From 5f8b49fd56158b07f10333cb8873b1b80fc2f9ee Mon Sep 17 00:00:00 2001 From: Nicholas Noll Date: Tue, 2 Jun 2020 14:55:42 -0700 Subject: refactored stb font library into a cleaner unix library --- sys/libfont/font.c | 3298 ++++++++++++++++++++++++++++++++++++++++++++++++++ sys/libfont/rules.mk | 19 + sys/libfont/test.c | 62 + 3 files changed, 3379 insertions(+) create mode 100644 sys/libfont/font.c create mode 100644 sys/libfont/rules.mk create mode 100644 sys/libfont/test.c (limited to 'sys') diff --git a/sys/libfont/font.c b/sys/libfont/font.c new file mode 100644 index 0000000..f7dfce7 --- /dev/null +++ b/sys/libfont/font.c @@ -0,0 +1,3298 @@ +#include +#include +#include + +#define SAMPLE 8 /* should not be > 255 */ + +#define getshort(b) getbytes((b), 2) +#define getint(b) getbytes((b), 4) + +// ----------------------------------------------------------------------- +// internal types + +typedef struct Buffer Buffer; +typedef struct Edge Edge; +typedef struct ActiveEdge ActiveEdge; +typedef struct Point Point; + +struct Buffer +{ + uchar *data; + int cursor; + int size; +}; + +struct Edge { + float x0, y0, x1,y1; + int invert; +}; + +struct ActiveEdge +{ + struct ActiveEdge *next; + float fx,fdx,fdy; + float direction; + float sy; + float ey; +}; + +struct Point +{ + float x,y; +}; + +// ----------------------------------------------------------------------- +// opaque external types + +struct font·Info +{ + void *userdata; + uchar *data; // pointer to .ttf file + int fontstart; // offset of start of font + + int numglyphs; // number of glyphs, needed for range checking + + int loca,head,glyf,hhea,hmtx,kern,gpos,svg; // table locations as offset from start of .ttf + int index_map; // a cmap mapping for our chosen character encoding + int indexToLocFormat; // format needed to map from glyph index to glyph + + Buffer cff; // cff font data + Buffer charstrings; // the charstring index + Buffer gsubrs; // global charstring subroutines index + Buffer subrs; // private charstring subroutines index + Buffer fontdicts; // array of font dicts + Buffer fdselect; // map from glyph to fontdict +}; + +struct font·Bitmap +{ + int w; + int h; + int stride; + uchar *pixels; +}; + +typedef int test_oversample_pow2[(SAMPLE & (SAMPLE-1)) == 0 ? 1 : -1]; + +// ----------------------------------------------------------------------- +// buf helpers to parse data from file + +static +uchar +getbyte(Buffer *b) +{ + if (b->cursor >= b->size) + return 0; + return b->data[b->cursor++]; +} + +static +uchar +peek(Buffer *b) +{ + if (b->cursor >= b->size) + return 0; + return b->data[b->cursor]; +} + +static +void +seek(Buffer *b, int o) +{ + assert(!(o > b->size || o < 0)); + b->cursor = (o > b->size || o < 0) ? b->size : o; +} + +static +void +skip(Buffer *b, int o) +{ + seek(b, b->cursor + o); +} + +static +uint32 +getbytes(Buffer *b, int n) +{ + uint32 v = 0; + int i; + assert(n >= 1 && n <= 4); + for (i = 0; i < n; i++) + v = (v << 8) | getbyte(b); + return v; +} + +static +Buffer +makebuf(const void *p, size_t size) +{ + Buffer r; + assert(size < 0x40000000); + r.data = (uchar*) p; + r.size = (int) size; + r.cursor = 0; + return r; +} + +static +Buffer +slice(const Buffer *b, int o, int s) +{ + Buffer r = makebuf(nil, 0); + if (o < 0 || s < 0 || o > b->size || s > b->size - o) return r; + r.data = b->data + o; + r.size = s; + return r; +} + +static +Buffer +cff_index(Buffer *b) +{ + int count, start, offsize; + + start = b->cursor; + count = getshort(b); + if (count) { + offsize = getbyte(b); + assert(offsize >= 1 && offsize <= 4); + skip(b, offsize * count); + skip(b, getbytes(b, offsize) - 1); + } + return slice(b, start, b->cursor - start); +} + +static +uint32 +cff_int(Buffer *b) +{ + int b0 = getbyte(b); + if (b0 >= 32 && b0 <= 246) return b0 - 139; + else if (b0 >= 247 && b0 <= 250) return (b0 - 247)*256 + getbyte(b) + 108; + else if (b0 >= 251 && b0 <= 254) return -(b0 - 251)*256 - getbyte(b) - 108; + else if (b0 == 28) return getshort(b); + else if (b0 == 29) return getint(b); + assert(0); + return 0; +} + +static +void +skip_operand(Buffer *b) { + int v, b0 = peek(b); + assert(b0 >= 28); + if (b0 == 30) { + skip(b, 1); + while (b->cursor < b->size) { + v = getbyte(b); + if ((v & 0xF) == 0xF || (v >> 4) == 0xF) + break; + } + } else { + cff_int(b); + } +} + +static +Buffer +dict_get(Buffer *b, int key) +{ + seek(b, 0); + while (b->cursor < b->size) { + int start = b->cursor, end, op; + while (peek(b) >= 28) + skip_operand(b); + end = b->cursor; + op = getbyte(b); + if (op == 12) op = getbyte(b) | 0x100; + if (op == key) return slice(b, start, end-start); + } + return slice(b, 0, 0); +} + +static +void +dict_get_ints(Buffer *b, int key, int outcount, uint32 *out) +{ + int i; + Buffer operands = dict_get(b, key); + for (i = 0; i < outcount && operands.cursor < operands.size; i++) + out[i] = cff_int(&operands); +} + +static +int +cff_index_count(Buffer *b) +{ + seek(b, 0); + return getshort(b); +} + +static +Buffer +cff_index_get(Buffer b, int i) +{ + int count, offsize, start, end; + seek(&b, 0); + count = getshort(&b); + offsize = getbyte(&b); + assert(i >= 0 && i < count); + assert(offsize >= 1 && offsize <= 4); + skip(&b, i*offsize); + start = getbytes(&b, offsize); + end = getbytes(&b, offsize); + return slice(&b, 2+(count+1)*offsize+start, end - start); +} + +// ----------------------------------------------------------------------- +// accessors to parse data from file + +/* + * on platforms that don't allow misaligned reads, if we want to allow + * truetype fonts that aren't padded to alignment, define ALLOW_UNALIGNED_TRUETYPE + */ + +#define ttBYTE(p) (* (uchar *) (p)) +#define ttCHAR(p) (* (char *) (p)) +#define ttFixed(p) ttLONG(p) + +static ushort ttUSHORT(uchar *p) { return p[0]*256 + p[1]; } +static short ttSHORT(uchar *p) { return p[0]*256 + p[1]; } +static uint32 ttULONG(uchar *p) { return (p[0]<<24) + (p[1]<<16) + (p[2]<<8) + p[3]; } +static int32 ttLONG(uchar *p) { return (p[0]<<24) + (p[1]<<16) + (p[2]<<8) + p[3]; } + +#define font·tag4(p,c0,c1,c2,c3) ((p)[0] == (c0) && (p)[1] == (c1) && (p)[2] == (c2) && (p)[3] == (c3)) +#define font·tag(p,str) font·tag4(p,str[0],str[1],str[2],str[3]) + +static +int +isfont(uchar *font) +{ + // check the version number + if (font·tag4(font, '1',0,0,0)) return 1; // TrueType 1 + if (font·tag(font, "typ1")) return 1; // TrueType with type 1 font -- we don't support this! + if (font·tag(font, "OTTO")) return 1; // OpenType with CFF + if (font·tag4(font, 0,1,0,0)) return 1; // OpenType 1.0 + if (font·tag(font, "true")) return 1; // Apple specification for TrueType fonts + + return 0; +} + +// @OPTIMIZE: binary search +static +uint32 +find_table(uchar *data, uint32 fontstart, const char *tag) +{ + int i; + int32 ntab; + uint32 tabdir; + + ntab = ttUSHORT(data+fontstart+4); + tabdir = fontstart + 12; + for (i=0; i < ntab; ++i) { + uint32 loc = tabdir + 16*i; + if (font·tag(data+loc+0, tag)) + return ttULONG(data+loc+8); + } + return 0; +} + +int +font·offsetfor(uchar *font_collection, int index) +{ + // if it's just a font, there's only one valid index + if (isfont(font_collection)) + return index == 0 ? 0 : -1; + + // check if it's a TTC + if (font·tag(font_collection, "ttcf")) { + // version 1? + if (ttULONG(font_collection+4) == 0x00010000 || ttULONG(font_collection+4) == 0x00020000) { + int32 n = ttLONG(font_collection+8); + if (index >= n) + return -1; + return ttULONG(font_collection+12+index*4); + } + } + return -1; +} + +int +font·number(uchar *font_collection) +{ + // if it's just a font, there's only one valid font + if (isfont(font_collection)) + return 1; + + // check if it's a TTC + if (font·tag(font_collection, "ttcf")) { + // version 1? + if (ttULONG(font_collection+4) == 0x00010000 || ttULONG(font_collection+4) == 0x00020000) { + return ttLONG(font_collection+8); + } + } + return 0; +} + +static +Buffer +get_subrs(Buffer cff, Buffer fontdict) +{ + uint32 subrsoff = 0, private_loc[2] = { 0, 0 }; + Buffer pdict; + dict_get_ints(&fontdict, 18, 2, private_loc); + if (!private_loc[1] || !private_loc[0]) return makebuf(nil, 0); + pdict = slice(&cff, private_loc[1], private_loc[0]); + dict_get_ints(&pdict, 19, 1, &subrsoff); + if (!subrsoff) return makebuf(nil, 0); + seek(&cff, private_loc[1]+subrsoff); + return cff_index(&cff); +} + +// since most people won't use this, find this table the first time it's needed +static +int +get_svg(font·Info *info) +{ + uint32 t; + if (info->svg < 0) { + t = find_table(info->data, info->fontstart, "SVG "); + if (t) { + uint32 offset = ttULONG(info->data + t + 2); + info->svg = t + offset; + } else { + info->svg = 0; + } + } + return info->svg; +} + +static +int +init(font·Info *info, uchar *data, int fontstart) +{ + uint32 cmap, t; + int32 i,numTables; + + info->data = data; + info->fontstart = fontstart; + info->cff = makebuf(nil, 0); + + cmap = find_table(data, fontstart, "cmap"); // required + info->loca = find_table(data, fontstart, "loca"); // required + info->head = find_table(data, fontstart, "head"); // required + info->glyf = find_table(data, fontstart, "glyf"); // required + info->hhea = find_table(data, fontstart, "hhea"); // required + info->hmtx = find_table(data, fontstart, "hmtx"); // required + info->kern = find_table(data, fontstart, "kern"); // not required + info->gpos = find_table(data, fontstart, "GPOS"); // not required + + if (!cmap || !info->head || !info->hhea || !info->hmtx) + return 0; + if (info->glyf) { + // required for truetype + if (!info->loca) + return 1; + } else { + // initialization for CFF / Type2 fonts (OTF) + Buffer b, topdict, topdictidx; + uint32 cstype = 2, charstrings = 0, fdarrayoff = 0, fdselectoff = 0; + uint32 cff; + + cff = find_table(data, fontstart, "CFF "); + if (!cff) + return 1; + + info->fontdicts = makebuf(nil, 0); + info->fdselect = makebuf(nil, 0); + + // @TODO this should use size from table (not 512MB) + info->cff = makebuf(data+cff, 512*1024*1024); + b = info->cff; + + // read the header + skip(&b, 2); + seek(&b, getbyte(&b)); // hdrsize + + // @TODO the name INDEX could list multiple fonts, + // but we just use the first one. + cff_index(&b); // name INDEX + topdictidx = cff_index(&b); + topdict = cff_index_get(topdictidx, 0); + cff_index(&b); // string INDEX + info->gsubrs = cff_index(&b); + + dict_get_ints(&topdict, 17, 1, &charstrings); + dict_get_ints(&topdict, 0x100 | 6, 1, &cstype); + dict_get_ints(&topdict, 0x100 | 36, 1, &fdarrayoff); + dict_get_ints(&topdict, 0x100 | 37, 1, &fdselectoff); + info->subrs = get_subrs(b, topdict); + + // we only support Type 2 charstrings + if (cstype != 2) + return 1; + if (charstrings == 0) + return 1; + + if (fdarrayoff) { + // looks like a CID font + if (!fdselectoff) + return 1; + seek(&b, fdarrayoff); + info->fontdicts = cff_index(&b); + info->fdselect = slice(&b, fdselectoff, b.size-fdselectoff); + } + + seek(&b, charstrings); + info->charstrings = cff_index(&b); + } + + t = find_table(data, fontstart, "maxp"); + if (t) + info->numglyphs = ttUSHORT(data+t+4); + else + info->numglyphs = 0xffff; + + info->svg = -1; + + // find a cmap encoding table we understand *now* to avoid searching + // later. (todo: could make this installable) + // the same regardless of glyph. + numTables = ttUSHORT(data + cmap + 2); + info->index_map = 0; + for (i=0; i < numTables; ++i) { + uint32 encoding_record = cmap + 4 + 8 * i; + // find an encoding we understand: + switch(ttUSHORT(data+encoding_record)) { + case font·platform_unicode: + // Mac/iOS has these + // all the encodingIDs are unicode, so we don't bother to check it + info->index_map = cmap + ttULONG(data+encoding_record+4); + break; + default: + ; + } + } + if (info->index_map == 0) { + return 1; + } + + info->indexToLocFormat = ttUSHORT(data+info->head + 50); + return 0; +} + +font·Info * +font·make(uchar *data, int fontstart) +{ + int err; + font·Info *info; + + info = calloc(1, sizeof(*info)); + err = init(info, data, fontstart); + if (err) { + free(info); + info = nil; + } + + return info; +} + +void +font·free(font·Info *info) +{ + free(info); +} + +int +font·glyph_index(font·Info *info, int unicode_codepoint) +{ + uchar *data = info->data; + uint32 index_map = info->index_map; + + ushort format = ttUSHORT(data + index_map + 0); + if (format == 0) { // apple byte encoding + int32 bytes = ttUSHORT(data + index_map + 2); + if (unicode_codepoint < bytes-6) + return ttBYTE(data + index_map + 6 + unicode_codepoint); + return 0; + } else if (format == 6) { + uint32 first = ttUSHORT(data + index_map + 6); + uint32 count = ttUSHORT(data + index_map + 8); + if ((uint32) unicode_codepoint >= first && (uint32) unicode_codepoint < first+count) + return ttUSHORT(data + index_map + 10 + (unicode_codepoint - first)*2); + return 0; + } else if (format == 2) { + assert(0); // @TODO: high-byte mapping for japanese/chinese/korean + return 0; + } else if (format == 4) { // standard mapping for windows fonts: binary search collection of ranges + ushort segcount = ttUSHORT(data+index_map+6) >> 1; + ushort searchRange = ttUSHORT(data+index_map+8) >> 1; + ushort entrySelector = ttUSHORT(data+index_map+10); + ushort rangeShift = ttUSHORT(data+index_map+12) >> 1; + + // do a binary search of the segments + uint32 endCount = index_map + 14; + uint32 search = endCount; + + if (unicode_codepoint > 0xffff) + return 0; + + // they lie from endCount .. endCount + segCount + // but searchRange is the nearest power of two, so... + if (unicode_codepoint >= ttUSHORT(data + search + rangeShift*2)) + search += rangeShift*2; + + // now decrement to bias correctly to find smallest + search -= 2; + while (entrySelector) { + ushort end; + searchRange >>= 1; + end = ttUSHORT(data + search + searchRange*2); + if (unicode_codepoint > end) + search += searchRange*2; + --entrySelector; + } + search += 2; + + { + ushort offset, start; + ushort item = (ushort) ((search - endCount) >> 1); + + assert(unicode_codepoint <= ttUSHORT(data + endCount + 2*item)); + start = ttUSHORT(data + index_map + 14 + segcount*2 + 2 + 2*item); + if (unicode_codepoint < start) + return 0; + + offset = ttUSHORT(data + index_map + 14 + segcount*6 + 2 + 2*item); + if (offset == 0) + return (ushort) (unicode_codepoint + ttSHORT(data + index_map + 14 + segcount*4 + 2 + 2*item)); + + return ttUSHORT(data + offset + (unicode_codepoint-start)*2 + index_map + 14 + segcount*6 + 2 + 2*item); + } + } else if (format == 12 || format == 13) { + uint32 ngroups = ttULONG(data+index_map+12); + int32 low,high; + low = 0; high = (int32)ngroups; + // Binary search the right group. + while (low < high) { + int32 mid = low + ((high-low) >> 1); // rounds down, so low <= mid < high + uint32 start_char = ttULONG(data+index_map+16+mid*12); + uint32 end_char = ttULONG(data+index_map+16+mid*12+4); + if ((uint32) unicode_codepoint < start_char) + high = mid; + else if ((uint32) unicode_codepoint > end_char) + low = mid+1; + else { + uint32 start_glyph = ttULONG(data+index_map+16+mid*12+8); + if (format == 12) + return start_glyph + unicode_codepoint-start_char; + else // format == 13 + return start_glyph; + } + } + return 0; // not found + } + // @TODO + assert(0); + return 0; +} + +int +font·code_shape(font·Info *info, int unicode_codepoint, font·Vertex **vertices) +{ + return font·glyph_shape(info, font·glyph_index(info, unicode_codepoint), vertices); +} + +static +void +setvertex(font·Vertex *v, uchar type, int32 x, int32 y, int32 cx, int32 cy) +{ + v->type = type; + v->x = (short) x; + v->y = (short) y; + v->cx = (short) cx; + v->cy = (short) cy; +} + +static +int +glyph_offset(const font·Info *info, int glyph_index) +{ + int g1,g2; + + assert(!info->cff.size); + + if (glyph_index >= info->numglyphs) return -1; // glyph index out of range + if (info->indexToLocFormat >= 2) return -1; // unknown index->glyph map format + + if (info->indexToLocFormat == 0) { + g1 = info->glyf + ttUSHORT(info->data + info->loca + glyph_index * 2) * 2; + g2 = info->glyf + ttUSHORT(info->data + info->loca + glyph_index * 2 + 2) * 2; + } else { + g1 = info->glyf + ttULONG (info->data + info->loca + glyph_index * 4); + g2 = info->glyf + ttULONG (info->data + info->loca + glyph_index * 4 + 4); + } + + return g1==g2 ? -1 : g1; // if length is 0, return -1 +} + +static int glyph_info_t2(font·Info *info, int glyph_index, int *x0, int *y0, int *x1, int *y1); + +int +font·glyph_box(font·Info *info, int glyph_index, int *x0, int *y0, int *x1, int *y1) +{ + if (info->cff.size) { + glyph_info_t2(info, glyph_index, x0, y0, x1, y1); + } else { + int g = glyph_offset(info, glyph_index); + if (g < 0) return 0; + + if (x0) *x0 = ttSHORT(info->data + g + 2); + if (y0) *y0 = ttSHORT(info->data + g + 4); + if (x1) *x1 = ttSHORT(info->data + g + 6); + if (y1) *y1 = ttSHORT(info->data + g + 8); + } + return 1; +} + +int +font·code_box(font·Info *info, int codepoint, int *x0, int *y0, int *x1, int *y1) +{ + return font·glyph_box(info, font·glyph_index(info,codepoint), x0,y0,x1,y1); +} + +int +font·glyph_empty(font·Info *info, int glyph_index) +{ + short numberOfContours; + int g; + if (info->cff.size) + return glyph_info_t2(info, glyph_index, nil, nil, nil, nil) == 0; + g = glyph_offset(info, glyph_index); + if (g < 0) return 1; + numberOfContours = ttSHORT(info->data + g); + return numberOfContours == 0; +} + +static +int +close_shape(font·Vertex *vertices, int num_vertices, int was_off, int start_off, + int32 sx, int32 sy, int32 scx, int32 scy, int32 cx, int32 cy) +{ + if (start_off) { + if (was_off) + setvertex(&vertices[num_vertices++], font·Vcurve, (cx+scx)>>1, (cy+scy)>>1, cx,cy); + setvertex(&vertices[num_vertices++], font·Vcurve, sx,sy,scx,scy); + } else { + if (was_off) + setvertex(&vertices[num_vertices++], font·Vcurve,sx,sy,cx,cy); + else + setvertex(&vertices[num_vertices++], font·Vline,sx,sy,0,0); + } + return num_vertices; +} + +static +int +glyph_shape_tt(font·Info *info, int glyph_index, font·Vertex **pvertices) +{ + short numberOfContours; + uchar *endPtsOfContours; + uchar *data = info->data; + font·Vertex *vertices=0; + int num_vertices=0; + int g = glyph_offset(info, glyph_index); + + *pvertices = nil; + + if (g < 0) return 0; + + numberOfContours = ttSHORT(data + g); + + if (numberOfContours > 0) { + uchar flags=0,flagcount; + int32 ins, i,j=0,m,n, next_move, was_off=0, off, start_off=0; + int32 x,y,cx,cy,sx,sy, scx,scy; + uchar *points; + endPtsOfContours = (data + g + 10); + ins = ttUSHORT(data + g + 10 + numberOfContours * 2); + points = data + g + 10 + numberOfContours * 2 + 2 + ins; + + n = 1+ttUSHORT(endPtsOfContours + numberOfContours*2-2); + + m = n + 2*numberOfContours; // a loose bound on how many vertices we might need + vertices = malloc(m * sizeof(vertices[0])); + if (vertices == 0) + return 0; + + next_move = 0; + flagcount=0; + + // in first pass, we load uninterpreted data into the allocated array + // above, shifted to the end of the array so we won't overwrite it when + // we create our final data starting from the front + + off = m - n; // starting offset for uninterpreted data, regardless of how m ends up being calculated + + // first load flags + + for (i=0; i < n; ++i) { + if (flagcount == 0) { + flags = *points++; + if (flags & 8) + flagcount = *points++; + } else + --flagcount; + vertices[off+i].type = flags; + } + + // now load x coordinates + x=0; + for (i=0; i < n; ++i) { + flags = vertices[off+i].type; + if (flags & 2) { + short dx = *points++; + x += (flags & 16) ? dx : -dx; // ??? + } else { + if (!(flags & 16)) { + x = x + (short) (points[0]*256 + points[1]); + points += 2; + } + } + vertices[off+i].x = (short) x; + } + + // now load y coordinates + y=0; + for (i=0; i < n; ++i) { + flags = vertices[off+i].type; + if (flags & 4) { + short dy = *points++; + y += (flags & 32) ? dy : -dy; // ??? + } else { + if (!(flags & 32)) { + y = y + (short) (points[0]*256 + points[1]); + points += 2; + } + } + vertices[off+i].y = (short) y; + } + + // now convert them to our format + num_vertices=0; + sx = sy = cx = cy = scx = scy = 0; + for (i=0; i < n; ++i) { + flags = vertices[off+i].type; + x = (short) vertices[off+i].x; + y = (short) vertices[off+i].y; + + if (next_move == i) { + if (i != 0) + num_vertices = close_shape(vertices, num_vertices, was_off, start_off, sx,sy,scx,scy,cx,cy); + + // now start the new one + start_off = !(flags & 1); + if (start_off) { + // if we start off with an off-curve point, then when we need to find a point on the curve + // where we can start, and we need to save some state for when we wraparound. + scx = x; + scy = y; + if (!(vertices[off+i+1].type & 1)) { + // next point is also a curve point, so interpolate an on-point curve + sx = (x + (int32) vertices[off+i+1].x) >> 1; + sy = (y + (int32) vertices[off+i+1].y) >> 1; + } else { + // otherwise just use the next point as our start point + sx = (int32) vertices[off+i+1].x; + sy = (int32) vertices[off+i+1].y; + ++i; // we're using point i+1 as the starting point, so skip it + } + } else { + sx = x; + sy = y; + } + setvertex(&vertices[num_vertices++], font·Vmove,sx,sy,0,0); + was_off = 0; + next_move = 1 + ttUSHORT(endPtsOfContours+j*2); + ++j; + } else { + if (!(flags & 1)) { // if it's a curve + if (was_off) // two off-curve control points in a row means interpolate an on-curve midpoint + setvertex(&vertices[num_vertices++], font·Vcurve, (cx+x)>>1, (cy+y)>>1, cx, cy); + cx = x; + cy = y; + was_off = 1; + } else { + if (was_off) + setvertex(&vertices[num_vertices++], font·Vcurve, x,y, cx, cy); + else + setvertex(&vertices[num_vertices++], font·Vline, x,y,0,0); + was_off = 0; + } + } + } + num_vertices = close_shape(vertices, num_vertices, was_off, start_off, sx,sy,scx,scy,cx,cy); + } else if (numberOfContours < 0) { + // Compound shapes. + int more = 1; + uchar *comp = data + g + 10; + num_vertices = 0; + vertices = 0; + while (more) { + ushort flags, gidx; + int comp_num_verts = 0, i; + font·Vertex *comp_verts = 0, *tmp = 0; + float mtx[6] = {1,0,0,1,0,0}, m, n; + + flags = ttSHORT(comp); comp+=2; + gidx = ttSHORT(comp); comp+=2; + + if (flags & 2) { // XY values + if (flags & 1) { // shorts + mtx[4] = ttSHORT(comp); comp+=2; + mtx[5] = ttSHORT(comp); comp+=2; + } else { + mtx[4] = ttCHAR(comp); comp+=1; + mtx[5] = ttCHAR(comp); comp+=1; + } + } + else { + // @TODO handle matching point + assert(0); + } + if (flags & (1<<3)) { // WE_HAVE_A_SCALE + mtx[0] = mtx[3] = ttSHORT(comp)/16384.0f; comp+=2; + mtx[1] = mtx[2] = 0; + } else if (flags & (1<<6)) { // WE_HAVE_AN_X_AND_YSCALE + mtx[0] = ttSHORT(comp)/16384.0f; comp+=2; + mtx[1] = mtx[2] = 0; + mtx[3] = ttSHORT(comp)/16384.0f; comp+=2; + } else if (flags & (1<<7)) { // WE_HAVE_A_TWO_BY_TWO + mtx[0] = ttSHORT(comp)/16384.0f; comp+=2; + mtx[1] = ttSHORT(comp)/16384.0f; comp+=2; + mtx[2] = ttSHORT(comp)/16384.0f; comp+=2; + mtx[3] = ttSHORT(comp)/16384.0f; comp+=2; + } + + // Find transformation scales. + m = (float) sqrt(mtx[0]*mtx[0] + mtx[1]*mtx[1]); + n = (float) sqrt(mtx[2]*mtx[2] + mtx[3]*mtx[3]); + + // Get indexed glyph. + comp_num_verts = font·glyph_shape(info, gidx, &comp_verts); + if (comp_num_verts > 0) { + // Transform vertices. + for (i = 0; i < comp_num_verts; ++i) { + font·Vertex* v = &comp_verts[i]; + short x,y; + x=v->x; y=v->y; + v->x = (short)(m * (mtx[0]*x + mtx[2]*y + mtx[4])); + v->y = (short)(n * (mtx[1]*x + mtx[3]*y + mtx[5])); + x=v->cx; y=v->cy; + v->cx = (short)(m * (mtx[0]*x + mtx[2]*y + mtx[4])); + v->cy = (short)(n * (mtx[1]*x + mtx[3]*y + mtx[5])); + } + // Append vertices. + tmp = malloc((num_vertices+comp_num_verts)*sizeof(font·Vertex)); + if (!tmp) { + if (vertices) free(vertices); + if (comp_verts) free(comp_verts); + return 0; + } + if (num_vertices > 0) + memcpy(tmp, vertices, num_vertices*sizeof(font·Vertex)); + + memcpy(tmp+num_vertices, comp_verts, comp_num_verts*sizeof(font·Vertex)); + + if (vertices) + free(vertices); + + vertices = tmp; + free(comp_verts); + num_vertices += comp_num_verts; + } + // More components ? + more = flags & (1<<5); + } + } else { + // numberOfCounters == 0, do nothing + } + + *pvertices = vertices; + return num_vertices; +} + +typedef struct +{ + int bounds; + int started; + float first_x, first_y; + float x, y; + int32 min_x, max_x, min_y, max_y; + + font·Vertex *pvertices; + int num_vertices; +} csctx; + +#define CSCTX_INIT(bounds) {bounds,0, 0,0, 0,0, 0,0,0,0, nil, 0} + +static void track_vertex(csctx *c, int32 x, int32 y) +{ + if (x > c->max_x || !c->started) c->max_x = x; + if (y > c->max_y || !c->started) c->max_y = y; + if (x < c->min_x || !c->started) c->min_x = x; + if (y < c->min_y || !c->started) c->min_y = y; + c->started = 1; +} + +static void csctx_v(csctx *c, uchar type, int32 x, int32 y, int32 cx, int32 cy, int32 cx1, int32 cy1) +{ + if (c->bounds) { + track_vertex(c, x, y); + if (type == font·Vcubic) { + track_vertex(c, cx, cy); + track_vertex(c, cx1, cy1); + } + } else { + setvertex(&c->pvertices[c->num_vertices], type, x, y, cx, cy); + c->pvertices[c->num_vertices].cx1 = (short) cx1; + c->pvertices[c->num_vertices].cy1 = (short) cy1; + } + c->num_vertices++; +} + +static void csctx_close_shape(csctx *ctx) +{ + if (ctx->first_x != ctx->x || ctx->first_y != ctx->y) + csctx_v(ctx, font·Vline, (int)ctx->first_x, (int)ctx->first_y, 0, 0, 0, 0); +} + +static void csctx_rmove_to(csctx *ctx, float dx, float dy) +{ + csctx_close_shape(ctx); + ctx->first_x = ctx->x = ctx->x + dx; + ctx->first_y = ctx->y = ctx->y + dy; + csctx_v(ctx, font·Vmove, (int)ctx->x, (int)ctx->y, 0, 0, 0, 0); +} + +static void csctx_rline_to(csctx *ctx, float dx, float dy) +{ + ctx->x += dx; + ctx->y += dy; + csctx_v(ctx, font·Vline, (int)ctx->x, (int)ctx->y, 0, 0, 0, 0); +} + +static void csctx_rccurve_to(csctx *ctx, float dx1, float dy1, float dx2, float dy2, float dx3, float dy3) +{ + float cx1 = ctx->x + dx1; + float cy1 = ctx->y + dy1; + float cx2 = cx1 + dx2; + float cy2 = cy1 + dy2; + ctx->x = cx2 + dx3; + ctx->y = cy2 + dy3; + csctx_v(ctx, font·Vcubic, (int)ctx->x, (int)ctx->y, (int)cx1, (int)cy1, (int)cx2, (int)cy2); +} + +static Buffer get_subr(Buffer idx, int n) +{ + int count = cff_index_count(&idx); + int bias = 107; + if (count >= 33900) + bias = 32768; + else if (count >= 1240) + bias = 1131; + n += bias; + if (n < 0 || n >= count) + return makebuf(nil, 0); + return cff_index_get(idx, n); +} + +static Buffer cid_get_glyph_subrs(const font·Info *info, int glyph_index) +{ + Buffer fdselect = info->fdselect; + int nranges, start, end, v, fmt, fdselector = -1, i; + + seek(&fdselect, 0); + fmt = getbyte(&fdselect); + if (fmt == 0) { + // untested + skip(&fdselect, glyph_index); + fdselector = getbyte(&fdselect); + } else if (fmt == 3) { + nranges = getshort(&fdselect); + start = getshort(&fdselect); + for (i = 0; i < nranges; i++) { + v = getbyte(&fdselect); + end = getshort(&fdselect); + if (glyph_index >= start && glyph_index < end) { + fdselector = v; + break; + } + start = end; + } + } + if (fdselector == -1) makebuf(nil, 0); + return get_subrs(info->cff, cff_index_get(info->fontdicts, fdselector)); +} + +static +int +run_charstring(font·Info *info, int glyph_index, csctx *c) +{ + int in_header = 1, maskbits = 0, subr_stack_height = 0, sp = 0, v, i, b0; + int has_subrs = 0, clear_stack; + float s[48]; + Buffer subr_stack[10], subrs = info->subrs, b; + float f; + +#define STBTT__CSERR(s) (0) + + // this currently ignores the initial width value, which isn't needed if we have hmtx + b = cff_index_get(info->charstrings, glyph_index); + while (b.cursor < b.size) { + i = 0; + clear_stack = 1; + b0 = getbyte(&b); + switch (b0) { + // @TODO implement hinting + case 0x13: // hintmask + case 0x14: // cntrmask + if (in_header) + maskbits += (sp / 2); // implicit "vstem" + in_header = 0; + skip(&b, (maskbits + 7) / 8); + break; + + case 0x01: // hstem + case 0x03: // vstem + case 0x12: // hstemhm + case 0x17: // vstemhm + maskbits += (sp / 2); + break; + + case 0x15: // rmoveto + in_header = 0; + if (sp < 2) return STBTT__CSERR("rmoveto stack"); + csctx_rmove_to(c, s[sp-2], s[sp-1]); + break; + case 0x04: // vmoveto + in_header = 0; + if (sp < 1) return STBTT__CSERR("vmoveto stack"); + csctx_rmove_to(c, 0, s[sp-1]); + break; + case 0x16: // hmoveto + in_header = 0; + if (sp < 1) return STBTT__CSERR("hmoveto stack"); + csctx_rmove_to(c, s[sp-1], 0); + break; + + case 0x05: // rlineto + if (sp < 2) return STBTT__CSERR("rlineto stack"); + for (; i + 1 < sp; i += 2) + csctx_rline_to(c, s[i], s[i+1]); + break; + + // hlineto/vlineto and vhcurveto/hvcurveto alternate horizontal and vertical + // starting from a different place. + + case 0x07: // vlineto + if (sp < 1) return STBTT__CSERR("vlineto stack"); + goto vlineto; + case 0x06: // hlineto + if (sp < 1) return STBTT__CSERR("hlineto stack"); + for (;;) { + if (i >= sp) break; + csctx_rline_to(c, s[i], 0); + i++; + vlineto: + if (i >= sp) break; + csctx_rline_to(c, 0, s[i]); + i++; + } + break; + + case 0x1F: // hvcurveto + if (sp < 4) return STBTT__CSERR("hvcurveto stack"); + goto hvcurveto; + case 0x1E: // vhcurveto + if (sp < 4) return STBTT__CSERR("vhcurveto stack"); + for (;;) { + if (i + 3 >= sp) break; + csctx_rccurve_to(c, 0, s[i], s[i+1], s[i+2], s[i+3], (sp - i == 5) ? s[i + 4] : 0.0f); + i += 4; + hvcurveto: + if (i + 3 >= sp) break; + csctx_rccurve_to(c, s[i], 0, s[i+1], s[i+2], (sp - i == 5) ? s[i+4] : 0.0f, s[i+3]); + i += 4; + } + break; + + case 0x08: // rrcurveto + if (sp < 6) return STBTT__CSERR("rcurveline stack"); + for (; i + 5 < sp; i += 6) + csctx_rccurve_to(c, s[i], s[i+1], s[i+2], s[i+3], s[i+4], s[i+5]); + break; + + case 0x18: // rcurveline + if (sp < 8) return STBTT__CSERR("rcurveline stack"); + for (; i + 5 < sp - 2; i += 6) + csctx_rccurve_to(c, s[i], s[i+1], s[i+2], s[i+3], s[i+4], s[i+5]); + if (i + 1 >= sp) return STBTT__CSERR("rcurveline stack"); + csctx_rline_to(c, s[i], s[i+1]); + break; + + case 0x19: // rlinecurve + if (sp < 8) return STBTT__CSERR("rlinecurve stack"); + for (; i + 1 < sp - 6; i += 2) + csctx_rline_to(c, s[i], s[i+1]); + if (i + 5 >= sp) return STBTT__CSERR("rlinecurve stack"); + csctx_rccurve_to(c, s[i], s[i+1], s[i+2], s[i+3], s[i+4], s[i+5]); + break; + + case 0x1A: // vvcurveto + case 0x1B: // hhcurveto + if (sp < 4) return STBTT__CSERR("(vv|hh)curveto stack"); + f = 0.0; + if (sp & 1) { f = s[i]; i++; } + for (; i + 3 < sp; i += 4) { + if (b0 == 0x1B) + csctx_rccurve_to(c, s[i], f, s[i+1], s[i+2], s[i+3], 0.0); + else + csctx_rccurve_to(c, f, s[i], s[i+1], s[i+2], 0.0, s[i+3]); + f = 0.0; + } + break; + + case 0x0A: // callsubr + if (!has_subrs) { + if (info->fdselect.size) + subrs = cid_get_glyph_subrs(info, glyph_index); + has_subrs = 1; + } + // fallthrough + case 0x1D: // callgsubr + if (sp < 1) return STBTT__CSERR("call(g|)subr stack"); + v = (int) s[--sp]; + if (subr_stack_height >= 10) return STBTT__CSERR("recursion limit"); + subr_stack[subr_stack_height++] = b; + b = get_subr(b0 == 0x0A ? subrs : info->gsubrs, v); + if (b.size == 0) return STBTT__CSERR("subr not found"); + b.cursor = 0; + clear_stack = 0; + break; + + case 0x0B: // return + if (subr_stack_height <= 0) return STBTT__CSERR("return outside subr"); + b = subr_stack[--subr_stack_height]; + clear_stack = 0; + break; + + case 0x0E: // endchar + csctx_close_shape(c); + return 1; + + case 0x0C: { // two-byte escape + float dx1, dx2, dx3, dx4, dx5, dx6, dy1, dy2, dy3, dy4, dy5, dy6; + float dx, dy; + int b1 = getbyte(&b); + switch (b1) { + // @TODO These "flex" implementations ignore the flex-depth and resolution, + // and always draw beziers. + case 0x22: // hflex + if (sp < 7) return STBTT__CSERR("hflex stack"); + dx1 = s[0]; + dx2 = s[1]; + dy2 = s[2]; + dx3 = s[3]; + dx4 = s[4]; + dx5 = s[5]; + dx6 = s[6]; + csctx_rccurve_to(c, dx1, 0, dx2, dy2, dx3, 0); + csctx_rccurve_to(c, dx4, 0, dx5, -dy2, dx6, 0); + break; + + case 0x23: // flex + if (sp < 13) return STBTT__CSERR("flex stack"); + dx1 = s[0]; + dy1 = s[1]; + dx2 = s[2]; + dy2 = s[3]; + dx3 = s[4]; + dy3 = s[5]; + dx4 = s[6]; + dy4 = s[7]; + dx5 = s[8]; + dy5 = s[9]; + dx6 = s[10]; + dy6 = s[11]; + //fd is s[12] + csctx_rccurve_to(c, dx1, dy1, dx2, dy2, dx3, dy3); + csctx_rccurve_to(c, dx4, dy4, dx5, dy5, dx6, dy6); + break; + + case 0x24: // hflex1 + if (sp < 9) return STBTT__CSERR("hflex1 stack"); + dx1 = s[0]; + dy1 = s[1]; + dx2 = s[2]; + dy2 = s[3]; + dx3 = s[4]; + dx4 = s[5]; + dx5 = s[6]; + dy5 = s[7]; + dx6 = s[8]; + csctx_rccurve_to(c, dx1, dy1, dx2, dy2, dx3, 0); + csctx_rccurve_to(c, dx4, 0, dx5, dy5, dx6, -(dy1+dy2+dy5)); + break; + + case 0x25: // flex1 + if (sp < 11) return STBTT__CSERR("flex1 stack"); + dx1 = s[0]; + dy1 = s[1]; + dx2 = s[2]; + dy2 = s[3]; + dx3 = s[4]; + dy3 = s[5]; + dx4 = s[6]; + dy4 = s[7]; + dx5 = s[8]; + dy5 = s[9]; + dx6 = dy6 = s[10]; + dx = dx1+dx2+dx3+dx4+dx5; + dy = dy1+dy2+dy3+dy4+dy5; + if (fabs(dx) > fabs(dy)) + dy6 = -dy; + else + dx6 = -dx; + csctx_rccurve_to(c, dx1, dy1, dx2, dy2, dx3, dy3); + csctx_rccurve_to(c, dx4, dy4, dx5, dy5, dx6, dy6); + break; + + default: + return STBTT__CSERR("unimplemented"); + } + } break; + + default: + if (b0 != 255 && b0 != 28 && (b0 < 32 || b0 > 254)) + return STBTT__CSERR("reserved operator"); + + // push immediate + if (b0 == 255) { + f = (float)(int32)getint(&b) / 0x10000; + } else { + skip(&b, -1); + f = (float)(short)cff_int(&b); + } + if (sp >= 48) return STBTT__CSERR("push stack overflow"); + s[sp++] = f; + clear_stack = 0; + break; + } + if (clear_stack) sp = 0; + } + return STBTT__CSERR("no endchar"); + +#undef STBTT__CSERR +} + +static int glyph_shape_t2(font·Info *info, int glyph_index, font·Vertex **pvertices) +{ + // runs the charstring twice, once to count and once to output (to avoid realloc) + csctx count_ctx = CSCTX_INIT(1); + csctx output_ctx = CSCTX_INIT(0); + if (run_charstring(info, glyph_index, &count_ctx)) { + *pvertices = malloc(count_ctx.num_vertices*sizeof(font·Vertex)); + output_ctx.pvertices = *pvertices; + if (run_charstring(info, glyph_index, &output_ctx)) { + assert(output_ctx.num_vertices == count_ctx.num_vertices); + return output_ctx.num_vertices; + } + } + *pvertices = nil; + return 0; +} + +static +int +glyph_info_t2(font·Info *info, int glyph_index, int *x0, int *y0, int *x1, int *y1) +{ + csctx c = CSCTX_INIT(1); + int r = run_charstring(info, glyph_index, &c); + if (x0) *x0 = r ? c.min_x : 0; + if (y0) *y0 = r ? c.min_y : 0; + if (x1) *x1 = r ? c.max_x : 0; + if (y1) *y1 = r ? c.max_y : 0; + return r ? c.num_vertices : 0; +} + +int +font·glyph_shape(font·Info *info, int glyph_index, font·Vertex **pvertices) +{ + if (!info->cff.size) + return glyph_shape_tt(info, glyph_index, pvertices); + else + return glyph_shape_t2(info, glyph_index, pvertices); +} + +void +font·glyph_hmetrics(font·Info *info, int glyph_index, int *advanceWidth, int *leftSideBearing) +{ + ushort numOfLongHorMetrics = ttUSHORT(info->data+info->hhea + 34); + if (glyph_index < numOfLongHorMetrics) { + if (advanceWidth) *advanceWidth = ttSHORT(info->data + info->hmtx + 4*glyph_index); + if (leftSideBearing) *leftSideBearing = ttSHORT(info->data + info->hmtx + 4*glyph_index + 2); + } else { + if (advanceWidth) *advanceWidth = ttSHORT(info->data + info->hmtx + 4*(numOfLongHorMetrics-1)); + if (leftSideBearing) *leftSideBearing = ttSHORT(info->data + info->hmtx + 4*numOfLongHorMetrics + 2*(glyph_index - numOfLongHorMetrics)); + } +} + +int +font·kerntablen(font·Info *info) +{ + uchar *data = info->data + info->kern; + + // we only look at the first table. it must be 'horizontal' and format 0. + if (!info->kern) + return 0; + if (ttUSHORT(data+2) < 1) // number of tables, need at least 1 + return 0; + if (ttUSHORT(data+8) != 1) // horizontal flag must be set in format + return 0; + + return ttUSHORT(data+10); +} + +int +font·kerntab(font·Info *info, font·TabElt* table, int table_length) +{ + uchar *data = info->data + info->kern; + int k, length; + + // we only look at the first table. it must be 'horizontal' and format 0. + if (!info->kern) + return 0; + if (ttUSHORT(data+2) < 1) // number of tables, need at least 1 + return 0; + if (ttUSHORT(data+8) != 1) // horizontal flag must be set in format + return 0; + + length = ttUSHORT(data+10); + if (table_length < length) + length = table_length; + + for (k = 0; k < length; k++) + { + table[k].glyph1 = ttUSHORT(data+18+(k*6)); + table[k].glyph2 = ttUSHORT(data+20+(k*6)); + table[k].advance = ttSHORT(data+22+(k*6)); + } + + return length; +} + +static +int +glyph_kernadvance(const font·Info *info, int glyph1, int glyph2) +{ + uchar *data = info->data + info->kern; + uint32 needle, straw; + int l, r, m; + + // we only look at the first table. it must be 'horizontal' and format 0. + if (!info->kern) + return 0; + if (ttUSHORT(data+2) < 1) // number of tables, need at least 1 + return 0; + if (ttUSHORT(data+8) != 1) // horizontal flag must be set in format + return 0; + + l = 0; + r = ttUSHORT(data+10) - 1; + needle = glyph1 << 16 | glyph2; + while (l <= r) { + m = (l + r) >> 1; + straw = ttULONG(data+18+(m*6)); // note: unaligned read + if (needle < straw) + r = m - 1; + else if (needle > straw) + l = m + 1; + else + return ttSHORT(data+22+(m*6)); + } + return 0; +} + +static +int32 +coverage_index(uchar *coverageTable, int glyph) +{ + ushort coverageFormat = ttUSHORT(coverageTable); + switch(coverageFormat) { + case 1: { + ushort glyphCount = ttUSHORT(coverageTable + 2); + + // Binary search. + int32 l=0, r=glyphCount-1, m; + int straw, needle=glyph; + while (l <= r) { + uchar *glyphArray = coverageTable + 4; + ushort glyphID; + m = (l + r) >> 1; + glyphID = ttUSHORT(glyphArray + 2 * m); + straw = glyphID; + if (needle < straw) + r = m - 1; + else if (needle > straw) + l = m + 1; + else { + return m; + } + } + } break; + + case 2: { + ushort rangeCount = ttUSHORT(coverageTable + 2); + uchar *rangeArray = coverageTable + 4; + + // Binary search. + int32 l=0, r=rangeCount-1, m; + int strawStart, strawEnd, needle=glyph; + while (l <= r) { + uchar *rangeRecord; + m = (l + r) >> 1; + rangeRecord = rangeArray + 6 * m; + strawStart = ttUSHORT(rangeRecord); + strawEnd = ttUSHORT(rangeRecord + 2); + if (needle < strawStart) + r = m - 1; + else if (needle > strawEnd) + l = m + 1; + else { + ushort startCoverageIndex = ttUSHORT(rangeRecord + 4); + return startCoverageIndex + glyph - strawStart; + } + } + } break; + + default: { + // There are no other cases. + assert(0); + } break; + } + + return -1; +} + +static +int32 +glyph_class(uchar *classDefTable, int glyph) +{ + ushort classDefFormat = ttUSHORT(classDefTable); + switch(classDefFormat) + { + case 1: { + ushort startGlyphID = ttUSHORT(classDefTable + 2); + ushort glyphCount = ttUSHORT(classDefTable + 4); + uchar *classDef1ValueArray = classDefTable + 6; + + if (glyph >= startGlyphID && glyph < startGlyphID + glyphCount) + return (int32)ttUSHORT(classDef1ValueArray + 2 * (glyph - startGlyphID)); + + classDefTable = classDef1ValueArray + 2 * glyphCount; + } break; + + case 2: { + ushort classRangeCount = ttUSHORT(classDefTable + 2); + uchar *classRangeRecords = classDefTable + 4; + + // Binary search. + int32 l=0, r=classRangeCount-1, m; + int strawStart, strawEnd, needle=glyph; + while (l <= r) { + uchar *classRangeRecord; + m = (l + r) >> 1; + classRangeRecord = classRangeRecords + 6 * m; + strawStart = ttUSHORT(classRangeRecord); + strawEnd = ttUSHORT(classRangeRecord + 2); + if (needle < strawStart) + r = m - 1; + else if (needle > strawEnd) + l = m + 1; + else + return (int32)ttUSHORT(classRangeRecord + 4); + } + + classDefTable = classRangeRecords + 6 * classRangeCount; + } break; + + default: { + // There are no other cases. + assert(0); + } break; + } + + return -1; +} + +static +int32 +glyph_gposadvance(const font·Info *info, int glyph1, int glyph2) +{ + ushort lookupListOffset; + uchar *lookupList; + ushort lookupCount; + uchar *data; + int32 i; + + if (!info->gpos) return 0; + + data = info->data + info->gpos; + + if (ttUSHORT(data+0) != 1) return 0; // Major version 1 + if (ttUSHORT(data+2) != 0) return 0; // Minor version 0 + + lookupListOffset = ttUSHORT(data+8); + lookupList = data + lookupListOffset; + lookupCount = ttUSHORT(lookupList); + + for (i=0; i> 1; + pairValue = pairValueArray + (2 + valueRecordPairSizeInBytes) * m; + secondGlyph = ttUSHORT(pairValue); + straw = secondGlyph; + if (needle < straw) + r = m - 1; + else if (needle > straw) + l = m + 1; + else { + short xAdvance = ttSHORT(pairValue + 2); + return xAdvance; + } + } + } break; + + case 2: { + ushort valueFormat1 = ttUSHORT(table + 4); + ushort valueFormat2 = ttUSHORT(table + 6); + + ushort classDef1Offset = ttUSHORT(table + 8); + ushort classDef2Offset = ttUSHORT(table + 10); + int glyph1class = glyph_class(table + classDef1Offset, glyph1); + int glyph2class = glyph_class(table + classDef2Offset, glyph2); + + ushort class1Count = ttUSHORT(table + 12); + ushort class2Count = ttUSHORT(table + 14); + assert(glyph1class < class1Count); + assert(glyph2class < class2Count); + + // TODO: Support more formats. + if (valueFormat1 != 4) return 0; + if (valueFormat2 != 0) return 0; + + if (glyph1class >= 0 && glyph1class < class1Count && glyph2class >= 0 && glyph2class < class2Count) { + uchar *class1Records = table + 16; + uchar *class2Records = class1Records + 2 * (glyph1class * class2Count); + short xAdvance = ttSHORT(class2Records + 2 * glyph2class); + return xAdvance; + } + } break; + + default: { + // There are no other cases. + assert(0); + break; + }; + } + } + break; + }; + + default: + // TODO: Implement other stuff. + break; + } + } + + return 0; +} + +int +font·glyph_kernadvance(font·Info *info, int g1, int g2) +{ + int xAdvance = 0; + + if (info->gpos) + xAdvance += glyph_gposadvance(info, g1, g2); + else if (info->kern) + xAdvance += glyph_kernadvance(info, g1, g2); + + return xAdvance; +} + +int +font·code_kernadvance(font·Info *info, int ch1, int ch2) +{ + if (!info->kern && !info->gpos) // if no kerning table, don't waste time looking up both codepoint->glyphs + return 0; + return font·glyph_kernadvance(info, font·glyph_index(info,ch1), font·glyph_index(info,ch2)); +} + +void +font·code_hmetrics(font·Info *info, int codepoint, int *advanceWidth, int *lsb) +{ + font·glyph_hmetrics(info, font·glyph_index(info,codepoint), advanceWidth, lsb); +} + +void +font·vmetrics(font·Info *info, int *ascent, int *descent, int *lineGap) +{ + if (ascent ) *ascent = ttSHORT(info->data+info->hhea + 4); + if (descent) *descent = ttSHORT(info->data+info->hhea + 6); + if (lineGap) *lineGap = ttSHORT(info->data+info->hhea + 8); +} + +void +font·bbox(font·Info *info, int *x0, int *y0, int *x1, int *y1) +{ + *x0 = ttSHORT(info->data + info->head + 36); + *y0 = ttSHORT(info->data + info->head + 38); + *x1 = ttSHORT(info->data + info->head + 40); + *y1 = ttSHORT(info->data + info->head + 42); +} + +float +font·scaleheightto(font·Info *info, float height) +{ + int fheight = ttSHORT(info->data + info->hhea + 4) - ttSHORT(info->data + info->hhea + 6); + return (float) height / fheight; +} + +float +font·scaleheighttoem(font·Info *info, float pixels) +{ + int unitsPerEm = ttUSHORT(info->data + info->head + 18); + return pixels / unitsPerEm; +} + +void +font·freeshape(font·Info *info, font·Vertex *v) +{ + free(v); +} + +static +uchar * +find_svg(const font·Info *info, int gl) +{ + int i; + uchar *data = info->data; + uchar *svg_doc_list = data + get_svg((font·Info *) info); + + int numEntries = ttUSHORT(svg_doc_list); + uchar *svg_docs = svg_doc_list + 2; + + for(i=0; i= ttUSHORT(svg_doc)) && (gl <= ttUSHORT(svg_doc + 2))) + return svg_doc; + } + return 0; +} + +int +font·glyph_svg(font·Info *info, int gl, char **svg) +{ + uchar *data = info->data; + uchar *svg_doc; + + if (info->svg == 0) + return 0; + + svg_doc = find_svg(info, gl); + if (svg_doc != nil) { + *svg = (char *) data + info->svg + ttULONG(svg_doc + 4); + return ttULONG(svg_doc + 8); + } else { + return 0; + } +} + +int +font·code_svg(font·Info *info, int unicode_codepoint, char **svg) +{ + return font·glyph_svg(info, font·glyph_index(info, unicode_codepoint), svg); +} + +// ----------------------------------------------------------------------- +// antialiasing software rasterizer + +void +font·glyph_bitmapbox_subpixel(font·Info *font, int glyph, float scale_x, float scale_y,float shift_x, float shift_y, int *ix0, int *iy0, int *ix1, int *iy1) +{ + int x0=0,y0=0,x1,y1; // =0 suppresses compiler warning + if (!font·glyph_box(font, glyph, &x0,&y0,&x1,&y1)) { + // e.g. space character + if (ix0) *ix0 = 0; + if (iy0) *iy0 = 0; + if (ix1) *ix1 = 0; + if (iy1) *iy1 = 0; + } else { + // move to integral bboxes (treating pixels as little squares, what pixels get touched)? + if (ix0) *ix0 = (int)floor( x0 * scale_x + shift_x); + if (iy0) *iy0 = (int)floor(-y1 * scale_y + shift_y); + if (ix1) *ix1 = (int)ceil( x1 * scale_x + shift_x); + if (iy1) *iy1 = (int)ceil(-y0 * scale_y + shift_y); + } +} + +void +font·glyph_bitmapbox(font·Info *font, int glyph, float scale_x, float scale_y, int *ix0, int *iy0, int *ix1, int *iy1) +{ + font·glyph_bitmapbox_subpixel(font, glyph, scale_x, scale_y,0.0f,0.0f, ix0, iy0, ix1, iy1); +} + +void +font·code_bitmapbox_subpixel(font·Info *font, int codepoint, float scale_x, float scale_y, float shift_x, float shift_y, int *ix0, int *iy0, int *ix1, int *iy1) +{ + font·glyph_bitmapbox_subpixel(font, font·glyph_index(font,codepoint), scale_x, scale_y,shift_x,shift_y, ix0,iy0,ix1,iy1); +} + +void +font·code_bitmapbox(font·Info *font, int codepoint, float scale_x, float scale_y, int *ix0, int *iy0, int *ix1, int *iy1) +{ + font·code_bitmapbox_subpixel(font, codepoint, scale_x, scale_y,0.0f,0.0f, ix0,iy0,ix1,iy1); +} + +// ------------------------------------------------------------------------ +// Rasterizer + +typedef struct hheap_chunk +{ + struct hheap_chunk *next; +} hheap_chunk; + +typedef struct hheap +{ + struct hheap_chunk *head; + void *first_free; + int num_remaining_in_head_chunk; +} hheap; + +static +void * +hheap_alloc(hheap *hh, size_t size, void *userdata) +{ + if (hh->first_free) { + void *p = hh->first_free; + hh->first_free = * (void **) p; + return p; + } else { + if (hh->num_remaining_in_head_chunk == 0) { + int count = (size < 32 ? 2000 : size < 128 ? 800 : 100); + hheap_chunk *c = malloc(sizeof(hheap_chunk) + size * count); + if (c == nil) + return nil; + c->next = hh->head; + hh->head = c; + hh->num_remaining_in_head_chunk = count; + } + --hh->num_remaining_in_head_chunk; + return (char *) (hh->head) + sizeof(hheap_chunk) + size * hh->num_remaining_in_head_chunk; + } +} + +static +void +hheap_free(hheap *hh, void *p) +{ + *(void **) p = hh->first_free; + hh->first_free = p; +} + +static +void +hheap_cleanup(hheap *hh, void *userdata) +{ + hheap_chunk *c = hh->head; + while (c) { + hheap_chunk *n = c->next; + free(c); + c = n; + } +} + +static +ActiveEdge * +new_active(hheap *hh, Edge *e, int off_x, float start_point, void *userdata) +{ + ActiveEdge *z = (ActiveEdge *) hheap_alloc(hh, sizeof(*z), userdata); + float dxdy = (e->x1 - e->x0) / (e->y1 - e->y0); + assert(z != nil); + //assert(e->y0 <= start_point); + if (!z) return z; + z->fdx = dxdy; + z->fdy = dxdy != 0.0f ? (1.0f/dxdy) : 0.0f; + z->fx = e->x0 + dxdy * (start_point - e->y0); + z->fx -= off_x; + z->direction = e->invert ? 1.0f : -1.0f; + z->sy = e->y0; + z->ey = e->y1; + z->next = 0; + return z; +} + +// the edge passed in here does not cross the vertical line at x or the vertical line at x+1 +// (i.e. it has already been clipped to those) +static +void +handle_clipped_edge(float *scanline, int x, ActiveEdge *e, float x0, float y0, float x1, float y1) +{ + if (y0 == y1) return; + assert(y0 < y1); + assert(e->sy <= e->ey); + if (y0 > e->ey) return; + if (y1 < e->sy) return; + if (y0 < e->sy) { + x0 += (x1-x0) * (e->sy - y0) / (y1-y0); + y0 = e->sy; + } + if (y1 > e->ey) { + x1 += (x1-x0) * (e->ey - y1) / (y1-y0); + y1 = e->ey; + } + + if (x0 == x) + assert(x1 <= x+1); + else if (x0 == x+1) + assert(x1 >= x); + else if (x0 <= x) + assert(x1 <= x); + else if (x0 >= x+1) + assert(x1 >= x+1); + else + assert(x1 >= x && x1 <= x+1); + + if (x0 <= x && x1 <= x) + scanline[x] += e->direction * (y1-y0); + else if (x0 >= x+1 && x1 >= x+1) + ; + else { + assert(x0 >= x && x0 <= x+1 && x1 >= x && x1 <= x+1); + scanline[x] += e->direction * (y1-y0) * (1-((x0-x)+(x1-x))/2); // coverage = 1 - average x position + } +} + +static +void +fill_active_edges_new(float *scanline, float *scanline_fill, int len, ActiveEdge *e, float y_top) +{ + float y_bottom = y_top+1; + + while (e) { + // brute force every pixel + + // compute intersection points with top & bottom + assert(e->ey >= y_top); + + if (e->fdx == 0) { + float x0 = e->fx; + if (x0 < len) { + if (x0 >= 0) { + handle_clipped_edge(scanline,(int) x0,e, x0,y_top, x0,y_bottom); + handle_clipped_edge(scanline_fill-1,(int) x0+1,e, x0,y_top, x0,y_bottom); + } else { + handle_clipped_edge(scanline_fill-1,0,e, x0,y_top, x0,y_bottom); + } + } + } else { + float x0 = e->fx; + float dx = e->fdx; + float xb = x0 + dx; + float x_top, x_bottom; + float sy0,sy1; + float dy = e->fdy; + assert(e->sy <= y_bottom && e->ey >= y_top); + + // compute endpoints of line segment clipped to this scanline (if the + // line segment starts on this scanline. x0 is the intersection of the + // line with y_top, but that may be off the line segment. + if (e->sy > y_top) { + x_top = x0 + dx * (e->sy - y_top); + sy0 = e->sy; + } else { + x_top = x0; + sy0 = y_top; + } + if (e->ey < y_bottom) { + x_bottom = x0 + dx * (e->ey - y_top); + sy1 = e->ey; + } else { + x_bottom = xb; + sy1 = y_bottom; + } + + if (x_top >= 0 && x_bottom >= 0 && x_top < len && x_bottom < len) { + // from here on, we don't have to range check x values + + if ((int) x_top == (int) x_bottom) { + float height; + // simple case, only spans one pixel + int x = (int) x_top; + height = sy1 - sy0; + assert(x >= 0 && x < len); + scanline[x] += e->direction * (1-((x_top - x) + (x_bottom-x))/2) * height; + scanline_fill[x] += e->direction * height; // everything right of this pixel is filled + } else { + int x,x1,x2; + float y_crossing, step, sign, area; + // covers 2+ pixels + if (x_top > x_bottom) { + // flip scanline vertically; signed area is the same + float t; + sy0 = y_bottom - (sy0 - y_top); + sy1 = y_bottom - (sy1 - y_top); + t = sy0, sy0 = sy1, sy1 = t; + t = x_bottom, x_bottom = x_top, x_top = t; + dx = -dx; + dy = -dy; + t = x0, x0 = xb, xb = t; + } + + x1 = (int) x_top; + x2 = (int) x_bottom; + // compute intersection with y axis at x1+1 + y_crossing = (x1+1 - x0) * dy + y_top; + + sign = e->direction; + // area of the rectangle covered from y0..y_crossing + area = sign * (y_crossing-sy0); + // area of the triangle (x_top,y0), (x+1,y0), (x+1,y_crossing) + scanline[x1] += area * (1-((x_top - x1)+(x1+1-x1))/2); + + step = sign * dy; + for (x = x1+1; x < x2; ++x) { + scanline[x] += area + step/2; + area += step; + } + y_crossing += dy * (x2 - (x1+1)); + + assert(fabs(area) <= 1.01f); + + scanline[x2] += area + sign * (1-((x2-x2)+(x_bottom-x2))/2) * (sy1-y_crossing); + + scanline_fill[x2] += sign * (sy1-sy0); + } + } else { + // if edge goes outside of box we're drawing, we require + // clipping logic. since this does not match the intended use + // of this library, we use a different, very slow brute + // force implementation + int x; + for (x=0; x < len; ++x) { + // cases: + // + // there can be up to two intersections with the pixel. any intersection + // with left or right edges can be handled by splitting into two (or three) + // regions. intersections with top & bottom do not necessitate case-wise logic. + // + // the old way of doing this found the intersections with the left & right edges, + // then used some simple logic to produce up to three segments in sorted order + // from top-to-bottom. however, this had a problem: if an x edge was epsilon + // across the x border, then the corresponding y position might not be distinct + // from the other y segment, and it might ignored as an empty segment. to avoid + // that, we need to explicitly produce segments based on x positions. + + // rename variables to clearly-defined pairs + float y0 = y_top; + float x1 = (float) (x); + float x2 = (float) (x+1); + float x3 = xb; + float y3 = y_bottom; + + // x = e->x + e->dx * (y-y_top) + // (y-y_top) = (x - e->x) / e->dx + // y = (x - e->x) / e->dx + y_top + float y1 = (x - x0) / dx + y_top; + float y2 = (x+1 - x0) / dx + y_top; + + if (x0 < x1 && x3 > x2) { // three segments descending down-right + handle_clipped_edge(scanline,x,e, x0,y0, x1,y1); + handle_clipped_edge(scanline,x,e, x1,y1, x2,y2); + handle_clipped_edge(scanline,x,e, x2,y2, x3,y3); + } else if (x3 < x1 && x0 > x2) { // three segments descending down-left + handle_clipped_edge(scanline,x,e, x0,y0, x2,y2); + handle_clipped_edge(scanline,x,e, x2,y2, x1,y1); + handle_clipped_edge(scanline,x,e, x1,y1, x3,y3); + } else if (x0 < x1 && x3 > x1) { // two segments across x, down-right + handle_clipped_edge(scanline,x,e, x0,y0, x1,y1); + handle_clipped_edge(scanline,x,e, x1,y1, x3,y3); + } else if (x3 < x1 && x0 > x1) { // two segments across x, down-left + handle_clipped_edge(scanline,x,e, x0,y0, x1,y1); + handle_clipped_edge(scanline,x,e, x1,y1, x3,y3); + } else if (x0 < x2 && x3 > x2) { // two segments across x+1, down-right + handle_clipped_edge(scanline,x,e, x0,y0, x2,y2); + handle_clipped_edge(scanline,x,e, x2,y2, x3,y3); + } else if (x3 < x2 && x0 > x2) { // two segments across x+1, down-left + handle_clipped_edge(scanline,x,e, x0,y0, x2,y2); + handle_clipped_edge(scanline,x,e, x2,y2, x3,y3); + } else { // one segment + handle_clipped_edge(scanline,x,e, x0,y0, x3,y3); + } + } + } + } + e = e->next; + } +} + +// directly AA rasterize edges w/o supersampling +static +void +rasterize_sorted_edges(font·Bitmap *result, Edge *e, int n, int vsubsample, int off_x, int off_y, void *userdata) +{ + hheap hh = { 0, 0, 0 }; + ActiveEdge *active = nil; + int y,j=0, i; + float scanline_data[129], *scanline, *scanline2; + + if (result->w > 64) + scanline = malloc((result->w*2+1) * sizeof(float)); + else + scanline = scanline_data; + + scanline2 = scanline + result->w; + + y = off_y; + e[n].y0 = (float) (off_y + result->h) + 1; + + while (j < result->h) { + // find center of pixel for this scanline + float scan_y_top = y + 0.0f; + float scan_y_bottom = y + 1.0f; + ActiveEdge **step = &active; + + memset(scanline , 0, result->w*sizeof(scanline[0])); + memset(scanline2, 0, (result->w+1)*sizeof(scanline[0])); + + // update all active edges; + // remove all active edges that terminate before the top of this scanline + while (*step) { + ActiveEdge * z = *step; + if (z->ey <= scan_y_top) { + *step = z->next; // delete from list + assert(z->direction); + z->direction = 0; + hheap_free(&hh, z); + } else { + step = &((*step)->next); // advance through list + } + } + + // insert all edges that start before the bottom of this scanline + while (e->y0 <= scan_y_bottom) { + if (e->y0 != e->y1) { + ActiveEdge *z = new_active(&hh, e, off_x, scan_y_top, userdata); + if (z != nil) { + if (j == 0 && off_y != 0) { + if (z->ey < scan_y_top) { + // this can happen due to subpixel positioning and some kind of fp rounding error i think + z->ey = scan_y_top; + } + } + assert(z->ey >= scan_y_top); // if we get really unlucky a tiny bit of an edge can be out of bounds + // insert at front + z->next = active; + active = z; + } + } + ++e; + } + + // now process all active edges + if (active) + fill_active_edges_new(scanline, scanline2+1, result->w, active, scan_y_top); + + { + float sum = 0; + for (i=0; i < result->w; ++i) { + float k; + int m; + sum += scanline2[i]; + k = scanline[i] + sum; + k = (float) fabs(k)*255 + 0.5f; + m = (int) k; + if (m > 255) m = 255; + result->pixels[j*result->stride + i] = (uchar) m; + } + } + // advance all the edges + step = &active; + while (*step) { + ActiveEdge *z = *step; + z->fx += z->fdx; // advance to position for current scanline + step = &((*step)->next); // advance through list + } + + ++y; + ++j; + } + + hheap_cleanup(&hh, userdata); + + if (scanline != scanline_data) + free(scanline); +} + +#define CMP_Y0(a,b) ((a)->y0 < (b)->y0) + +static +void +sort_edges_ins_sort(Edge *p, int n) +{ + int i,j; + for (i=1; i < n; ++i) { + Edge t = p[i], *a = &t; + j = i; + while (j > 0) { + Edge *b = &p[j-1]; + int c = CMP_Y0(a,b); + if (!c) break; + p[j] = p[j-1]; + --j; + } + if (i != j) + p[j] = t; + } +} + +static +void +sort_edges_quicksort(Edge *p, int n) +{ + /* threshold for transitioning to insertion sort */ + while (n > 12) { + Edge t; + int c01,c12,c,m,i,j; + + /* compute median of three */ + m = n >> 1; + c01 = CMP_Y0(&p[0],&p[m]); + c12 = CMP_Y0(&p[m],&p[n-1]); + /* if 0 >= mid >= end, or 0 < mid < end, then use mid */ + if (c01 != c12) { + /* otherwise, we'll need to swap something else to middle */ + int z; + c = CMP_Y0(&p[0],&p[n-1]); + /* 0>mid && midn => n; 0 0 */ + /* 0n: 0>n => 0; 0 n */ + z = (c == c12) ? 0 : n-1; + t = p[z]; + p[z] = p[m]; + p[m] = t; + } + /* now p[m] is the median-of-three */ + /* swap it to the beginning so it won't move around */ + t = p[0]; + p[0] = p[m]; + p[m] = t; + + /* partition loop */ + i=1; + j=n-1; + for(;;) { + /* handling of equality is crucial here */ + /* for sentinels & efficiency with duplicates */ + for (;;++i) { + if (!CMP_Y0(&p[i], &p[0])) break; + } + for (;;--j) { + if (!CMP_Y0(&p[0], &p[j])) break; + } + /* make sure we haven't crossed */ + if (i >= j) break; + t = p[i]; + p[i] = p[j]; + p[j] = t; + + ++i; + --j; + } + /* recurse on smaller side, iterate on larger */ + if (j < (n-i)) { + sort_edges_quicksort(p,j); + p = p+i; + n = n-i; + } else { + sort_edges_quicksort(p+i, n-i); + n = j; + } + } +} + +static +void +sort_edges(Edge *p, int n) +{ + sort_edges_quicksort(p, n); + sort_edges_ins_sort(p, n); +} + +static +void +rasterize(font·Bitmap *result, Point *pts, int *wcount, int windings, float scale_x, float scale_y, float shift_x, float shift_y, int off_x, int off_y, int invert, void *userdata) +{ + float y_scale_inv = invert ? -scale_y : scale_y; + Edge *e; + int n,i,j,k,m; + int vsubsample = 1; + // vsubsample should divide 255 evenly; otherwise we won't reach full opacity + + // now we have to blow out the windings into explicit edge lists + n = 0; + for (i=0; i < windings; ++i) + n += wcount[i]; + + e = malloc(sizeof(*e) * (n+1)); // add an extra one as a sentinel + if (e == 0) return; + n = 0; + + m=0; + for (i=0; i < windings; ++i) { + Point *p = pts + m; + m += wcount[i]; + j = wcount[i]-1; + for (k=0; k < wcount[i]; j=k++) { + int a=k,b=j; + // skip the Edge if horizontal + if (p[j].y == p[k].y) + continue; + // add edge from j to k to the list + e[n].invert = 0; + if (invert ? p[j].y > p[k].y : p[j].y < p[k].y) { + e[n].invert = 1; + a=j,b=k; + } + e[n].x0 = p[a].x * scale_x + shift_x; + e[n].y0 = (p[a].y * y_scale_inv + shift_y) * vsubsample; + e[n].x1 = p[b].x * scale_x + shift_x; + e[n].y1 = (p[b].y * y_scale_inv + shift_y) * vsubsample; + ++n; + } + } + + // now sort the edges by their highest point (should snap to integer, and then by x) + //STBTT_sort(e, n, sizeof(e[0]), edge_compare); + sort_edges(e, n); + + // now, traverse the scanlines and find the intersections on each scanline, use xor winding rule + rasterize_sorted_edges(result, e, n, vsubsample, off_x, off_y, userdata); + + free(e); +} + +static +void +add_point(Point *points, int n, float x, float y) +{ + if (!points) return; // during first pass, it's unallocated + points[n].x = x; + points[n].y = y; +} + +// tessellate until threshold p is happy... @TODO warped to compensate for non-linear stretching +static +int +tesselate_curve(Point *points, int *num_points, float x0, float y0, float x1, float y1, float x2, float y2, float objspace_flatness_squared, int n) +{ + // midpoint + float mx = (x0 + 2*x1 + x2)/4; + float my = (y0 + 2*y1 + y2)/4; + // versus directly drawn line + float dx = (x0+x2)/2 - mx; + float dy = (y0+y2)/2 - my; + if (n > 16) // 65536 segments on one curve better be enough! + return 1; + if (dx*dx+dy*dy > objspace_flatness_squared) { // half-pixel error allowed... need to be smaller if AA + tesselate_curve(points, num_points, x0,y0, (x0+x1)/2.0f,(y0+y1)/2.0f, mx,my, objspace_flatness_squared,n+1); + tesselate_curve(points, num_points, mx,my, (x1+x2)/2.0f,(y1+y2)/2.0f, x2,y2, objspace_flatness_squared,n+1); + } else { + add_point(points, *num_points,x2,y2); + *num_points = *num_points+1; + } + return 1; +} + +static +void +tesselate_cubic(Point *points, int *num_points, float x0, float y0, float x1, float y1, float x2, float y2, float x3, float y3, float objspace_flatness_squared, int n) +{ + // @TODO this "flatness" calculation is just made-up nonsense that seems to work well enough + float dx0 = x1-x0; + float dy0 = y1-y0; + float dx1 = x2-x1; + float dy1 = y2-y1; + float dx2 = x3-x2; + float dy2 = y3-y2; + float dx = x3-x0; + float dy = y3-y0; + float longlen = (float) (sqrt(dx0*dx0+dy0*dy0)+sqrt(dx1*dx1+dy1*dy1)+sqrt(dx2*dx2+dy2*dy2)); + float shortlen = (float) sqrt(dx*dx+dy*dy); + float flatness_squared = longlen*longlen-shortlen*shortlen; + + if (n > 16) // 65536 segments on one curve better be enough! + return; + + if (flatness_squared > objspace_flatness_squared) { + float x01 = (x0+x1)/2; + float y01 = (y0+y1)/2; + float x12 = (x1+x2)/2; + float y12 = (y1+y2)/2; + float x23 = (x2+x3)/2; + float y23 = (y2+y3)/2; + + float xa = (x01+x12)/2; + float ya = (y01+y12)/2; + float xb = (x12+x23)/2; + float yb = (y12+y23)/2; + + float mx = (xa+xb)/2; + float my = (ya+yb)/2; + + tesselate_cubic(points, num_points, x0,y0, x01,y01, xa,ya, mx,my, objspace_flatness_squared,n+1); + tesselate_cubic(points, num_points, mx,my, xb,yb, x23,y23, x3,y3, objspace_flatness_squared,n+1); + } else { + add_point(points, *num_points,x3,y3); + *num_points = *num_points+1; + } +} + +// returns number of contours +static +Point * +flatten(font·Vertex *vertices, int num_verts, float objspace_flatness, int **contour_lengths, int *num_contours, void *userdata) +{ + Point *points=0; + int num_points=0; + + float objspace_flatness_squared = objspace_flatness * objspace_flatness; + int i,n=0,start=0, pass; + + // count how many "moves" there are to get the contour count + for (i=0; i < num_verts; ++i) + if (vertices[i].type == font·Vmove) + ++n; + + *num_contours = n; + if (n == 0) return 0; + + *contour_lengths = malloc(sizeof(**contour_lengths) * n); + + if (*contour_lengths == 0) { + *num_contours = 0; + return 0; + } + + // make two passes through the points so we don't need to realloc + for (pass=0; pass < 2; ++pass) { + float x=0,y=0; + if (pass == 1) { + points = malloc(num_points * sizeof(points[0])); + if (!points) + goto error; + } + num_points = 0; + n= -1; + for (i=0; i < num_verts; ++i) { + switch (vertices[i].type) { + case font·Vmove: + // start the next contour + if (n >= 0) + (*contour_lengths)[n] = num_points - start; + ++n; + start = num_points; + + x = vertices[i].x, y = vertices[i].y; + add_point(points, num_points++, x,y); + break; + case font·Vline: + x = vertices[i].x, y = vertices[i].y; + add_point(points, num_points++, x, y); + break; + case font·Vcurve: + tesselate_curve(points, &num_points, x,y, + vertices[i].cx, vertices[i].cy, + vertices[i].x, vertices[i].y, + objspace_flatness_squared, 0); + x = vertices[i].x, y = vertices[i].y; + break; + case font·Vcubic: + tesselate_cubic(points, &num_points, x,y, + vertices[i].cx, vertices[i].cy, + vertices[i].cx1, vertices[i].cy1, + vertices[i].x, vertices[i].y, + objspace_flatness_squared, 0); + x = vertices[i].x, y = vertices[i].y; + break; + } + } + (*contour_lengths)[n] = num_points - start; + } + + return points; +error: + free(points); + free(*contour_lengths); + *contour_lengths = 0; + *num_contours = 0; + return nil; +} + +void +font·rasterize(font·Bitmap *result, float flatness_in_pixels, font·Vertex *vertices, int num_verts, float scale_x, float scale_y, float shift_x, float shift_y, int x_off, int y_off, int invert, void *userdata) +{ + float scale = scale_x > scale_y ? scale_y : scale_x; + int winding_count = 0; + int *winding_lengths = nil; + Point *windings = flatten(vertices, num_verts, flatness_in_pixels / scale, &winding_lengths, &winding_count, userdata); + if (windings) { + rasterize(result, windings, winding_lengths, winding_count, scale_x, scale_y, shift_x, shift_y, x_off, y_off, invert, userdata); + free(winding_lengths); + free(windings); + } +} + +void +font·freebitmap(uchar *bm, void *userdata) +{ + free(bm); +} + +uchar * +font·glyph_makebitmap_subpixel(font·Info *info, float scale_x, float scale_y, float shift_x, float shift_y, int glyph, int *width, int *height, int *xoff, int *yoff) +{ + int ix0,iy0,ix1,iy1; + font·Bitmap gbm; + font·Vertex *vertices; + int num_verts = font·glyph_shape(info, glyph, &vertices); + + if (scale_x == 0) scale_x = scale_y; + if (scale_y == 0) { + if (scale_x == 0) { + free(vertices); + return nil; + } + scale_y = scale_x; + } + + font·glyph_bitmapbox_subpixel(info, glyph, scale_x, scale_y, shift_x, shift_y, &ix0,&iy0,&ix1,&iy1); + + // now we get the size + gbm.w = (ix1 - ix0); + gbm.h = (iy1 - iy0); + gbm.pixels = nil; // in case we error + + if (width ) *width = gbm.w; + if (height) *height = gbm.h; + if (xoff ) *xoff = ix0; + if (yoff ) *yoff = iy0; + + if (gbm.w && gbm.h) { + gbm.pixels = malloc(gbm.w * gbm.h); + if (gbm.pixels) { + gbm.stride = gbm.w; + + font·rasterize(&gbm, 0.35f, vertices, num_verts, scale_x, scale_y, shift_x, shift_y, ix0, iy0, 1, info->userdata); + } + } + free(vertices); + return gbm.pixels; +} + +uchar * +font·glyph_makebitmap(font·Info *info, float scale_x, float scale_y, int glyph, int *width, int *height, int *xoff, int *yoff) +{ + return font·glyph_makebitmap_subpixel(info, scale_x, scale_y, 0.0f, 0.0f, glyph, width, height, xoff, yoff); +} + +void +font·glyph_fillbitmap_subpixel(font·Info *info, uchar *output, int out_w, int out_h, int out_stride, float scale_x, float scale_y, float shift_x, float shift_y, int glyph) +{ + int ix0,iy0; + font·Vertex *vertices; + int num_verts = font·glyph_shape(info, glyph, &vertices); + font·Bitmap gbm; + + font·glyph_bitmapbox_subpixel(info, glyph, scale_x, scale_y, shift_x, shift_y, &ix0,&iy0,0,0); + gbm.pixels = output; + gbm.w = out_w; + gbm.h = out_h; + gbm.stride = out_stride; + + if (gbm.w && gbm.h) + font·rasterize(&gbm, 0.35f, vertices, num_verts, scale_x, scale_y, shift_x, shift_y, ix0,iy0, 1, info->userdata); + + free(vertices); +} + +void +font·glyph_fillbitmap(font·Info *info, unsigned char *output, int out_w, int out_h, int out_stride, float scale_x, float scale_y, int glyph) +{ + font·glyph_fillbitmap_subpixel(info, output, out_w, out_h, out_stride, scale_x, scale_y, 0.0f, 0.0f, glyph); +} + +uchar * +font·code_makebitmap_subpixel(font·Info *info, float scale_x, float scale_y, float shift_x, float shift_y, int codepoint, int *width, int *height, int *xoff, int *yoff) +{ + return font·glyph_makebitmap_subpixel(info, scale_x, scale_y,shift_x,shift_y, font·glyph_index(info,codepoint), width,height,xoff,yoff); +} + +void +font·code_fillbitmap_subpixel_prefilter(font·Info *info, unsigned char *output, int out_w, int out_h, int out_stride, float scale_x, float scale_y, float shift_x, float shift_y, int oversample_x, int oversample_y, float *sub_x, float *sub_y, int codepoint) +{ + font·glyph_fillbitmap_subpixel_prefilter(info, output, out_w, out_h, out_stride, scale_x, scale_y, shift_x, shift_y, oversample_x, oversample_y, sub_x, sub_y, font·glyph_index(info,codepoint)); +} + +void +font·code_fillbitmap_subpixel(font·Info *info, unsigned char *output, int out_w, int out_h, int out_stride, float scale_x, float scale_y, float shift_x, float shift_y, int codepoint) +{ + font·glyph_fillbitmap_subpixel(info, output, out_w, out_h, out_stride, scale_x, scale_y, shift_x, shift_y, font·glyph_index(info, codepoint)); +} + +uchar * +font·code_makebitmap(font·Info *info, float scale_x, float scale_y, int codepoint, int *width, int *height, int *xoff, int *yoff) +{ + return font·code_makebitmap_subpixel(info, scale_x, scale_y, 0.0f,0.0f, codepoint, width,height,xoff,yoff); +} + +void +font·code_fillbitmap(font·Info *info, unsigned char *output, int out_w, int out_h, int out_stride, float scale_x, float scale_y, int codepoint) +{ + font·code_fillbitmap_subpixel(info, output, out_w, out_h, out_stride, scale_x, scale_y, 0.0f,0.0f, codepoint); +} + +#define OVERMASK (SAMPLE-1) + +static +void +h_prefilter(uchar *pixels, int w, int h, int stride_in_bytes, unsigned int kernel_width) +{ + uchar buffer[SAMPLE]; + int safe_w = w - kernel_width; + int j; + memset(buffer, 0, SAMPLE); // suppress bogus warning from VS2013 -analyze + for (j=0; j < h; ++j) { + int i; + unsigned int total; + memset(buffer, 0, kernel_width); + + total = 0; + + // make kernel_width a constant in common cases so compiler can optimize out the divide + switch (kernel_width) { + case 2: + for (i=0; i <= safe_w; ++i) { + total += pixels[i] - buffer[i & OVERMASK]; + buffer[(i+kernel_width) & OVERMASK] = pixels[i]; + pixels[i] = (uchar) (total / 2); + } + break; + case 3: + for (i=0; i <= safe_w; ++i) { + total += pixels[i] - buffer[i & OVERMASK]; + buffer[(i+kernel_width) & OVERMASK] = pixels[i]; + pixels[i] = (uchar) (total / 3); + } + break; + case 4: + for (i=0; i <= safe_w; ++i) { + total += pixels[i] - buffer[i & OVERMASK]; + buffer[(i+kernel_width) & OVERMASK] = pixels[i]; + pixels[i] = (uchar) (total / 4); + } + break; + case 5: + for (i=0; i <= safe_w; ++i) { + total += pixels[i] - buffer[i & OVERMASK]; + buffer[(i+kernel_width) & OVERMASK] = pixels[i]; + pixels[i] = (uchar) (total / 5); + } + break; + default: + for (i=0; i <= safe_w; ++i) { + total += pixels[i] - buffer[i & OVERMASK]; + buffer[(i+kernel_width) & OVERMASK] = pixels[i]; + pixels[i] = (uchar) (total / kernel_width); + } + break; + } + + for (; i < w; ++i) { + assert(pixels[i] == 0); + total -= buffer[i & OVERMASK]; + pixels[i] = (uchar) (total / kernel_width); + } + + pixels += stride_in_bytes; + } +} + +static +void +v_prefilter(uchar *pixels, int w, int h, int stride_in_bytes, unsigned int kernel_width) +{ + uchar buffer[SAMPLE]; + int safe_h = h - kernel_width; + int j; + memset(buffer, 0, SAMPLE); + for (j=0; j < w; ++j) { + int i; + unsigned int total; + memset(buffer, 0, kernel_width); + + total = 0; + + // make kernel_width a constant in common cases so compiler can optimize out the divide + switch (kernel_width) { + case 2: + for (i=0; i <= safe_h; ++i) { + total += pixels[i*stride_in_bytes] - buffer[i & OVERMASK]; + buffer[(i+kernel_width) & OVERMASK] = pixels[i*stride_in_bytes]; + pixels[i*stride_in_bytes] = (uchar) (total / 2); + } + break; + case 3: + for (i=0; i <= safe_h; ++i) { + total += pixels[i*stride_in_bytes] - buffer[i & OVERMASK]; + buffer[(i+kernel_width) & OVERMASK] = pixels[i*stride_in_bytes]; + pixels[i*stride_in_bytes] = (uchar) (total / 3); + } + break; + case 4: + for (i=0; i <= safe_h; ++i) { + total += pixels[i*stride_in_bytes] - buffer[i & OVERMASK]; + buffer[(i+kernel_width) & OVERMASK] = pixels[i*stride_in_bytes]; + pixels[i*stride_in_bytes] = (uchar) (total / 4); + } + break; + case 5: + for (i=0; i <= safe_h; ++i) { + total += pixels[i*stride_in_bytes] - buffer[i & OVERMASK]; + buffer[(i+kernel_width) & OVERMASK] = pixels[i*stride_in_bytes]; + pixels[i*stride_in_bytes] = (uchar) (total / 5); + } + break; + default: + for (i=0; i <= safe_h; ++i) { + total += pixels[i*stride_in_bytes] - buffer[i & OVERMASK]; + buffer[(i+kernel_width) & OVERMASK] = pixels[i*stride_in_bytes]; + pixels[i*stride_in_bytes] = (uchar) (total / kernel_width); + } + break; + } + + for (; i < h; ++i) { + assert(pixels[i*stride_in_bytes] == 0); + total -= buffer[i & OVERMASK]; + pixels[i*stride_in_bytes] = (uchar) (total / kernel_width); + } + + pixels += 1; + } +} + +static +float +oversample_shift(int oversample) +{ + if (!oversample) + return 0.0f; + + // The prefilter is a box filter of width "oversample", + // which shifts phase by (oversample - 1)/2 pixels in + // oversampled space. We want to shift in the opposite + // direction to counter this. + return (float)-(oversample - 1) / (2.0f * (float)oversample); +} + +// rects array must be big enough to accommodate all characters in the given ranges +void +font·glyph_fillbitmap_subpixel_prefilter(font·Info *info, uchar *output, int out_w, int out_h, int out_stride, float scale_x, float scale_y, float shift_x, float shift_y, int prefilter_x, int prefilter_y, float *sub_x, float *sub_y, int glyph) +{ + font·glyph_fillbitmap_subpixel(info, + output, + out_w - (prefilter_x - 1), + out_h - (prefilter_y - 1), + out_stride, + scale_x, + scale_y, + shift_x, + shift_y, + glyph); + + if (prefilter_x > 1) + h_prefilter(output, out_w, out_h, out_stride, prefilter_x); + + if (prefilter_y > 1) + v_prefilter(output, out_w, out_h, out_stride, prefilter_y); + + *sub_x = oversample_shift(prefilter_x); + *sub_y = oversample_shift(prefilter_y); +} + +void +font·scaledvmetrics(uchar *fontdata, int index, float size, float *ascent, float *descent, float *lineGap) +{ + int i_ascent, i_descent, i_lineGap; + float scale; + font·Info info; + init(&info, fontdata, font·offsetfor(fontdata, index)); + scale = size > 0 ? font·scaleheightto(&info, size) : font·scaleheighttoem(&info, -size); + font·vmetrics(&info, &i_ascent, &i_descent, &i_lineGap); + *ascent = (float) i_ascent * scale; + *descent = (float) i_descent * scale; + *lineGap = (float) i_lineGap * scale; +} + +// ----------------------------------------------------------------------- +// sdf computation + +static +int +ray_intersect_bezier(float orig[2], float ray[2], float q0[2], float q1[2], float q2[2], float hits[2][2]) +{ + float q0perp = q0[1]*ray[0] - q0[0]*ray[1]; + float q1perp = q1[1]*ray[0] - q1[0]*ray[1]; + float q2perp = q2[1]*ray[0] - q2[0]*ray[1]; + float roperp = orig[1]*ray[0] - orig[0]*ray[1]; + + float a = q0perp - 2*q1perp + q2perp; + float b = q1perp - q0perp; + float c = q0perp - roperp; + + float s0 = 0., s1 = 0.; + int num_s = 0; + + if (a != 0.0) { + float discr = b*b - a*c; + if (discr > 0.0) { + float rcpna = -1 / a; + float d = (float) sqrt(discr); + s0 = (b+d) * rcpna; + s1 = (b-d) * rcpna; + if (s0 >= 0.0 && s0 <= 1.0) + num_s = 1; + if (d > 0.0 && s1 >= 0.0 && s1 <= 1.0) { + if (num_s == 0) s0 = s1; + ++num_s; + } + } + } else { + // 2*b*s + c = 0 + // s = -c / (2*b) + s0 = c / (-2 * b); + if (s0 >= 0.0 && s0 <= 1.0) + num_s = 1; + } + + if (num_s == 0) + return 0; + else { + float rcp_len2 = 1 / (ray[0]*ray[0] + ray[1]*ray[1]); + float rayn_x = ray[0] * rcp_len2, rayn_y = ray[1] * rcp_len2; + + float q0d = q0[0]*rayn_x + q0[1]*rayn_y; + float q1d = q1[0]*rayn_x + q1[1]*rayn_y; + float q2d = q2[0]*rayn_x + q2[1]*rayn_y; + float rod = orig[0]*rayn_x + orig[1]*rayn_y; + + float q10d = q1d - q0d; + float q20d = q2d - q0d; + float q0rd = q0d - rod; + + hits[0][0] = q0rd + s0*(2.0f - 2.0f*s0)*q10d + s0*s0*q20d; + hits[0][1] = a*s0+b; + + if (num_s > 1) { + hits[1][0] = q0rd + s1*(2.0f - 2.0f*s1)*q10d + s1*s1*q20d; + hits[1][1] = a*s1+b; + return 2; + } else { + return 1; + } + } +} + +static +int +equal(float *a, float *b) +{ + return (a[0] == b[0] && a[1] == b[1]); +} + +static +int +compute_crossings_x(float x, float y, int nverts, font·Vertex *verts) +{ + int i; + float orig[2], ray[2] = { 1, 0 }; + float y_frac; + int winding = 0; + + orig[0] = x; + orig[1] = y; + + // make sure y never passes through a vertex of the shape + y_frac = (float) fmod(y, 1.0f); + if (y_frac < 0.01f) + y += 0.01f; + else if (y_frac > 0.99f) + y -= 0.01f; + orig[1] = y; + + // test a ray from (-infinity,y) to (x,y) + for (i=0; i < nverts; ++i) { + if (verts[i].type == font·Vline) { + int x0 = (int) verts[i-1].x, y0 = (int) verts[i-1].y; + int x1 = (int) verts[i ].x, y1 = (int) verts[i ].y; + if (y > MIN(y0,y1) && y < MAX(y0,y1) && x > MIN(x0,x1)) { + float x_inter = (y - y0) / (y1 - y0) * (x1-x0) + x0; + if (x_inter < x) + winding += (y0 < y1) ? 1 : -1; + } + } + if (verts[i].type == font·Vcurve) { + int x0 = (int) verts[i-1].x , y0 = (int) verts[i-1].y ; + int x1 = (int) verts[i ].cx, y1 = (int) verts[i ].cy; + int x2 = (int) verts[i ].x , y2 = (int) verts[i ].y ; + int ax = MIN(x0,MIN(x1,x2)), ay = MIN(y0,MIN(y1,y2)); + int by = MAX(y0,MAX(y1,y2)); + if (y > ay && y < by && x > ax) { + float q0[2],q1[2],q2[2]; + float hits[2][2]; + q0[0] = (float)x0; + q0[1] = (float)y0; + q1[0] = (float)x1; + q1[1] = (float)y1; + q2[0] = (float)x2; + q2[1] = (float)y2; + if (equal(q0,q1) || equal(q1,q2)) { + x0 = (int)verts[i-1].x; + y0 = (int)verts[i-1].y; + x1 = (int)verts[i ].x; + y1 = (int)verts[i ].y; + if (y > MIN(y0,y1) && y < MAX(y0,y1) && x > MIN(x0,x1)) { + float x_inter = (y - y0) / (y1 - y0) * (x1-x0) + x0; + if (x_inter < x) + winding += (y0 < y1) ? 1 : -1; + } + } else { + int num_hits = ray_intersect_bezier(orig, ray, q0, q1, q2, hits); + if (num_hits >= 1) + if (hits[0][0] < 0) + winding += (hits[0][1] < 0 ? -1 : 1); + if (num_hits >= 2) + if (hits[1][0] < 0) + winding += (hits[1][1] < 0 ? -1 : 1); + } + } + } + } + return winding; +} + +static +float +cuberoot(float x) +{ + if (x<0) + return -(float) pow(-x,1.0f/3.0f); + else + return (float) pow( x,1.0f/3.0f); +} + +// x^3 + c*x^2 + b*x + a = 0 +static +int +solve_cubic(float a, float b, float c, float *r) +{ + float s = -a / 3; + float p = b - a*a / 3; + float q = a * (2*a*a - 9*b) / 27 + c; + float p3 = p*p*p; + float d = q*q + 4*p3 / 27; + if (d >= 0) { + float z = (float) sqrt(d); + float u = (-q + z) / 2; + float v = (-q - z) / 2; + u = cuberoot(u); + v = cuberoot(v); + r[0] = s + u + v; + return 1; + } else { + float u = (float) sqrt(-p/3); + float v = (float) acos(-sqrt(-27/p3) * q / 2) / 3; // p3 must be negative, since d is negative + float m = (float) cos(v); + float n = (float) cos(v-3.141592/2)*1.732050808f; + r[0] = s + u * 2 * m; + r[1] = s - u * (m + n); + r[2] = s - u * (m - n); + + return 3; + } +} + +uchar * +font·glyph_sdf(font·Info *info, float scale, int glyph, int padding, uchar onedge_value, float pixel_dist_scale, int *width, int *height, int *xoff, int *yoff) +{ + float scale_x = scale, scale_y = scale; + int ix0,iy0,ix1,iy1; + int w,h; + uchar *data; + + if (scale == 0) return nil; + + font·glyph_bitmapbox_subpixel(info, glyph, scale, scale, 0.0f,0.0f, &ix0,&iy0,&ix1,&iy1); + + // if empty, return nil + if (ix0 == ix1 || iy0 == iy1) + return nil; + + ix0 -= padding; + iy0 -= padding; + ix1 += padding; + iy1 += padding; + + w = (ix1 - ix0); + h = (iy1 - iy0); + + if (width ) *width = w; + if (height) *height = h; + if (xoff ) *xoff = ix0; + if (yoff ) *yoff = iy0; + + // invert for y-downwards bitmaps + scale_y = -scale_y; + + { + int x,y,i,j; + float *precompute; + font·Vertex *verts; + int num_verts = font·glyph_shape(info, glyph, &verts); + data = malloc(w * h); + precompute = malloc(num_verts * sizeof(float)); + + for (i=0,j=num_verts-1; i < num_verts; j=i++) { + if (verts[i].type == font·Vline) { + float x0 = verts[i].x*scale_x, y0 = verts[i].y*scale_y; + float x1 = verts[j].x*scale_x, y1 = verts[j].y*scale_y; + float dist = (float) sqrt((x1-x0)*(x1-x0) + (y1-y0)*(y1-y0)); + precompute[i] = (dist == 0) ? 0.0f : 1.0f / dist; + } else if (verts[i].type == font·Vcurve) { + float x2 = verts[j].x *scale_x, y2 = verts[j].y *scale_y; + float x1 = verts[i].cx*scale_x, y1 = verts[i].cy*scale_y; + float x0 = verts[i].x *scale_x, y0 = verts[i].y *scale_y; + float bx = x0 - 2*x1 + x2, by = y0 - 2*y1 + y2; + float len2 = bx*bx + by*by; + if (len2 != 0.0f) + precompute[i] = 1.0f / (bx*bx + by*by); + else + precompute[i] = 0.0f; + } else + precompute[i] = 0.0f; + } + + for (y=iy0; y < iy1; ++y) { + for (x=ix0; x < ix1; ++x) { + float val; + float min_dist = 999999.0f; + float sx = (float) x + 0.5f; + float sy = (float) y + 0.5f; + float x_gspace = (sx / scale_x); + float y_gspace = (sy / scale_y); + + int winding = compute_crossings_x(x_gspace, y_gspace, num_verts, verts); // @OPTIMIZE: this could just be a rasterization, but needs to be line vs. non-tesselated curves so a new path + + for (i=0; i < num_verts; ++i) { + float x0 = verts[i].x*scale_x, y0 = verts[i].y*scale_y; + + // check against every point here rather than inside line/curve primitives -- @TODO: wrong if multiple 'moves' in a row produce a garbage point, and given culling, probably more efficient to do within line/curve + float dist2 = (x0-sx)*(x0-sx) + (y0-sy)*(y0-sy); + if (dist2 < min_dist*min_dist) + min_dist = (float)sqrt(dist2); + + if (verts[i].type == font·Vline) { + float x1 = verts[i-1].x*scale_x, y1 = verts[i-1].y*scale_y; + + // coarse culling against bbox + //if (sx > MIN(x0,x1)-min_dist && sx < MAX(x0,x1)+min_dist && + // sy > MIN(y0,y1)-min_dist && sy < MAX(y0,y1)+min_dist) + float dist = (float) fabs((x1-x0)*(y0-sy) - (y1-y0)*(x0-sx)) * precompute[i]; + assert(i != 0); + if (dist < min_dist) { + // check position along line + // x' = x0 + t*(x1-x0), y' = y0 + t*(y1-y0) + // minimize (x'-sx)*(x'-sx)+(y'-sy)*(y'-sy) + float dx = x1-x0, dy = y1-y0; + float px = x0-sx, py = y0-sy; + // minimize (px+t*dx)^2 + (py+t*dy)^2 = px*px + 2*px*dx*t + t^2*dx*dx + py*py + 2*py*dy*t + t^2*dy*dy + // derivative: 2*px*dx + 2*py*dy + (2*dx*dx+2*dy*dy)*t, set to 0 and solve + float t = -(px*dx + py*dy) / (dx*dx + dy*dy); + if (t >= 0.0f && t <= 1.0f) + min_dist = dist; + } + } else if (verts[i].type == font·Vcurve) { + float x2 = verts[i-1].x *scale_x, y2 = verts[i-1].y *scale_y; + float x1 = verts[i ].cx*scale_x, y1 = verts[i ].cy*scale_y; + float box_x0 = MIN(MIN(x0,x1),x2); + float box_y0 = MIN(MIN(y0,y1),y2); + float box_x1 = MAX(MAX(x0,x1),x2); + float box_y1 = MAX(MAX(y0,y1),y2); + // coarse culling against bbox to avoid computing cubic unnecessarily + if (sx > box_x0-min_dist && sx < box_x1+min_dist && sy > box_y0-min_dist && sy < box_y1+min_dist) { + int num=0; + float ax = x1-x0, ay = y1-y0; + float bx = x0 - 2*x1 + x2, by = y0 - 2*y1 + y2; + float mx = x0 - sx, my = y0 - sy; + float res[3],px,py,t,it; + float a_inv = precompute[i]; + if (a_inv == 0.0) { // if a_inv is 0, it's 2nd degree so use quadratic formula + float a = 3*(ax*bx + ay*by); + float b = 2*(ax*ax + ay*ay) + (mx*bx+my*by); + float c = mx*ax+my*ay; + if (a == 0.0) { // if a is 0, it's linear + if (b != 0.0) { + res[num++] = -c/b; + } + } else { + float discriminant = b*b - 4*a*c; + if (discriminant < 0) + num = 0; + else { + float root = (float) sqrt(discriminant); + res[0] = (-b - root)/(2*a); + res[1] = (-b + root)/(2*a); + num = 2; // don't bother distinguishing 1-solution case, as code below will still work + } + } + } else { + float b = 3*(ax*bx + ay*by) * a_inv; // could precompute this as it doesn't depend on sample point + float c = (2*(ax*ax + ay*ay) + (mx*bx+my*by)) * a_inv; + float d = (mx*ax+my*ay) * a_inv; + num = solve_cubic(b, c, d, res); + } + if (num >= 1 && res[0] >= 0.0f && res[0] <= 1.0f) { + t = res[0], it = 1.0f - t; + px = it*it*x0 + 2*t*it*x1 + t*t*x2; + py = it*it*y0 + 2*t*it*y1 + t*t*y2; + dist2 = (px-sx)*(px-sx) + (py-sy)*(py-sy); + if (dist2 < min_dist * min_dist) + min_dist = (float) sqrt(dist2); + } + if (num >= 2 && res[1] >= 0.0f && res[1] <= 1.0f) { + t = res[1], it = 1.0f - t; + px = it*it*x0 + 2*t*it*x1 + t*t*x2; + py = it*it*y0 + 2*t*it*y1 + t*t*y2; + dist2 = (px-sx)*(px-sx) + (py-sy)*(py-sy); + if (dist2 < min_dist * min_dist) + min_dist = (float) sqrt(dist2); + } + if (num >= 3 && res[2] >= 0.0f && res[2] <= 1.0f) { + t = res[2], it = 1.0f - t; + px = it*it*x0 + 2*t*it*x1 + t*t*x2; + py = it*it*y0 + 2*t*it*y1 + t*t*y2; + dist2 = (px-sx)*(px-sx) + (py-sy)*(py-sy); + if (dist2 < min_dist * min_dist) + min_dist = (float) sqrt(dist2); + } + } + } + } + if (winding == 0) + min_dist = -min_dist; // if outside the shape, value is negative + val = onedge_value + pixel_dist_scale * min_dist; + if (val < 0) + val = 0; + else if (val > 255) + val = 255; + data[(y-iy0)*w+(x-ix0)] = (uchar) val; + } + } + free(precompute); + free(verts); + } + return data; +} + +uchar * +font·code_sdf(font·Info *info, float scale, int codepoint, int padding, uchar onedge_value, float pixel_dist_scale, int *width, int *height, int *xoff, int *yoff) +{ + return font·glyph_sdf(info, scale, font·glyph_index(info, codepoint), padding, onedge_value, pixel_dist_scale, width, height, xoff, yoff); +} + +void +font·freesdf(uchar *bitmap, void *userdata) +{ + free(bitmap); +} + +char* +font·name(font·Info *font, int *length, int platformID, int encodingID, int languageID, int nameID) +{ + int32 i,count,stringOffset; + uchar *fc = font->data; + uint32 offset = font->fontstart; + uint32 nm = find_table(fc, offset, "name"); + if (!nm) return nil; + + count = ttUSHORT(fc+nm+2); + stringOffset = nm + ttUSHORT(fc+nm+4); + for (i=0; i < count; ++i) { + uint32 loc = nm + 6 + 12 * i; + if (platformID == ttUSHORT(fc+loc+0) && encodingID == ttUSHORT(fc+loc+2) + && languageID == ttUSHORT(fc+loc+4) && nameID == ttUSHORT(fc+loc+6)) { + *length = ttUSHORT(fc+loc+8); + return (char *) (fc+stringOffset+ttUSHORT(fc+loc+10)); + } + } + return nil; +} + +#if 0 +static +int +matchpair(uchar *fc, uint32 nm, uchar *name, int32 nlen, int32 target_id, int32 next_id) +{ + int32 i; + int32 count = ttUSHORT(fc+nm+2); + int32 stringOffset = nm + ttUSHORT(fc+nm+4); + + for (i=0; i < count; ++i) { + uint32 loc = nm + 6 + 12 * i; + int32 id = ttUSHORT(fc+loc+6); + if (id == target_id) { + // find the encoding + int32 platform = ttUSHORT(fc+loc+0), encoding = ttUSHORT(fc+loc+2), language = ttUSHORT(fc+loc+4); + + // is this a Unicode encoding? + if (platform == 0 || (platform == 3 && encoding == 1) || (platform == 3 && encoding == 10)) { + int32 slen = ttUSHORT(fc+loc+8); + int32 off = ttUSHORT(fc+loc+10); + + // check if there's a prefix match + int32 matchlen = CompareUTF8toUTF16_bigendian_prefix(name, nlen, fc+stringOffset+off,slen); + if (matchlen >= 0) { + // check for target_id+1 immediately following, with same encoding & language + if (i+1 < count && ttUSHORT(fc+loc+12+6) == next_id && ttUSHORT(fc+loc+12) == platform && ttUSHORT(fc+loc+12+2) == encoding && ttUSHORT(fc+loc+12+4) == language) { + slen = ttUSHORT(fc+loc+12+8); + off = ttUSHORT(fc+loc+12+10); + if (slen == 0) { + if (matchlen == nlen) + return 1; + } else if (matchlen < nlen && name[matchlen] == ' ') { + ++matchlen; + if (font·CompareUTF8toUTF16_bigendian((char*) (name+matchlen), nlen-matchlen, (char*)(fc+stringOffset+off),slen)) + return 1; + } + } else { + // if nothing immediately following + if (matchlen == nlen) + return 1; + } + } + } + + // @TODO handle other encodings + } + } + return 0; +} + +static +int +matches(uchar *fc, uint32 offset, uchar *name, int32 flags) +{ + int32 nlen = (int32) strlen((char *) name); + uint32 nm, hd; + if (!isfont(fc+offset)) + return 0; + + // check italics/bold/underline flags in macStyle... + if (flags) { + hd = find_table(fc, offset, "head"); + if ((ttUSHORT(fc+hd+44) & 7) != (flags & 7)) return 0; + } + + nm = find_table(fc, offset, "name"); + if (!nm) return 0; + + if (flags) { + // if we checked the macStyle flags, then just check the family and ignore the subfamily + if (matchpair(fc, nm, name, nlen, 16, -1)) return 1; + if (matchpair(fc, nm, name, nlen, 1, -1)) return 1; + if (matchpair(fc, nm, name, nlen, 3, -1)) return 1; + } else { + if (matchpair(fc, nm, name, nlen, 16, 17)) return 1; + if (matchpair(fc, nm, name, nlen, 1, 2)) return 1; + if (matchpair(fc, nm, name, nlen, 3, -1)) return 1; + } + + return 0; +} + +int +font·findmatch(uchar *font_collection, char *name_utf8, int32 flags) +{ + int32 i; + for (i=0;;++i) { + int32 off = font·offsetfor(font_collection, i); + if (off < 0) return off; + if (matches((uchar *) font_collection, off, (uchar*) name_utf8, flags)) + return off; + } +} +#endif diff --git a/sys/libfont/rules.mk b/sys/libfont/rules.mk new file mode 100644 index 0000000..af3e8fa --- /dev/null +++ b/sys/libfont/rules.mk @@ -0,0 +1,19 @@ +include share/push.mk +# Iterate through subdirectory tree + +# Local sources +SRCS_$(d) := $(d)/font.c +LIBS_$(d) := $(d)/libfont.a +TSTS_$(d) := $(d)/test.c + +include share/paths.mk + +# Local rules +$(LIBS_$(d)): $(OBJS_$(d)) + $(ARCHIVE) + +$(UNTS_$(d)): TCLIBS := $(LIBS_$(d)) $(OBJ_DIR)/libn/libn.a +$(UNTS_$(d)): $(TOBJS_$(d)) $(LIBS_$(d)) + $(LINK) + +include share/pop.mk diff --git a/sys/libfont/test.c b/sys/libfont/test.c new file mode 100644 index 0000000..b92a56f --- /dev/null +++ b/sys/libfont/test.c @@ -0,0 +1,62 @@ +#include +#include +#include + +#define STB_IMAGE_WRITE_IMPLEMENTATION +#include "stb_image_write.h" + +#define W 512 +#define H 128 +#define L 64 + +static char *phrase = "the quick brown"; + +int +main() +{ + int i, err; + float scale; + uchar *bitmap; + font·Info *info; + mmap·Reader fontfile; + int x, y, as, ds, lg, ax, lsb, off, kern, r[2], c0[2], c1[2]; + + err = 0; + fontfile = mmap·open("/home/nolln/root/data/DejaVuSans.ttf"); + if (!fontfile.len) { + err = 1; + goto end; + } + info = font·make(fontfile.ubuf, 0); + if (!info) + panicf("failed to load info"); + + bitmap = calloc(W*H, sizeof(*bitmap)); + scale = font·scaleheightto(info, L); + + font·vmetrics(info, &as, &ds, &lg); + as *= scale; + ds *= scale; + + x = 0; + for (i = 0; i < strlen(phrase); i++) { + font·code_hmetrics(info, phrase[i], &ax, &lsb); + font·code_bitmapbox(info, phrase[i], scale, scale, c0, c0+1, c1, c1+1); + + y = as + c0[1]; + off = x + lsb * scale + y * W; + font·code_fillbitmap(info, bitmap+off, c1[0]-c0[0], c1[1]-c0[1], W, scale, scale, phrase[i]); + + x += ax * scale; + kern = font·code_kernadvance(info, phrase[i], phrase[i+1]); + x += kern * scale; + } + + stbi_write_png("out.png", W, H, 1, bitmap, W); + + font·free(info); + free(bitmap); +end: + mmap·close(fontfile); + return err; +} -- cgit v1.2.1