kicad/include/font/outline_font.h

157 lines
5.8 KiB
C++

/*
* This program source code file is part of KICAD, a free EDA CAD application.
*
* Copyright (C) 2021 Ola Rinta-Koski
* Copyright (C) 2021-2022 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/graphics_abstraction_layer.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 <gal/opengl/opengl_freetype.h>
#include <harfbuzz/hb.h>
#include <font/font.h>
#include <font/glyph.h>
#include <font/outline_decomposer.h>
namespace KIFONT
{
/**
* Class OUTLINE_FONT implements outline font drawing.
*/
class OUTLINE_FONT : public FONT
{
public:
OUTLINE_FONT();
static wxString FreeTypeVersion();
bool IsOutline() const override { return true; }
bool IsBold() const override
{
return m_face && ( m_face->style_flags & FT_STYLE_FLAG_BOLD );
}
bool IsItalic() const override
{
return m_face && ( m_face->style_flags & FT_STYLE_FLAG_ITALIC );
}
/**
* Load an outline font. TrueType (.ttf) and OpenType (.otf) are supported.
* @param aFontFileName is the (platform-specific) fully qualified name of the font file
*/
static OUTLINE_FONT* LoadFont( const wxString& aFontFileName, bool aBold, bool aItalic );
/**
* Compute the vertical position of an overbar. This is the distance between the text
* baseline and the overbar.
*/
double ComputeOverbarVerticalPosition( double aGlyphHeight ) const override;
/**
* Compute the distance (interline) between 2 lines of text (for multiline texts). This is
* the distance between baselines, not the space between line bounding boxes.
*/
double GetInterline( double aGlyphHeight = 0.0, double aLineSpacing = 1.0 ) 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;
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 );
BOX2I getBoundingBox( const std::vector<std::unique_ptr<GLYPH>>& aGlyphs ) const;
private:
// FreeType variables
static FT_Library m_freeType;
FT_Face m_face;
const int m_faceSize;
// cache for glyphs converted to straight segments
// key is glyph index (FT_GlyphSlot field glyph_index)
std::map<unsigned int, GLYPH_POINTS_LIST> 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;
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;
static constexpr double m_overbarOffsetRatio = 0.02;
static constexpr double m_overbarThicknessRatio = 0.08;
};
} //namespace KIFONT
#endif // OUTLINE_FONT_H_