outline_font.h

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/*
 * This program source code file is part of KICAD, a free EDA CAD application.
 *
 * Copyright (C) 2021 Ola Rinta-Koski
 * Copyright (C) 2021-2023 Kicad Developers, see AUTHORS.txt for contributors.
 *
 * Outline font class
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, you may find one here:
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * or you may search the http://www.gnu.org website for the version 2 license,
 * or you may write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
 */
 
#ifndef OUTLINE_FONT_H_
#define OUTLINE_FONT_H_
 
#include <gal/gal.h>
#include <geometry/shape_poly_set.h>
#ifdef _MSC_VER
#include <ft2build.h>
#else
#include <freetype2/ft2build.h>
#endif
#include FT_FREETYPE_H
#include FT_OUTLINE_H
 
#include <font/font.h>
#include <font/glyph.h>
#include <font/outline_decomposer.h>
#include <embedded_files.h>
 
#include <mutex>
 
namespace KIFONT
{
class GAL_API OUTLINE_FONT : public FONT
{
public:
 
 enum class EMBEDDING_PERMISSION
 {
 INSTALLABLE,
 EDITABLE,
 PRINT_PREVIEW_ONLY,
 RESTRICTED,
 INVALID
 };
 
 OUTLINE_FONT();
 
 bool IsOutline() const override { return true; }
 
 bool IsBold() const override
 {
 return m_face && ( m_fakeBold || ( m_face->style_flags & FT_STYLE_FLAG_BOLD ) );
 }
 
 bool IsItalic() const override
 {
 return m_face && ( m_fakeItal || ( m_face->style_flags & FT_STYLE_FLAG_ITALIC ) );
 }
 
 void SetFakeBold()
 {
 m_fakeBold = true;
 }
 
 void SetFakeItal()
 {
 m_fakeItal = true;
 }
 
 const wxString& GetFileName() const { return m_fontFileName; }
 
 EMBEDDING_PERMISSION GetEmbeddingPermission() const;
 
 static OUTLINE_FONT* LoadFont( const wxString& aFontFileName, bool aBold, bool aItalic,
 const std::vector<wxString>* aEmbeddedFiles );
 
 double GetInterline( double aGlyphHeight, const METRICS& aFontMetrics ) const override;
 
 VECTOR2I GetTextAsGlyphs( BOX2I* aBoundingBox, std::vector<std::unique_ptr<GLYPH>>* aGlyphs,
 const wxString& aText, const VECTOR2I& aSize,
 const VECTOR2I& aPosition, const EDA_ANGLE& aAngle, bool aMirror,
 const VECTOR2I& aOrigin, TEXT_STYLE_FLAGS aTextStyle ) const override;
 
 void GetLinesAsGlyphs( std::vector<std::unique_ptr<GLYPH>>* aGlyphs, const wxString& aText,
 const VECTOR2I& aPosition, const TEXT_ATTRIBUTES& aAttrs,
 const METRICS& aFontMetrics ) const;
 
 const FT_Face& GetFace() const { return m_face; }
 
#if 0
 void RenderToOpenGLCanvas( KIGFX::OPENGL_FREETYPE& aTarget, const wxString& aString,
 const VECTOR2D& aSize, const wxPoint& aPosition,
 const EDA_ANGLE& aAngle, bool aMirror ) const;
#endif
 
protected:
 FT_Error loadFace( const wxString& aFontFileName, int aFaceIndex );
 
 BOX2I getBoundingBox( const std::vector<std::unique_ptr<GLYPH>>& aGlyphs ) const;
 
 VECTOR2I getTextAsGlyphs( BOX2I* aBoundingBox, std::vector<std::unique_ptr<GLYPH>>* aGlyphs,
 const wxString& aText, const VECTOR2I& aSize,
 const VECTOR2I& aPosition, const EDA_ANGLE& aAngle, bool aMirror,
 const VECTOR2I& aOrigin, TEXT_STYLE_FLAGS aTextStyle ) const;
 
private:
 VECTOR2I getTextAsGlyphsUnlocked( BOX2I* aBoundingBox,
 std::vector<std::unique_ptr<GLYPH>>* aGlyphs,
 const wxString& aText, const VECTOR2I& aSize,
 const VECTOR2I& aPosition, const EDA_ANGLE& aAngle,
 bool aMirror, const VECTOR2I& aOrigin,
 TEXT_STYLE_FLAGS aTextStyle ) const;
 
private:
 // FreeType variables
 
 static std::mutex m_freeTypeMutex;
 static FT_Library m_freeType;
 FT_Face m_face;
 
 const int m_faceSize;
 bool m_fakeBold;
 bool m_fakeItal;
 
 // cache for glyphs converted to straight segments
 // key is glyph index (FT_GlyphSlot field glyph_index)
 std::map<unsigned int, std::vector<std::vector<VECTOR2D>>> m_contourCache;
 
 // The height of the KiCad stroke font is the distance between stroke endpoints for a vertical
 // line of cap-height. So the cap-height of the font is actually stroke-width taller than its
 // height.
 // Outline fonts are normally scaled on full-height (including ascenders and descenders), so we
 // need to compensate to keep them from being much smaller than their stroked counterparts.
 static constexpr double m_outlineFontSizeCompensation = 1.4;
 
 // FT_Set_Char_Size() gets character width and height specified in 1/64ths of a point
 static constexpr int m_charSizeScaler = 64;
 
 // The KiCad stroke font uses a subscript/superscript size ratio of 0.7. This ratio is also
 // commonly used in LaTeX, but fonts with designed-in subscript and superscript glyphs are more
 // likely to use 0.58.
 // For auto-generated subscript and superscript glyphs in outline fonts we split the difference
 // with 0.64.
 static constexpr double m_subscriptSuperscriptSize = 0.64;
 
 static constexpr double m_underlineOffsetScaler = -0.16;
 
 int faceSize( int aSize ) const
 {
 return aSize * m_charSizeScaler * m_outlineFontSizeCompensation;
 };
 int faceSize() const { return faceSize( m_faceSize ); }
 
 // also for superscripts
 int subscriptSize( int aSize ) const
 {
 return KiROUND( faceSize( aSize ) * m_subscriptSuperscriptSize );
 }
 int subscriptSize() const { return subscriptSize( m_faceSize ); }
 
 static constexpr double m_subscriptVerticalOffset = -0.25;
 static constexpr double m_superscriptVerticalOffset = 0.45;
};
 
} //namespace KIFONT
 
#endif // OUTLINE_FONT_H_