otf: otf file support

[neatmkfn.git] / otf.c

#include <arpa/inet.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "sbuf.h"
#include "trfn.h"

#define MAX(a, b)       ((a) < (b) ? (b) : (a))
#define LEN(a)          (sizeof(a) / sizeof((a)[0]))

#define NGLYPHS         (1 << 14)
#define NLOOKUPS        (1 << 12)
#define GNLEN           (64)
#define NGRPS           2048

#define U32(buf, off)           (htonl(*(u32 *) ((buf) + (off))))
#define U16(buf, off)           (htons(*(u16 *) ((buf) + (off))))
#define U8(buf, off)            (*(u8 *) ((buf) + (off)))
#define S16(buf, off)           ((s16) htons(*(u16 *) ((buf) + (off))))
#define S32(buf, off)           ((s32) htonl(*(u32 *) ((buf) + (off))))

#define GCTXLEN         16      /* number of context backtrack coverage arrays */

typedef unsigned int u32;
typedef unsigned short u16;
typedef unsigned char u8;
typedef int s32;
typedef short s16;

static char glyph_name[NGLYPHS][GNLEN];
static int glyph_code[NGLYPHS];
static int glyph_bbox[NGLYPHS][4];
static int glyph_wid[NGLYPHS];
static int glyph_n;
static int upm;                 /* units per em */
static int res;                 /* device resolution */
static int kmin;                /* minimum kerning value */
static int warn;                /* report unsupported tables */

static char *macset[];
static char *stdset[];

static int owid(int w)
{
        return (w < 0 ? w * 1000 - upm / 2 : w * 1000 + upm / 2) / upm;
}

static int uwid(int w)
{
        int d = 7200 / res;
        return (w < 0 ? owid(w) - d / 2 : owid(w) + d / 2) / d;
}

/* weather the script is right-to-left */
static int otf_r2l(char *feat)
{
        char *scrp = strchr(feat, ':') + 1;
        return !strcmp("arab", scrp) || !strcmp("hebr", scrp);
}

/* report unsupported otf tables */
static void otf_unsupported(char *sub, int type, int fmt)
{
        if (warn) {
                fprintf(stderr, "neatmkfn: unsupported %s lookup %d", sub, type);
                if (fmt > 0)
                        fprintf(stderr, " format %d", fmt);
                fprintf(stderr, "\n");
        }
}

/* find the otf table with the given name */
static void *otf_table(void *otf, char *name)
{
        int nrecs = U16(otf, 4);
        int i;
        for (i = 0; i < nrecs; i++) {
                void *rec = otf + 12 + i * 16;  /* an otf table record */
                if (!strncmp(rec, name, 4))
                        return otf + U32(rec, 8);
        }
        return NULL;
}

/* obtain postscript font name from name table */
static void otf_name(void *otf, void *tab)
{
        char name[256];
        void *str = tab + U16(tab, 4);          /* storage area */
        int n = U16(tab, 2);                    /* number of name records */
        int i;
        for (i = 0; i < n; i++) {
                void *rec = tab + 6 + 12 * i;
                int pid = U16(rec, 0);          /* platform id */
                int eid = U16(rec, 2);          /* encoding id */
                int lid = U16(rec, 4);          /* language id */
                int nid = U16(rec, 6);          /* name id */
                int len = U16(rec, 8);          /* string length */
                int off = U16(rec, 10);         /* string offset  */
                if (pid == 1 && eid == 0 && lid == 0 && nid == 6) {
                        memcpy(name, str + off, len);
                        name[len] = '\0';
                        trfn_psfont(name);
                }
        }
}

/* parse otf cmap format 4 subtable */
static void otf_cmap4(void *otf, void *cmap4)
{
        int nsegs;
        void *ends, *begs, *deltas, *offsets;
        int beg, end, delta, offset;
        int i, j;
        nsegs = U16(cmap4, 6) / 2;
        ends = cmap4 + 14;
        begs = ends + 2 * nsegs + 2;
        deltas = begs + 2 * nsegs;
        offsets = deltas + 2 * nsegs;
        for (i = 0; i < nsegs; i++) {
                beg = U16(begs, 2 * i);
                end = U16(ends, 2 * i);
                delta = U16(deltas, 2 * i);
                offset = U16(offsets, 2 * i);
                if (offset) {
                        for (j = beg; j <= end; j++)
                                glyph_code[(U16(offsets + 2 * i,
                                        offset + (j - beg) * 2) + delta) & 0xffff] = j;
                } else {
                        for (j = beg; j <= end; j++)
                                glyph_code[(j + delta) & 0xffff] = j;
                }
        }
}

/* parse otf cmap header */
static void otf_cmap(void *otf, void *cmap)
{
        int nrecs = U16(cmap, 2);
        int i;
        for (i = 0; i < nrecs; i++) {
                void *rec = cmap + 4 + i * 8;   /* a cmap record */
                int plat = U16(rec, 0);
                int enc = U16(rec, 2);
                void *tab = cmap + U32(rec, 4); /* a cmap subtable */
                int fmt = U16(tab, 0);
                if (plat == 3 && enc == 1 && fmt == 4)
                        otf_cmap4(otf, tab);
        }
}

static void otf_post(void *otf, void *post)
{
        void *post2;                    /* version 2.0 header */
        void *index;                    /* glyph name indices */
        void *names;                    /* glyph names */
        int cname = 0;
        int i;
        post2 = post + 32;
        glyph_n = U16(post2, 0);
        if (U32(post, 0) != 0x20000)
                return;
        index = post2 + 2;
        names = index + 2 * glyph_n;
        for (i = 0; i < glyph_n; i++) {
                int idx = U16(index, 2 * i);
                if (idx < 258) {
                        strcpy(glyph_name[i], macset[idx]);
                } else {
                        memcpy(glyph_name[i], names + cname + 1,
                                U8(names, cname));
                        glyph_name[i][U8(names, cname)] = '\0';
                        cname += U8(names, cname) + 1;
                }
        }
}

static void otf_glyf(void *otf, void *glyf)
{
        void *maxp = otf_table(otf, "maxp");
        void *head = otf_table(otf, "head");
        void *loca = otf_table(otf, "loca");
        void *gdat;
        void *gdat_next;
        int n = U16(maxp, 4);
        int fmt = U16(head, 50);
        int i, j;
        for (i = 0; i < n; i++) {
                if (fmt) {
                        gdat = glyf + U32(loca, 4 * i);
                        gdat_next = glyf + U32(loca, 4 * (i + 1));
                } else {
                        gdat = glyf + U16(loca, 2 * i) * 2;
                        gdat_next = glyf + U16(loca, 2 * (i + 1)) * 2;
                }
                if (gdat < gdat_next)
                        for (j = 0; j < 4; j++)
                                glyph_bbox[i][j] = S16(gdat, 2 + 2 * j);
        }
}

static void otf_hmtx(void *otf, void *hmtx)
{
        void *hhea = otf_table(otf, "hhea");
        int n;
        int i;
        n = U16(hhea, 34);
        for (i = 0; i < n; i++)
                glyph_wid[i] = U16(hmtx, i * 4);
        for (i = n; i < glyph_n; i++)
                glyph_wid[i] = glyph_wid[n - 1];
}

static void otf_kern(void *otf, void *kern)
{
        int off = 4;
        int i, j;
        int n = U16(kern, 2);           /* number of kern subtables */
        for (i = 0; i < n; i++) {
                void *tab = kern + off; /* a kern subtable */
                int cov = U16(tab, 4);
                off += U16(tab, 2);
                if ((cov >> 8) == 0 && (cov & 1)) {     /* format 0 */
                        int npairs = U16(tab, 6);
                        for (j = 0; j < npairs; j++) {
                                int c1 = U16(tab, 14 + 6 * j);
                                int c2 = U16(tab, 14 + 6 * j + 2);
                                int val = S16(tab, 14 + 6 * j + 4);
                                trfn_kern(glyph_name[c1], glyph_name[c2],
                                        owid(val));
                        }
                }
        }
}

static int coverage(void *cov, int *out)
{
        int fmt = U16(cov, 0);
        int n = U16(cov, 2);
        int beg, end;
        int ncov = 0;
        int i, j;
        if (fmt == 1) {
                for (i = 0; i < n; i++)
                        out[ncov++] = U16(cov, 4 + 2 * i);
        }
        if (fmt == 2) {
                for (i = 0; i < n; i++) {
                        beg = U16(cov, 4 + 6 * i);
                        end = U16(cov, 4 + 6 * i + 2);
                        for (j = beg; j <= end; j++)
                                out[ncov++] = j;
                }
        }
        return ncov;
}

static int classdef(void *tab, int *gl, int *cls)
{
        int fmt = U16(tab, 0);
        int ngl = 0;
        int i, j;
        if (fmt == 1) {
                int beg = U16(tab, 2);
                ngl = U16(tab, 4);
                for (i = 0; i < ngl; i++) {
                        gl[i] = beg + i;
                        cls[i] = U16(tab, 6 + 2 * i);
                }
        }
        if (fmt == 2) {
                int n = U16(tab, 2);
                for (i = 0; i < n; i++) {
                        int beg = U16(tab, 4 + 6 * i);
                        int end = U16(tab, 4 + 6 * i + 2);
                        for (j = beg; j <= end; j++) {
                                gl[ngl] = j;
                                cls[ngl] = U16(tab, 4 + 6 * i + 4);
                                ngl++;
                        }
                }
        }
        return ngl;
}

static int intcmp(void *v1, void *v2)
{
        return *(int *) v1 - *(int *) v2;
}

static int ggrp_make(int *src, int n);

static int ggrp_class(int *src, int *cls, int nsrc, int id)
{
        int g[NGLYPHS];
        int n = 0;
        int i;
        for (i = 0; i < nsrc; i++)
                if (cls[i] == id)
                        g[n++] = src[i];
        qsort(g, n, sizeof(g[0]), (void *) intcmp);
        return ggrp_make(g, n);
}

static int ggrp_coverage(int *g, int n)
{
        qsort(g, n, sizeof(g[0]), (void *) intcmp);
        return ggrp_make(g, n);
}

static int valuerecord_len(int fmt)
{
        int off = 0;
        int i;
        for (i = 0; i < 8; i++)
                if (fmt & (1 << i))
                        off += 2;
        return off;
}

static void valuerecord_print(int fmt, void *rec)
{
        int vals[8] = {0};
        int off = 0;
        int i;
        for (i = 0; i < 8; i++) {
                if (fmt & (1 << i)) {
                        vals[i] = uwid(S16(rec, off));
                        off += 2;
                }
        }
        if (fmt)
                printf(":%+d%+d%+d%+d", vals[0], vals[1], vals[2], vals[3]);
}

static int valuerecord_small(int fmt, void *rec)
{
        int off = 0;
        int i;
        for (i = 0; i < 8; i++) {
                if (fmt & (1 << i)) {
                        if (abs(uwid(S16(rec, off))) >= MAX(1, kmin))
                                return 0;
                        off += 2;
                }
        }
        return 1;
}

/* single adjustment positioning */
static void otf_gpostype1(void *otf, void *sub, char *feat)
{
        int fmt = U16(sub, 0);
        int vfmt = U16(sub, 4);
        int cov[NGLYPHS];
        int ncov, nvals;
        int vlen = valuerecord_len(vfmt);
        int i;
        ncov = coverage(sub + U16(sub, 2), cov);
        if (fmt == 1) {
                for (i = 0; i < ncov; i++) {
                        if (valuerecord_small(vfmt, sub + 6))
                                continue;
                        printf("gpos %s 1 %s", feat, glyph_name[cov[i]]);
                        valuerecord_print(vfmt, sub + 6);
                        printf("\n");
                }
        }
        if (fmt == 2) {
                nvals = U16(sub, 6);
                for (i = 0; i < nvals; i++) {
                        if (valuerecord_small(vfmt, sub + 6))
                                continue;
                        printf("gpos %s 1 %s", feat, glyph_name[cov[i]]);
                        valuerecord_print(vfmt, sub + 8 + i * vlen);
                        printf("\n");
                }
        }
}

/* pair adjustment positioning */
static void otf_gpostype2(void *otf, void *sub, char *feat)
{
        int fmt = U16(sub, 0);
        int vfmt1 = U16(sub, 4);        /* valuerecord 1 */
        int vfmt2 = U16(sub, 6);        /* valuerecord 2 */
        int fmtoff1, fmtoff2;
        int vrlen;                      /* the length of vfmt1 and vfmt2 */
        int i, j;
        vrlen = valuerecord_len(vfmt1) + valuerecord_len(vfmt2);
        if (fmt == 1) {
                int cov[NGLYPHS];
                int nc1 = U16(sub, 8);
                coverage(sub + U16(sub, 2), cov);
                for (i = 0; i < nc1; i++) {
                        void *c2 = sub + U16(sub, 10 + 2 * i);
                        int nc2 = U16(c2, 0);
                        for (j = 0; j < nc2; j++) {
                                int second = U16(c2 + 2 + (2 + vrlen) * j, 0);
                                fmtoff1 = 2 + (2 + vrlen) * j + 2;
                                fmtoff2 = fmtoff1 + valuerecord_len(vfmt1);
                                if (valuerecord_small(vfmt1, c2 + fmtoff1) &&
                                        valuerecord_small(vfmt2, c2 + fmtoff2))
                                        continue;
                                printf("gpos %s 2", feat);
                                printf(" %s", glyph_name[cov[i]]);
                                valuerecord_print(vfmt1, c2 + fmtoff1);
                                printf(" %s", glyph_name[second]);
                                valuerecord_print(vfmt2, c2 + fmtoff2);
                                printf("\n");
                        }
                }
        }
        if (fmt == 2) {
                int gl1[NGLYPHS], gl2[NGLYPHS];
                int cls1[NGLYPHS], cls2[NGLYPHS];
                int grp1[NGLYPHS], grp2[NGLYPHS];
                int ngl1 = classdef(sub + U16(sub, 8), gl1, cls1);
                int ngl2 = classdef(sub + U16(sub, 10), gl2, cls2);
                int ncls1 = U16(sub, 12);
                int ncls2 = U16(sub, 14);
                for (i = 0; i < ncls1; i++)
                        grp1[i] = ggrp_class(gl1, cls1, ngl1, i);
                for (i = 0; i < ncls2; i++)
                        grp2[i] = ggrp_class(gl2, cls2, ngl2, i);
                for (i = 0; i < ncls1; i++) {
                        for (j = 0; j < ncls2; j++) {
                                fmtoff1 = 16 + (i * ncls2 + j) * vrlen;
                                fmtoff2 = fmtoff1 + valuerecord_len(vfmt1);
                                if (valuerecord_small(vfmt1, sub + fmtoff1) &&
                                        valuerecord_small(vfmt2, sub + fmtoff2))
                                        continue;
                                printf("gpos %s %d", feat, 2);
                                printf(" @%d", grp1[i]);
                                valuerecord_print(vfmt1, sub + fmtoff1);
                                printf(" @%d", grp2[j]);
                                valuerecord_print(vfmt2, sub + fmtoff2);
                                printf("\n");
                        }
                }
        }
}

/* cursive attachment positioning */
static void otf_gpostype3(void *otf, void *sub, char *feat)
{
        int fmt = U16(sub, 0);
        int cov[NGLYPHS];
        int icov[NGLYPHS];
        int ocov[NGLYPHS];
        int i, n;
        int icnt = 0;
        int ocnt = 0;
        int igrp, ogrp;
        coverage(sub + U16(sub, 2), cov);
        if (fmt != 1)
                return;
        n = U16(sub, 4);
        for (i = 0; i < n; i++)
                if (U16(sub, 6 + 4 * i))
                        ocov[ocnt++] = cov[i];
        for (i = 0; i < n; i++)
                if (U16(sub, 6 + 4 * i + 2))
                        icov[icnt++] = cov[i];
        igrp = ggrp_coverage(icov, icnt);
        ogrp = ggrp_coverage(ocov, ocnt);
        for (i = 0; i < n; i++) {
                int prev = U16(sub, 6 + 4 * i);
                int next = U16(sub, 6 + 4 * i + 2);
                if (prev) {
                        int dx = -uwid(S16(sub, prev + 2));
                        int dy = -uwid(S16(sub, prev + 4));
                        if (otf_r2l(feat)) {
                                dx += uwid(glyph_wid[cov[i]]);
                        }
                        printf("gpos %s 2 @%d %s:%+d%+d%+d%+d\n",
                                feat, igrp, glyph_name[cov[i]],
                                0, 0, dx, dy);
                }
                if (next) {
                        int dx = uwid(S16(sub, next + 2)) - uwid(glyph_wid[cov[i]]);
                        int dy = uwid(S16(sub, next + 4));
                        if (otf_r2l(feat)) {
                                dx += uwid(glyph_wid[cov[i]]);
                        }
                        printf("gpos %s 2 %s @%d:%+d%+d%+d%+d\n",
                                feat, glyph_name[cov[i]], ogrp,
                                0, 0, dx, dy);
                }
        }
}

/* mark-to-base attachment positioning */
static void otf_gpostype4(void *otf, void *sub, char *feat)
{
        int fmt = U16(sub, 0);
        int mcov[NGLYPHS];      /* mark coverage */
        int bcov[NGLYPHS];      /* base coverage */
        int cgrp[1024];         /* glyph groups assigned to classes */
        int bgrp;               /* the group assigned to base glyphs */
        int mcnt;               /* mark coverage size */
        int bcnt;               /* base coverage size */
        int ccnt;               /* class count */
        void *marks;            /* mark array table */
        void *bases;            /* base array table */
        int i, j;
        if (fmt != 1)
                return;
        mcnt = coverage(sub + U16(sub, 2), mcov);
        bcnt = coverage(sub + U16(sub, 4), bcov);
        ccnt = U16(sub, 6);
        marks = sub + U16(sub, 8);
        bases = sub + U16(sub, 10);
        bgrp = ggrp_coverage(bcov, bcnt);
        for (i = 0; i < ccnt; i++) {
                int grp[NGLYPHS];
                int cnt = 0;
                for (j = 0; j < mcnt; j++)
                        if (U16(marks, 2 + 4 * j) == i)
                                grp[cnt++] = mcov[j];
                cgrp[i] = ggrp_coverage(grp, cnt);
        }
        for (i = 0; i < mcnt; i++) {
                void *mark = marks + U16(marks, 2 + 4 * i + 2); /* mark anchor */
                int dx = -uwid(S16(mark, 2));
                int dy = -uwid(S16(mark, 4));
                if (otf_r2l(feat)) {
                        dx += uwid(glyph_wid[mcov[i]]);
                        dy = -dy;
                }
                printf("gpos %s 2 @%d %s:%+d%+d%+d%+d\n",
                        feat, bgrp, glyph_name[mcov[i]], dx, dy, 0, 0);
        }
        for (i = 0; i < bcnt; i++) {
                for (j = 0; j < ccnt; j++) {
                        void *base = bases + U16(bases, 2 + ccnt * 2 * i + 2 * j);
                        int dx = uwid(S16(base, 2)) - uwid(glyph_wid[bcov[i]]);
                        int dy = uwid(S16(base, 4));
                        if (otf_r2l(feat)) {
                                dx += uwid(glyph_wid[bcov[i]]);
                                dy = -dy;
                        }
                        printf("gpos %s 2 %s @%d:%+d%+d%+d%+d\n",
                                feat, glyph_name[bcov[i]], cgrp[j], dx, dy, 0, 0);
                }
        }
}

/* gsub context */
struct gctx {
        int bgrp[GCTXLEN];      /* backtrack coverage arrays */
        int igrp[GCTXLEN];      /* input coverage arrays */
        int lgrp[GCTXLEN];      /* lookahead coverage arrays*/
        int bn, in, ln;         /* size of b[], i[], l[] */
        int seqidx;             /* sequence index */
};

static int gctx_len(struct gctx *ctx, int patlen)
{
        return ctx ? ctx->bn + ctx->in + ctx->ln - patlen : 0;
}

static void gctx_backtrack(struct gctx *ctx)
{
        int i;
        if (!ctx)
                return;
        for (i = 0; i < ctx->bn; i++)
                printf(" =@%d", ctx->bgrp[i]);
        for (i = 0; i < ctx->seqidx; i++)
                printf(" =@%d", ctx->igrp[i]);
}

static void gctx_lookahead(struct gctx *ctx, int patlen)
{
        int i;
        if (!ctx)
                return;
        for (i = ctx->seqidx + patlen; i < ctx->in; i++)
                printf(" =@%d", ctx->igrp[i]);
        for (i = 0; i < ctx->ln; i++)
                printf(" =@%d", ctx->lgrp[i]);
}

/* single substitution */
static void otf_gsubtype1(void *otf, void *sub, char *feat, struct gctx *ctx)
{
        int cov[NGLYPHS];
        int fmt = U16(sub, 0);
        int ncov;
        int i;
        ncov = coverage(sub + U16(sub, 2), cov);
        if (fmt == 1) {
                for (i = 0; i < ncov; i++) {
                        printf("gsub %s %d", feat, 2 + gctx_len(ctx, 1));
                        gctx_backtrack(ctx);
                        printf(" -%s +%s", glyph_name[cov[i]],
                                glyph_name[cov[i] + S16(sub, 4)]);
                        gctx_lookahead(ctx, 1);
                        printf("\n");
                }
        }
        if (fmt == 2) {
                int n = U16(sub, 4);
                for (i = 0; i < n; i++) {
                        printf("gsub %s %d", feat, 2 + gctx_len(ctx, 1));
                        gctx_backtrack(ctx);
                        printf(" -%s +%s", glyph_name[cov[i]],
                                glyph_name[U16(sub, 6 + 2 * i)]);
                        gctx_lookahead(ctx, 1);
                        printf("\n");
                }
        }
}

/* alternate substitution */
static void otf_gsubtype3(void *otf, void *sub, char *feat, struct gctx *ctx)
{
        int cov[NGLYPHS];
        int fmt = U16(sub, 0);
        int n, i, j;
        if (fmt != 1)
                return;
        coverage(sub + U16(sub, 2), cov);
        n = U16(sub, 4);
        for (i = 0; i < n; i++) {
                void *alt = sub + U16(sub, 6 + 2 * i);
                int nalt = U16(alt, 0);
                for (j = 0; j < nalt; j++) {
                        printf("gsub %s %d", feat, 2 + gctx_len(ctx, 1));
                        gctx_backtrack(ctx);
                        printf(" -%s +%s", glyph_name[cov[i]],
                                glyph_name[U16(alt, 2 + 2 * j)]);
                        gctx_lookahead(ctx, 1);
                        printf("\n");
                }
        }
}

/* ligature substitution */
static void otf_gsubtype4(void *otf, void *sub, char *feat, struct gctx *ctx)
{
        int fmt = U16(sub, 0);
        int cov[NGLYPHS];
        int n, i, j, k;
        if (fmt != 1)
                return;
        coverage(sub + U16(sub, 2), cov);
        n = U16(sub, 4);
        for (i = 0; i < n; i++) {
                void *set = sub + U16(sub, 6 + 2 * i);
                int nset = U16(set, 0);
                for (j = 0; j < nset; j++) {
                        void *lig = set + U16(set, 2 + 2 * j);
                        int nlig = U16(lig, 2);
                        printf("gsub %s %d", feat, nlig + 1 + gctx_len(ctx, nlig));
                        gctx_backtrack(ctx);
                        printf(" -%s", glyph_name[cov[i]]);
                        for (k = 0; k < nlig - 1; k++)
                                printf(" -%s", glyph_name[U16(lig, 4 + 2 * k)]);
                        printf(" +%s", glyph_name[U16(lig, 0)]);
                        gctx_lookahead(ctx, nlig);
                        printf("\n");
                }
        }
}

/* chaining contextual substitution */
static void otf_gsubtype6(void *otf, void *sub, char *feat, void *gsub)
{
        struct gctx ctx = {{0}};
        void *lookups = gsub + U16(gsub, 8);
        int fmt = U16(sub, 0);
        int cov[NGLYPHS];
        int i, j, nsub, ncov;
        int off = 2;
        if (fmt != 3) {
                otf_unsupported("GSUB", 6, fmt);
                return;
        }
        ctx.bn = U16(sub, off);
        for (i = 0; i < ctx.bn; i++) {
                ncov = coverage(sub + U16(sub, off + 2 + 2 * i), cov);
                ctx.bgrp[i] = ggrp_coverage(cov, ncov);
        }
        off += 2 + 2 * ctx.bn;
        ctx.in = U16(sub, off);
        for (i = 0; i < ctx.in; i++) {
                ncov = coverage(sub + U16(sub, off + 2 + 2 * i), cov);
                ctx.igrp[i] = ggrp_coverage(cov, ncov);
        }
        off += 2 + 2 * ctx.in;
        ctx.ln = U16(sub, off);
        for (i = 0; i < ctx.ln; i ++) {
                ncov = coverage(sub + U16(sub, off + 2 + 2 * i), cov);
                ctx.lgrp[i] = ggrp_coverage(cov, ncov);
        }
        off += 2 + 2 * ctx.ln;
        nsub = U16(sub, off);   /* nsub > 1 is not supported */
        for (i = 0; i < nsub && i < 1; i++) {
                int lidx = U16(sub, off + 2 + 4 * i + 2);
                void *lookup = lookups + U16(lookups, 2 + 2 * lidx);
                int ltype = U16(lookup, 0);
                int ntabs = U16(lookup, 4);
                ctx.seqidx = U16(sub, off + 2 + 4 * i);
                for (j = 0; j < ntabs; j++) {
                        void *tab = lookup + U16(lookup, 6 + 2 * j);
                        int type = ltype;
                        if (type == 7) {        /* extension substitution */
                                type = U16(tab, 2);
                                tab = tab + U32(tab, 4);
                        }
                        if (type == 1)
                                otf_gsubtype1(otf, tab, feat, &ctx);
                        if (type == 3)
                                otf_gsubtype3(otf, tab, feat, &ctx);
                        if (type == 4)
                                otf_gsubtype4(otf, tab, feat, &ctx);
                }
        }
}

/* an otf gsub/gpos lookup */
struct otflookup {
        char scrp[8];           /* script name */
        char feat[8];           /* feature name */
        int lookup;             /* index into the lookup table */
};

/* parse the given gsub/gpos feature table */
static int otf_featrec(void *otf, void *gtab, void *featrec, char *script, struct otflookup *lookups)
{
        void *feats = gtab + U16(gtab, 6);
        void *feat = feats + U16(featrec, 4);
        int nlookups = U16(feat, 2);
        int i;
        for (i = 0; i < nlookups; i++) {
                memcpy(lookups[i].feat, featrec, 4);
                lookups[i].feat[4] = '\0';
                strcpy(lookups[i].scrp, script);
                lookups[i].lookup = U16(feat, 4 + 2 * i);
        }
        return nlookups;
}

/* parse the given language table and its feature tables */
static int otf_lang(void *otf, void *gtab, void *lang, char *script, struct otflookup *lookups)
{
        void *feats = gtab + U16(gtab, 6);
        int featidx = U16(lang, 2);
        int nfeat = U16(lang, 4);
        int n = 0;
        int i;
        if (featidx != 0xffff)
                n += otf_featrec(otf, gtab, feats + 2 + 6 * featidx, script, lookups + n);
        for (i = 0; i < nfeat; i++)
                n += otf_featrec(otf, gtab,
                                feats + 2 + 6 * U16(lang, 6 + 2 * i), script, lookups + n);
        return n;
}

static int lookupcmp(void *v1, void *v2)
{
        struct otflookup *l1 = v1;
        struct otflookup *l2 = v2;
        if (strcmp(l1->scrp, l2->scrp))
                return strcmp(l1->scrp, l2->scrp);
        if (trfn_featrank(l1->scrp, l1->feat) != trfn_featrank(l1->scrp, l2->feat))
                return trfn_featrank(l1->scrp, l1->feat) - trfn_featrank(l1->scrp, l2->feat);
        return l1->lookup - l2->lookup;
}

/* extract lookup tables for all features of the given gsub/gpos table */
static int otf_gtab(void *otf, void *gpos, struct otflookup *lookups)
{
        void *scripts = gpos + U16(gpos, 4);
        int nscripts, nlangs;
        void *script;
        char stag[8], ltag[8];          /* script and language tags */
        int i, j;
        int n = 0;
        nscripts = U16(scripts, 0);
        for (i = 0; i < nscripts; i++) {
                void *grec = scripts + 2 + 6 * i;
                memcpy(stag, grec, 4);
                stag[4] = '\0';
                if (!trfn_script(stag, nscripts))
                        continue;
                script = scripts + U16(grec, 4);
                nlangs = U16(script, 2);
                if (U16(script, 0) && trfn_lang(NULL, nlangs + (U16(script, 0) != 0)))
                        n += otf_lang(otf, gpos, script + U16(script, 0),
                                                stag, lookups + n);
                for (j = 0; j < nlangs; j++) {
                        void *lrec = script + 4 + 6 * j;
                        memcpy(ltag, lrec, 4);
                        ltag[4] = '\0';
                        if (trfn_lang(ltag, nlangs + (U16(script, 0) != 0)))
                                n += otf_lang(otf, gpos, script + U16(lrec, 4),
                                                stag, lookups + n);
                }
        }
        qsort(lookups, n, sizeof(lookups[0]), (void *) lookupcmp);
        return n;
}

static void otf_gpos(void *otf, void *gpos)
{
        struct otflookup lookups[NLOOKUPS];
        void *lookuplist = gpos + U16(gpos, 8);
        int nlookups = otf_gtab(otf, gpos, lookups);
        char tag[16];
        int i, j;
        for (i = 0; i < nlookups; i++) {
                void *lookup = lookuplist + U16(lookuplist, 2 + 2 * lookups[i].lookup);
                int ltype = U16(lookup, 0);
                int ntabs = U16(lookup, 4);
                sprintf(tag, "%s:%s", lookups[i].feat,
                                lookups[i].scrp[0] ? lookups[i].scrp : "DFLT");
                for (j = 0; j < ntabs; j++) {
                        void *tab = lookup + U16(lookup, 6 + 2 * j);
                        int type = ltype;
                        if (type == 9) {        /* extension positioning */
                                type = U16(tab, 2);
                                tab = tab + U32(tab, 4);
                        }
                        switch (type) {
                        case 1:
                                otf_gpostype1(otf, tab, tag);
                                break;
                        case 2:
                                otf_gpostype2(otf, tab, tag);
                                break;
                        case 3:
                                otf_gpostype3(otf, tab, tag);
                                break;
                        case 4:
                                otf_gpostype4(otf, tab, tag);
                                break;
                        default:
                                otf_unsupported("GPOS", type, 0);
                        }
                }
        }
}

static void otf_gsub(void *otf, void *gsub)
{
        struct otflookup lookups[NLOOKUPS];
        void *lookuplist = gsub + U16(gsub, 8);
        int nlookups = otf_gtab(otf, gsub, lookups);
        char tag[16];
        int i, j;
        for (i = 0; i < nlookups; i++) {
                void *lookup = lookuplist + U16(lookuplist, 2 + 2 * lookups[i].lookup);
                int ltype = U16(lookup, 0);
                int ntabs = U16(lookup, 4);
                sprintf(tag, "%s:%s", lookups[i].feat,
                                lookups[i].scrp[0] ? lookups[i].scrp : "DFLT");
                for (j = 0; j < ntabs; j++) {
                        void *tab = lookup + U16(lookup, 6 + 2 * j);
                        int type = ltype;
                        if (type == 7) {        /* extension substitution */
                                type = U16(tab, 2);
                                tab = tab + U32(tab, 4);
                        }
                        switch (type) {
                        case 1:
                                otf_gsubtype1(otf, tab, tag, NULL);
                                break;
                        case 3:
                                otf_gsubtype3(otf, tab, tag, NULL);
                                break;
                        case 4:
                                otf_gsubtype4(otf, tab, tag, NULL);
                                break;
                        case 6:
                                otf_gsubtype6(otf, tab, tag, gsub);
                                break;
                        default:
                                otf_unsupported("GSUB", type, 0);
                        }
                }
        }
}

/* read a cff offset, which has sz bytes */
static int cff_int(void *tab, int off, int sz)
{
        int i;
        int n = 0;
        for (i = 0; i < sz; i++)
                n = n * 256 + U8(tab, off + i);
        return n;
}

/* cff dict operand/operator */
static int cff_op(void *tab, int off, int *val)
{
        int b0 = U8(tab, off);
        int i;
        if (b0 >= 32 && b0 <= 246) {
                *val = b0 - 139;
                return 1;
        }
        if (b0 >= 247 && b0 <= 250) {
                *val = (b0 - 247) * 256 + U8(tab, off + 1) + 108;
                return 2;
        }
        if (b0 >= 251 && b0 <= 254) {
                *val = -(b0 - 251) * 256 - U8(tab, off + 1) - 108;
                return 2;
        }
        if (b0 == 28) {
                *val = (U8(tab, off + 1) << 8) | U8(tab, off + 2);
                return 3;
        }
        if (b0 == 29) {
                *val = (U8(tab, off + 1) << 24) | (U8(tab, off + 2) << 16) |
                        (U8(tab, off + 3) << 8) | U8(tab, off + 4);
                return 5;
        }
        if (b0 == 30) {
                for (i = 1; i < 32; i++) {
                        int nib = U8(tab, off + i);
                        if ((nib & 0x0f) == 0x0f || (nib & 0xf0) == 0xf0)
                                break;
                }
                *val = 0;
                return i + 1;
        }
        *val = b0;
        return 1;
}

static int cffidx_cnt(void *idx)
{
        return U16(idx, 0);
}

static void *cffidx_get(void *idx, int i)
{
        int cnt = U16(idx, 0);
        int sz = U8(idx, 2);
        return idx + 3 + (cnt + 1) * sz - 1 + cff_int(idx, 3 + i * sz, sz);
}

static int cffidx_len(void *idx, int i)
{
        return cffidx_get(idx, i + 1) - cffidx_get(idx, i);
}

static void *cffidx_end(void *idx)
{
        return cffidx_get(idx, cffidx_cnt(idx));
}

static int cffdict_get(void *dict, int len, int key)
{
        int off = 0;
        int op = 0;
        int val = 0;
        /* operators: keys (one or two bytes); operands: values */
        while (off < len) {
                val = op;
                off += cff_op(dict, off, &op);
                if (op == 12) {                 /* two-byte operator */
                        off += cff_op(dict, off, &op);
                        op += 1200;
                }
                if (op == key)
                        return val;
        }
        return 0;
}

static void cff_char(void *stridx, int id, char *dst)
{
        int len;
        if (id < 391) {
                strcpy(dst, stdset[id]);
                return;
        }
        id -= 391;
        len = cffidx_len(stridx, id);
        memcpy(dst, cffidx_get(stridx, id), len);
        dst[len] = '\0';
}

static void otf_cff(void *otf, void *cff)
{
        void *nameidx;          /* name index */
        void *topidx;           /* top dict index */
        void *stridx;           /* string idx */
        void *chridx;           /* charstrings index */
        void *charset;          /* charset offset of top dict table */
        int i, j;
        if (U8(cff, 0) != 1)
                return;
        nameidx = cff + U8(cff, 2);
        topidx = cffidx_end(nameidx);
        if (cffidx_cnt(nameidx) < 1)
                return;
        stridx = cffidx_end(topidx);
        chridx = cff + cffdict_get(cffidx_get(topidx, 0), cffidx_len(topidx, 0), 17);
        charset = cff + cffdict_get(cffidx_get(topidx, 0), cffidx_len(topidx, 0), 15);
        glyph_n = cffidx_cnt(chridx);
        strcpy(glyph_name[0], ".notdef");
        if (U8(charset, 0) == 0) {
                for (i = 0; i < glyph_n; i++)
                        cff_char(stridx, i, glyph_name[i]);
        }
        if (U8(charset, 0) == 1) {
                int g = 1;
                for (i = 0; g < glyph_n; i++) {
                        int sid = U16(charset, 1 + i * 3);
                        int cnt = U8(charset, 1 + i * 3 + 2);
                        for (j = 0; j <= cnt && g < glyph_n; j++) {
                                cff_char(stridx, sid + j, glyph_name[g]);
                                g++;
                        }
                }
        }
        if (U8(charset, 0) == 2) {
                int g = 1;
                for (i = 0; g < glyph_n; i++) {
                        int sid = U16(charset, 1 + i * 4);
                        int cnt = U16(charset, 1 + i * 4 + 2);
                        for (j = 0; j <= cnt && g < glyph_n; j++) {
                                cff_char(stridx, sid + j, glyph_name[g]);
                                g++;
                        }
                }
        }
}

static void *otf_input(int fd)
{
        struct sbuf *sb = sbuf_make();
        char buf[1 << 12];
        int nr = 0;
        while ((nr = read(fd, buf, sizeof(buf))) > 0)
                sbuf_mem(sb, buf, nr);
        return sbuf_done(sb);
}

static char *otf_buf;

int otf_read(void)
{
        int i;
        otf_buf = otf_input(0);
        upm = U16(otf_table(otf_buf, "head"), 18);
        otf_name(otf_buf, otf_table(otf_buf, "name"));
        otf_cmap(otf_buf, otf_table(otf_buf, "cmap"));
        otf_post(otf_buf, otf_table(otf_buf, "post"));
        if (otf_table(otf_buf, "glyf"))
                otf_glyf(otf_buf, otf_table(otf_buf, "glyf"));
        if (otf_table(otf_buf, "CFF "))
                otf_cff(otf_buf, otf_table(otf_buf, "CFF "));
        otf_hmtx(otf_buf, otf_table(otf_buf, "hmtx"));
        for (i = 0; i < glyph_n; i++) {
                trfn_char(glyph_name[i], -1,
                        glyph_code[i] != 0xffff ? glyph_code[i] : 0,
                        owid(glyph_wid[i]),
                        owid(glyph_bbox[i][0]), owid(glyph_bbox[i][1]),
                        owid(glyph_bbox[i][2]), owid(glyph_bbox[i][3]));
        }
        if (otf_table(otf_buf, "kern"))
                otf_kern(otf_buf, otf_table(otf_buf, "kern"));
        return 0;
}

void otf_feat(int r, int k, int w)
{
        res = r;
        kmin = k;
        warn = w;
        if (otf_table(otf_buf, "GSUB"))
                otf_gsub(otf_buf, otf_table(otf_buf, "GSUB"));
        if (otf_table(otf_buf, "GPOS"))
                otf_gpos(otf_buf, otf_table(otf_buf, "GPOS"));
}

/* glyph groups */
static int *ggrp_g[NGRPS];
static int ggrp_len[NGRPS];
static int ggrp_n;

static int ggrp_find(int *src, int n)
{
        int i, j;
        for (i = 0; i < ggrp_n; i++) {
                if (ggrp_len[i] == n) {
                        for (j = 0; j < n; j++)
                                if (src[j] != ggrp_g[i][j])
                                        break;
                        if (j == n)
                                return i;
                }
        }
        return -1;
}

static int ggrp_make(int *src, int n)
{
        int id = ggrp_find(src, n);
        int i;
        if (id >= 0)
                return id;
        id = ggrp_n++;
        ggrp_g[id] = malloc(n * sizeof(ggrp_g[id][0]));
        ggrp_len[id] = n;
        for (i = 0; i < n; i++)
                ggrp_g[id][i] = src[i];
        printf("ggrp %d %d", id, n);
        for (i = 0; i < n; i++)
                printf(" %s", glyph_name[src[i]]);
        printf("\n");
        return id;
}

static char *macset[] = {
        ".notdef", ".null", "nonmarkingreturn", "space", "exclam",
        "quotedbl", "numbersign", "dollar", "percent", "ampersand",
        "quotesingle", "parenleft", "parenright", "asterisk", "plus",
        "comma", "hyphen", "period", "slash", "zero",
        "one", "two", "three", "four", "five",
        "six", "seven", "eight", "nine", "colon",
        "semicolon", "less", "equal", "greater", "question",
        "at", "A", "B", "C", "D",
        "E", "F", "G", "H", "I",
        "J", "K", "L", "M", "N",
        "O", "P", "Q", "R", "S",
        "T", "U", "V", "W", "X",
        "Y", "Z", "bracketleft", "backslash", "bracketright",
        "asciicircum", "underscore", "grave", "a", "b",
        "c", "d", "e", "f", "g",
        "h", "i", "j", "k", "l",
        "m", "n", "o", "p", "q",
        "r", "s", "t", "u", "v",
        "w", "x", "y", "z", "braceleft",
        "bar", "braceright", "asciitilde", "Adieresis", "Aring",
        "Ccedilla", "Eacute", "Ntilde", "Odieresis", "Udieresis",
        "aacute", "agrave", "acircumflex", "adieresis", "atilde",
        "aring", "ccedilla", "eacute", "egrave", "ecircumflex",
        "edieresis", "iacute", "igrave", "icircumflex", "idieresis",
        "ntilde", "oacute", "ograve", "ocircumflex", "odieresis",
        "otilde", "uacute", "ugrave", "ucircumflex", "udieresis",
        "dagger", "degree", "cent", "sterling", "section",
        "bullet", "paragraph", "germandbls", "registered", "copyright",
        "trademark", "acute", "dieresis", "notequal", "AE",
        "Oslash", "infinity", "plusminus", "lessequal", "greaterequal",
        "yen", "mu", "partialdiff", "summation", "product",
        "pi", "integral", "ordfeminine", "ordmasculine", "Omega",
        "ae", "oslash", "questiondown", "exclamdown", "logicalnot",
        "radical", "florin", "approxequal", "Delta", "guillemotleft",
        "guillemotright", "ellipsis", "nonbreakingspace", "Agrave", "Atilde",
        "Otilde", "OE", "oe", "endash", "emdash",
        "quotedblleft", "quotedblright", "quoteleft", "quoteright", "divide",
        "lozenge", "ydieresis", "Ydieresis", "fraction", "currency",
        "guilsinglleft", "guilsinglright", "fi", "fl", "daggerdbl",
        "periodcentered", "quotesinglbase", "quotedblbase", "perthousand", "Acircumflex",
        "Ecircumflex", "Aacute", "Edieresis", "Egrave", "Iacute",
        "Icircumflex", "Idieresis", "Igrave", "Oacute", "Ocircumflex",
        "apple", "Ograve", "Uacute", "Ucircumflex", "Ugrave",
        "dotlessi", "circumflex", "tilde", "macron", "breve",
        "dotaccent", "ring", "cedilla", "hungarumlaut", "ogonek",
        "caron", "Lslash", "lslash", "Scaron", "scaron",
        "Zcaron", "zcaron", "brokenbar", "Eth", "eth",
        "Yacute", "yacute", "Thorn", "thorn", "minus",
        "multiply", "onesuperior", "twosuperior", "threesuperior", "onehalf",
        "onequarter", "threequarters", "franc", "Gbreve", "gbreve",
        "Idotaccent", "Scedilla", "scedilla", "Cacute", "cacute",
        "Ccaron", "ccaron", "dcroat",
};

static char *stdset[] = {
        ".notdef", "space", "exclam", "quotedbl", "numbersign",
        "dollar", "percent", "ampersand", "quoteright", "parenleft",
        "parenright", "asterisk", "plus", "comma", "hyphen",
        "period", "slash", "zero", "one", "two",
        "three", "four", "five", "six", "seven",
        "eight", "nine", "colon", "semicolon", "less",
        "equal", "greater", "question", "at", "A",
        "B", "C", "D", "E", "F",
        "G", "H", "I", "J", "K",
        "L", "M", "N", "O", "P",
        "Q", "R", "S", "T", "U",
        "V", "W", "X", "Y", "Z",
        "bracketleft", "backslash", "bracketright", "asciicircum", "underscore",
        "quoteleft", "a", "b", "c", "d",
        "e", "f", "g", "h", "i",
        "j", "k", "l", "m", "n",
        "o", "p", "q", "r", "s",
        "t", "u", "v", "w", "x",
        "y", "z", "braceleft", "bar", "braceright",
        "asciitilde", "exclamdown", "cent", "sterling", "fraction",
        "yen", "florin", "section", "currency", "quotesingle",
        "quotedblleft", "guillemotleft", "guilsinglleft", "guilsinglright", "fi",
        "fl", "endash", "dagger", "daggerdbl", "periodcentered",
        "paragraph", "bullet", "quotesinglbase", "quotedblbase", "quotedblright",
        "guillemotright", "ellipsis", "perthousand", "questiondown", "grave",
        "acute", "circumflex", "tilde", "macron", "breve",
        "dotaccent", "dieresis", "ring", "cedilla", "hungarumlaut",
        "ogonek", "caron", "emdash", "AE", "ordfeminine",
        "Lslash", "Oslash", "OE", "ordmasculine", "ae",
        "dotlessi", "lslash", "oslash", "oe", "germandbls",
        "onesuperior", "logicalnot", "mu", "trademark", "Eth",
        "onehalf", "plusminus", "Thorn", "onequarter", "divide",
        "brokenbar", "degree", "thorn", "threequarters", "twosuperior",
        "registered", "minus", "eth", "multiply", "threesuperior",
        "copyright", "Aacute", "Acircumflex", "Adieresis", "Agrave",
        "Aring", "Atilde", "Ccedilla", "Eacute", "Ecircumflex",
        "Edieresis", "Egrave", "Iacute", "Icircumflex", "Idieresis",
        "Igrave", "Ntilde", "Oacute", "Ocircumflex", "Odieresis",
        "Ograve", "Otilde", "Scaron", "Uacute", "Ucircumflex",
        "Udieresis", "Ugrave", "Yacute", "Ydieresis", "Zcaron",
        "aacute", "acircumflex", "adieresis", "agrave", "aring",
        "atilde", "ccedilla", "eacute", "ecircumflex", "edieresis",
        "egrave", "iacute", "icircumflex", "idieresis", "igrave",
        "ntilde", "oacute", "ocircumflex", "odieresis", "ograve",
        "otilde", "scaron", "uacute", "ucircumflex", "udieresis",
        "ugrave", "yacute", "ydieresis", "zcaron", "exclamsmall",
        "Hungarumlautsmall", "dollaroldstyle", "dollarsuperior", "ampersandsmall", "Acutesmall",
        "parenleftsuperior", "parenrightsuperior", "twodotenleader", "onedotenleader", "zerooldstyle",
        "oneoldstyle", "twooldstyle", "threeoldstyle", "fouroldstyle", "fiveoldstyle",
        "sixoldstyle", "sevenoldstyle", "eightoldstyle", "nineoldstyle", "commasuperior",
        "threequartersemdash", "periodsuperior", "questionsmall", "asuperior", "bsuperior",
        "centsuperior", "dsuperior", "esuperior", "isuperior", "lsuperior",
        "msuperior", "nsuperior", "osuperior", "rsuperior", "ssuperior",
        "tsuperior", "ff", "ffi", "ffl", "parenleftinferior",
        "parenrightinferior", "Circumflexsmall", "hyphensuperior", "Gravesmall", "Asmall",
        "Bsmall", "Csmall", "Dsmall", "Esmall", "Fsmall",
        "Gsmall", "Hsmall", "Ismall", "Jsmall", "Ksmall",
        "Lsmall", "Msmall", "Nsmall", "Osmall", "Psmall",
        "Qsmall", "Rsmall", "Ssmall", "Tsmall", "Usmall",
        "Vsmall", "Wsmall", "Xsmall", "Ysmall", "Zsmall",
        "colonmonetary", "onefitted", "rupiah", "Tildesmall", "exclamdownsmall",
        "centoldstyle", "Lslashsmall", "Scaronsmall", "Zcaronsmall", "Dieresissmall",
        "Brevesmall", "Caronsmall", "Dotaccentsmall", "Macronsmall", "figuredash",
        "hypheninferior", "Ogoneksmall", "Ringsmall", "Cedillasmall", "questiondownsmall",
        "oneeighth", "threeeighths", "fiveeighths", "seveneighths", "onethird",
        "twothirds", "zerosuperior", "foursuperior", "fivesuperior", "sixsuperior",
        "sevensuperior", "eightsuperior", "ninesuperior", "zeroinferior", "oneinferior",
        "twoinferior", "threeinferior", "fourinferior", "fiveinferior", "sixinferior",
        "seveninferior", "eightinferior", "nineinferior", "centinferior", "dollarinferior",
        "periodinferior", "commainferior", "Agravesmall", "Aacutesmall", "Acircumflexsmall",
        "Atildesmall", "Adieresissmall", "Aringsmall", "AEsmall", "Ccedillasmall",
        "Egravesmall", "Eacutesmall", "Ecircumflexsmall", "Edieresissmall", "Igravesmall",
        "Iacutesmall", "Icircumflexsmall", "Idieresissmall", "Ethsmall", "Ntildesmall",
        "Ogravesmall", "Oacutesmall", "Ocircumflexsmall", "Otildesmall", "Odieresissmall",
        "OEsmall", "Oslashsmall", "Ugravesmall", "Uacutesmall", "Ucircumflexsmall",
        "Udieresissmall", "Yacutesmall", "Thornsmall", "Ydieresissmall", "001.000",
        "001.001", "001.002", "001.003", "Black", "Bold",
        "Book", "Light", "Medium", "Regular", "Roman",
        "Semibold",
};