egfx/text.d

   1 /* E-Mail Client
   2  * coded by Ketmar // Invisible Vector <ketmar@ketmar.no-ip.org>
   3  * Understanding is not required. Only obedience.
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, version 3 of the License ONLY.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  16  */
  17 module egfx.text /*is aliced*/;
  18 private:
  19
  20 import arsd.simpledisplay;
  21
  22 import iv.alice;
  23 import iv.bclamp;
  24 import iv.cmdcon;
  25 import iv.fontconfig;
  26 import iv.freetype;
  27 import iv.utfutil;
  28 import iv.vfs;
  29
  30 import egfx.config;
  31 import egfx.base;
  32
  33
  34 // ////////////////////////////////////////////////////////////////////////// //
  35 enum ReplacementChar = 0xFFFD;
  36 //__gshared string chiFontName = "Arial:pixelsize=16";
  37 //__gshared string chiFontName = "Verdana:pixelsize=16";
  38 __gshared string chiFontName = "Verdana:weight=bold:pixelsize=16";
  39 __gshared string chiFontFile;
  40 __gshared int fontSize;
  41 __gshared int fontHeight;
  42 __gshared int fontBaselineOfs;
  43
  44
  45 // ////////////////////////////////////////////////////////////////////////// //
  46 __gshared ubyte* ttfontdata;
  47 __gshared uint ttfontdatasize;
  48
  49 __gshared FT_Library ttflibrary;
  50 __gshared FTC_Manager ttfcache;
  51 __gshared FTC_CMapCache ttfcachecmap;
  52 __gshared FTC_ImageCache ttfcacheimage;
  53
  54
  55 shared static ~this () {
  56   if (ttflibrary) {
  57     if (ttfcache) {
  58       FTC_Manager_Done(ttfcache);
  59       ttfcache = null;
  60     }
  61     FT_Done_FreeType(ttflibrary);
  62     ttflibrary = null;
  63   }
  64 }
  65
  66
  67 enum FontID = cast(FTC_FaceID)1;
  68
  69
  70 extern(C) nothrow {
  71   void ttfFontFinalizer (void* obj) {
  72     import core.stdc.stdlib : free;
  73     if (obj is null) return;
  74     auto tf = cast(iv.freetype.FT_Face)obj;
  75     if (tf.generic.data !is ttfontdata) return;
  76     if (ttfontdata !is null) {
  77       version(aliced) conwriteln("TTF CACHE: freeing loaded font...");
  78       free(ttfontdata);
  79       ttfontdata = null;
  80       ttfontdatasize = 0;
  81     }
  82   }
  83
  84   FT_Error ttfFontLoader (FTC_FaceID face_id, FT_Library library, FT_Pointer request_data, iv.freetype.FT_Face* aface) {
  85     if (face_id == FontID) {
  86       try {
  87         if (ttfontdata is null) {
  88           conwriteln("TTF CACHE: loading '", chiFontFile, "'...");
  89           import core.stdc.stdlib : malloc;
  90           auto fl = VFile(chiFontFile);
  91           auto fsz = fl.size;
  92           if (fsz < 16 || fsz > int.max/8) throw new Exception("invalid ttf size");
  93           ttfontdatasize = cast(uint)fsz;
  94           ttfontdata = cast(ubyte*)malloc(ttfontdatasize);
  95           if (ttfontdata is null) { import core.exception : onOutOfMemoryErrorNoGC; onOutOfMemoryErrorNoGC(); }
  96           fl.rawReadExact(ttfontdata[0..ttfontdatasize]);
  97         }
  98         auto res = FT_New_Memory_Face(library, cast(const(FT_Byte)*)ttfontdata, ttfontdatasize, 0, aface);
  99         if (res != 0) throw new Exception("error loading ttf: '"~chiFontFile~"'");
 100         (*aface).generic.data = ttfontdata;
 101         (*aface).generic.finalizer = &ttfFontFinalizer;
 102       } catch (Exception e) {
 103         if (ttfontdata !is null) {
 104           import core.stdc.stdlib : free;
 105           free(ttfontdata);
 106           ttfontdata = null;
 107           ttfontdatasize = 0;
 108         }
 109         version(aliced) conwriteln("ERROR loading font: ", e.msg);
 110         return FT_Err_Cannot_Open_Resource;
 111       }
 112       return FT_Err_Ok;
 113     } else {
 114       version(aliced) conwriteln("TTF CACHE: invalid font id");
 115     }
 116     return FT_Err_Cannot_Open_Resource;
 117   }
 118 }
 119
 120
 121 void ttfLoad () nothrow {
 122   if (FT_Init_FreeType(&ttflibrary)) assert(0, "can't initialize FreeType");
 123   if (FTC_Manager_New(ttflibrary, 0, 0, 0, &ttfFontLoader, null, &ttfcache)) assert(0, "can't initialize FreeType cache manager");
 124   if (FTC_CMapCache_New(ttfcache, &ttfcachecmap)) assert(0, "can't initialize FreeType cache manager");
 125   if (FTC_ImageCache_New(ttfcache, &ttfcacheimage)) assert(0, "can't initialize FreeType cache manager");
 126   {
 127     FTC_ScalerRec fsc;
 128     fsc.face_id = FontID;
 129     fsc.width = 0;
 130     fsc.height = fontSize;
 131     fsc.pixel = 1; // size in pixels
 132
 133     FT_Size ttfontsz;
 134     if (FTC_Manager_LookupSize(ttfcache, &fsc, &ttfontsz)) assert(0, "cannot find FreeType font");
 135     fontHeight = cast(int)ttfontsz.metrics.height>>6; // 26.6
 136     fontBaselineOfs = cast(int)((ttfontsz.metrics.height+ttfontsz.metrics.descender)>>6);
 137     if (fontHeight < 2 || fontHeight > 128) assert(0, "invalid FreeType font metrics");
 138   }
 139   version(aliced) conwriteln("TTF CACHE initialized.");
 140 }
 141
 142
 143 void initFontEngine () nothrow {
 144   if (ttflibrary is null) {
 145     import std.string : fromStringz, toStringz;
 146     if (!FcInit()) assert(0, "cannot init fontconfig");
 147     iv.fontconfig.FcPattern* pat = FcNameParse(chiFontName.toStringz);
 148     if (pat is null) assert(0, "cannot parse font name");
 149     if (!FcConfigSubstitute(null, pat, FcMatchPattern)) assert(0, "cannot find fontconfig substitute");
 150     FcDefaultSubstitute(pat);
 151     // find the font
 152     iv.fontconfig.FcResult result;
 153     iv.fontconfig.FcPattern* font = FcFontMatch(null, pat, &result);
 154     if (font !is null) {
 155       char* file = null;
 156       if (FcPatternGetString(font, FC_FILE, 0, &file) == FcResultMatch) {
 157         version(aliced) conwriteln("font file: [", file, "]");
 158         chiFontFile = file.fromStringz.idup;
 159       }
 160       double pixelsize;
 161       if (FcPatternGetDouble(font, FC_PIXEL_SIZE, 0, &pixelsize) == FcResultMatch) {
 162         version(aliced) conwriteln("pixel size: ", pixelsize);
 163         fontSize = cast(int)pixelsize;
 164       }
 165     }
 166     FcPatternDestroy(pat);
 167     // arbitrary limits
 168     if (fontSize < 6) fontSize = 6;
 169     if (fontSize > 42) fontSize = 42;
 170     ttfLoad();
 171   }
 172 }
 173
 174
 175 // ////////////////////////////////////////////////////////////////////////// //
 176 public void utfByDChar (const(char)[] s, scope void delegate (dchar ch) nothrow @trusted dg) nothrow @trusted {
 177   if (dg is null) return;
 178   Utf8DecoderFast dc;
 179   foreach (char ch; s) {
 180     if (dc.decode(cast(ubyte)ch)) dg(dc.complete ? dc.codepoint : dc.replacement);
 181   }
 182 }
 183
 184
 185 public void utfByDCharSPos (const(char)[] s, scope void delegate (dchar ch, usize stpos) nothrow @trusted dg) nothrow @trusted {
 186   if (dg is null) return;
 187   Utf8DecoderFast dc;
 188   usize stpos = 0;
 189   foreach (immutable idx, char ch; s) {
 190     if (dc.decode(cast(ubyte)ch)) {
 191       dg(dc.complete ? dc.codepoint : dc.replacement, stpos);
 192       stpos = idx+1;
 193     }
 194   }
 195 }
 196
 197
 198 // ////////////////////////////////////////////////////////////////////////// //
 199 void drawFTBitmap (int x, int y, in ref FT_Bitmap bitmap, uint clr) nothrow @trusted @nogc {
 200   if (bitmap.pixel_mode != FT_PIXEL_MODE_MONO) return; // alas
 201   if (bitmap.rows < 1 || bitmap.width < 1) return; // nothing to do
 202   if (gxIsTransparent(clr)) return; // just in case
 203   // prepare
 204   bool topdown = true;
 205   const(ubyte)* src = bitmap.buffer;
 206   int spt = bitmap.pitch;
 207   if (spt < 0) {
 208     topdown = false;
 209     spt = -spt;
 210     src += spt*(bitmap.rows-1);
 211   }
 212   if (!gxIsSolid(clr)) {
 213     // let this be slow
 214     foreach (immutable int dy; 0..bitmap.rows) {
 215       ubyte count = 0, b = 0;
 216       auto ss = src;
 217       foreach (immutable int dx; 0..bitmap.width) {
 218         if (count-- == 0) { count = 7; b = *ss++; } else b <<= 1;
 219         if (b&0x80) gxPutPixel(x+dx, y, clr);
 220       }
 221       ++y;
 222       if (topdown) src += spt; else src -= spt;
 223     }
 224     return;
 225   }
 226   // check if we can use the fastest path
 227   auto brc = GxRect(x, y, bitmap.width, bitmap.rows);
 228   if (gxClipRect.contains(brc) && GxRect(0, 0, VBufWidth, VBufHeight).contains(brc)) {
 229     // yay, the fastest one!
 230     uint* dptr = vglTexBuf+y*VBufWidth+x;
 231     foreach (immutable int dy; 0..bitmap.rows) {
 232       ubyte count = 0, b = 0;
 233       auto ss = src;
 234       auto curptr = dptr;
 235       foreach (immutable int dx; 0..bitmap.width) {
 236         if (count-- == 0) { count = 7; b = *ss++; } else b <<= 1;
 237         if (b&0x80) *curptr = clr;
 238         ++curptr;
 239       }
 240       if (topdown) src += spt; else src -= spt;
 241       dptr += VBufWidth;
 242     }
 243   } else {
 244     // do it slow
 245     foreach (immutable int dy; 0..bitmap.rows) {
 246       ubyte count = 0, b = 0;
 247       auto ss = src;
 248       foreach (immutable int dx; 0..bitmap.width) {
 249         if (count-- == 0) { count = 7; b = *ss++; } else b <<= 1;
 250         if (b&0x80) gxSetPixel(x+dx, y, clr);
 251       }
 252       ++y;
 253       if (topdown) src += spt; else src -= spt;
 254     }
 255   }
 256 }
 257
 258
 259 // y is baseline; returns advance
 260 int ttfDrawGlyph (bool firstchar, int scale, int x, int y, int glyphidx, uint clr) nothrow @trusted {
 261   enum mono = true;
 262   if (glyphidx == 0) return 0;
 263
 264   FTC_ImageTypeRec fimg;
 265   fimg.face_id = FontID;
 266   fimg.width = 0;
 267   fimg.height = fontSize*scale;
 268   static if (mono) {
 269     fimg.flags = FT_LOAD_TARGET_MONO|(gxIsTransparent(clr) ? 0 : FT_LOAD_MONOCHROME|FT_LOAD_RENDER);
 270   } else {
 271     fimg.flags = (gxIsTransparent(clr) ? 0 : FT_LOAD_RENDER);
 272   }
 273
 274   FT_Glyph fg;
 275   if (FTC_ImageCache_Lookup(ttfcacheimage, &fimg, glyphidx, &fg, null)) return 0;
 276
 277   int advdec = 0;
 278   if (!gxIsTransparent(clr)) {
 279     if (fg.format != FT_GLYPH_FORMAT_BITMAP) return 0;
 280     FT_BitmapGlyph fgi = cast(FT_BitmapGlyph)fg;
 281     int x0 = x+fgi.left;
 282     if (firstchar && fgi.bitmap.width > 0) { x0 -= fgi.left; advdec = fgi.left; }
 283     drawFTBitmap(x0, y-fgi.top, fgi.bitmap, clr);
 284   }
 285   return cast(int)(fg.advance.x>>16)-advdec;
 286 }
 287
 288
 289 int ttfGetKerning (int scale, int gl0idx, int gl1idx) nothrow @trusted {
 290   if (gl0idx == 0 || gl1idx == 0) return 0;
 291
 292   FTC_ScalerRec fsc;
 293   fsc.face_id = FontID;
 294   fsc.width = 0;
 295   fsc.height = fontSize*scale;
 296   fsc.pixel = 1; // size in pixels
 297
 298   FT_Size ttfontsz;
 299   if (FTC_Manager_LookupSize(ttfcache, &fsc, &ttfontsz)) return 0;
 300   if (!FT_HAS_KERNING(ttfontsz.face)) return 0;
 301
 302   FT_Vector kk;
 303   if (FT_Get_Kerning(ttfontsz.face, gl0idx, gl1idx, FT_KERNING_UNSCALED, &kk)) return 0;
 304   if (!kk.x) return 0;
 305   auto kadvfrac = FT_MulFix(kk.x, ttfontsz.metrics.x_scale); // 1/64 of pixel
 306   return cast(int)((kadvfrac/*+(kadvfrac < 0 ? -32 : 32)*/)>>6);
 307 }
 308
 309
 310 // ////////////////////////////////////////////////////////////////////////// //
 311 public int gxCharWidthScaled (int scale, dchar ch) nothrow @trusted {
 312   if (scale < 1) return 0;
 313
 314   initFontEngine();
 315
 316   int glyph = FTC_CMapCache_Lookup(ttfcachecmap, FontID, -1, ch);
 317   if (glyph == 0) glyph = FTC_CMapCache_Lookup(ttfcachecmap, FontID, -1, ReplacementChar);
 318   if (glyph == 0) return 0;
 319
 320   FTC_ImageTypeRec fimg;
 321   fimg.face_id = FontID;
 322   fimg.width = 0;
 323   fimg.height = fontSize*scale;
 324   fimg.flags = FT_LOAD_TARGET_MONO;
 325
 326   FT_Glyph fg;
 327   if (FTC_ImageCache_Lookup(ttfcacheimage, &fimg, glyph, &fg, null)) return -666;
 328
 329   int res = cast(int)fg.advance.x>>16;
 330   return (res > 0 ? res : 0);
 331 }
 332
 333 public int gxCharWidth (dchar ch) nothrow @trusted { return gxCharWidthScaled(1, ch); }
 334
 335 // return char width
 336 public int gxDrawChar (int x, int y, dchar ch, uint fg, int prevcp=-1) nothrow @trusted { return gxDrawCharScaled(1, x, y, ch, fg, prevcp); }
 337 public int gxDrawChar() (in auto ref GxPoint p, char ch, uint fg, int prevcp=-1) nothrow @trusted { return gxDrawCharScaled(1, p.x, p.y, ch, fg, prevcp); }
 338
 339
 340 // ////////////////////////////////////////////////////////////////////////// //
 341 // return char width
 342 public int gxDrawCharScaled (int scale, int x, int y, dchar ch, uint clr, int prevcp=-1) nothrow @trusted {
 343   if (scale < 1) return 0;
 344
 345   int glyph = FTC_CMapCache_Lookup(ttfcachecmap, FontID, -1, ch);
 346   if (glyph == 0) glyph = FTC_CMapCache_Lookup(ttfcachecmap, FontID, -1, ReplacementChar);
 347   if (glyph == 0) return 0;
 348
 349   int kadv = ttfGetKerning(scale, (prevcp >= 0 ? FTC_CMapCache_Lookup(ttfcachecmap, FontID, -1, prevcp) : 0), glyph);
 350   return ttfDrawGlyph(false, scale, x+kadv, y+fontBaselineOfs*scale, glyph, clr);
 351 }
 352
 353 public int gxDrawCharScaled() (int scale, in auto ref GxPoint p, char ch, uint fg, int prevcp=-1) nothrow @trusted { return gxDrawCharScaled(scale, p.x, p.y, ch, fg, prevcp); }
 354
 355
 356 // ////////////////////////////////////////////////////////////////////////// //
 357 public struct GxKerning {
 358   int prevgidx = 0;
 359   int wdt = 0;
 360   int lastadv = 0;
 361   int lastcw = 0;
 362   int tabsize = 0;
 363   int scale = 1;
 364   bool firstchar = true;
 365
 366 nothrow @trusted:
 367   this (int atabsize, int ascale=1, bool firstCharIsFull=false) {
 368     initFontEngine();
 369     firstchar = !firstCharIsFull;
 370     scale = ascale;
 371     if ((tabsize = (atabsize > 0 ? atabsize : 0)) != 0) tabsize = tabsize*gxCharWidthScaled(ascale, ' ');
 372   }
 373
 374   void reset (int atabsize) {
 375     initFontEngine();
 376     prevgidx = 0;
 377     wdt = 0;
 378     lastadv = 0;
 379     lastcw = 0;
 380     if ((tabsize = (atabsize > 0 ? atabsize : 0)) != 0) tabsize = tabsize*gxCharWidthScaled(scale, ' ');
 381     firstchar = true;
 382   }
 383
 384   // tab length for current position
 385   int tablength () { pragma(inline, true); return (tabsize > 0 ? (wdt/tabsize+1)*tabsize-wdt : 0); }
 386
 387   int fixWidthPre (dchar ch) {
 388     immutable int prevgl = prevgidx;
 389     wdt += lastadv;
 390     lastadv = 0;
 391     lastcw = 0;
 392     prevgidx = 0;
 393     if (ch == '\t' && tabsize > 0) {
 394       // tab
 395       lastadv = lastcw = tablength;
 396       firstchar = false;
 397     } else {
 398       initFontEngine();
 399       int glyph = FTC_CMapCache_Lookup(ttfcachecmap, FontID, -1, ch);
 400       if (glyph == 0) glyph = FTC_CMapCache_Lookup(ttfcachecmap, FontID, -1, ReplacementChar);
 401       if (glyph != 0) {
 402         wdt += ttfGetKerning(scale, prevgl, glyph);
 403
 404         FTC_ImageTypeRec fimg;
 405         fimg.face_id = FontID;
 406         fimg.width = 0;
 407         fimg.height = fontSize*scale;
 408         version(none) {
 409           fimg.flags = FT_LOAD_TARGET_MONO;
 410         } else {
 411           fimg.flags = FT_LOAD_TARGET_MONO|FT_LOAD_MONOCHROME|FT_LOAD_RENDER;
 412         }
 413
 414         FT_Glyph fg;
 415         version(none) {
 416           if (FTC_ImageCache_Lookup(ttfcacheimage, &fimg, glyph, &fg, null) == 0) {
 417             prevgidx = glyph;
 418             lastadv = fg.advance.x>>16;
 419           }
 420         } else {
 421           if (FTC_ImageCache_Lookup(ttfcacheimage, &fimg, glyph, &fg, null) == 0) {
 422             int advdec = 0;
 423             if (fg.format == FT_GLYPH_FORMAT_BITMAP) {
 424               FT_BitmapGlyph fgi = cast(FT_BitmapGlyph)fg;
 425               if (firstchar && fgi.bitmap.width > 0) {
 426                 lastcw = fgi.bitmap.width;
 427                 advdec = fgi.left;
 428                 if (lastcw < 1) { advdec = 0; lastcw = cast(int)fg.advance.x>>16; }
 429               } else {
 430                 lastcw = fgi.left+fgi.bitmap.width;
 431                 if (lastcw < 1) lastcw = cast(int)fg.advance.x>>16;
 432               }
 433             }
 434             prevgidx = glyph;
 435             lastadv = (cast(int)fg.advance.x>>16)-advdec;
 436             firstchar = false;
 437           }
 438         }
 439       }
 440     }
 441     return wdt;
 442   }
 443
 444   @property int finalWidth () const { pragma(inline, true); return wdt+/*lastadv*/lastcw; }
 445
 446   // BUGGY!
 447   @property int nextCharOfs () const { pragma(inline, true); return wdt+lastadv; }
 448
 449   @property int currOfs () const { pragma(inline, true); return wdt; }
 450
 451   @property int nextOfsNoSpacing () const { pragma(inline, true); return wdt+lastcw; }
 452 }
 453
 454
 455 // ////////////////////////////////////////////////////////////////////////// //
 456 public struct GxDrawTextOptions {
 457   int tabsize = 0;
 458   uint clr = gxTransparent;
 459   int scale = 1;
 460   bool firstCharIsFull = false;
 461
 462 static pure nothrow @safe @nogc:
 463   auto Color (uint aclr) { pragma(inline, true); return GxDrawTextOptions(0, aclr, 1, false); }
 464   auto Tab (int atabsize) { pragma(inline, true); return GxDrawTextOptions(atabsize, gxTransparent, 1, false); }
 465   auto TabColor (int atabsize, uint aclr) { pragma(inline, true); return GxDrawTextOptions(atabsize, aclr, 1, false); }
 466   auto TabColorFirstFull (int atabsize, uint aclr, bool fcf) { pragma(inline, true); return GxDrawTextOptions(atabsize, aclr, 1, fcf); }
 467   auto ScaleTabColor (int ascale, int atabsize, uint aclr) { pragma(inline, true); return GxDrawTextOptions(atabsize, aclr, ascale, false); }
 468   auto ColorNFC (uint aclr) { pragma(inline, true); return GxDrawTextOptions(0, aclr, 1, true); }
 469   auto TabColorNFC (int atabsize, uint aclr) { pragma(inline, true); return GxDrawTextOptions(atabsize, aclr, 1, true); }
 470   auto ScaleTabColorNFC (int ascale, int atabsize, uint aclr) { pragma(inline, true); return GxDrawTextOptions(atabsize, aclr, ascale, true); }
 471   // more ctors?
 472 }
 473
 474 public struct GxDrawTextState {
 475   usize spos; // current codepoint starting position
 476   usize epos; // current codepoint ending position (exclusive; i.e. *after* codepoint)
 477   int curx; // current x (before drawing the glyph)
 478 }
 479
 480
 481 // delegate should return color
 482 public int gxDrawTextUtf(R) (in auto ref GxDrawTextOptions opt, int x, int y, auto ref R srng, uint delegate (in ref GxDrawTextState state) nothrow @trusted clrdg=null) nothrow @trusted
 483 if (Imp!"std.range.primitives".isInputRange!R && is(Imp!"std.range.primitives".ElementEncodingType!R == char))
 484 {
 485   // rely on the assumption that font face won't be unloaded while we are in this function
 486   if (opt.scale < 1) return 0;
 487
 488   initFontEngine();
 489
 490   GxDrawTextState state;
 491
 492   y += fontBaselineOfs*opt.scale;
 493
 494   immutable int tabpix = (opt.tabsize > 0 ? opt.tabsize*gxCharWidthScaled(opt.scale, ' ') : 0);
 495
 496   FT_Size ttfontsz;
 497
 498   int prevglyph = 0;
 499   immutable int stx = x;
 500
 501   bool dokern = true;
 502   bool firstchar = !opt.firstCharIsFull;
 503   Utf8DecoderFast dc;
 504
 505   while (!srng.empty) {
 506     immutable ubyte srbyte = cast(ubyte)srng.front;
 507     srng.popFront();
 508     ++state.epos;
 509
 510     if (dc.decode(srbyte)) {
 511       int ch = (dc.complete ? dc.codepoint : dc.replacement);
 512       int pgl = prevglyph;
 513       prevglyph = 0;
 514       state.curx = x;
 515
 516       if (opt.tabsize > 0) {
 517         if (ch == '\t') {
 518           firstchar = false;
 519           int wdt = x-stx;
 520           state.curx = x;
 521           x += (wdt/tabpix+1)*tabpix-wdt;
 522           if (clrdg !is null) clrdg(state);
 523           state.spos = state.epos;
 524           continue;
 525         }
 526       }
 527
 528       int glyph = FTC_CMapCache_Lookup(ttfcachecmap, FontID, -1, ch);
 529       if (glyph == 0) glyph = FTC_CMapCache_Lookup(ttfcachecmap, FontID, -1, ReplacementChar);
 530       if (glyph != 0) {
 531         // kerning
 532         int kadv = 0;
 533         if (pgl != 0 && dokern) {
 534           if (ttfontsz is null) {
 535             FTC_ScalerRec fsc;
 536             fsc.face_id = FontID;
 537             fsc.width = 0;
 538             fsc.height = fontSize*opt.scale;
 539             fsc.pixel = 1; // size in pixels
 540             if (FTC_Manager_LookupSize(ttfcache, &fsc, &ttfontsz)) {
 541               dokern = false;
 542               ttfontsz = null;
 543             } else {
 544               dokern = (FT_HAS_KERNING(ttfontsz.face) != 0);
 545             }
 546           }
 547           if (dokern) {
 548             FT_Vector kk;
 549             if (FT_Get_Kerning(ttfontsz.face, pgl, glyph, FT_KERNING_UNSCALED, &kk) == 0) {
 550               if (kk.x) {
 551                 auto kadvfrac = FT_MulFix(kk.x, ttfontsz.metrics.x_scale); // 1/64 of pixel
 552                 kadv = cast(int)((kadvfrac/*+(kadvfrac < 0 ? -32 : 32)*/)>>6);
 553               }
 554             }
 555           }
 556         }
 557         x += kadv;
 558         uint clr = opt.clr;
 559         if (clrdg !is null) { state.curx = x; clr = clrdg(state); }
 560         x += ttfDrawGlyph(firstchar, opt.scale, x, y, glyph, clr);
 561         firstchar = false;
 562       }
 563       state.spos = state.epos;
 564       prevglyph = glyph;
 565     }
 566   }
 567
 568   return x-stx;
 569 }
 570
 571
 572 public int gxDrawTextUtf() (in auto ref GxDrawTextOptions opt, int x, int y, const(char)[] s, uint delegate (in ref GxDrawTextState state) nothrow @trusted clrdg=null) nothrow @trusted {
 573   static struct StrIterator {
 574   private:
 575     const(char)[] str;
 576   public pure nothrow @trusted @nogc:
 577     this (const(char)[] s) { pragma(inline, true); str = s; }
 578     @property bool empty () const { pragma(inline, true); return (str.length == 0); }
 579     @property char front () const { pragma(inline, true); return (str.length ? str.ptr[0] : 0); }
 580     void popFront () { if (str.length) str = str[1..$]; }
 581   }
 582
 583   return gxDrawTextUtf(opt, x, y, StrIterator(s), clrdg);
 584 }
 585
 586
 587 public int gxTextWidthScaledUtf (int scale, const(char)[] s, int tabsize=0, bool firstCharIsFull=false) nothrow @trusted {
 588   if (scale < 1) return 0;
 589   auto kern = GxKerning(tabsize, scale, firstCharIsFull);
 590   s.utfByDChar(delegate (dchar ch) @trusted { kern.fixWidthPre(ch); });
 591   return kern.finalWidth;
 592 }
 593
 594
 595
 596 // ////////////////////////////////////////////////////////////////////////// //
 597 public int gxTextHeightUtf () nothrow @trusted { initFontEngine(); return fontHeight; }
 598 public int gxTextHeightScaledUtf (int scale) nothrow @trusted { initFontEngine(); return (scale < 1 ? 0 : fontHeight*scale); }
 599
 600 public int gxTextWidthUtf (const(char)[] s, int tabsize=0, bool firstCharIsFull=false) nothrow @trusted { return gxTextWidthScaledUtf(1, s, tabsize, firstCharIsFull); }
 601
 602 public int gxDrawTextUtf() (int x, int y, const(char)[] s, uint clr) nothrow @trusted { return gxDrawTextUtf(GxDrawTextOptions.Color(clr), x, y, s); }
 603 public int gxDrawTextUtf() (in auto ref GxPoint p, const(char)[] s, uint clr) nothrow @trusted { return gxDrawTextUtf(p.x, p.y, s, clr); }
 604
 605
 606 public int gxDrawTextOutScaledUtf (int scale, int x, int y, const(char)[] s, uint clr, uint clrout) nothrow @trusted {
 607   if (scale < 1) return 0;
 608   auto opt = GxDrawTextOptions.ScaleTabColor(scale, 0, clrout);
 609   foreach (immutable dy; -1*scale..2*scale) {
 610     foreach (immutable dx; -1*scale..2*scale) {
 611       if (dx || dy) gxDrawTextUtf(opt, x+dx, y+dy, s);
 612     }
 613   }
 614   opt.clr = clr;
 615   return gxDrawTextUtf(opt, x, y, s);
 616 }