread(f->bin, f->cvtu, len); p = (u8int *) f->cvtu; f->ncvtu = len / 2; w = f->cvtu; for(i = 0; i < f->ncvtu; i++){ x = (short)(p[0] << 8 | p[1]); p += 2; *w++ = x; } return 0; } static int ttfparseos2(TTFontU *f) { int len; u16int usWinAscent, usWinDescent; len = ttfgototable(f, "OS/2 "); if(len < 0) return -1; if(len < 78){ werrstr("OS/2 table too short"); return -1; } ttfunpack(f, "68 6 ww", &usWinAscent, &usWinDescent); f->ascent = usWinAscent; f->descent = usWinDescent; return 0; } static void ttfcloseu(TTFontU *u) { int i; if(u == nil) return; Bterm(u->bin); for(i = 0; i < u->ncmap; i++) free(u->cmap[i].tab); free(u->cmap); free(u->ginfo); free(u->tab); free(u->cvtu); free(u); } void ttfclose(TTFont *f) { int i; if(f == nil) return; if(--f->u->ref <= 0) ttfcloseu(f->u); for(i = 0; i < f->u->maxFunctionDefs; i++) free(f->func[i].pgm); free(f->hintstack); free(f->func); free(f->storage); free(f->twilight); free(f->twiorg); free(f->cvt); free(f); } static TTFont * ttfscaleu(TTFontU *u, int ppem) { TTFont *f; int i; f = mallocz(sizeof(TTFont), 1); if(f == nil) return nil; f->u = u; u->ref++; f->ppem = ppem; f->ncvt = u->ncvtu; f->cvt = malloc(sizeof(int) * u->ncvtu); if(f->cvt == nil) goto error; for(i = 0; i < u->ncvtu; i++) f->cvt[i] = ttfrounddiv(u->cvtu[i] * ppem * 64, u->emsize); f->hintstack = mallocz(sizeof(u32int) * u->maxStackElements, 1); f->func = mallocz(sizeof(TTFunction) * u->maxFunctionDefs, 1); f->storage = mallocz(sizeof(u32int) * u->maxStorage, 1); f->twilight = mallocz(sizeof(TTPoint) * u->maxTwilightPoints, 1); f->twiorg = mallocz(sizeof(TTPoint) * u->maxTwilightPoints, 1); if(f->hintstack == nil || f->func == nil || f->storage == nil || f->twilight == nil || f->twiorg == nil) goto error; f->ascentpx = (u->ascent * ppem + u->emsize - 1) / (u->emsize); f->descentpx = (u->descent * ppem + u->emsize - 1) / (u->emsize); if(ttfrunfpgm(f) < 0) goto error; if(ttfruncvt(f) < 0) goto error; return f; error: ttfclose(f); return nil; } TTFont * ttfopen(char *name, int ppem, int) { Biobuf *b; TTFontU *u; if(ppem < 0){ werrstr("invalid ppem argument"); return nil; } b = Bopen(name, OREAD); if(b == nil) return nil; u = mallocz(sizeof(TTFontU), 1); if(u == nil) return nil; u->bin = b; u->nkern = -1; if(directory(u) < 0) goto error; if(ttfgototable(u, "head") < 0) goto error; ttfunpack(u, "16 w W 16 wwww 6 w", &u->flags, &u->emsize, &u->xmin, &u->ymin, &u->xmax, &u->ymax, &u->longloca); if(ttfgototable(u, "maxp") < 0) goto error; ttfunpack(u, "4 wwwwwwwwwwwwww", &u->numGlyphs, &u->maxPoints, &u->maxCountours, &u->maxComponentPoints, &u->maxComponentCountours, &u->maxZones, &u->maxTwilightPoints, &u->maxStorage, &u->maxFunctionDefs, &u->maxInstructionDefs, &u->maxStackElements, &u->maxSizeOfInstructions, &u->maxComponentElements, &u->maxComponentDepth); u->ginfo = mallocz(sizeof(TTGlyphInfo) * (u->numGlyphs + 1), 1); if(u->ginfo == nil) goto error; if(ttfgototable(u, "hhea") < 0) goto error; ttfunpack(u, "10 wwww 16 w", &u->advanceWidthMax, &u->minLeftSideBearing, &u->minRightSideBearing, &u->xMaxExtent, &u->numOfLongHorMetrics); if(ttfparseloca(u) < 0) goto error; if(ttfparsehmtx(u) < 0) goto error; if(ttfparsecvt(u) < 0) goto error; if(ttfparsecmap(u) < 0) goto error; if(ttfparseos2(u) < 0) goto error; return ttfscaleu(u, ppem); error: ttfcloseu(u); return nil; } TTFont * ttfscale(TTFont *f, int ppem, int) { return ttfscaleu(f->u, ppem); } int ttfrounddiv(int a, int b) { if(b < 0){ a = -a; b = -b; } if(a > 0) return (a + b/2) / b; else return (a - b/2) / b; } int ttfvrounddiv(vlong a, int b) { if(b < 0){ a = -a; b = -b; } if(a > 0) return (a + b/2) / b; else return (a - b/2) / b; }