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-rw-r--r--sys/libfont/font.c3419
1 files changed, 0 insertions, 3419 deletions
diff --git a/sys/libfont/font.c b/sys/libfont/font.c
deleted file mode 100644
index 53988f6..0000000
--- a/sys/libfont/font.c
+++ /dev/null
@@ -1,3419 +0,0 @@
-#include "font.h"
-
-// -----------------------------------------------------------------------
-// buffer 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;
- int i;
- assert(n >= 1 && n <= 4);
-
- v = 0;
- for (i = 0; i < n; i++)
- v = (v << 8) | getbyte(b);
- return v;
-}
-
-static
-Buffer
-makebuffer(void *p, uintptr size)
-{
- Buffer r;
- assert(size < 0x40000000);
-
- r.data = (uchar*) p;
- r.size = (int)size;
- r.cursor = 0;
-
- return r;
-}
-
-static
-Buffer
-slice(Buffer *b, int o, int s)
-{
- Buffer r = makebuffer(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);
-
- panicf("unreachable");
- 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 ttf·tag4(p,c0,c1,c2,c3) ((p)[0] == (c0) && (p)[1] == (c1) && (p)[2] == (c2) && (p)[3] == (c3))
-#define ttf·tag(p,str) ttf·tag4(p,str[0],str[1],str[2],str[3])
-
-static
-int
-isfont(uchar *font)
-{
- // check the version number
- if (ttf·tag4(font, '1',0,0,0)) return 1; // TrueType 1
- if (ttf·tag(font, "typ1")) return 1; // TrueType with type 1 font -- we don't support this!
- if (ttf·tag(font, "OTTO")) return 1; // OpenType with CFF
- if (ttf·tag4(font, 0,1,0,0)) return 1; // OpenType 1.0
- if (ttf·tag(font, "true")) return 1; // Apple specification for TrueType fonts
-
- return 0;
-}
-
-// @OPTIMIZE: binary search
-static
-uint32
-find_table(uchar *data, uint32 offset, char *tag)
-{
- int i;
- int32 ntab;
- uint32 tabdir, loc;
-
- ntab = ttushort(data+offset+4);
- tabdir = offset + 12;
- for (i=0; i < ntab; ++i) {
- loc = tabdir + 16*i;
- if (ttf·tag(data+loc+0, tag))
- return ttulong(data+loc+8);
- }
- return 0;
-}
-
-int
-font·offsetfor(uchar *collection, int index)
-{
- // if it's just a font, there's only one valid index
- if (isfont(collection))
- return index == 0 ? 0 : -1;
-
- // check if it's a TTC
- if (ttf·tag(collection, "ttcf")) {
- // version 1?
- if (ttulong(collection+4) == 0x00010000 || ttulong(collection+4) == 0x00020000) {
- int32 n = ttlong(collection+8);
- if (index >= n)
- return -1;
- return ttulong(collection+12+index*4);
- }
- }
- return -1;
-}
-
-int
-font·number(uchar *collection)
-{
- // if it's just a font, there's only one valid font
- if (isfont(collection))
- return 1;
-
- // check if it's a TTC
- if (ttf·tag(collection, "ttcf")) {
- // version 1?
- if (ttulong(collection+4) == 0x00010000 || ttulong(collection+4) == 0x00020000) {
- return ttlong(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 makebuffer(nil, 0);
- pdict = slice(&cff, private_loc[1], private_loc[0]);
- dict_get_ints(&pdict, 19, 1, &subrsoff);
- if (!subrsoff)
- return makebuffer(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 offset)
-{
- uint32 cmap, t;
- int32 i, ntab;
-
- info->data = data;
- info->fontstart = offset;
- info->cff = makebuffer(nil, 0);
-
- cmap = find_table(data, offset, "cmap"); // required
- info->loca = find_table(data, offset, "loca"); // required
- info->head = find_table(data, offset, "head"); // required
- info->glyf = find_table(data, offset, "glyf"); // required
- info->hhea = find_table(data, offset, "hhea"); // required
- info->hmtx = find_table(data, offset, "hmtx"); // required
- info->kern = find_table(data, offset, "kern"); // not required
- info->gpos = find_table(data, offset, "GPOS"); // not required
- info->fpgm = find_table(data, offset, "fpgm"); // not required (execute once per load)
- info->cvt = find_table(data, offset, "cvt"); // not required (execute once per resize)
-
- printf("cvt found at %d\n", info->cvt);
- printf("fpgm found at %d\n", info->cvt);
-
- if (!cmap || !info->head || !info->hhea || !info->hmtx)
- return 1;
- 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, offset, "CFF ");
- if (!cff)
- return 1;
-
- info->fontdicts = makebuffer(nil, 0);
- info->fdselect = makebuffer(nil, 0);
-
- // @TODO this should use size from table (not 512MB)
- info->cff = makebuffer(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, offset, "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.
- ntab = ttushort(data + cmap + 2);
- info->index_map = 0;
- for (i=0; i < ntab; ++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->index_fmt = ttushort(data+info->head + 50);
- return 0;
-}
-
-font·Info *
-font·make(uchar *file, int offset, mem·Allocator mem, void *heap)
-{
- int err;
- font·Info *info;
-
- info = mem.alloc(heap, 1, sizeof(*info));
- info->mal = mem;
- info->heap = heap;
-
- err = init(info, file, offset);
- if (err) {
- mem.free(heap, info);
- info = nil;
- }
-
- return info;
-}
-
-void
-font·free(font·Info *info)
-{
- void *heap;
- mem·Allocator mem;
-
- heap = info->heap;
- mem = info->mal;
-
- mem.free(heap, info);
-}
-
-int
-font·glyph_index(font·Info *info, int unicode_codepoint)
-{
- uchar *data;
- ushort fmt;
- uint32 index_map;
- union {
- int32 bytes;
- struct {
- uint32 first;
- uint32 count;
- };
- struct {
- ushort segcount;
- ushort srchrange;
- ushort entrysel;
- ushort rangeshft;
-
- uint32 end;
- uint32 search;
- };
- struct {
- uint32 begg, begc, endc, ngroups;
- int32 low, mid, high;
- };
- } v;
-
- data = info->data;
- index_map = info->index_map;
-
- /*
- * useful discussion of table formats:
- * https://docs.microsoft.com/en-us/typography/opentype/spec/cmap
- */
- fmt = ttushort(data + index_map + 0);
- switch (fmt) {
- case 0: /* apple byte encoding */
- v.bytes = ttushort(data + index_map + 2);
- if (unicode_codepoint < v.bytes-6)
- return ttbyte(data + index_map + 6 + unicode_codepoint);
- return 0;
-
- case 6:
- v.first = ttushort(data + index_map + 6);
- v.count = ttushort(data + index_map + 8);
- if ((uint32)unicode_codepoint >= v.first && (uint32)unicode_codepoint < v.first+v.count)
- return ttushort(data + index_map + 10 + (unicode_codepoint - v.first)*2);
- return 0;
-
- case 2:
- panicf("high-byte mapping for asian characters not implemented");
- return 0;
-
- case 4: /* standard mapping for windows fonts: binary search collection of ranges */
- v.segcount = ttushort(data+index_map+6) >> 1;
- v.srchrange = ttushort(data+index_map+8) >> 1;
- v.entrysel = ttushort(data+index_map+10);
- v.rangeshft = ttushort(data+index_map+12) >> 1;
-
- // do a binary search of the segments
- v.end = index_map + 14;
- v.search = v.end;
-
- 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 + v.search + v.rangeshft*2))
- v.search += v.rangeshft*2;
-
- // now decrement to bias correctly to find smallest
- v.search -= 2;
- while (v.entrysel) {
- ushort end;
- v.srchrange >>= 1;
- end = ttushort(data + v.search + v.srchrange*2);
- if (unicode_codepoint > end)
- v.search += v.srchrange*2;
- --v.entrysel;
- }
- v.search += 2;
-
- {
- ushort offset, start;
- ushort item = (ushort) ((v.search - v.end) >> 1);
-
- assert(unicode_codepoint <= ttushort(data + v.end+ 2*item));
- start = ttushort(data + index_map + 14 + v.segcount*2 + 2 + 2*item);
- if (unicode_codepoint < start)
- return 0;
-
- offset = ttushort(data + index_map + 14 + v.segcount*6 + 2 + 2*item);
- if (offset == 0)
- return (ushort) (unicode_codepoint + ttshort(data + index_map + 14 + v.segcount*4 + 2 + 2*item));
-
- return ttushort(data + offset + (unicode_codepoint-start)*2 + index_map + 14 + v.segcount*6 + 2 + 2*item);
- }
-
- case 12: case 13:
- v.ngroups = ttulong(data+index_map+12);
- v.low = 0; v.high = (int32)v.ngroups;
- // Binary search the right group.
- while (v.low < v.high) {
- v.mid = v.low + ((v.high-v.low) >> 1); // rounds down, so low <= mid < high
- v.begc = ttulong(data+index_map+16+v.mid*12);
- v.endc = ttulong(data+index_map+16+v.mid*12+4);
- if ((uint32)unicode_codepoint < v.begc)
- v.high = v.mid;
- else if ((uint32) unicode_codepoint > v.endc)
- v.low = v.mid+1;
- else {
- v.begg = ttulong(data+index_map+16+v.mid*12+8);
- if (fmt == 12)
- return v.begg + unicode_codepoint-v.begc;
- else // fmt == 13
- return v.begg;
- }
- }
- return 0; // not found
-
- default:
- ;
- }
-
- // @TODO
- assert(0);
- return 0;
-}
-
-int
-font·code_shape(font·Info *info, int unicode_codepoint, font·Vertex **verts)
-{
- return font·glyph_shape(info, font·glyph_index(info, unicode_codepoint), verts);
-}
-
-static
-void
-setvertex(font·Vertex *v, uchar type, int32 x, int32 y, int32 cx, int32 cy)
-{
- v->type = type;
- v->x = (slong)x;
- v->y = (slong)y;
- v->cx = (slong)cx;
- v->cy = (slong)cy;
-}
-
-static
-int
-glyph_offset(font·Info *info, int glyph_index)
-{
- int gb, ge;
-
- assert(!info->cff.size);
-
- if (glyph_index >= info->numglyphs) return -1; // glyph index out of range
- if (info->index_fmt >= 2) return -1; // unknown index->glyph map format
-
- if (info->index_fmt == 0) {
- gb = info->glyf + 2*ttushort(info->data + info->loca + 2*glyph_index);
- ge = info->glyf + 2*ttushort(info->data + info->loca + 2*glyph_index + 2);
- } else {
- gb = info->glyf + 1*ttulong (info->data + info->loca + 4*glyph_index);
- ge = info->glyf + 1*ttulong (info->data + info->loca + 4*glyph_index + 4);
- }
-
- return (gb==ge) ? -1 : gb; // 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)
-{
- int g;
- if (info->cff.size) {
- glyph_info_t2(info, glyph_index, x0, y0, x1, y1);
- } else {
- 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)
-{
- int g;
- short numc;
-
- 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;
-
- numc = ttshort(info->data + g);
- return numc == 0;
-}
-
-static
-int
-close_shape(font·Vertex *verts, int numv, 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(&verts[numv++], font·Vcurve, (cx+scx)>>1, (cy+scy)>>1, cx,cy);
- setvertex(&verts[numv++], font·Vcurve, sx,sy,scx,scy);
- } else {
- if (was_off)
- setvertex(&verts[numv++], font·Vcurve,sx,sy,cx,cy);
- else
- setvertex(&verts[numv++], font·Vline,sx,sy,0,0);
- }
- return numv;
-}
-
-static
-int
-glyph_shape_tt(font·Info *info, int glyph_index, font·Vertex **pverts)
-{
- short numc;
- uchar *contourend;
- uchar *data = info->data;
- font·Vertex *verts = nil;
- int numv = 0;
- int g = glyph_offset(info, glyph_index);
-
- *pverts = nil;
-
- /* glyph not found */
- if (g < 0)
- return 0;
-
- numc = ttshort(data + g);
-
- if (numc > 0) {
- uchar flags=0, flagcount;
- int32 nins, 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;
- contourend = data + g + 10;
- nins = ttushort(data + g + 10 + numc * 2);
- points = data + g + 10 + 2*numc + 2 + nins;
- printf("number of instructions %d\n", nins);
-
- n = 1+ttushort(contourend + numc*2-2);
-
- m = n + 2*numc; // a loose bound on how many verts we might need
- verts = info->alloc(info->heap, m, sizeof(verts[0]));
- if (verts == 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;
- verts[off+i].type = flags;
- }
-
- // now load x coordinates
- x=0;
- for (i = 0; i < n; ++i) {
- flags = verts[off+i].type;
- if (flags & 2) {
- slong dx = *points++;
- x += (flags & 16) ? dx : -dx; // ???
- } else {
- if (!(flags & 16)) {
- x = x + (short)(points[0]*256 + points[1]); // this cast is critical
- points += 2;
- }
- }
- verts[off+i].x = (slong)x;
- }
-
- // now load y coordinates
- y = 0;
- for (i = 0; i < n; ++i) {
- flags = verts[off+i].type;
- if (flags & 4) {
- slong dy = *points++;
- y += (flags & 32) ? dy : -dy; // ???
- } else {
- if (!(flags & 32)) {
- y = y + (short)(points[0]*256 + points[1]); // this cast is critical
- points += 2;
- }
- }
- verts[off+i].y = (slong)y;
- }
-
- // now convert them to our format
- numv = 0;
- sx = sy = cx = cy = scx = scy = 0;
- for (i=0; i < n; ++i) {
- flags = verts[off+i].type;
- x = (slong)verts[off+i].x;
- y = (slong)verts[off+i].y;
-
- if (next_move == i) {
- if (i != 0)
- numv = close_shape(verts, numv, 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 (!(verts[off+i+1].type & 1)) {
- // next point is also a curve point, so interpolate an on-point curve
- sx = (x + (int32) verts[off+i+1].x) >> 1;
- sy = (y + (int32) verts[off+i+1].y) >> 1;
- } else {
- // otherwise just use the next point as our start point
- sx = (int32) verts[off+i+1].x;
- sy = (int32) verts[off+i+1].y;
- ++i; // we're using point i+1 as the starting point, so skip it
- }
- } else {
- sx = x;
- sy = y;
- }
- setvertex(&verts[numv++], font·Vmove,sx,sy,0,0);
- was_off = 0;
- next_move = 1 + ttushort(contourend+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(&verts[numv++], font·Vcurve, (cx+x)>>1, (cy+y)>>1, cx, cy);
- cx = x;
- cy = y;
- was_off = 1;
- } else {
- if (was_off)
- setvertex(&verts[numv++], font·Vcurve, x,y, cx, cy);
- else
- setvertex(&verts[numv++], font·Vline, x,y,0,0);
- was_off = 0;
- }
- }
- }
- numv = close_shape(verts, numv, was_off, start_off, sx, sy, scx, scy, cx, cy);
- } else if (numc < 0) {
- // Compound shapes.
- int more = 1;
- uchar *comp = data + g + 10;
- numv = 0;
- verts = 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 verts.
- 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 verts.
- tmp = info->alloc(info->heap, numv+comp_num_verts, sizeof(font·Vertex));
- if (!tmp) {
- if (verts) info->free(info->heap, verts);
- if (comp_verts) info->free(info->heap, comp_verts);
- return 0;
- }
- if (numv > 0)
- memcpy(tmp, verts, numv*sizeof(font·Vertex));
-
- memcpy(tmp+numv, comp_verts, comp_num_verts*sizeof(font·Vertex));
-
- if (verts)
- info->free(info->heap, verts);
-
- verts = tmp;
- info->free(info->heap, comp_verts);
- numv += comp_num_verts;
- }
- // More components ?
- more = flags & (1<<5);
- }
- }
-
- *pverts = verts;
- return numv;
-}
-
-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 *pverts;
- int numv;
-} 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;
-}
-
-/* decode curve sequences */
-
-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->pverts[c->numv], type, x, y, cx, cy);
- c->pverts[c->numv].cx1 = (short) cx1;
- c->pverts[c->numv].cy1 = (short) cy1;
- }
- c->numv++;
-}
-
-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 makebuffer(nil, 0);
-
- return cff_index_get(idx, n);
-}
-
-static
-Buffer
-cid_get_glyph_subrs(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) makebuffer(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;
-
- // 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) {
- errorf("rmoveto stack");
- return 0;
- }
- csctx_rmove_to(c, s[sp-2], s[sp-1]);
- break;
-
- case 0x04: // vmoveto
- in_header = 0;
- if (sp < 1) {
- errorf("vmoveto stack");
- return 0;
- }
- csctx_rmove_to(c, 0, s[sp-1]);
- break;
-
- case 0x16: // hmoveto
- in_header = 0;
- if (sp < 1) {
- errorf("hmoveto stack");
- return 0;
- }
- csctx_rmove_to(c, s[sp-1], 0);
- break;
-
- case 0x05: // rlineto
- if (sp < 2) {
- errorf("rlineto stack");
- return 0;
- }
- 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) {
- errorf("vlineto stack");
- return 0;
- }
- goto vlineto;
- case 0x06: // hlineto
- if (sp < 1) {
- errorf("hlineto stack");
- return 0;
- }
- 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) {
- errorf("hvcurveto stack");
- return 0;
- }
- goto hvcurveto;
- case 0x1E: // vhcurveto
- if (sp < 4) {
- errorf("vhcurveto stack");
- return 0;
- }
- 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) {
- errorf("rcurveline stack");
- return 0;
- }
- 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) {
- errorf("rcurveline stack");
- return 0;
- }
- 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) {
- errorf("rcurveline stack");
- return 0;
- }
- csctx_rline_to(c, s[i], s[i+1]);
- break;
-
- case 0x19: // rlinecurve
- if (sp < 8) {
- errorf("rlinecurve stack");
- return 0;
- }
- for (; i + 1 < sp - 6; i += 2)
- csctx_rline_to(c, s[i], s[i+1]);
- if (i + 5 >= sp) {
- errorf("rlinecurve stack");
- return 0;
- }
- 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) {
- errorf("(vv|hh)curveto stack");
- return 0;
- }
- 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) {
- errorf("call(g|)subr stack");
- return 0;
- }
- v = (int)s[--sp];
- if (subr_stack_height >= 10) {
- errorf("recursion limit");
- return 0;
- }
- subr_stack[subr_stack_height++] = b;
- b = get_subr(b0 == 0x0A ? subrs : info->gsubrs, v);
- if (b.size == 0) {
- errorf("subr not found");
- return 0;
- }
- b.cursor = 0;
- clear_stack = 0;
- break;
-
- case 0x0B: // return
- if (subr_stack_height <= 0) {
- errorf("return outside subr");
- return 0;
- }
- 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) {
- errorf("hflex stack");
- return 0;
- }
- 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) {
- errorf("flex stack");
- return 0;
- }
- 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) {
- errorf("hflex1 stack");
- return 0;
- }
- 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) {
- errorf("flex1 stack");
- return 0;
- }
- 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:
- panicf("unimplemented");
- return 0;
- }
- } break;
-
- default:
- if (b0 != 255 && b0 != 28 && (b0 < 32 || b0 > 254)) {
- errorf("reserved operator");
- return 0;
- }
-
- // push immediate
- if (b0 == 255) {
- f = (float)(int32)getint(&b) / 0x10000;
- } else {
- skip(&b, -1);
- f = (float)(short)cff_int(&b);
- }
- if (sp >= 48) {
- errorf("push stack overflow");
- return 0;
- }
- s[sp++] = f;
- clear_stack = 0;
- break;
- }
- if (clear_stack) sp = 0;
- }
-
- errorf("no endchar");
- return 0;
-
-}
-
-static
-int
-glyph_shape_t2(font·Info *info, int glyph_index, font·Vertex **pverts)
-{
- // 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)) {
- *pverts = info->alloc(info->heap, count_ctx.numv, sizeof(font·Vertex));
- output_ctx.pverts = *pverts;
- if (run_charstring(info, glyph_index, &output_ctx)) {
- assert(output_ctx.numv == count_ctx.numv);
- return output_ctx.numv;
- }
- }
-
- *pverts = 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.numv : 0;
-}
-
-int
-font·glyph_shape(font·Info *info, int glyph_index, font·Vertex **pverts)
-{
- if (!info->cff.size)
- return glyph_shape_tt(info, glyph_index, pverts);
- else
- return glyph_shape_t2(info, glyph_index, pverts);
-}
-
-void
-font·glyph_hmetrics(font·Info *info, int glyph_index, int *adv, int *lsb)
-{
- ushort n;
-
- n = ttushort(info->data+info->hhea + 34);
- if (glyph_index < n) {
- if (adv) *adv = ttshort(info->data + info->hmtx + 4*glyph_index);
- if (lsb) *lsb = ttshort(info->data + info->hmtx + 4*glyph_index + 2);
- } else {
- if (adv) *adv = ttshort(info->data + info->hmtx + 4*(n-1));
- if (lsb) *lsb = ttshort(info->data + info->hmtx + 4*n + 2*(glyph_index - n));
- }
-}
-
-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(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(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<lookupCount; ++i) {
- ushort lookupOffset = ttushort(lookupList + 2 + 2 * i);
- uchar *lookupTable = lookupList + lookupOffset;
-
- ushort lookupType = ttushort(lookupTable);
- ushort subTableCount = ttushort(lookupTable + 4);
- uchar *subTableOffsets = lookupTable + 6;
- switch(lookupType) {
- case 2: { // Pair Adjustment Positioning Subtable
- int32 sti;
- for (sti=0; sti<subTableCount; sti++) {
- ushort subtableOffset = ttushort(subTableOffsets + 2 * sti);
- uchar *table = lookupTable + subtableOffset;
- ushort posFormat = ttushort(table);
- ushort coverageOffset = ttushort(table + 2);
- int32 coverageIndex = coverage_index(table + coverageOffset, glyph1);
- if (coverageIndex == -1) continue;
-
- switch (posFormat) {
- case 1: {
- int32 l, r, m;
- int straw, needle;
- ushort valueFormat1 = ttushort(table + 4);
- ushort valueFormat2 = ttushort(table + 6);
- int32 valueRecordPairSizeInBytes = 2;
- ushort pairSetCount = ttushort(table + 8);
- ushort pairPosOffset = ttushort(table + 10 + 2 * coverageIndex);
- uchar *pairValueTable = table + pairPosOffset;
- ushort pairValueCount = ttushort(pairValueTable);
- uchar *pairValueArray = pairValueTable + 2;
- // TODO: Support more formats.
- if (valueFormat1 != 4) return 0;
- if (valueFormat2 != 0) return 0;
-
- assert(coverageIndex < pairSetCount);
-
- needle=glyph2;
- r=pairValueCount-1;
- l=0;
-
- // Binary search.
- while (l <= r) {
- ushort secondGlyph;
- uchar *pairValue;
- m = (l + r) >> 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 no kerning table, don't waste time looking up both codepoint->glyphs
- if (!info->kern && !info->gpos)
- 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)
-{
- info->free(info->heap, v);
-}
-
-static
-uchar *
-find_svg(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<numEntries; i++) {
- uchar *svg_doc = svg_docs + (12 * i);
- if ((gl >= 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_bbox_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;
- 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_bbox(font·Info *font, int glyph, float scale_x, float scale_y, int *ix0, int *iy0, int *ix1, int *iy1)
-{
- font·glyph_bbox_subpixel(font, glyph, scale_x, scale_y,0.0f,0.0f, ix0, iy0, ix1, iy1);
-}
-
-void
-font·code_bbox_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_bbox_subpixel(font, font·glyph_index(font,codepoint), scale_x, scale_y, shift_x, shift_y, ix0, iy0, ix1, iy1);
-}
-
-void
-font·code_bbox(font·Info *font, int codepoint, float scale_x, float scale_y, int *ix0, int *iy0, int *ix1, int *iy1)
-{
- font·code_bbox_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 nrem;
-} hheap;
-
-static
-void *
-hheap_alloc(hheap *hh, uintptr size, mem·Allocator mem, void *heap)
-{
- int n;
- void *p;
- if (hh->first_free) {
- p = hh->first_free;
- hh->first_free = * (void **) p;
- return p;
- } else {
- if (hh->nrem == 0) {
- n = (size < 32 ? 2000 : size < 128 ? 800 : 100);
- hheap_chunk *c = mem.alloc(heap, 1, sizeof(hheap_chunk) + size * n);
- if (c == nil)
- return nil;
-
- c->next = hh->head;
- hh->head = c;
- hh->nrem = n;
- }
- --hh->nrem;
- return (char *)(hh->head) + sizeof(hheap_chunk) + size * hh->nrem;
- }
-}
-
-static
-void
-hheap_free(hheap *hh, void *p)
-{
- *(void **) p = hh->first_free;
- hh->first_free = p;
-}
-
-static
-void
-hheap_cleanup(hheap *hh, mem·Allocator mem, void *heap)
-{
- hheap_chunk *c = hh->head;
- while (c) {
- hheap_chunk *n = c->next;
- mem.free(heap, c);
- c = n;
- }
-}
-
-static
-ActiveEdge *
-new_active(hheap *hh, Edge *e, int off_x, float start_point, mem·Allocator mem, void *heap)
-{
- ActiveEdge *z = (ActiveEdge *) hheap_alloc(hh, sizeof(*z), mem, heap);
- 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;
-}
-
-// assumes: 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_bot = 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_bot);
- handle_clipped_edge(scanline_fill-1,(int) x0+1,e, x0,y_top, x0,y_bot);
- } else {
- handle_clipped_edge(scanline_fill-1,0,e, x0,y_top, x0,y_bot);
- }
- }
- } else {
- float x0 = e->fx;
- float dx = e->fdx;
- float xb = x0 + dx;
- float x_top, x_bot;
- float sy0,sy1;
- float dy = e->fdy;
- assert(e->sy <= y_bot && 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_bot) {
- x_bot = x0 + dx * (e->ey - y_top);
- sy1 = e->ey;
- } else {
- x_bot = xb;
- sy1 = y_bot;
- }
-
- if (x_top >= 0 && x_bot >= 0 && x_top < len && x_bot < len) {
- // from here on, we don't have to range check x values
-
- if ((int)x_top == (int)x_bot) {
- 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_bot-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_bot) {
- // flip scanline vertically; signed area is the same
- float t;
- sy0 = y_bot - (sy0 - y_top);
- sy1 = y_bot - (sy1 - y_top);
- t = sy0, sy0 = sy1, sy1 = t;
- t = x_bot, x_bot = x_top, x_top = t;
- dx = -dx;
- dy = -dy;
- t = x0, x0 = xb, xb = t;
- }
-
- x1 = (int)x_top;
- x2 = (int)x_bot;
- // 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_bot-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_bot;
-
- float y1 = (x+0 - 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, mem·Allocator mem, void *heap)
-{
- hheap hh = { 0 };
- ActiveEdge *active = nil;
- int y,j=0, i;
- float scanline_data[129], *scanline, *scanline2;
-
- if (result->w > 64)
- scanline = mem.alloc(heap, (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_bot = y + 1.0f;
- ActiveEdge **step = &active;
-
- memset(scanline , 0, (result->w+0)*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_bot) {
- if (e->y0 != e->y1) {
- ActiveEdge *z = new_active(&hh, e, off_x, scan_y_top, mem, heap);
- 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, mem, heap);
-
- if (scanline != scanline_data)
- mem.free(heap, 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 && mid<n: 0>n => n; 0<n => 0 */
- /* 0<mid && mid>n: 0>n => 0; 0<n => 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_points(font·Bitmap *result, Point *pts, int *wcount, int nwinding, float scale_x, float scale_y, float shift_x, float shift_y, int off_x, int off_y, int invert, mem·Allocator mem, void *heap)
-{
- 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 nwinding into explicit edge lists
- n = 0;
- for (i = 0; i < nwinding; ++i)
- n += wcount[i];
-
- e = mem.alloc(heap, n+1, sizeof(*e)); // add an extra one as a sentinel
- if (e == 0)
- return;
- n = 0;
-
- m = 0;
- for (i = 0; i < nwinding; ++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)
- 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, mem, heap);
-
- mem.free(heap, 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 *npts, 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, npts, x0,y0, (x0+x1)/2.0f,(y0+y1)/2.0f, mx,my, objspace_flatness_squared,n+1);
- tesselate_curve(points, npts, mx,my, (x1+x2)/2.0f,(y1+y2)/2.0f, x2,y2, objspace_flatness_squared,n+1);
- } else {
- add_point(points, *npts,x2,y2);
- *npts = *npts+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 *verts, int numv, float objspace_flatness, int **contour_lengths, int *num_contours, mem·Allocator mem, void *heap)
-{
- 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 < numv; ++i)
- if (verts[i].type == font·Vmove)
- ++n;
-
- *num_contours = n;
- if (n == 0)
- return 0;
-
- *contour_lengths = mem.alloc(heap, n, sizeof(**contour_lengths));
-
- 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 = mem.alloc(heap, num_points, sizeof(points[0]));
- if (!points)
- goto nomemory;
- }
- num_points = 0;
- n = -1;
- for (i=0; i < numv; ++i) {
- switch (verts[i].type) {
- case font·Vmove:
- // start the next contour
- if (n >= 0)
- (*contour_lengths)[n] = num_points - start;
- ++n;
- start = num_points;
-
- x = verts[i].x, y = verts[i].y;
- add_point(points, num_points++, x, y);
- break;
- case font·Vline:
- x = verts[i].x, y = verts[i].y;
- add_point(points, num_points++, x, y);
- break;
- case font·Vcurve:
- tesselate_curve(points, &num_points, x,y,
- verts[i].cx, verts[i].cy,
- verts[i].x, verts[i].y,
- objspace_flatness_squared, 0);
- x = verts[i].x, y = verts[i].y;
- break;
- case font·Vcubic:
- tesselate_cubic(points, &num_points, x,y,
- verts[i].cx, verts[i].cy,
- verts[i].cx1, verts[i].cy1,
- verts[i].x, verts[i].y,
- objspace_flatness_squared, 0);
- x = verts[i].x, y = verts[i].y;
- break;
- }
- }
- (*contour_lengths)[n] = num_points - start;
- }
- return points;
-
-nomemory:
- mem.free(heap, points);
- mem.free(heap, *contour_lengths);
- *contour_lengths = nil;
- *num_contours = 0;
- return nil;
-}
-
-static
-void
-rasterize(font·Bitmap *result, float flatness_in_pixels, font·Vertex *verts, int numv, float scale_x, float scale_y, float shift_x, float shift_y, int x_off, int y_off, int invert, mem·Allocator mal, void *heap)
-{
- float scale = MIN(scale_x, scale_y);
- int winding_count = 0;
- int *winding_lens = nil;
-
- Point *windings = flatten(verts, numv, flatness_in_pixels / scale, &winding_lens, &winding_count, mal, heap);
- if (windings) {
- rasterize_points(result, windings, winding_lens, winding_count, scale_x, scale_y, shift_x, shift_y, x_off, y_off, invert, mal, heap);
- mal.free(heap, windings);
- mal.free(heap, winding_lens);
- }
-}
-
-void
-font·freebitmap(font·Info *info, uchar *bm)
-{
- info->free(info->heap, 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 *verts;
- int numv = font·glyph_shape(info, glyph, &verts);
-
- if (scale_x == 0) scale_x = scale_y;
- if (scale_y == 0) {
- if (scale_x == 0) {
- info->free(info->heap, verts);
- return nil;
- }
- scale_y = scale_x;
- }
-
- font·glyph_bbox_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 = info->alloc(info->heap, 1, gbm.h*gbm.w);
- if (gbm.pixels) {
- gbm.stride = gbm.w;
-
- rasterize(&gbm, 0.35f, verts, numv, scale_x, scale_y, shift_x, shift_y, ix0, iy0, 1, info->mal, info->heap);
- }
- }
- info->free(info->heap, verts);
- 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, nv;
- font·Vertex *verts;
- font·Bitmap gbm;
-
- nv = font·glyph_shape(info, glyph, &verts);
-
- font·glyph_bbox_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)
- rasterize(&gbm, 0.35f, verts, nv, scale_x, scale_y, shift_x, shift_y, ix0,iy0, 1, info->mal, info->heap);
-
- info->free(info->heap, verts);
-}
-
-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, uint kern)
-{
- uchar buffer[SAMPLE];
- int safe_w = w - kern;
- int j;
- memset(buffer, 0, SAMPLE);
- for (j=0; j < h; ++j) {
- int i;
- uint total;
- memset(buffer, 0, kern);
-
- total = 0;
-
- // make kern a constant in common cases so compiler can optimize out the divide
- switch (kern) {
- case 2:
- for (i=0; i <= safe_w; ++i) {
- total += pixels[i] - buffer[i & OVERMASK];
- buffer[(i+kern) & 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+kern) & 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+kern) & 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+kern) & 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+kern) & OVERMASK] = pixels[i];
- pixels[i] = (uchar) (total / kern);
- }
- break;
- }
-
- for (; i < w; ++i) {
- assert(pixels[i] == 0);
- total -= buffer[i & OVERMASK];
- pixels[i] = (uchar) (total / kern);
- }
-
- pixels += stride_in_bytes;
- }
-}
-
-static
-void
-v_prefilter(uchar *pixels, int w, int h, int stride_in_bytes, uint kern)
-{
- uchar buffer[SAMPLE];
- int safe_h = h - kern;
- int j;
- memset(buffer, 0, SAMPLE);
-
- for (j=0; j < w; ++j) {
- int i;
- uint total;
- memset(buffer, 0, kern);
-
- total = 0;
-
- // make kern a constant in common cases so compiler can optimize out the divide
- switch (kern) {
- case 2:
- for (i=0; i <= safe_h; ++i) {
- total += pixels[i*stride_in_bytes] - buffer[i & OVERMASK];
- buffer[(i+kern) & 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+kern) & 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+kern) & 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+kern) & 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+kern) & OVERMASK] = pixels[i*stride_in_bytes];
- pixels[i*stride_in_bytes] = (uchar) (total / kern);
- }
- break;
- }
-
- for (; i < h; ++i) {
- assert(pixels[i*stride_in_bytes] == 0);
- total -= buffer[i & OVERMASK];
- pixels[i*stride_in_bytes] = (uchar)(total / kern);
- }
-
- pixels += 1;
- }
-}
-
-static
-float
-oversample_shift(int width)
-{
- if (!width)
- 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)width - 1.0f) / (2.0f * (float)width);
-}
-
-// 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_bbox_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 numv = font·glyph_shape(info, glyph, &verts);
- data = info->alloc(info->heap, 1, w * h);
- precompute = info->alloc(info->heap, numv, sizeof(float));
-
- for (i=0,j=numv-1; i < numv; 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, numv, 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 < numv; ++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;
- }
- }
- info->free(info->heap,precompute);
- info->free(info->heap, 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(font·Info* info, uchar *bitmap)
-{
- info->free(info->heap, 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 *collection, char *name_utf8, int32 flags)
-{
- int32 i;
- for (i=0;;++i) {
- int32 off = font·offsetfor(collection, i);
- if (off < 0) return off;
- if (matches((uchar *) collection, off, (uchar*) name_utf8, flags))
- return off;
- }
-}
-#endif
generated by cgit v1.2.1 (git 2.18.0) at 2024-07-02 10:12:39 +0000