Layout-TNG-Scanline-Maker.h

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Inkscape::Text::Layout::ScanlineMaker - text layout engine shape measurers
 *
 * Authors:
 *   Richard Hughes <cyreve@users.sf.net>
 *
 * Copyright (C) 2005 Richard Hughes
 *
 * Released under GNU GPL v2+, read the file 'COPYING' for more information.
 */
#ifndef LAYOUT_TNG_SCANLINE_MAKER_H
#define LAYOUT_TNG_SCANLINE_MAKER_H
 
#include <vector>
#include <cmath>
#include "libnrtype/Layout-TNG.h"
 
class Shape;
 
namespace Inkscape {
namespace Text {
 
class Layout::ScanlineMaker
{
public:
    virtual ~ScanlineMaker() = default;
 
    struct ScanRun
    {
        double y;  
        double x_start;    // these are not flipped according to the text direction
        double x_end;
        inline double width() const {return std::abs(x_start - x_end);}
    };
 
    virtual std::vector<ScanRun> makeScanline(Layout::FontMetrics const &line_height) = 0;
 
    virtual void completeLine() = 0;
 
    virtual double yCoordinate() = 0;
    
    virtual void setNewYCoordinate(double new_y) = 0;
 
    virtual bool canExtendCurrentScanline(Layout::FontMetrics const &line_height) = 0;
 
    virtual void setLineHeight(Layout::FontMetrics const &line_height) = 0;
};
 
class Layout::InfiniteScanlineMaker : public Layout::ScanlineMaker
{
public:
    InfiniteScanlineMaker(double initial_x, double initial_y, Layout::Direction block_progression);
    ~InfiniteScanlineMaker() override;
 
    std::vector<ScanRun> makeScanline(Layout::FontMetrics const &line_height) override;
 
    void completeLine() override;
 
    double yCoordinate() override { return _y; }
 
    void setNewYCoordinate(double new_y) override;
 
    bool canExtendCurrentScanline(Layout::FontMetrics const &line_height) override;
 
    void setLineHeight(Layout::FontMetrics const &line_height) override;
 
private:
    double _x, _y;
    Layout::FontMetrics _current_line_height;
    bool _negative_block_progression;     
};
 
class Layout::ShapeScanlineMaker : public Layout::ScanlineMaker
{
public:
    ShapeScanlineMaker(Shape const *shape, Layout::Direction block_progression);
    ~ShapeScanlineMaker() override;
 
    std::vector<ScanRun> makeScanline(Layout::FontMetrics const &line_height) override;
 
    void completeLine() override;
 
    double yCoordinate() override;
 
    void setNewYCoordinate(double new_y) override;
 
    bool canExtendCurrentScanline(Layout::FontMetrics const &line_height) override;
 
    void setLineHeight(Layout::FontMetrics const &line_height) override;
 
private:
    Shape *_rotated_shape;
 
    bool _shape_needs_freeing;
 
    // Shape::BeginRaster() needs floats rather than doubles
    float _bounding_box_top, _bounding_box_bottom;
    float _y;
    float _rasterizer_y;
    int _current_rasterization_point;
    float _current_line_height;
 
    bool _negative_block_progression;     
};
 
} // namespace Text
} // namespace Inkscape
 
#endif // LAYOUT_TNG_SCANLINE_MAKER_H
 
/*
  Local Variables:
  mode:c++
  c-file-style:"stroustrup"
  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
  indent-tabs-mode:nil
  fill-column:99
  End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :