GLImage.h

#pragma once
#include "GLType.h"
#include "GLTexture2D.h"

namespace ParaEngine
{

    typedef struct _MipmapInfo
    {
        unsigned char* address;
        int len;
        _MipmapInfo() :address(NULL), len(0) {}
    }MipmapInfo;


    class Image : public CRefCountedOne
    {
    public:
        
        Image();
        
        // config
        static bool supportsS3TC;
        static bool PNG_PREMULTIPLIED_ALPHA_ENABLED;
        static int MaxTextureSize;

    public:
        enum class Format
        {
            JPG,
            PNG,
            TIFF,
            WEBP,
            PVR,
            ETC,
            S3TC,
            ATITC,
            TGA,
            RAW_DATA,
            UNKNOWN
        };

    public:

        bool initWithImageData(const unsigned char * data, size_t dataLen);
        bool initWithRawData(const unsigned char * data, size_t dataLen, int width, int height, int bitsPerComponent, bool preMulti = false);
        bool saveToFile(const std::string &filename, bool isToRGB = true);


        float               getWidth() { return _width; }
        float               getHeight() { return _height; }

        Texture2D::PixelFormat getRenderFormat() { return _renderFormat; }

        int getNumberOfMipmaps() { return _numberOfMipmaps; }


        const char* getFilePath() const { return ""; }
        unsigned char* getData() const { return _data; }
        int getDataLen() const { return _dataLen; }
        MipmapInfo* getMipmaps() { return _mipmaps; }
        bool    isCompressed() const { return false; }
        bool    hasPremultipliedAlpha() const { return Texture2D::getPixelFormatInfoMap().at(_renderFormat).compressed; }

    protected:
        static const int MIPMAP_MAX = 16;

        Texture2D::PixelFormat _renderFormat;

        float _width;
        float _height;

        bool _hasPremultipliedAlpha;
        int _dataLen;
        unsigned char* _data;

        Format _fileType;

        int _numberOfMipmaps;
        MipmapInfo _mipmaps[MIPMAP_MAX];   // pointer to mipmap images



        bool isPng(const unsigned char * data, size_t dataLen);
        bool isEtc(const unsigned char * data, size_t dataLen);
        bool isS3TC(const unsigned char * data, size_t dataLen);
        bool isATITC(const unsigned char *data, size_t dataLen);
        bool isJpg(const unsigned char * data, size_t dataLen);
        bool isTiff(const unsigned char * data, size_t dataLen);
        bool isWebp(const unsigned char * data, size_t dataLen);
        bool isPvr(const unsigned char * data, size_t dataLen);
        Format detectFormat(const unsigned char *, size_t unpackedLen);

        bool initWithJpgData(const unsigned char* unpackedData, size_t unpackedLen);
        bool initWithPngData(const unsigned char* unpackedData, size_t unpackedLen);
        bool initWithS3TCData(const unsigned char* unpackedData, size_t unpackedLen);


        void premultipliedAlpha();


    };
}