DtTextLayout.h

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/*****************************************************************************
 * Copyright (c) 2021 MAK Technologies, Inc.
 * All rights reserved.
 *****************************************************************************/


#pragma once

#include <vrvGraphics/vrvGraphics.h>
#include <vrvGraphics/DtTextLayoutInterface.h>
#include <vrvUtil/DtUnicode.h>

struct hb_buffer_t;
struct hb_font_t;
struct hb_glyph_position_t;
struct hb_glyph_info_t;

namespace makVrv
{
   class DtFreeTypeFace;
   class DtBoundingBox;

   class DT_DLL_VRVGRAPHICS DtTextLayout : public DtTextLayoutInterface
   {
   public:
      class HarfBuzzShaper
      {
      public:
         HarfBuzzShaper();

         virtual ~HarfBuzzShaper();

         void setFont(const DtFontSP& f);

         void layoutText(const DtUnicode& string);

         hb_glyph_position_t *getGlyphPositions(unsigned int* glyph_count) const;

         hb_glyph_info_t* getGlyphInfos(unsigned int* glyph_count) const;

      protected:
         hb_font_t* myHarfBuzzFont;
         hb_buffer_t *myHarfBuzzBuffer;
      };

   public:
      DtTextLayout();

      virtual ~DtTextLayout();

      DtTextLayout(
         const DtTextLayout &other) = delete;

      DtTextLayout &operator=(
         const DtTextLayout &other) = delete;

      virtual void renderText(DtTexturedGlyphRenderer*, const DtTextProxy*, DtFontSP, const DtBoundingBox&);

      virtual DtUnicode bidiFix(const DtUnicode&) const;

      virtual Dt2dPoint calculateGlyphSize(const DtFontSP& font, const DtPen& pen, 
         const DtUnicode& string, unsigned int pos = 0, int len = -1) const;
      
      virtual DtBoundingBox calculateBoundingBox(const DtFontSP& font, const DtPen& pen, 
         const DtUnicode& string, unsigned int pos = 0, int len = -1) const;

      virtual bool isShaped(void) const{ return true; }

      virtual void layoutRightToLeft(const DtTextProxy*, DtFontSP, const DtBoundingBox&);
      virtual void layoutLeftToRight(const DtTextProxy*, DtFontSP, const DtBoundingBox&);

   protected:
      virtual bool renderCharacter(DtGlyphRenderer& renderer, 
         DtPen& pen, const DtFontSP& font, const unsigned int& character);

      virtual void renderLayout(DtTexturedGlyphRenderer*, const DtTextProxy*, DtFontSP, const DtBoundingBox&);

   protected:
      HarfBuzzShaper myShaper;

      std::vector<std::string> myFontFilePaths;
      unsigned int myPointSize;
      DtUnicode myLastStringRendered;
      DtUnicode myRenderedText;

      struct CharacterInformation
      {
         CharacterInformation() : advance(0.0f), offset(0.0f), glyphIndex(0), changeColor(false), glyphDefined(true) 
         {
            color[0] = color[1] = color[2] = color[3] = 1.0;
         };
         CharacterInformation(const CharacterInformation& orig) :
         advance(orig.advance), offset(orig.offset), glyphIndex(orig.glyphIndex), changeColor(orig.changeColor),
         glyphDefined(orig.glyphDefined) { memcpy(color, orig.color, sizeof(color)); };

         float color[4];
         Dt2dPoint advance;
         Dt2dPoint offset;
         unsigned short glyphIndex;
         bool changeColor;
         bool glyphDefined;
      };

      struct LineInformation
      {
         LineInformation() : margin(0.0f), alignment(0) {}
         LineInformation(const LineInformation& orig) :
         margin(orig.margin), alignment(orig.alignment), characters(orig.characters) {};

         float margin;
         unsigned int alignment;
         std::vector<CharacterInformation> characters;
      };

      typedef std::vector<LineInformation> Lines;
      Lines myLines;

      double myLineLength;
      bool myRightToLeftLayout;
   };
}