/* -*-c++-*- */
/* osgEarth - Geospatial SDK for OpenSceneGraph
 * Copyright 2020 Pelican Mapping
 * http://osgearth.org
 *
 * osgEarth is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 */

#ifndef OSGEARTHSYMBOLOGY_STROKE_H
#define OSGEARTHSYMBOLOGY_STROKE_H 1

#include <osgEarth/Common>
#include <osgEarth/Color>
#include <osgEarth/Config>
#include <osgEarth/Units>


namespace osgEarth
{
    /**
     * Drawing parameters for a line.
     */
    class OSGEARTH_EXPORT Stroke
    {
    public:

        /** Style for rendering the end caps of a line string. */
        enum LineCapStyle
        {
            LINECAP_FLAT,   /** no endcap. the line ends at the terminal point. */
            LINECAP_SQUARE, /** endcap extends width()/2 past the terminal point and is squared off. */
            LINECAP_ROUND   /** endcap extends width()/2 past the terminal point and is rounded off. */
        };

        /** Style for rendering the joins between line segments. */
        enum LineJoinStyle
        {
            LINEJOIN_MITRE, /** outside joins form a sharp point. */
            LINEJOIN_ROUND  /** outside joins form an arc. */
        };

    public:
        Stroke();
        Stroke(float r, float g, float b, float a );
        Stroke(const Color& color );
        Stroke(const Config& conf );
        Stroke(const Stroke& rhs);

        virtual ~Stroke() { }

        /** Line color. */
        Color& color() { return _color; }
        const Color& color() const { return _color; }

        /** Capping of line ends. */
        optional<LineCapStyle>& lineCap() { return _lineCap; }
        const optional<LineCapStyle>& lineCap() const { return _lineCap; }

        /** How to render line joints in a LineString. */
        optional<LineJoinStyle>& lineJoin() { return _lineJoin; }
        const optional<LineJoinStyle>& lineJoin() const { return _lineJoin; }

        /** Line rendering width. */
        optional<float>& width() { return _width; }
        const optional<float>& width() const { return _width; }

        /** Units for the width property. (default = Units::PIXELS) */
        optional<UnitsType>& widthUnits() { return _widthUnits; }
        const optional<UnitsType>& widthUnits() const { return _widthUnits; }

        /** Minimum with of a line in pixels (default = 0.0, no minimum).
            This typically only applies to lines with map unit width, and
            tells the renderer to maintain a minimum pixel width so that 
            the geometry is always visible. */
        optional<float>& minPixels() { return _minPixels; }
        const optional<float>& minPixels() const { return _minPixels; }

        /** Stippling pattern. Bitmask of pixels to draw. */
        optional<unsigned short>& stipplePattern() { return _stipplePattern; }
        const optional<unsigned short>& stipplePattern() const { return _stipplePattern; }

        /** Stippling factor; number of times to repeat each bit in the stipplePattern. */
        optional<unsigned>& stippleFactor() { return _stippleFactor; }
        const optional<unsigned>& stippleFactor() const { return _stippleFactor; }

        /** Backwards-compatibility only */
        optional<unsigned short>& stipple() { return _stipplePattern; }
        const optional<unsigned short>& stipple() const { return _stipplePattern; }

        /** Smoothing/antialiasing */
        optional<bool>& smooth() { return _smooth; }
        const optional<bool>& smooth() const { return _smooth; }

        /** Rounding ratio - when rounding corners/caps, this is the ratio
            of rounded-segment length to width(). The smaller this value,
            the more detailed the rounding will be. (Default is 0.4) */
        optional<float>& roundingRatio() { return _roundingRatio; }
        const optional<float>& roundingRatio() const { return _roundingRatio; }

        //! Outline color
        OE_OPTION(Color, outlineColor);
        OE_OPTION(Distance, outlineWidth);

    public:
        virtual Config getConfig() const;
        virtual void mergeConfig( const Config& conf );

    protected:
        Color                    _color;
        optional<LineCapStyle>   _lineCap;
        optional<LineJoinStyle>  _lineJoin;
        optional<float>          _width;
        optional<UnitsType>      _widthUnits;
        optional<unsigned>       _stippleFactor;
        optional<unsigned short> _stipplePattern;
        optional<float>          _roundingRatio;
        optional<float>          _minPixels;
        optional<bool>           _smooth;

        void init();
    };
} // namespace osgEarth

OSGEARTH_SPECIALIZE_CONFIG(osgEarth::Stroke);

#endif // OSGEARTHSYMBOLOGY_STROKE_H