// Copyright (C) 2016 The Qt Company Ltd.

// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only

#ifndef QOUTLINEMAPPER_P_H

#define QOUTLINEMAPPER_P_H

//

//  W A R N I N G

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

//

// This file is not part of the Qt API.  It exists purely as an

// implementation detail.  This header file may change from version to

// version without notice, or even be removed.

//

// We mean it.

//

#include <QtGui/private/qtguiglobal_p.h>

#include <QtCore/qrect.h>

#include <QtGui/qtransform.h>

#include <QtGui/qpainterpath.h>

#define QT_FT_BEGIN_HEADER

#define QT_FT_END_HEADER

#include <private/qrasterdefs_p.h>

#include <private/qdatabuffer_p.h>

#include "qpaintengineex_p.h"

QT_BEGIN_NAMESPACE

// These limitations comes from qrasterizer.cpp, qcosmeticstroker.cpp, and qgrayraster.c.

// Any higher and rasterization of shapes will produce incorrect results.

#if Q_PROCESSOR_WORDSIZE == 8

constexpr int QT_RASTER_COORD_LIMIT = ((1<<23) - 1); // F24dot8 in qgrayraster.c

#else

constexpr int QT_RASTER_COORD_LIMIT = ((1<<15) - 1); // F16dot16 in qrasterizer.cpp and qcosmeticstroker.cpp

#endif

//#define QT_DEBUG_CONVERT

Q_GUI_EXPORT bool qt_scaleForTransform(const QTransform &transform, qreal *scale);

/********************************************************************************

 * class QOutlineMapper

 *

 * Used to map between QPainterPath and the QT_FT_Outline structure used by the

 * freetype scanconverter.

 *

 * The outline mapper uses a path iterator to get points from the path,

 * so that it is possible to transform the points as they are converted. The

 * callback can be a noop, translate or full-fledged xform. (Tests indicated

 * that using a C callback was low cost).

 */

class QOutlineMapper

{

public:

    QOutlineMapper() :

        m_element_types(0),

        m_elements(0),

        m_points(0),

        m_tags(0),

        m_contours(0),

        m_in_clip_elements(false)

    {

    }

    /*!

      Sets up the matrix to be used for conversion. This also

      sets up the qt_path_iterator function that is used as a callback

      to get points.

    */

    void setMatrix(const QTransform &m)

    {

        m_transform = m;

        qreal scale;

        qt_scaleForTransform(m, &scale);

        m_curve_threshold = scale == 0 ? qreal(0.25) : (qreal(0.25) / scale);

    }

    void setClipRect(QRect clipRect);

    void beginOutline(Qt::FillRule fillRule)

    {

#ifdef QT_DEBUG_CONVERT

        printf("QOutlineMapper::beginOutline rule=%d\n", fillRule);

#endif

        m_valid = true;

        m_elements.reset();

        m_element_types.reset();

        m_points.reset();

        m_tags.reset();

        m_contours.reset();

        m_outline.flags = fillRule == Qt::WindingFill

                          ? QT_FT_OUTLINE_NONE

                          : QT_FT_OUTLINE_EVEN_ODD_FILL;

        m_subpath_start = 0;

    }

    void endOutline();

    void clipElements(const QPointF *points, const QPainterPath::ElementType *types, int count);

    void convertElements(const QPointF *points, const QPainterPath::ElementType *types, int count);

    inline void moveTo(const QPointF &pt) {

#ifdef QT_DEBUG_CONVERT

        printf("QOutlineMapper::moveTo() (%f, %f)\n", pt.x(), pt.y());

#endif

        closeSubpath();

        m_subpath_start = m_elements.size();

        m_elements << pt;

        m_element_types << QPainterPath::MoveToElement;

    }

    inline void lineTo(const QPointF &pt) {

#ifdef QT_DEBUG_CONVERT

        printf("QOutlineMapper::lineTo() (%f, %f)\n", pt.x(), pt.y());

#endif

        m_elements.add(pt);

        m_element_types << QPainterPath::LineToElement;

    }

    void curveTo(const QPointF &cp1, const QPointF &cp2, const QPointF &ep);

    inline void closeSubpath() {

        int element_count = m_elements.size();

        if (element_count > 0) {

            if (m_elements.at(element_count-1) != m_elements.at(m_subpath_start)) {

#ifdef QT_DEBUG_CONVERT

                printf(" - implicitly closing\n");

#endif

                // Put the object on the stack to avoid the odd case where

                // lineTo reallocs the databuffer and the QPointF & will

                // be invalidated.

                QPointF pt = m_elements.at(m_subpath_start);

                // only do lineTo if we have element_type array...

                if (m_element_types.size())

                    lineTo(pt);

                else

                    m_elements << pt;

            }

        }

    }

    QT_FT_Outline *outline() {

        if (m_valid)

            return &m_outline;

        return nullptr;

    }

    QT_FT_Outline *convertPath(const QPainterPath &path);

    QT_FT_Outline *convertPath(const QVectorPath &path);

    inline QPainterPath::ElementType *elementTypes() const { return m_element_types.size() == 0 ? nullptr : m_element_types.data(); }

public:

    QDataBuffer<QPainterPath::ElementType> m_element_types;

    QDataBuffer<QPointF> m_elements;

    QDataBuffer<QT_FT_Vector> m_points;

    QDataBuffer<char> m_tags;

    QDataBuffer<int> m_contours;

    QRect m_clip_rect;

    QRectF m_clip_trigger_rect;

    QRectF controlPointRect; // only valid after endOutline()

    QT_FT_Outline m_outline;

    int m_subpath_start;

    QTransform m_transform;

    qreal m_curve_threshold;

    bool m_valid;

    bool m_in_clip_elements;

};

QT_END_NAMESPACE

#endif // QOUTLINEMAPPER_P_H