axmol/core/base/NinePatchImageParser.h

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 Copyright (c) 2013-2016 Chukong Technologies Inc.
 Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.

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#pragma once

#include "platform/PlatformMacros.h"
#include "math/Math.h"

NS_AX_BEGIN

class Image;
class SpriteFrame;

/**
 * A class for paring Android .9 patch image.
 * For more about Android .9 patch image format, please refer to
 * http://developer.android.com/tools/help/draw9patch.html
 *
 * The class could parse a single .9 patch image and produce the capInsets
 * as well as a sprite atlas and store all the capInsets infos in a Texture2D.
 *  Note:
 *  - Currently only PixelFormat::RGBA8 is supported.
 *  - TexturePacker Trim mode is not supported at the moment.
 */

class AX_DLL NinePatchImageParser
{
public:
    /**
     * Determines whether a filename contains ".9.png" suffix.
     * @param filename A 9-patch image name.
     *
     * @return If the filename contains ".9.png", then return true, otherwise false.
     */
    static bool isNinePatchImage(std::string_view filename);

    /**
     * Default constructor.
     *
     */
    NinePatchImageParser();

    /**
     * Instantiate a NinePatchImageParser with a Image object.
     *
     * @param image A Image object pointer.
     *
     * @return A NinePatchImageParser instance.
     */
    explicit NinePatchImageParser(Image* image);

    /**
     * Instantiate a NinePatchImageParser with a Image object and the spriteFrame info.
     * The spriteFrame contains the frame rect in the image atlas and whether it
     * is rotated or not.
     *
     * @param image A Image object pointer.
     * @param frameRect The sprite frame rect in the image atlas.
     * @param rotated Whether is sprite frame is rotated in the image atlas.
     */
    NinePatchImageParser(Image* image, const Rect& frameRect, bool rotated);

    /**
     * Change the sprite frame info.
     * It is useful when parsing multiple sprite frame with only on NinePatchImageParser.
     *
     * @param frameRect The sprite frame rect in the image atlas.
     * @param rotated Whether is sprite frame is rotated in the image atlas.
     */
    void setSpriteFrameInfo(Image* image, const Rect& frameRect, bool rotated);

    /**
     * Default destructor.
     */
    virtual ~NinePatchImageParser();

    /**
     * Parsing the image data and extract the capInsets info.
     * @return The capInsets Rect.
     */
    Rect parseCapInset() const;

private:
    enum class Direction
    {
        HORIZONTAL,
        VERTICAL
    };
    int getPixelOriginOffset(Direction direction) const;
    Vec2 parseHorizontalMargin() const;
    Vec2 parseVerticalMargin() const;
    int getFrameWidth() const;
    int getFrameHeight() const;

    Image* _image;
    Rect _imageFrame;
    bool _isRotated;
};

NS_AX_END