SDF Font Code prototype

dglFontMeshBuilder.h

//-----------------------------------------------------------------------------
// Copyright (c) 2023 tgemit contributors.
// See AUTHORS file and git repository for contributor information.
//
// SPDX-License-Identifier: MIT
//-----------------------------------------------------------------------------
#pragma once

#include "dgl/gFont.h"

/// Helper class which turns text into a mesh for rendering
class DGLFontMeshBuilder
{
protected:
   enum
   {
      SheetChunkSize = 4096,
      
      COLOR_INDEX_BITMAP_MODULATION=0,
      COLOR_INDEX_ANCHOR=1,
      COLOR_INDEX_COLOR_TABLE=2,
   };
   
   struct DrawChar
   {
      Point2F pos; // NOTE: non-scaled
      U16 charCode;
      U16 colorIndex;
   };
   
   struct DrawSheet
   {
      U16 bitmapIndex;
      U16 charsUsed;
      DrawChar firstChar;
      
      DrawChar* getChars()
      {
         return &firstChar;
      }
   };
   
   /// Main font we are drawing with
   GFont* mFont;
   
   /// Allocator for DrawSheet
   DataChunker mSheetChunker;
   
   /// Sheets to output to
   Vector<DrawSheet*> mDrawSheets;
   
   /// Sheets we have outputted
   Vector<DrawSheet*> mOutputSheets;
   
   /// Color State
   /// {
   ColorF mBitmapModulation;
   
   ColorF mAnchorColor;
   
   const ColorI* mColorTable;
   
   U32 mColorTableSize;
   
   U32 mColorIndex;
   
   U32 mSavedColorIndex;
   /// }
   
   /// Offset we start at
   Point2F mDrawOrigin;
   
   /// Where we are
   Point2F mCurrentPoint;
   
   MatrixF mBaseTransform;
   
public:
   
   DGLFontMeshBuilder() :
   mFont(NULL),
   mBitmapModulation(1.0f,1.0f,1.0f,1.0f),
   mAnchorColor(1.0f,1.0f,1.0f,1.0f),
   mColorTable(NULL),
   mColorTableSize(0),
   mColorIndex(0),
   mSavedColorIndex(0),
   mDrawOrigin(0,0),
   mCurrentPoint(0,0),
   mBaseTransform(1)
   {
   }
   
   RectI getDrawBounds()
   {
      Point2F minP = Point2F(F32_MAX, F32_MAX);
      Point2F maxP = Point2F(F32_MIN, F32_MIN);
      
      for (DrawSheet* outSheet : mOutputSheets)
      {
         for (S32 i=0; i<outSheet->charsUsed; i += std::max<S32>(outSheet->charsUsed-1, 1))
         {
            auto info = outSheet->getChars()[i];
            const PlatformFont::CharInfo &ci = mFont->getCharInfo(info.charCode);
            
            Point2F ep1 = info.pos;
            Point2F ep2 = info.pos + Point2F(ci.width, ci.height);
            minP.x = std::min(minP.x, ep1.x);
            minP.y = std::min(minP.y, ep1.y);
            
            maxP.x = std::max(maxP.x, ep1.x);
            maxP.y = std::max(maxP.y, ep1.y);
            
            minP.x = std::min(minP.x, ep2.x);
            minP.y = std::min(minP.y, ep2.y);
            
            maxP.x = std::max(maxP.x, ep2.x);
            maxP.y = std::max(maxP.y, ep2.y);
         }
      }
      
      return RectI(mDrawOrigin.x + minP.x, mDrawOrigin.y + minP.y, maxP.x - minP.x, maxP.y - minP.y);
   }
   
   inline void setLastDrawPoint(const Point2F point) { mCurrentPoint = point; }
   inline Point2F getLastDrawPoint() const { return mCurrentPoint; }
   
   inline bool getDrawSheet(DrawSheet** outSheet, U32 bitmapIndex)
   {
      if (bitmapIndex >= mDrawSheets.size())
      {
         *outSheet = NULL;
         return false;
      }
      
      DrawSheet* sheet = mDrawSheets[bitmapIndex];
      if (!sheet)
      {
         sheet = allocSheet(bitmapIndex);
         mDrawSheets[bitmapIndex] = sheet;
      }
      
      *outSheet = sheet;
      return true;
   }
   
   /// Returns color for index
   inline DGLPackedPointU16 getColor(U32 index)
   {
      switch (index)
      {
         case COLOR_INDEX_BITMAP_MODULATION:
            return mBitmapModulation;
            break;
         case COLOR_INDEX_ANCHOR:
            return mAnchorColor;
            break;
         default:
            U32 realIndex = index-COLOR_INDEX_COLOR_TABLE;
            return mColorTable ? mColorTable[realIndex] : ColorI(255,255,255,255);
            break;
      }
   }
   
   /// Allocate a sheet to draw
   DrawSheet* allocSheet(U16 bitmapIndex)
   {
      const U32 allocSize = sizeof(DrawSheet) + (sizeof(DrawChar) * SheetChunkSize);
      DrawSheet* sheet = (DrawSheet*)mSheetChunker.alloc(allocSize);
      sheet->bitmapIndex = bitmapIndex;
      memset(sheet, '\0', allocSize);
      
      mOutputSheets.push_back(sheet);
      
      return sheet;
   }
   
   /// Begin drawing a line at origin
   void begin(GFont* font, Point2I origin, F32 rot=0.0f, const ColorI* colorTable=NULL, U32 maxColorIndex=0)
   {
      clear();
      
      mFont = font;
      dglGetTextAnchorColor(&mAnchorColor);
      dglGetBitmapModulation(&mBitmapModulation);
      mColorIndex = COLOR_INDEX_BITMAP_MODULATION;
      mSavedColorIndex = COLOR_INDEX_BITMAP_MODULATION;
      mColorTable = colorTable;
      mColorTableSize = maxColorIndex;
      
      mDrawSheets.setSize(font->mTextureSheets.size());
      for (auto itr = mDrawSheets.begin(), itrEnd = mDrawSheets.end(); itr != itrEnd; itr++)
      {
         *itr = NULL;
      }
      
      mDrawOrigin = Point2F(origin.x, origin.y);
      mCurrentPoint = Point2F(0,0); // relative to mDrawOrigin
      mBaseTransform = MatrixF( EulerF( 0.0, 0.0, mDegToRad( rot ) ) );
   }
   
   /// Add text to batch
   U32 addText(U32 numChars, const UTF16* chars)
   {
      const F32 invMetricScale = mFont->getInvMetricScale();
      const F32 invTexScale = 1.0f / mFont->getTextureScale();
      
      Point2F pt = mCurrentPoint;
      DrawSheet* currentSheet = NULL;
      U32 lastBitmapIndex = UINT_MAX;
      U32 i = 0;
      
      for (i=0; i<numChars; i++)
      {
         UTF16 c = chars[i];
         
         // We have to do a little dance here since \t = 0x9, \n = 0xa, and \r = 0xd
         if ((c >=  1 && c <=  7) ||
             (c >= 11 && c <= 12) ||
             (c == 14))
         {
            // Color code
            if (mColorTable)
            {
               static U8 remap[15] =
               {
                  0x0, // 0 special null terminator
                  0x0, // 1 ascii start-of-heading??
                  0x1,
                  0x2,
                  0x3,
                  0x4,
                  0x5,
                  0x6,
                  0x0, // 8 special backspace
                  0x0, // 9 special tab
                  0x0, // a special \n
                  0x7,
                  0x8,
                  0x0, // a special \r
                  0x9
               };
               
               U8 remapped = remap[c];
               // Ignore if the color is greater than the specified max index:
               if ( remapped <= mColorTableSize )
               {
                  mColorIndex = COLOR_INDEX_COLOR_TABLE + remapped;
               }
            }
            continue;
         }
         
         // reset color?
         if ( c == 15 )
         {
            mColorIndex = COLOR_INDEX_ANCHOR;
            continue;
         }
         
         // push color:
         if ( c == 16 )
         {
            mSavedColorIndex = mColorIndex;
            continue;
         }
         
         // pop color:
         if ( c == 17 )
         {
            mColorIndex = mSavedColorIndex;
            continue;
         }
         
         // Tab character
         if ( c == dT('\t') )
         {
            const PlatformFont::CharInfo &ci = mFont->getCharInfo( dT(' ') );
            pt.x += ci.xIncrement * GFont::TabWidthInSpaces * invMetricScale;
            continue;
         }
         
         if( !mFont->isValidChar( c ) )
            continue;
         
         const PlatformFont::CharInfo &ci = mFont->getCharInfo(c);
         const F32 realXOrigin = ci.xOrigin * invMetricScale;
         const F32 realYOrigin = ci.yOrigin * invMetricScale;
         
         if (ci.bitmapIndex == -1)
         {
            pt.x += (realXOrigin * invTexScale * invMetricScale) + (ci.xIncrement * invMetricScale);
            continue;
         }
         
         if (ci.bitmapIndex != lastBitmapIndex)
         {
            // Grab sheet
            if (!getDrawSheet(&currentSheet, ci.bitmapIndex))
            {
               lastBitmapIndex = UINT_MAX;
               continue;
            }
            
            lastBitmapIndex = ci.bitmapIndex;
         }
         
         if (ci.width != 0 && ci.height != 0)
         {
            pt.y = mFont->getBaseline() - (realYOrigin * invTexScale);
            F32 charExtra = realXOrigin * invTexScale;
            pt.x += charExtra;
            
            DrawChar outChar = {};
            outChar.pos   = pt;
            outChar.colorIndex = mColorIndex;
            outChar.charCode = c;
            
            currentSheet->getChars()[currentSheet->charsUsed++] = outChar;
            
            // End sheet if full
            if (currentSheet->charsUsed >= SheetChunkSize)
            {
               mDrawSheets[ci.bitmapIndex] = NULL;
               currentSheet = NULL;
               lastBitmapIndex = UINT_MAX;
            }
            
            pt.x += (ci.xIncrement * invMetricScale) - charExtra;
         }
         else
         {
            pt.x += ci.xIncrement * invMetricScale;
         }
      }
      
      mCurrentPoint = pt;
      return i;
   }
   
   /// Fill in mesh info
   void fillAllocParams(DGLMeshAllocParams& params)
   {
      U32 vertCount = 0;
      U32 indCount = 0;
      U32 primCount = 0;
      
      for (DrawSheet* outSheet : mOutputSheets)
      {
         vertCount += outSheet->charsUsed * 4;
         indCount += outSheet->charsUsed * 6;
         primCount++;
      }
      
      params.primType = DGLPrimitiveTriangle;
      params.vertCode = GuiVert::getFmtCode();
      params.numVerts = vertCount;
      params.numInds = indCount;
      params.numPrims = primCount;
   }
   
   template<class Y> void fillAlloc(DGLGuiMeshDataRef &outRef, Y* pipeline)
   {
      const F32 invMetricScale = mFont->getInvMetricScale();
      const F32 invTexScale = 1.0f / mFont->getTextureScale();
      GuiVert* outVerts = outRef.vertPtr;
      U16* outInds = outRef.indexPtr;
      DGLPrimitive* outPrims = outRef.primPtr;
      U16 curInd = 0;
      
      for (DrawSheet* outSheet : mOutputSheets)
      {
         TextureObject* lastTexture = mFont->getTextureHandle(outSheet->bitmapIndex);
         if (lastTexture == NULL)
            continue;
         
         DGLPrimitive prim = {};
         GuiVert* startVertPtr = outVerts;
         U16* startIndPtr = outInds;
         prim.primType = DGLPrimitiveTriangle;
         prim.startVert = (U32)(outVerts - outRef.vertPtr);
         prim.startInd = (U32)(outInds - outRef.indexPtr);
         prim.indexed = 1;
         curInd = 0;
         Point3F points[4];
         
         for (U32 cn=0; cn < outSheet->charsUsed; cn++)
         {
            DrawChar& dc = outSheet->getChars()[cn];
            const PlatformFont::CharInfo &ci = mFont->getCharInfo(dc.charCode);
            Point2F pt = dc.pos;
            DGLPackedPointU16 currentColor = getColor(dc.colorIndex);
            
            F32 texLeft   = F32(ci.xOffset)             / F32(lastTexture->getTextureWidth());
            F32 texRight  = F32(ci.xOffset + ci.width)  / F32(lastTexture->getTextureWidth());
            F32 texTop    = F32(ci.yOffset)             / F32(lastTexture->getTextureHeight());
            F32 texBottom = F32(ci.yOffset + ci.height) / F32(lastTexture->getTextureHeight());
            
            F32 screenLeft   = pt.x;
            F32 screenRight  = pt.x + (ci.width * invTexScale);
            F32 screenTop    = pt.y;
            F32 screenBottom = pt.y + (ci.height * invTexScale);
            
            points[0] = Point3F( screenLeft,   screenTop, 0.0);
            points[1] = Point3F( screenRight,  screenTop, 0.0);
            points[2] = Point3F( screenLeft,  screenBottom, 0.0);
            points[3] = Point3F( screenRight, screenBottom, 0.0);
            
            for( int i=0; i<4; i++ )
            {
               mBaseTransform.mulP( points[i] );
               points[i] += Point3F(mDrawOrigin.x, mDrawOrigin.y, 0.0f);
            }
            
            // Verts
            outVerts[0].setValues(points[0], Point2F(texLeft, texTop), currentColor);
            outVerts[1].setValues(points[1], Point2F(texRight, texTop), currentColor);
            outVerts[2].setValues(points[2], Point2F(texLeft, texBottom), currentColor);
            outVerts[3].setValues(points[3], Point2F(texRight, texBottom), currentColor);
            
            // Indices
            outInds[0] = curInd;
            outInds[1] = curInd+1;
            outInds[2] = curInd+2;
            
            outInds[3] = curInd+2;
            outInds[4] = curInd+1;
            outInds[5] = curInd+3;
            
            outVerts += 4;
            curInd += 4;
            outInds += 6;
         }
         
         prim.numVerts = (U32)(outVerts - startVertPtr);
         prim.numElements = (U32)(outInds - startIndPtr);
         *outPrims++ = prim;
         
         outInds += prim.numElements;
         outVerts += prim.numVerts;
      }
   }
   
   /// Outputs to a pipeline mesh outRef
   template<typename T> void endToPipelineMesh(T* pipeline, DGLGuiMeshDataRef& outRef)
   {
      DGLMeshAllocParams allocParams = {};
      fillAllocParams(allocParams);
      
      if (pipeline->allocMesh(allocParams, outRef))
      {
         fillAlloc(outRef, pipeline);
      }
   }
   
   void clear()
   {
      mOutputSheets.clear();
      mSheetChunker.freeBlocks(true);
      mDrawSheets.clear();
   }
   
   /// Helper function to draw output sheets to the pipeline with the correct textures
   void drawPipelineMesh(DGLMeshIndex outMeshIndex, DGLPipelineState* pipeline)
   {
      U32 primNum = 0;
      
      for (DrawSheet* outSheet : mOutputSheets)
      {
         TextureObject* lastTexture = mFont->getTextureHandle(outSheet->bitmapIndex);
         if (lastTexture == NULL)
            continue;
         
         pipeline->quickSetTexture(lastTexture->getGLTextureName(), DGLSamplerStates::GuiText);
         pipeline->drawMesh(outMeshIndex, primNum++);
      }
   }
   
   static DGLFontMeshBuilder* getInstance();
};

gFont.cc

//-----------------------------------------------------------------------------
// Copyright (c) 2013 GarageGames, LLC
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//-----------------------------------------------------------------------------

#include "platform/platform.h"
#include "core/stream.h"
#include "core/frameAllocator.h"
#include "core/findMatch.h"
#include "core/unicode.h"
#include "dgl/gFont.h"
#include "dgl/gBitmap.h"
#include "core/fileStream.h"
#include "dgl/gTexManager.h"
#include "util/safeDelete.h"
#include "platform/profiler.h"
#include "zlib.h"
#include <algorithm>

S32 GFont::smSheetIdCount = 0;
const U32 GFont::csm_fileVersion = 3;
U32 GFont::BaseTextureSheetSize = 256;

ConsoleFunction(populateFontCacheString, void, 4, 4, "(faceName, size, string) "
                "Populate the font cache for the specified font with characters from the specified string."
                "@param faceName The font's name\n"
                "@param size The size of the font.\n"
                "@param string The string to use to fill font cache\n"
                "@return No return value.")
{
   Resource<GFont> f = GFont::create(argv[1], dAtoi(argv[2]), Con::getVariable("$GUI::fontCacheDirectory"));

   if(f.isNull())
   {
      Con::errorf("populateFontCacheString - could not load font '%s %d'!", argv[1], dAtoi(argv[2]));
      return;
   }

   if(!f->hasPlatformFont())
   {
      Con::errorf("populateFontCacheString - font '%s %d' has no platform font! Cannot generate more characters.", argv[1], dAtoi(argv[2]));
      return;
   }

   // This has the side effect of generating character info, including the bitmaps.
   f->getStrWidthPrecise(argv[3]);
}

ConsoleFunction(populateFontCacheRange, void, 5, 5, "(faceName, size, rangeStart, rangeEnd) - "
                "Populate the font cache for the specified font with Unicode code points in the specified range. "
                "Note we only support BMP-0, so code points range from 0 to 65535."
                "@param faceName The name of the font\n"
                "@param size The size of the font.\n"
                "@param rangeStart The initial Unicode point\n"
                "@param rangeEnd The final Unicode point in range\n"
                "@return No return value")
{
   Resource<GFont> f = GFont::create(argv[1], dAtoi(argv[2]), Con::getVariable("$GUI::fontCacheDirectory"));

   if(f.isNull())
   {
      Con::errorf("populateFontCacheRange - could not load font '%s %d'!", argv[1], dAtoi(argv[2]));
      return;
   }

   U32 rangeStart = dAtoi(argv[3]);
   U32 rangeEnd   = dAtoi(argv[4]);

   if(rangeStart > rangeEnd)
   {
      Con::errorf("populateFontCacheRange - range start is after end!");
      return;
   }

   if(!f->hasPlatformFont())
   {
      Con::errorf("populateFontCacheRange - font '%s %d' has no platform font! Cannot generate more characters.", argv[1], dAtoi(argv[2]));
      return;
   }

   // This has the side effect of generating character info, including the bitmaps.
   for(U32 i=rangeStart; i<rangeEnd; i++)
   {
      if(f->isValidChar(i))
         f->getCharWidth(i);
      else
         Con::warnf("populateFontCacheRange - skipping invalid char 0x%x",  i);
   }

   // All done!
}

ConsoleFunction(dumpFontCacheStatus, void, 1, 1, "() Dump a full description "
                "of all cached fonts, along with info on the codepoints each contains.\n"
                "@return No return value")
{
   FindMatch match("*.uft", 4096);
   ResourceManager->findMatches(&match);

   Con::printf("--------------------------------------------------------------------------");
   Con::printf("   Font Cache Usage Report (%d fonts found)", match.numMatches());

   for (U32 i = 0; i < (U32)match.numMatches(); i++)
   {
      char *curMatch = match.matchList[i];
      Resource<GFont> font = ResourceManager->load(curMatch);

      // Deal with inexplicably missing or failed to load fonts.
      if (font.isNull())
      {
         Con::errorf(" o Couldn't load font : %s", curMatch);
         continue;
      }

      // Ok, dump info!
      font->dumpInfo();
   }
}

ConsoleFunction(writeFontCache, void, 1, 1, "() force all cached fonts to"
                "serialize themselves to the cache."
                "@return No return value")
{
   FindMatch match("*.uft", 4096);
   ResourceManager->findMatches(&match);

   Con::printf("--------------------------------------------------------------------------");
   Con::printf("   Writing font cache to disk (%d fonts found)", match.numMatches());

   for (U32 i = 0; i < (U32)match.numMatches(); i++)
   {
      char *curMatch = match.matchList[i];
      Resource<GFont> font = ResourceManager->load(curMatch);

      // Deal with inexplicably missing or failed to load fonts.
      if (font.isNull())
      {
         Con::errorf(" o Couldn't find font : %s", curMatch);
         continue;
      }

      // Ok, dump info!
      FileStream stream;
      if(ResourceManager->openFileForWrite(stream, curMatch)) 
      {
         Con::printf("      o Writing '%s' to disk...", curMatch);
         font->write(stream);
         stream.close();
      }
      else
      {
         Con::errorf("      o Could not open '%s' for write!", curMatch);
      }
   }
}

ConsoleFunction(populateAllFontCacheString, void, 2, 2, "(string inString) "
                "Populate the font cache for all fonts with characters from the specified string.\n"
                "@param inString The string to use to set the font caches\n"
                "@return No return value.")
{
   FindMatch match("*.uft", 4096);
   ResourceManager->findMatches(&match);

   Con::printf("Populating font cache with string '%s' (%d fonts found)", argv[1], match.numMatches());

   for (U32 i = 0; i < (U32)match.numMatches(); i++)
   {
      char *curMatch = match.matchList[i];
      Resource<GFont> font = ResourceManager->load(curMatch);

      // Deal with inexplicably missing or failed to load fonts.
      if (font.isNull())
      {
         Con::errorf(" o Couldn't load font : %s", curMatch);
         continue;
      }

      if(!font->hasPlatformFont())
      {
         Con::errorf("populateAllFontCacheString - font '%s' has no platform font! Cannot generate more characters.", curMatch);
         continue;
      }

      // This has the side effect of generating character info, including the bitmaps.
      font->getStrWidthPrecise(argv[1]);
   }
}

ConsoleFunction(populateAllFontCacheRange, void, 3, 3, "(rangeStart, rangeEnd) "
                "Populate the font cache for all fonts with Unicode code points in the specified range. "
                "Note we only support BMP-0, so code points range from 0 to 65535.\n"
                "@param rangeStart, rangeEnd The range of the unicode points to populate caches with\n"
                "@return No return value")
{
   U32 rangeStart = dAtoi(argv[1]);
   U32 rangeEnd   = dAtoi(argv[2]);

   if(rangeStart > rangeEnd)
   {
      Con::errorf("populateAllFontCacheRange - range start is after end!");
      return;
   }

   FindMatch match("*.uft", 4096);
   ResourceManager->findMatches(&match);

   Con::printf("Populating font cache with range 0x%x to 0x%x (%d fonts found)", rangeStart, rangeEnd, match.numMatches());

   for (U32 i = 0; i < (U32)match.numMatches(); i++)
   {
      char *curMatch = match.matchList[i];
      Resource<GFont> font = ResourceManager->load(curMatch);

      // Deal with inexplicably missing or failed to load fonts.
      if (font.isNull())
      {
         Con::errorf(" o Couldn't load font : %s", curMatch);
         continue;
      }

      if(!font->hasPlatformFont())
      {
         Con::errorf("populateAllFontCacheRange - font '%s' has no platform font! Cannot generate more characters.", curMatch);
         continue;
      }

      // This has the side effect of generating character info, including the bitmaps.
      Con::printf("   o Populating font '%s'", curMatch);
      for(U32 i=rangeStart; i<rangeEnd; i++)
      {
         if(font->isValidChar(i))
            font->getCharWidth(i);
         else
            Con::warnf("populateAllFontCacheRange - skipping invalid char 0x%x",  i);
      }
   }
   // All done!
}

ConsoleFunction(exportCachedFont, void, 6, 6, "(fontName, size, fileName, padding, kerning) - "
                "Export specified font to the specified filename as a PNG. The "
                "image can then be processed in Photoshop or another tool and "
                "reimported using importCachedFont. Characters in the font are"
                "exported as one long strip.\n"
                "@param fontName The name of the font to export.\n"
                "@param size The size of the font\n"
                "@param fileName The export file name.\n"
                "@param padding Desired padding settings.\n"
                "@param kerning Kerning settings (space between elements)\n"
                "@return No return value.")
{
   // Read in some params.
   const char *fileName = argv[3];
   S32 padding    = dAtoi(argv[4]);
   S32 kerning    = dAtoi(argv[5]);

   // Tell the font to export itself.
   Resource<GFont> f = GFont::create(argv[1], dAtoi(argv[2]), Con::getVariable("$GUI::fontCacheDirectory"));

   if(f.isNull())
   {
      Con::errorf("populateFontCacheString - could not load font '%s %d'!", argv[1], dAtoi(argv[2]));
      return;
   }

   f->exportStrip(fileName, padding, kerning);
}

ConsoleFunction(importCachedFont, void, 6, 6, "(fontName, size, fileName, padding, kerning) "
                "Import an image strip from exportCachedFont. Call with the "
                "same parameters you called exportCachedFont."
                "@param fontName The name of the font to import.\n"
                "@param size The size of the font\n"
                "@param fileName The imported file name.\n"
                "@param padding Desired padding settings.\n"
                "@param kerning Kerning settings (space between elements)\n"
                "@return No return value.")
{
   // Read in some params.
   const char *fileName = argv[3];
   S32 padding    = dAtoi(argv[4]);
   S32 kerning    = dAtoi(argv[5]);

   // Tell the font to import itself.
   Resource<GFont> f = GFont::create(argv[1], dAtoi(argv[2]), Con::getVariable("$GUI::fontCacheDirectory"));

   if(f.isNull())
   {
      Con::errorf("populateFontCacheString - could not load font '%s %d'!", argv[1], dAtoi(argv[2]));
      return;
   }

   f->importStrip(fileName, padding, kerning);
}

ConsoleFunction(duplicateCachedFont, void, 4, 4, "(oldFontName, oldFontSize, newFontName) "
                "Copy the specified old font to a new name. The new copy will not have a "
                "platform font backing it, and so will never have characters added to it. "
                "But this is useful for making copies of fonts to add postprocessing effects "
                "to via exportCachedFont.\n"
                "@param oldFontName The original font.\n"
                "@param oldFontSize The original font's size property.\n"
                "@param newFontName The name to set the copy to.\n"
                "@return No return value.")
{
   char newFontFile[256];
   GFont::getFontCacheFilename(argv[3], dAtoi(argv[2]), 256, newFontFile);

   // Load the original font.
   Resource<GFont> font = GFont::create(argv[1], dAtoi(argv[2]), Con::getVariable("$GUI::fontCacheDirectory"));

   // Deal with inexplicably missing or failed to load fonts.
   if (font.isNull())
   {
      Con::errorf(" o Couldn't find font : %s", newFontFile);
      return;
   }

   // Ok, dump info!
   FileStream stream;
   if(ResourceManager->openFileForWrite(stream, newFontFile)) 
   {
      Con::printf("      o Writing duplicate font '%s' to disk...", newFontFile);
      font->write(stream);
      stream.close();
   }
   else
   {
      Con::errorf("      o Could not open '%s' for write!", newFontFile);
   }
}

static PlatformFont* createSafePlatformFont(const char *name, U32 size, U32 charset = TGE_ANSI_CHARSET)
{
   PlatformFont *platFont = createPlatformFont(name, size, charset);
   
   if (platFont == NULL)
   {
      Con::errorf("Loading platform font failed, trying font fallbacks...");
      // Couldn't load the requested font.  This probably will be common
      // since many unix boxes don't have arial or lucida console installed.
      // Attempt to map the font name into a font we're pretty sure exist
      // Lucida Console is a common code & console font on windows, and
      // Monaco is the recommended code & console font on mac.

      // this is the name of the final fallback font.

      #ifdef TORQUE_OS_LINUX
      const char* fallback = "Arial";
      #else
      const char* fallback = "Helvetica";
      #endif

      if(dStricmp(name, fallback) == 0)
      {
         Con::errorf("Font fallback utterly failed.");
         return NULL;
      }
      else if (dStricmp(name, "arial") == 0)
         fallback = "Helvetica";
      else if (dStricmp(name, "lucida console") == 0)
         fallback = "Monaco";
      else if (dStricmp(name, "monaco") == 0)
         fallback = "Courier";

      platFont = createSafePlatformFont(fallback, size, charset);
   }
   
   return platFont;
}

ResourceInstance* constructNewFont(Stream& stream)
{
   GFont *ret = new GFont;

   if(!ret->read(stream))
   {
      SAFE_DELETE(ret);
   }

   if(ret)
   {
      ret->mPlatformFont = createSafePlatformFont(ret->mFaceName, ret->mSize, ret->mCharSet);
   }
   
   return ret;
}

void GFont::getFontCacheFilename(const char *faceName, U32 size, U32 buffLen, char *outBuff)
{
   dSprintf(outBuff, buffLen, "%s/%s %d (%s).uft", Con::getVariable("$GUI::fontCacheDirectory"), faceName, size, getFontCharSetName(0));
}

Resource<GFont> GFont::create(const char *faceName, U32 size, const char *cacheDirectory, U32 charset /* = TGE_ANSI_CHARSET */)
{
   char buf[256];
   dSprintf(buf, sizeof(buf), "%s/%s %d (%s).uft", cacheDirectory, faceName, size, getFontCharSetName(charset));

   Resource<GFont> ret = ResourceManager->load(buf);
   if(bool(ret))
   {
      ret->mGFTFile = StringTable->insert(buf);
      return ret;
   }

   PlatformFont *platFont = createSafePlatformFont(faceName, size, charset);
   
   AssertFatal(platFont, "platFont is null");
    
   GFont *resFont = new GFont;
   resFont->mPlatformFont = platFont;
   resFont->addSheet();
   resFont->mGFTFile = StringTable->insert(buf);
   resFont->mFaceName = StringTable->insert(faceName);
   resFont->mSize = size;
   resFont->mCharSet = charset;

   resFont->mHeight   = platFont->getFontHeight();
   resFont->mBaseline = platFont->getFontBaseLine();
   resFont->mAscent   = platFont->getFontBaseLine();
   resFont->mDescent  = platFont->getFontHeight() - platFont->getFontBaseLine();

   resFont->mTexLineHeight = platFont->getTexLineHeight();
   resFont->mTextureScale = platFont->getTexScale();
   resFont->mMetricScale = platFont->getMetricScale();
   resFont->mSDF = platFont->isSDF();

   ResourceManager->add(buf, resFont, false);
   return ResourceManager->load(buf);
}

//-------------------------------------------------------------------------

GFont::GFont()
{
   VECTOR_SET_ASSOCIATION(mCharInfoList);
   VECTOR_SET_ASSOCIATION(mTextureSheets);

   for (U32 i = 0; i < (sizeof(mRemapTable) / sizeof(S32)); i++)
      mRemapTable[i] = -1;

   mCurX = mCurY = mCurSheet = -1;

   mPlatformFont = NULL;
   mGFTFile = NULL;
   mFaceName = NULL;
   mSize = 0;
   mCharSet = 0;
   mNeedSave = false;
   mSDF = false;
   mTexLineHeight = 0;
   mTextureScale = 1.0f;
   mMetricScale = 1.0f;
   
   mMutex = Mutex::createMutex();
}

GFont::~GFont()
{
   
   // Need to stop this for now!
   mNeedSave = false; 
   if(mNeedSave)
   {
      FileStream stream;
      if(ResourceManager->openFileForWrite(stream, mGFTFile)) 
      {
         write(stream);
         stream.close();
      }
   }
   
   S32 i;

   for(i = 0;i < mCharInfoList.size();i++)
   {
       SAFE_DELETE_ARRAY(mCharInfoList[i].bitmapData);
   }

   //Luma:  decrement reference of the texture handles too
   for(i=0;i<mTextureSheets.size();i++)
   {
       mTextureSheets[i] = 0;
   }
   
   SAFE_DELETE(mPlatformFont);
   
   Mutex::destroyMutex(mMutex);
}

void GFont::dumpInfo()
{
   // Number and extent of mapped characters?
   U32 mapCount = 0, mapBegin=0xFFFF, mapEnd=0;
   for(U32 i=0; i<0x10000; i++)
   {
      if(mRemapTable[i] != -1)
      {
         mapCount++;
         if(i<mapBegin) mapBegin = i;
         if(i>mapEnd)   mapEnd   = i;
      }
   }


   // Let's write out all the info we can on this font.
   Con::printf("   '%s' %dpt", mFaceName, mSize);
   Con::printf("      - %d texture sheets, %d mapped characters.", mTextureSheets.size(), mapCount);

   if(mapCount)
      Con::printf("      - Codepoints range from 0x%x to 0x%x.", mapBegin, mapEnd);
   else
      Con::printf("      - No mapped codepoints.", mapBegin, mapEnd);
   Con::printf("      - Platform font is %s.", (mPlatformFont ? "present" : "not present") );
}

//////////////////////////////////////////////////////////////////////////

bool GFont::loadCharInfo(const UTF16 ch)
{
    if(mRemapTable[ch] != -1)
        return true;    // Not really an error

    if(mPlatformFont && mPlatformFont->isValidChar(ch))
    {
        Mutex::lockMutex(mMutex); // the CharInfo returned by mPlatformFont is static data, must protect from changes.
        PlatformFont::CharInfo &ci = mPlatformFont->getCharInfo(ch);
        if(ci.bitmapData)
            addBitmap(ci);

        mCharInfoList.push_back(ci);
        mRemapTable[ch] = mCharInfoList.size() - 1;
//don't save UFTs on the iPhone
#ifndef TORQUE_OS_IOS
        mNeedSave = true;
#endif

        Mutex::unlockMutex(mMutex);
        return true;
    }

    return false;
}

void GFont::addBitmap(PlatformFont::CharInfo &charInfo)
{
   U32 platformHeight = std::max(mPlatformFont ? mPlatformFont->getTexLineHeight() : 0, mTexLineHeight);

   const U32 padding = mSDF ? 2 : 1; // jamesu - best to have padding here in all cases I think
   U32 nextCurX = U32(mCurX + charInfo.width + padding); /*7) & ~0x3;*/
   U32 nextCurY = U32(mCurY + platformHeight + padding); // + 7) & ~0x3;
   
   if (charInfo.height > mTexLineHeight)
   {
      U32 delta = charInfo.height - mTexLineHeight;
      mTexLineHeight = charInfo.height;
      Con::warnf("Character for font %s %u exceeds texture height by %u pixels, extending.", mFaceName, mSize, delta);
   }

   // These are here for postmortem debugging.
   bool routeA = false, routeB = false;

   const U32 RealTextureSheetSize = mSDF ? 2*BaseTextureSheetSize : BaseTextureSheetSize;

   if(mCurSheet == -1 || nextCurY >= RealTextureSheetSize)
   {
      routeA = true;
      addSheet();

      // Recalc our nexts.
      nextCurX = U32(mCurX + charInfo.width + padding); // + 7) & ~0x3;
      nextCurY = U32(mCurY + platformHeight + padding); // + 7) & ~0x3;
   }

   if( nextCurX >= RealTextureSheetSize)
   {
      routeB = true;
    mCurX = 0;
      mCurY = nextCurY;
      mCurX = 0;

      // Recalc our nexts.
      nextCurX = U32(mCurX + charInfo.width + padding); // + 7) & ~0x3;
      nextCurY = U32(mCurY + platformHeight + padding); // + 7) & ~0x3;
   }

   // Check the Y once more - sometimes we advance to a new row and run off
   // the end.
   if(nextCurY >= RealTextureSheetSize)
   {
      routeA = true;
      addSheet();

      // Recalc our nexts.
      nextCurX = U32(mCurX + charInfo.width + padding); // + 7) & ~0x3;
      nextCurY = U32(mCurY + platformHeight + padding); // + 7) & ~0x3;
   }

   charInfo.bitmapIndex = mCurSheet;
   charInfo.xOffset = mCurX;
   charInfo.yOffset = mCurY;

   mCurX = nextCurX;

   GBitmap *bmp = mTextureSheets[mCurSheet].getBitmap();

   AssertFatal(bmp->getFormat() == GBitmap::Alpha, "GFont::addBitmap - cannot added characters to non-greyscale textures!");

   for(S32 y = 0;y < charInfo.height;y++)
      for(S32 x = 0;x < charInfo.width;x++)
         *bmp->getAddress(x + charInfo.xOffset, y + charInfo.yOffset) = charInfo.bitmapData[y * charInfo.width + x];
   
   mTextureSheets[mCurSheet].refresh();
}

void GFont::addSheet()
{
    char buf[30];
    dSprintf(buf, sizeof(buf), "newfont_%d", smSheetIdCount++);

    const U32 RealTextureSheetSize = mSDF ? 2*BaseTextureSheetSize : BaseTextureSheetSize;
    GBitmap *bitmap = new GBitmap(RealTextureSheetSize, RealTextureSheetSize, false, GBitmap::Alpha);

    // Set everything to transparent.
    U8 *bits = bitmap->getWritableBits();
    dMemset(bits, 0, RealTextureSheetSize*RealTextureSheetSize);

    TextureHandle handle = TextureHandle(buf, bitmap, BitmapKeepTexture);
    handle.setFilterNearest();

    mTextureSheets.increment();
    constructInPlace(&mTextureSheets.last());
    mTextureSheets.last() = handle;

    mCurX = 0;
    mCurY = 0;
    mCurSheet = mTextureSheets.size() - 1;
}

//////////////////////////////////////////////////////////////////////////

const PlatformFont::CharInfo &GFont::getCharInfo(const UTF16 in_charIndex)
{
   PROFILE_START(NewFontGetCharInfo);

   AssertFatal(in_charIndex, "GFont::getCharInfo - can't get info for char 0!");

   if(mRemapTable[in_charIndex] == -1)
   {
      loadCharInfo(in_charIndex);
   }

   AssertFatal(mRemapTable[in_charIndex] != -1, "No remap info for this character");

   PROFILE_END();

   // if we still have no character info, return the default char info.
   if(mRemapTable[in_charIndex] == -1)
      return getDefaultCharInfo();
   else
      return mCharInfoList[mRemapTable[in_charIndex]];
}

const PlatformFont::CharInfo &GFont::getDefaultCharInfo()
{
   static PlatformFont::CharInfo c;
   // c is initialized by the CharInfo default constructor.
   return c;
}

//////////////////////////////////////////////////////////////////////////

U32 GFont::getStrWidth(const UTF8* in_pString)
{
   AssertFatal(in_pString != NULL, "GFont::getStrWidth: String is NULL, width is undefined");
   // If we ain't running debug...
   if (in_pString == NULL || *in_pString == '\0')
      return 0;

   return getStrNWidth(in_pString, dStrlen(in_pString));
}

U32 GFont::getStrWidthPrecise(const UTF8* in_pString)
{
   AssertFatal(in_pString != NULL, "GFont::getStrWidth: String is NULL, height is undefined");
   // If we ain't running debug...
   if (in_pString == NULL)
      return 0;

   return getStrNWidthPrecise(in_pString, dStrlen(in_pString));
}

//////////////////////////////////////////////////////////////////////////
U32 GFont::getStrNWidth(const UTF8 *str, U32 n)
{
   // UTF8 conversion is expensive. Avoid converting in a tight loop.
   FrameTemp<UTF16> str16(n + 1);
   convertUTF8toUTF16(str, str16, n+1);
   return getStrNWidth(str16, dStrlen(str16));
}

U32 GFont::getStrNWidth(const UTF16 *str, U32 n)
{
   AssertFatal(str != NULL, "GFont::getStrNWidth: String is NULL");

   if (str == NULL || str[0] == '\0' || n == 0)   
      return 0;
      
   F32 totWidth = 0;
   UTF16 curChar;
   U32 charCount;
   
   for(charCount = 0; charCount < n; charCount++)
   {
      curChar = str[charCount];
      if(curChar == '\0')
         break;

      if(isValidChar(curChar))
      {
         const PlatformFont::CharInfo& rChar = getCharInfo(curChar);
         totWidth += rChar.xIncrement;
      }
      else if (curChar == dT('\t'))
      {
         const PlatformFont::CharInfo& rChar = getCharInfo(dT(' '));
         totWidth += rChar.xIncrement * TabWidthInSpaces;
      }
   }

   totWidth *= getInvMetricScale();

   return (U32)mCeil(totWidth);
}

U32 GFont::getStrNWidthPrecise(const UTF8 *str, U32 n)
{
   FrameTemp<UTF16> str16(n + 1);
   convertUTF8toUTF16(str, str16, n+1);
   return getStrNWidthPrecise(str16, n);
}

U32 GFont::getStrNWidthPrecise(const UTF16 *str, U32 n)
{
   AssertFatal(str != NULL, "GFont::getStrNWidth: String is NULL");

   if (str == NULL || str[0] == '\0' || n == 0)   
      return(0);
      
   F32 totWidth = 0;
   UTF16 curChar;
   S32 charCount = 0;
   const F32 invTexScale = 1.0f / getTextureScale();
   
   for(charCount = 0; charCount < n; charCount++)
   {
      curChar = str[charCount];
      if(curChar == '\0')
      {
         n = charCount;
         break;
      }
         
      if(isValidChar(curChar))
      {
         const PlatformFont::CharInfo& rChar = getCharInfo(curChar);
         totWidth += rChar.xIncrement;
      }
      else if (curChar == dT('\t'))
      {
         const PlatformFont::CharInfo& rChar = getCharInfo(dT(' '));
         totWidth += rChar.xIncrement * TabWidthInSpaces;
      }
   }
   
   // Add in width after last char
   UTF16 endChar = str[getMax(0, ((S32)n)-1)];
   if (isValidChar(endChar))
   {
      const PlatformFont::CharInfo& rChar = getCharInfo(endChar);
      U32 realMetricWidth = mCeil((F32)rChar.width * invTexScale * getMetricScale());
      if (realMetricWidth > rChar.xIncrement)
         totWidth += (realMetricWidth - rChar.xIncrement);
   }
   
   totWidth *= getInvMetricScale();
   
   return (U32)mCeil(totWidth);
}

U32 GFont::getBreakPos(const UTF16 *str16, U32 slen, U32 width, bool breakOnWhitespace)
{
   // Some early out cases.
   if(slen==0)
      return 0;

   U32 ret = 0;
   U32 lastws = 0;
   UTF16 c;
   U32 charCount = 0;

   const F32 metricScale = getMetricScale();
   const F32 invMetricScale = getInvMetricScale();
   U32 scaledWidth = width * metricScale;

   for( charCount=0; charCount < slen; charCount++)
   {
      c = str16[charCount];
      if(c == '\0')
         break;
         
      if(c == dT('\t'))
         c = dT(' ');
      if(!isValidChar(c))
      {
         ret++;
         continue;
      }
      if(c == dT(' '))
         lastws = ret+1;
      const PlatformFont::CharInfo& rChar = getCharInfo(c);

      if(rChar.width > scaledWidth || rChar.xIncrement > (S32)scaledWidth)
      {
         if(lastws && breakOnWhitespace)
            return lastws;
         return ret;
      }

      scaledWidth -= rChar.xIncrement;
      
      ret++;
   }
   return ret;
}

void GFont::wrapString(const UTF8 *txt, U32 lineWidth, Vector<U32> &startLineOffset, Vector<U32> &lineLen)
{
   Con::errorf("GFont::wrapString(): Not yet converted to be UTF-8 safe");

   startLineOffset.clear();
   lineLen.clear();

   if (!txt || !txt[0] || lineWidth < getCharWidth('W')) //make sure the line width is greater then a single character
      return;

   U32 len = dStrlen(txt);

   U32 startLine; 
   U32 scaledLineWidth = lineWidth * getMetricScale();

   for (U32 i = 0; i < len;)
   {
      startLine = i;
      startLineOffset.push_back(startLine);

      // loop until the string is too large
      bool needsNewLine = false;
      U32 lineStrWidth = 0;
      for (; i < len; i++)
      {
         if(isValidChar(txt[i]))
         {
            lineStrWidth += getCharInfo(txt[i]).xIncrement;
            if ( txt[i] == '\n' || lineStrWidth > scaledLineWidth )
            {
               needsNewLine = true;
               break;      
            }
         }
      }

      if (!needsNewLine)
      {
         // we are done!
         lineLen.push_back(i - startLine);
         return;
      }

      // now determine where to put the newline
      // else we need to backtrack until we find a either space character 
      // or \\ character to break up the line. 
      S32 j;
      for (j = i - 1; j >= (S32)startLine; j--)
      {
         if (dIsspace(txt[j]))
            break;
      }

      if (j < (S32)startLine)
      {
         // the line consists of a single word!              
         // So, just break up the word
         j = i - 1;
      }
      lineLen.push_back(j - startLine);
      i = j;

      // now we need to increment through any space characters at the
      // beginning of the next line
      for (i++; i < len; i++)
      {
         if (!dIsspace(txt[i]) || txt[i] == '\n')
            break;
      }
   }
}

//////////////////////////////////////////////////////////////////////////

bool GFont::read(Stream& io_rStream)
{
    // Handle versioning
    U32 version;
    io_rStream.read(&version);
    if((version & 0xFF) != csm_fileVersion)
        return false;
   
    mSDF = (version & GFont::SDFFlag) != 0;

    char buf[256];
    io_rStream.readString(buf);
    mFaceName = StringTable->insert(buf);

    io_rStream.read(&mSize);
    io_rStream.read(&mCharSet);

    io_rStream.read(&mHeight);
    io_rStream.read(&mBaseline);
    io_rStream.read(&mAscent);
    io_rStream.read(&mDescent);

    if ((version & GFont::VariantHeightFlag) != 0)
    {
       io_rStream.read(&mTexLineHeight);
    }
    else
    {
       mTexLineHeight = mHeight;
    }

    if ((version & GFont::CustomScaleFlag) != 0)
    {
       io_rStream.read(&mTextureScale);
       io_rStream.read(&mMetricScale);
    }
    else
    {
       mTextureScale = 1.0f;
       mMetricScale = 1.0f;
    }

    U32 size = 0;
    io_rStream.read(&size);
    mCharInfoList.setSize(size);
    U32 i;
    for(i = 0; i < size; i++)
    {
        PlatformFont::CharInfo *ci = &mCharInfoList[i];
        io_rStream.read(&ci->bitmapIndex);
        io_rStream.read(&ci->xOffset);
        io_rStream.read(&ci->yOffset);
        io_rStream.read(&ci->width);
        io_rStream.read(&ci->height);
        io_rStream.read(&ci->xOrigin);
        io_rStream.read(&ci->yOrigin);
        io_rStream.read(&ci->xIncrement);
        ci->bitmapData = NULL;
   }

   U32 numSheets = 0;
   io_rStream.read(&numSheets);
   
   for(i = 0; i < numSheets; i++)
   {
       GBitmap *bmp = new GBitmap;
       if(!bmp->readPNG(io_rStream))
       {
           delete bmp;
           return false;
       }

       char buf[30];
       dSprintf(buf, sizeof(buf), "font_%d", smSheetIdCount++);

       mTextureSheets.increment();
       constructInPlace(&mTextureSheets.last());
       mTextureSheets.last() = TextureHandle(buf, bmp, BitmapKeepTexture);
       mTextureSheets.last().setFilterNearest();
   }
   
   // Read last position info
   io_rStream.read(&mCurX);
   io_rStream.read(&mCurY);
   io_rStream.read(&mCurSheet);

   // Read the remap table.
   U32 minGlyph, maxGlyph;
   io_rStream.read(&minGlyph);
   io_rStream.read(&maxGlyph);

   if(maxGlyph >= minGlyph)
   {
      // Length of buffer..
      U32 buffLen;
      io_rStream.read(&buffLen);

      // Read the buffer.
      FrameTemp<S32> inBuff(buffLen);
      io_rStream.read(buffLen, inBuff);

      // Decompress.
      uLongf destLen = (maxGlyph-minGlyph+1)*sizeof(S32);
      uncompress((Bytef*)&mRemapTable[minGlyph], &destLen, (Bytef*)(S32*)inBuff, buffLen);

      AssertISV(destLen == (maxGlyph-minGlyph+1)*sizeof(S32), "GFont::read - invalid remap table data!");

      // Make sure we've got the right endianness.
      for(i = minGlyph; i <= maxGlyph; i++) {
         mRemapTable[i] = convertBEndianToHost(mRemapTable[i]);
         //if( mRemapTable[i] == -1 ) {
         //    Con::errorf( "bogus mRemapTable[i] value in %s %i", mFaceName, mSize );
         //}
      }
   }
   
   return (io_rStream.getStatus() == Stream::Ok);
}

bool GFont::write(Stream& stream)
{
    // Handle versioning
    U32 extraFlags = 0;
    if (mSDF) extraFlags |= GFont::SDFFlag;
    if (mTexLineHeight != mHeight) extraFlags |= GFont::VariantHeightFlag;
    if (mTextureScale != 1.0f || mMetricScale != 1.0f) extraFlags |= GFont::CustomScaleFlag;
    stream.write(csm_fileVersion | extraFlags); 

    // Write font info
    stream.writeString(mFaceName);
    stream.write(mSize);
    stream.write(mCharSet);
   
    stream.write(mHeight);
    stream.write(mBaseline);
    stream.write(mAscent);
    stream.write(mDescent);

    if ((extraFlags & GFont::VariantHeightFlag) != 0)
    {
       stream.write(mTexLineHeight);
    }

    if ((extraFlags & GFont::CustomScaleFlag) != 0)
    {
       stream.write(&mTextureScale);
       stream.write(&mMetricScale);
    }
    else
    {
       mTextureScale = 1.0f;
       mMetricScale = 1.0f;
    }

   // Get the min/max we have values for, and only write that range out.
   S32 minGlyph = S32_MAX, maxGlyph = 0;
   S32 i;

   for(i = 0; i < 65536; i++)
   {
       if(mRemapTable[i] != -1)
       {
           if(i > maxGlyph) maxGlyph = i;
           if(i < minGlyph) minGlyph = i;
       }
   }

   //-Mat make sure all our character info is good before writing it
   for(i = minGlyph; i <= maxGlyph; i++) {
       if( mRemapTable[i] == -1 ) {
           //-Mat get info and try this again
           getCharInfo(i);
           if( mRemapTable[i] == -1 ) {
               Con::errorf( "GFont::write() couldn't get character info for char %i", i);
           }
       }
   }

    // Write char info list
    stream.write(U32(mCharInfoList.size()));
    for(i = 0; i < mCharInfoList.size(); i++)
    {
        const PlatformFont::CharInfo *ci = &mCharInfoList[i];
        stream.write(ci->bitmapIndex);
        stream.write(ci->xOffset);
        stream.write(ci->yOffset);
        stream.write(ci->width);
        stream.write(ci->height);
        stream.write(ci->xOrigin);
        stream.write(ci->yOrigin);
        stream.write(ci->xIncrement);
   }

   stream.write(mTextureSheets.size());
   for(i = 0; i < mTextureSheets.size(); i++) {
       mTextureSheets[i].getBitmap()->writePNG(stream);
   }

   stream.write(mCurX);
   stream.write(mCurY);
   stream.write(mCurSheet);


   stream.write(minGlyph);
   stream.write(maxGlyph);

   // Skip it if we don't have any glyphs to do...
   if(maxGlyph >= minGlyph)
   {
      // Put everything big endian, to be consistent. Do this inplace.
      for(i = minGlyph; i <= maxGlyph; i++)
         mRemapTable[i] = convertHostToBEndian(mRemapTable[i]);

      {
         // Compress.
         const U32 buffSize = 128 * 1024;
         FrameTemp<S32> outBuff(buffSize);
         uLongf destLen = buffSize * sizeof(S32);
         compress2((Bytef*)(S32*)outBuff, &destLen, (Bytef*)(S32*)&mRemapTable[minGlyph], (maxGlyph-minGlyph+1)*sizeof(S32), 9);

         // Write out.
         stream.write((U32)destLen);
         stream.write(destLen, outBuff);
      }

      // Put us back to normal.
      for(i = minGlyph; i <= maxGlyph; i++) {
         mRemapTable[i] = convertBEndianToHost(mRemapTable[i]);

         //if( mRemapTable[i] == -1 ) {
         //    Con::errorf( "bogus mRemapTable[i] value in %s %i", mFaceName, mSize );
         //}
      }
   }
   
   return (stream.getStatus() == Stream::Ok);
}

void GFont::exportStrip(const char *fileName, U32 padding, U32 kerning)
{
   // Figure dimensions of our strip by iterating over all the char infos.
   U32 totalHeight = 0;
   U32 totalWidth = 0;

   S32 heightMin=0, heightMax=0;

   for(S32 i=0; i<mCharInfoList.size(); i++)
   {
      totalWidth += mCharInfoList[i].width + kerning + 2*padding;
      heightMin = getMin((S32)heightMin, (S32)getBaseline() - (S32)mCharInfoList[i].yOrigin);
      heightMax = getMax((S32)heightMax, (S32)getBaseline() - (S32)mCharInfoList[i].yOrigin + (S32)mCharInfoList[i].height);
   }

   totalHeight = heightMax - heightMin + 2*padding;

   // Make the bitmap.
   GBitmap gb(totalWidth, totalHeight, false, mTextureSheets[0].getBitmap()->getFormat());

   dMemset(gb.getWritableBits(), 0, sizeof(U8) * totalHeight * totalWidth );

   // Ok, copy some rects, taking into account padding, kerning, offset.
   U32 curWidth = kerning + padding;

   for(S32 i=0; i<mCharInfoList.size(); i++)
   {
      // Skip invalid stuff.
      if(mCharInfoList[i].bitmapIndex == -1 || mCharInfoList[i].height == 0 || mCharInfoList[i].width == 0)
         continue;

      // Copy the rect.
      U32 bitmap = mCharInfoList[i].bitmapIndex;

      RectI ri(mCharInfoList[i].xOffset, mCharInfoList[i].yOffset, mCharInfoList[i].width, mCharInfoList[i].height );
      Point2I outRi(curWidth, padding + getBaseline() - mCharInfoList[i].yOrigin);
      gb.copyRect(mTextureSheets[bitmap].getBitmap(), ri, outRi); 

      // Advance.
      curWidth +=  mCharInfoList[i].width + kerning + 2*padding;
   }

   // Write the image!
   FileStream fs;
   
   if(!ResourceManager->openFileForWrite(fs, fileName))
   {
      Con::errorf("GFont::exportStrip - failed to open '%s' for writing.", fileName);
      return;
   }
 
   // Done!
   gb.writePNG(fs, false);
}

/// Used for repacking in GFont::importStrip.
struct GlyphMap
{
   U32 charId;
   GBitmap *bitmap;
};

static S32 QSORT_CALLBACK GlyphMapCompare(const void *a, const void *b)
{
   S32 ha = ((GlyphMap *) a)->bitmap->height;
   S32 hb = ((GlyphMap *) b)->bitmap->height;

   return hb - ha;
}


void GFont::importStrip(const char *fileName, U32 padding, U32 kerning)
{
   // Wipe our texture sheets, and reload bitmap data from the specified file.
   // Also deal with kerning.
   // Also, we may have to load RGBA instead of RGB.

   // Wipe our texture sheets.
   mCurSheet = mCurX = mCurY = 0;
   mTextureSheets.clear();

   //  Now, load the font strip.
   GBitmap *strip = GBitmap::load(fileName);

   if(!strip)
   {
      Con::errorf("GFont::importStrip - could not load file '%s'!", fileName);
      return;
   }

   // And get parsing and copying - load up all the characters as separate
   // GBitmaps, sort, then pack. Not terribly efficient but this is basically
   // on offline task anyway.

   // Ok, snag some glyphs.
   Vector<GlyphMap> glyphList;
   glyphList.reserve(mCharInfoList.size());

   U32 curWidth = 0;
   for(S32 i=0; i<mCharInfoList.size(); i++)
   {
      // Skip invalid stuff.
      if(mCharInfoList[i].bitmapIndex == -1 || mCharInfoList[i].height == 0 || mCharInfoList[i].width == 0)
         continue;

      // Allocate a new bitmap for this glyph, taking into account kerning and padding.
      glyphList.increment();
      glyphList.last().bitmap = new GBitmap(mCharInfoList[i].width + kerning + 2*padding, mCharInfoList[i].height + 2*padding, false, strip->getFormat());
      glyphList.last().charId = i;

      // Copy the rect.
      RectI ri(curWidth, getBaseline() - mCharInfoList[i].yOrigin, glyphList.last().bitmap->width, glyphList.last().bitmap->height);
      Point2I outRi(0,0);
      glyphList.last().bitmap->copyRect(strip, ri, outRi); 

      // Update glyph attributes.
      mCharInfoList[i].width = glyphList.last().bitmap->width;
      mCharInfoList[i].height = glyphList.last().bitmap->height;
      mCharInfoList[i].xOffset -= kerning + padding;
      mCharInfoList[i].xIncrement += kerning;
      mCharInfoList[i].yOffset -= padding;

      // Advance.
      curWidth += ri.extent.x;
   }

   // Ok, we have a big list of glyphmaps now. So let's sort them, then pack them.
   dQsort(glyphList.address(), glyphList.size(), sizeof(GlyphMap), GlyphMapCompare);

   // They're sorted by height, so now we can do some sort of awesome packing.
   Point2I curSheetSize(256, 256);
   Vector<U32> sheetSizes;

   S32 curY = 0;
   S32 curX = 0;
   S32 curLnHeight = 0;
   S32 maxHeight = 0;
   for(U32 i = 0; i < (U32)glyphList.size(); i++)
   {
      PlatformFont::CharInfo *ci = &mCharInfoList[glyphList[i].charId];
      
      if(ci->height > (U32)maxHeight)
         maxHeight = ci->height;

      if(curX + ci->width > (U32)curSheetSize.x)
      {
         curY += curLnHeight;
         curX = 0;
         curLnHeight = 0;
      }

      if(curY + ci->height > (U32)curSheetSize.y)
      {
         sheetSizes.push_back(curSheetSize.y);
         curX = 0;
         curY = 0;
         curLnHeight = 0;
      }

      if(ci->height > (U32)curLnHeight)
         curLnHeight = ci->height;
      
      ci->bitmapIndex = sheetSizes.size();
      ci->xOffset = curX;
      ci->yOffset = curY;
      curX += ci->width;
   }

   // Terminate the packing loop calculations.
   curY += curLnHeight;

   if(curY < 64)
      curSheetSize.y = 64;
   else if(curY < 128)
      curSheetSize.y = 128;

   sheetSizes.push_back(curSheetSize.y);

   if(getHeight() + padding * 2 > (U32)maxHeight)
      maxHeight = getHeight() + padding * 2;

   // Allocate texture pages.
   for(S32 i=0; i<sheetSizes.size(); i++)
   {
      char buf[30];
      dSprintf(buf, sizeof(buf), "newfont_%d", smSheetIdCount++);

      GBitmap *bitmap = new GBitmap(BaseTextureSheetSize, BaseTextureSheetSize, false, strip->getFormat());

      // Set everything to transparent.
      U8 *bits = bitmap->getWritableBits();
      dMemset(bits, 0, sizeof(U8) *BaseTextureSheetSize*BaseTextureSheetSize * strip->bytesPerPixel);

      TextureHandle handle = TextureHandle( buf, bitmap, BitmapKeepTexture );
      mTextureSheets.increment();
      constructInPlace(&mTextureSheets.last());
      mTextureSheets.last() = handle;
   }


   // Alright, we're ready to copy bits!
   for(S32 i=0; i<glyphList.size(); i++)
   {
      // Copy each glyph into the appropriate place.
      PlatformFont::CharInfo *ci = &mCharInfoList[glyphList[i].charId];
      U32 bi = ci->bitmapIndex;
      mTextureSheets[bi].getBitmap()->copyRect(glyphList[i].bitmap, RectI(0,0, glyphList[i].bitmap->width,glyphList[i].bitmap->height), Point2I(ci->xOffset, ci->yOffset));
   }

   // Ok, all done! Just refresh some textures and we're set.
   for(S32 i=0; i<sheetSizes.size(); i++)
      mTextureSheets[i].refresh();
}

ConsoleFunction(fontAtlasTest, void, 1, 1, "")
{
   Resource<GFont> f = GFont::create("Arial", 12, Con::getVariable("$GUI::fontCacheDirectory"));
   f->getStrWidthPrecise("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789 !");

   
   for(int i = 0; i < f->mTextureSheets.size(); i++) {
      FileStream fs;

      char buf[1024];
      dSprintf(buf, 1024, "%s-%u.png", "Arial", i);
      fs.open(buf, FileStream::Write);
       f->mTextureSheets[i].getBitmap()->writePNG(fs);
   }
}

gFont.h

//-----------------------------------------------------------------------------
// Copyright (c) 2013 GarageGames, LLC
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//-----------------------------------------------------------------------------

#ifndef _GFONT_H_
#define _GFONT_H_

//Includes
#ifndef _PLATFORM_H_
#include "platform/platform.h"
#endif
#ifndef _GBITMAP_H_
#include "dgl/gBitmap.h"
#endif
#ifndef _TVECTOR_H_
#include "core/tVector.h"
#endif
#ifndef _MRECT_H_
#include "math/mRect.h"
#endif
#ifndef _RESMANAGER_H_
#include "core/resManager.h"
#endif
#ifndef _GTEXMANAGER_H_
#include "dgl/gTexManager.h"
#endif

//-Mat use this to make space characters default to a certain x increment
#define PUAP_SPACE_CHAR_X_INCREMENT 5




extern ResourceInstance* constructNewFont(Stream& stream);

class TextureHandle;

class GFont : public ResourceInstance
{
   friend ResourceInstance* constructNewFont(Stream& stream);

   static const U32 csm_fileVersion;
   static S32 smSheetIdCount;
   
   // Enumerations and structs available to everyone...
public:

   enum Constants 
   {
      TabWidthInSpaces = 3,
      SDFFlag = (1<<31),
      VariantHeightFlag = (1<<30),
      CustomScaleFlag = (1<<29)
   };


   // Enumerations and structures available to derived classes
private:
   PlatformFont *mPlatformFont;
   public: 
   Vector<TextureHandle> mTextureSheets;

   S32 mCurX;
   S32 mCurY;
   S32 mCurSheet;

   bool mNeedSave;
   bool mSDF; // Uses a signed distance field
   StringTableEntry mGFTFile;
   StringTableEntry mFaceName;
   U32 mSize;
   U32 mCharSet;

   U32 mHeight;
   U32 mBaseline;
   U32 mAscent;
   U32 mDescent;

   U32 mTexLineHeight;   ///< Texture padding may differ, thus this
   F32 mTextureScale;    ///< Additional scale for font texture (e.g. when doing retina)
   F32 mMetricScale;     ///< Scale for CharInfo metric values (since they are stored as ints)

   Vector<PlatformFont::CharInfo>  mCharInfoList;       // - List of character info structures, must
                                          //    be accessed through the getCharInfo(U32)
                                          //    function to account for remapping...
   S32             mRemapTable[65536];    // - Index remapping
public:
   GFont();
   virtual ~GFont();

protected:
    bool loadCharInfo(const UTF16 ch);
    void addBitmap(PlatformFont::CharInfo &charInfo);
    void addSheet(void);
    void assignSheet(S32 sheetNum, GBitmap *bmp);

    void *mMutex;

public:
   static Resource<GFont> create(const char *faceName, U32 size, const char *cacheDirectory, U32 charset = TGE_ANSI_CHARSET);

   TextureHandle getTextureHandle(S32 index)
   {
       return mTextureSheets[index];
   }

   const PlatformFont::CharInfo& getCharInfo(const UTF16 in_charIndex);
   static const PlatformFont::CharInfo& getDefaultCharInfo();

   U32  getCharHeight(const UTF16 in_charIndex);
   U32  getCharWidth(const UTF16 in_charIndex);
   U32  getCharXIncrement(const UTF16 in_charIndex);
   
   bool isValidChar(const UTF16 in_charIndex) const;

   const U32 getHeight() const   { return mHeight; }
   const U32 getBaseline() const { return mBaseline; }
   const U32 getAscent() const   { return mAscent; }
   const U32 getDescent() const  { return mDescent; }
   const F32 getTextureScale() const   { return mTextureScale; }
   const F32 getMetricScale() const    { return mMetricScale; }
   const F32 getInvMetricScale() const { return 1.0f / mMetricScale; }

   U32 getBreakPos(const UTF16 *string, U32 strlen, U32 width, bool breakOnWhitespace);

   /// These are the preferred width functions.
   U32 getStrNWidth(const UTF16*, U32 n);
   U32 getStrNWidthPrecise(const UTF16*, U32 n);
   
   /// These UTF8 versions of the width functions will be deprecated, please avoid them.
   U32 getStrWidth(const UTF8*);   // Note: ignores c/r
   U32 getStrNWidth(const UTF8*, U32 n);

   U32 getStrWidthPrecise(const UTF8*);   // Note: ignores c/r
   U32 getStrNWidthPrecise(const UTF8*, U32 n);
   
   void wrapString(const UTF8 *string, U32 width, Vector<U32> &startLineOffset, Vector<U32> &lineLen);

   /// Dump information about this font to the console.
   void dumpInfo();

   /// Export to an image strip for image processing.
   void exportStrip(const char *fileName, U32 padding, U32 kerning);

   /// Import an image strip generated with exportStrip, make sure parameters match!
   void importStrip(const char *fileName, U32 padding, U32 kerning);

   /// Query as to presence of platform font. If absent, we cannot generate more
   /// chars!
   const bool hasPlatformFont() const
   {
      return mPlatformFont != NULL;
   }

   /// Query to determine if we should use add or modulate (as A8 textures
   /// are treated as having 0 for RGB).
   bool isAlphaOnly()
   {
      return mTextureSheets[0].getBitmap()->getFormat() == GBitmap::Alpha;
   }

   /// Get the filename for a cached font.
   static void getFontCacheFilename(const char *faceName, U32 faceSize, U32 buffLen, char *outBuff);

   /// Get the face name of the font.
   StringTableEntry getFontFaceName() const { return mFaceName; };

   bool read(Stream& io_rStream);
   bool write(Stream& io_rStream);

   /// Override existing platform font if any with a new one from an external
   /// source. This is primarily used in font processing tools to enable
   /// trickery (ie, putting characters from multiple fonts in a single
   /// GFT) and should be used with caution!
   void forcePlatformFont(PlatformFont  *pf)
   {
      mPlatformFont = pf;
   }

   static U32 BaseTextureSheetSize;
};

inline U32 GFont::getCharXIncrement(const UTF16 in_charIndex)
{
    const PlatformFont::CharInfo& rChar = getCharInfo(in_charIndex);
    return rChar.xIncrement;
}

inline U32 GFont::getCharWidth(const UTF16 in_charIndex)
{
    const PlatformFont::CharInfo& rChar = getCharInfo(in_charIndex);
    return rChar.width;
}

inline U32 GFont::getCharHeight(const UTF16 in_charIndex)
{
    const PlatformFont::CharInfo& rChar = getCharInfo(in_charIndex);
    return rChar.height;
}

inline bool GFont::isValidChar(const UTF16 in_charIndex) const
{
   if(mRemapTable[in_charIndex] != -1)
      return true;

   if(mPlatformFont)
      return mPlatformFont->isValidChar(in_charIndex);

   return false;
}

#endif //_GFONT_H_

sdP.hlsl

float4 main( float4 color_in : COLOR0, 
             float2 texCoord_in : TEXCOORD0,
             uniform sampler2D diffuseMap : register(S0) ) : COLOR0
{
   float distance = tex2D(diffuseMap, texCoord_in).a;
   const float w = 0.5/3;
   const float threshold = 0.5f;
   float alpha = smoothstep( threshold-w, threshold+w, distance );
   return float4(color_in.rgb,alpha * color_in.a);
}

STB Font Prototype Code

AUTHORS

James S Urquhart (jamesu@gmail.com)

stbFont.cc

//-----------------------------------------------------------------------------
// Copyright (c) 2021 tgemit contributors.
// See AUTHORS file and git repository for contributor information.
//
// SPDX-License-Identifier: MIT
//-----------------------------------------------------------------------------

#include "platform/platform.h"
#include "core/unicode.h"
#include "console/console.h"
#include "platformGeneric/stbFont.h"
#include "core/tVector.h"
#include "core/stringTable.h"
#include "core/fileStream.h"
#include <unordered_map>
#include <algorithm>


#define STB_TRUETYPE_IMPLEMENTATION
#include "stb/stb_truetype.h"

Vector<STBFont::SizeCorrection> STBFont::smCorrectedSizes;
Vector<STBFont::FontSubstitution> STBFont::smSubstitutions;
bool gSTBInit;

// 
class STBFontCollection
{
public:

   struct LoadedInfo
   {
      U8* data;
      StringTableEntry filename;
   };

   Vector<LoadedInfo> loadedFontData;
   std::unordered_map<StringTableEntry, stbtt_fontinfo*> loadedFonts;

   static STBFontCollection smInstance;

   ~STBFontCollection()
   {
      for (LoadedInfo info : loadedFontData)
      {
         delete info.data;
      }
      for (auto &kv : loadedFonts)
      {
         delete kv.second;
      }
      loadedFontData.clear();
      loadedFonts.clear();
   }

   bool loadData(const char* path)
   {
       FileStream fs;
       if (fs.open(path, FileStream::Read))
       {
          U32 len = fs.getStreamSize();
          U8* data = new U8[len];
          fs.read(len, data);
          fs.close();

          LoadedInfo info = {data, StringTable->insert(path)};
          loadedFontData.push_back(info);
          //printf("FONT FILE LOADED %s\n", path);
       }
   }

   void loadDataFolder(const char* path)
   {
      Vector<Platform::FileInfo> files;
      Platform::dumpPath(path, files, 2);

      for (Platform::FileInfo &file : files)
      {
         const char *ext = dStrrchr(file.pFileName, '.');
         if (ext && (dStricmp(ext, ".ttf") == 0 || dStricmp(ext, ".otf") == 0))
         {
            char buffer[4096];
            dSprintf(buffer, sizeof(buffer), "%s/%s", file.pFullPath, file.pFileName);
            loadData(buffer);
         }
      }
   }

   stbtt_fontinfo* findFont(const char* name)
   {
      char buffer[256];
      const char* namePtr = name;
      bool valid = false;
      stbtt_fontinfo* info = NULL;

      StringTableEntry realName = STBFont::getCorrectName(StringTable->insert(name));
      
      auto itr = loadedFonts.find(realName);
      if (itr != loadedFonts.end())
      {
         return info;
      }

      auto tryLoadFont = [this, &realName, &info](const LoadedInfo dataBlock) {
         int fontOffset = stbtt_FindMatchingFont(dataBlock.data, realName, STBTT_MACSTYLE_DONTCARE);
         if (fontOffset != -1)
         {
            info = new stbtt_fontinfo;

            if (stbtt_InitFont(info, dataBlock.data, fontOffset) == 0)
            {
               Con::errorf("STBFontCollection couldn't init font %s!", realName);
               delete info;
               info = NULL;
            }
            else
            {
               loadedFonts[realName] = info;
               return true;
            }
         }

         return false;
      };

      std::find_if(loadedFontData.begin(), loadedFontData.end(), tryLoadFont);
      
      // Try x Regular
      if (info == NULL)
      {
         dSprintf(buffer, 256, "%s Regular", realName);
         realName = STBFont::getCorrectName(StringTable->insert(&buffer[0]));
         std::find_if(loadedFontData.begin(), loadedFontData.end(), tryLoadFont);
      }
      
      return info;
   }
};

STBFontCollection STBFontCollection::smInstance;

STBFont::STBFont() :
   mBaseline(0),
   mHeight(0),
   mTexLineHeight(0),
   mSize(0),
   mScaleMapping(0.0f),
   mTextureScale(1.0f),
   mMetricScale(10.0f),
   mFont(NULL),
   mSDF(false)
{
}

STBFont::~STBFont()
{
}

bool STBFont::isValidChar(const UTF16 ch) const
{
   return (ch < 0x20) ? false : true;
}

bool STBFont::isValidChar(const UTF8 *str) const
{
   UTF32 theChar = oneUTF8toUTF32(str);
   return isValidChar(theChar);
}

PlatformFont::CharInfo &STBFont::getCharInfo(const UTF16 ch) const
{
   static PlatformFont::CharInfo cinfo;
   memset(&cinfo, 0, sizeof(cinfo));
   
   // prep values for GFont::addBitmap()
   cinfo.bitmapIndex = 0;
   cinfo.xOffset = 0;
   cinfo.yOffset = 0;
   
   int leftSideBearing = 0;
   int width = 0;
   int height = 0;
   int __ix0,__iy0,__ix1,__iy1;
   int box_w,box_h;
   int glyph = stbtt_FindGlyphIndex(mFont, ch);

   // Basic metrics
   stbtt_GetGlyphHMetrics(mFont, glyph, &cinfo.xIncrement, &leftSideBearing); // leftSideBearing?

   stbtt_GetGlyphBitmapBoxSubpixel(mFont, glyph, mScaleMapping, mScaleMapping, 0.0f,0.0f, &__ix0,&__iy0,&__ix1,&__iy1);
   box_w = (__ix1 - __ix0);
   box_h = (__iy1 - __iy0);

   U8* field = NULL;

   if (mSDF)
   {
      // SDF
      field = stbtt_GetGlyphSDF(mFont, mScaleMapping * mTextureScale, glyph, 2, 128, 128.0/3.0, &width, &height, &cinfo.xOrigin, &cinfo.yOrigin);
   }
   else
   {
      F32 theScale = mScaleMapping * mTextureScale;
      field = stbtt_GetGlyphBitmap(mFont, theScale, theScale, glyph, &width, &height, &cinfo.xOrigin, &cinfo.yOrigin);
   }

   cinfo.width = width;
   cinfo.height = height;
   
   // ascent = baseline - yOrigin
   cinfo.yOrigin = ((float)-cinfo.yOrigin) * mMetricScale;
   cinfo.xOrigin = ((float)cinfo.xOrigin) * mMetricScale;
   
   cinfo.xIncrement *= mScaleMapping * mMetricScale;
   
   if (cinfo.height > getTexLineHeight())
   {
      Con::warnf("Warning: Not enough texure height for glyph %u, atlas height will be extended.", (U32)ch);
   }
   
   // Finish if character is undrawable.
   if ( (cinfo.width == 0 && cinfo.height == 0) || field == NULL )
   {
      if (field && mSDF)
         stbtt_FreeSDF(field, NULL);
      else if (field && !mSDF)
         stbtt_FreeBitmap(field, NULL);
      return cinfo;
   }
   
   // Allocate a bitmap surface.
   const U32 bitmapSize = cinfo.width * cinfo.height;
   if (bitmapSize > 0)
   {
      cinfo.bitmapData = new U8[cinfo.width * cinfo.height];
      memcpy(cinfo.bitmapData, field, cinfo.width * cinfo.height);
   }

   if (field)
   {
      if (mSDF)
         stbtt_FreeSDF(field, NULL);
      else
         stbtt_FreeBitmap(field, NULL);
   }
   
#if 0
   Con::printf("Char %u Width:%f, Height:%f, OriginX:%f, OriginY:%f",
               character,
               cinfo.width,
               cinfo.height,
               cinfo.xOrigin,
               cinfo.yOrigin );
#endif
   
   // Return character information.
   return cinfo;
}

PlatformFont::CharInfo &STBFont::getCharInfo(const UTF8 *str) const
{
   return getCharInfo(oneUTF32toUTF16(oneUTF8toUTF32(str, NULL)));
}

bool STBFont::create(const char *name, U32 size, U32 charset)
{
   stbtt_fontinfo* info = STBFontCollection::smInstance.findFont(name);
   if (info == NULL)
   {
      if (STBFontCollection::smInstance.loadedFontData.size() != 0)
         Con::errorf( "Could not generate a font reference to font name '%s' of size '%d'", name, size );
      return false;
   }
   
   // See if we have a correction value
   StringTableEntry steName = StringTable->insert(name);
   for (STBFont::SizeCorrection &correction : smCorrectedSizes)
   {
      if (correction.name == steName && size == correction.inSize)
      {
         size = correction.outSize;
         break;
      }
   }
   
   mFont = info;
   mSize = size;
   
   mScaleMapping = stbtt_ScaleForMappingEmToPixels(mFont, mSize);
   mTextureScale = mSDF ? 2.0 : 1.0f;
   mMetricScale = 10.0f;
   
   // Fetch font metrics.
   int ascent=0;
   int descent=0;
   stbtt_GetFontVMetrics(mFont, &ascent, &descent, 0);
   stbtt_GetFontVMetricsOS2(mFont, &ascent, &descent, 0);
   
   AssertFatal(descent <= 0, "unexpected value");
   
   int act_height = (ascent + (-descent));
   F32 basicDesignScale = (mSize) / (act_height);
   
   // Set metrics

   mBaseline = (U32)roundf((F32)ascent * mScaleMapping);
   
   ascent = STBTT_iceil(ascent * mScaleMapping);
   descent = STBTT_ifloor(descent * mScaleMapping);
   
   mTexLineHeight = ((ceilf((ascent + (-descent)))) * mTextureScale) + 2 + 2;
   mHeight = ceilf((ascent + (-descent)));
   
   return true;
}

StringTableEntry STBFont::getCorrectName(StringTableEntry name)
{
   auto itr = std::find_if(smSubstitutions.begin(), smSubstitutions.end(), [name](auto &val){
      return name == val.inName;
   });

   return (itr == smSubstitutions.end() ? name : itr->outName);
}

static void initSTBDefaults()
{
   #if defined(TORQUE_OS_WIN32)
   STBFontCollection::smInstance.loadDataFolder("C:\\Windows\\Fonts");
   #elif defined(TORQUE_OS_LINUX)
   STBFontCollection::smInstance.loadDataFolder("/usr/share/fonts/truetype");
   STBFontCollection::smInstance.loadDataFolder("/usr/share/fonts/opentype");
   #elif defined(TORQUE_OS_OSX)
   STBFontCollection::smInstance.loadDataFolder("/System/Library/Fonts");
   #endif

   gSTBInit = true;
}

void PlatformFont::enumeratePlatformFonts( Vector<StringTableEntry>& fonts )
{
   if (!gSTBInit)
   {
      initSTBDefaults();
   }
}

ConsoleFunction(addPlatformFontDirectory, void, 2, 2, "path")
{
   gSTBInit = true;
   STBFontCollection::smInstance.loadDataFolder(argv[1]);
}

ConsoleFunction(adjustPlatformFontSize, void, 4, 4, "name, old size, new size")
{
   STBFont::SizeCorrection size;
   size.name = StringTable->insert(argv[1]);
   size.inSize = dAtof(argv[2]);
   size.outSize = dAtof(argv[3]);
   STBFont::smCorrectedSizes.push_back(size);
}

ConsoleFunction(adjustPlatformFontName, void, 3, 3, "old name, new name")
{
   STBFont::FontSubstitution correction;
   correction.inName = StringTable->insert(argv[1]);
   correction.outName = StringTable->insert(argv[2]);
   STBFont::smSubstitutions.push_back(correction);
}


PlatformFont* createPlatformFont( const char* name, U32 size, U32 charset )
{
   if (!gSTBInit)
   {
      initSTBDefaults();
   }

   PlatformFont* pFont = new STBFont();

   if ( pFont->create(name, size, charset) )
      return pFont;

   delete pFont;

   return NULL;
}

stbFont.h

//-----------------------------------------------------------------------------
// Copyright (c) 2021 tgemit contributors.
// See AUTHORS file and git repository for contributor information.
//
// SPDX-License-Identifier: MIT
//-----------------------------------------------------------------------------
#ifndef _STB_FONT_H_
#define _STB_FONT_H_

#include "platform/platform.h"
#include "core/unicode.h"
#include "stb/stb_truetype.h"
#include <unordered_map>

struct stbtt_fontinfo;

class STBFont : public PlatformFont
{
public:

   struct FontSubstitution
   {
      StringTableEntry inName;
      StringTableEntry outName;
   };

   struct SizeCorrection
   {
      StringTableEntry name;
      U32 inSize;
      U32 outSize;
   };

   U32 mBaseline;      // i.e. ascent
   U32 mHeight;        // distance between lines 
   U32 mTexLineHeight; // distance + padding between lines in texture

   F32 mSize;         ///< Point size of font
   F32 mScaleMapping; ///< Font scale needed to match mSize (internal)
   F32 mTextureScale; ///< Scale of font texture
   F32 mMetricScale;  ///< Scale of font metrics

   bool mSDF;

   stbtt_fontinfo* mFont;

   STBFont();
   virtual ~STBFont();
   
   virtual bool isValidChar(const UTF16 ch) const;
   virtual bool isValidChar(const UTF8 *str) const;
   virtual bool isSDF() const { return mSDF; }

   virtual U32 getFontHeight()    const { return mHeight; }
   virtual U32 getFontBaseLine()  const { return mBaseline; }
   virtual U32 getTexLineHeight() const { return mTexLineHeight; }
   virtual F32 getTexScale()      const { return mTextureScale; }
   virtual F32 getMetricScale()   const { return mMetricScale; }

   virtual PlatformFont::CharInfo &getCharInfo(const UTF16 ch) const;
   virtual PlatformFont::CharInfo &getCharInfo(const UTF8 *str) const;
   virtual bool create(const char *name, U32 size, U32 charset = TGE_ANSI_CHARSET);

   static StringTableEntry getCorrectName(StringTableEntry name);
   static Vector<SizeCorrection> smCorrectedSizes;
   static Vector<FontSubstitution> smSubstitutions;
};

#endif