/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
 *
 * This library is open source and may be redistributed and/or modified under
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 *
 * This library 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
 * OpenSceneGraph Public License for more details.
*/

#ifndef OSG_IMAGE
#define OSG_IMAGE 1

#include <osg/BufferObject>
#include <osg/Vec2>
#include <osg/Vec3>
#include <osg/Vec4>
#include <osg/FrameStamp>
#include <osg/StateAttribute>

#include <string>
#include <vector>

#ifndef GL_VERSION_1_2
    // 1.2 definitions...
    #define GL_BGR                          0x80E0
    #define GL_BGRA                         0x80E1
    #define GL_UNSIGNED_BYTE_3_3_2          0x8032
    #define GL_UNSIGNED_BYTE_2_3_3_REV      0x8362
    #define GL_UNSIGNED_SHORT_5_6_5         0x8363
    #define GL_UNSIGNED_SHORT_5_6_5_REV     0x8364
    #define GL_UNSIGNED_SHORT_4_4_4_4       0x8033
    #define GL_UNSIGNED_SHORT_4_4_4_4_REV   0x8365
    #define GL_UNSIGNED_SHORT_5_5_5_1       0x8034
    #define GL_UNSIGNED_SHORT_1_5_5_5_REV   0x8366
    #define GL_UNSIGNED_INT_8_8_8_8         0x8035
    #define GL_UNSIGNED_INT_8_8_8_8_REV     0x8367
    #define GL_UNSIGNED_INT_10_10_10_2      0x8036
    #define GL_UNSIGNED_INT_2_10_10_10_REV  0x8368
#endif

#ifndef GL_COMPRESSED_ALPHA
    #define GL_COMPRESSED_ALPHA             0x84E9
    #define GL_COMPRESSED_LUMINANCE         0x84EA
    #define GL_COMPRESSED_LUMINANCE_ALPHA   0x84EB
    #define GL_COMPRESSED_INTENSITY         0x84EC
    #define GL_COMPRESSED_RGB               0x84ED
    #define GL_COMPRESSED_RGBA              0x84EE
#endif


#ifndef GL_ABGR_EXT
#define GL_ABGR_EXT                         0x8000
#endif

#if defined(OSG_GLES1_AVAILABLE) || defined(OSG_GLES2_AVAILABLE)
    #define GL_RED                  0x1903
    #define GL_GREEN                0x1904
    #define GL_BLUE                 0x1905
    #define GL_DEPTH_COMPONENT      0x1902
    #define GL_STENCIL_INDEX        0x1901
#endif

#if defined(OSG_GLES1_AVAILABLE) || defined(OSG_GLES2_AVAILABLE) || defined(OSG_GL3_AVAILABLE)
    #define GL_BITMAP               0x1A00
    #define GL_COLOR_INDEX          0x1900
    #define GL_INTENSITY12          0x804C
    #define GL_INTENSITY16          0x804D
    #define GL_INTENSITY4           0x804A
    #define GL_INTENSITY8           0x804B
    #define GL_LUMINANCE12          0x8041
    #define GL_LUMINANCE12_ALPHA4   0x8046
    #define GL_LUMINANCE12_ALPHA12  0x8047
    #define GL_LUMINANCE16          0x8042
    #define GL_LUMINANCE16_ALPHA16  0x8048
    #define GL_LUMINANCE4           0x803F
    #define GL_LUMINANCE4_ALPHA4    0x8043
    #define GL_LUMINANCE6_ALPHA2    0x8044
    #define GL_LUMINANCE8           0x8040
    #define GL_LUMINANCE8_ALPHA8    0x8045
    #define GL_RGBA8                0x8058
    #define GL_RGBA16               0x805B
    #define GL_PACK_ROW_LENGTH      0x0D02
#endif

#ifndef GL_PACK_SKIP_IMAGES
    #define GL_PACK_SKIP_IMAGES     0x806B
    #define GL_PACK_IMAGE_HEIGHT    0x806C
    #define GL_UNPACK_SKIP_IMAGES   0x806D
    #define GL_UNPACK_IMAGE_HEIGHT  0x806E
#endif

#ifndef GL_OES_compressed_ETC1_RGB8_texture
    #define GL_ETC1_RGB8_OES        0x8D64
#endif

#ifndef GL_DEPTH_COMPONENT
#define GL_DEPTH_COMPONENT              0x1902
#endif

#ifndef GL_VERSION_1_4
#define GL_DEPTH_COMPONENT16              0x81A5
#define GL_DEPTH_COMPONENT24              0x81A6
#define GL_DEPTH_COMPONENT32              0x81A7
#endif

#ifndef GL_DEPTH_COMPONENT32F
#define GL_DEPTH_COMPONENT32F             0x8CAC
#endif

#ifndef GL_DEPTH_COMPONENT32F_NV
#define GL_DEPTH_COMPONENT32F_NV          0x8DAB
#endif

namespace osg {

// forward declare
class NodeVisitor;

/** Image class for encapsulating the storage texture image data. */
class OSG_EXPORT Image : public BufferData
{

    public :

        Image();

        /** Copy constructor using CopyOp to manage deep vs shallow copy. */
        Image(const Image& image,const CopyOp& copyop=CopyOp::SHALLOW_COPY);

        virtual Object* cloneType() const { return new Image(); }
        virtual Object* clone(const CopyOp& copyop) const { return new Image(*this,copyop); }
        virtual bool isSameKindAs(const Object* obj) const { return dynamic_cast<const Image*>(obj)!=0; }
        virtual const char* libraryName() const { return "osg"; }
        virtual const char* className() const { return "Image"; }

        virtual osg::Image* asImage() { return this; }
        virtual const osg::Image* asImage() const { return this; }

        virtual const GLvoid*   getDataPointer() const { return data(); }
        virtual unsigned int    getTotalDataSize() const { return getTotalSizeInBytesIncludingMipmaps(); }

        /** Return -1 if *this < *rhs, 0 if *this==*rhs, 1 if *this>*rhs. */
        virtual int compare(const Image& rhs) const;

        void setFileName(const std::string& fileName);
        inline const std::string& getFileName() const { return _fileName; }

        enum WriteHint {
            NO_PREFERENCE,
            STORE_INLINE,
            EXTERNAL_FILE
        };

        void setWriteHint(WriteHint writeHint) { _writeHint = writeHint; }
        WriteHint getWriteHint() const { return _writeHint; }

        enum AllocationMode {
            NO_DELETE,
            USE_NEW_DELETE,
            USE_MALLOC_FREE
        };

        /** Set the method used for deleting data once it goes out of scope. */
        void setAllocationMode(AllocationMode mode) { _allocationMode = mode; }

        /** Get the method used for deleting data once it goes out of scope. */
        AllocationMode getAllocationMode() const { return _allocationMode; }


        /** Allocate a pixel block of specified size and type. */
        virtual void allocateImage(int s,int t,int r,
                           GLenum pixelFormat,GLenum type,
                           int packing=1);


        /** Set the image dimensions, format and data. */
        virtual void setImage(int s,int t,int r,
                      GLint internalTextureformat,
                      GLenum pixelFormat,GLenum type,
                      unsigned char* data,
                      AllocationMode mode,
                      int packing=1, int rowLength=0);

        /** Read pixels from current frame buffer at specified position and size, using glReadPixels.
          * Create memory for storage if required, reuse existing pixel coords if possible.
        */
        virtual void readPixels(int x,int y,int width,int height,
                        GLenum pixelFormat, GLenum type, int packing=1);


        /** Read the contents of the current bound texture, handling compressed pixelFormats if present.
          * Create memory for storage if required, reuse existing pixel coords if possible.
        */
        virtual void readImageFromCurrentTexture(unsigned int contextID, bool copyMipMapsIfAvailable, GLenum type = GL_UNSIGNED_BYTE, unsigned int face = 0);

        /** swap the data and settings between two image objects.*/
        void swap(osg::Image& rhs);

        /** Scale image to specified size. */
        void scaleImage(int s,int t,int r) { scaleImage(s,t,r, getDataType()); }

        /** Scale image to specified size and with specified data type. */
        virtual void scaleImage(int s,int t,int r, GLenum newDataType);

        /** Copy a source Image into a subpart of this Image at specified position.
          * Typically used to copy to an already allocated image, such as creating
          * a 3D image from a stack 2D images.
          * If this Image is empty then image data is created to
          * accomodate the source image in its offset position.
          * If source is NULL then no operation happens, this Image is left unchanged.
        */
        virtual void copySubImage(int s_offset, int t_offset, int r_offset, const osg::Image* source);


        enum Origin
        {
            BOTTOM_LEFT,
            TOP_LEFT
        };

        /** Set the origin of the image.
          * The default value is BOTTOM_LEFT and is consistent with OpenGL.
          * TOP_LEFT is used for imagery that follows standard Imagery convention, such as movies,
          * and hasn't been flipped yet.  For such images one much flip the t axis of the tex coords.
          * to handle this origin position. */
        void setOrigin(Origin origin) { _origin = origin; }

        /** Get the origin of the image.*/
        Origin getOrigin() const { return _origin; }


        /** Width of image. */
        inline int s() const { return _s; }

        /** Height of image. */
        inline int t() const { return _t; }

        /** Depth of image. */
        inline int r() const { return _r; }

        void setRowLength(int length);
        inline int getRowLength() const { return _rowLength; }

        void setInternalTextureFormat(GLint internalFormat);
        inline GLint getInternalTextureFormat() const { return _internalTextureFormat; }

        void setPixelFormat(GLenum pixelFormat);
        inline GLenum getPixelFormat() const { return _pixelFormat; }

        void setDataType(GLenum dataType);
        inline GLenum getDataType() const { return _dataType; }

        void setPacking(unsigned int packing) { _packing = packing; }
        inline unsigned int getPacking() const { return _packing; }

        /** Return true of the pixel format is an OpenGL compressed pixel format.*/
        bool isCompressed() const;

        /** Set the pixel aspect ratio, defined as the pixel width divided by the pixel height.*/
        inline void setPixelAspectRatio(float pixelAspectRatio) { _pixelAspectRatio = pixelAspectRatio; }

        /** Get the pixel aspect ratio.*/
        inline float getPixelAspectRatio() const { return _pixelAspectRatio; }

        /** Return the number of bits required for each pixel. */
        inline unsigned int getPixelSizeInBits() const { return computePixelSizeInBits(_pixelFormat,_dataType); }

        /** Return the number of bytes each row of pixels occupies once it has been packed. */
        inline unsigned int getRowSizeInBytes() const { return computeRowWidthInBytes(_s,_pixelFormat,_dataType,_packing); }

        /** Return the number of bytes between each successive row.
          * Note, getRowSizeInBytes() will only equal getRowStepInBytes() when isDataContiguous() return true. */
        inline unsigned int getRowStepInBytes() const { return computeRowWidthInBytes(_rowLength==0?_s:_rowLength,_pixelFormat,_dataType,_packing); }

        /** Return the number of bytes each image (_s*_t) of pixels occupies. */
        inline unsigned int getImageSizeInBytes() const { return getRowSizeInBytes()*_t; }

        /** Return the number of bytes between each successive image.
          * Note, getImageSizeInBytes() will only equal getImageStepInBytes() when isDataContiguous() return true. */
        inline unsigned int getImageStepInBytes() const { return getRowStepInBytes()*_t; }

        /** Return the number of bytes the whole row/image/volume of pixels occupies. */
        inline unsigned int getTotalSizeInBytes() const { return getImageSizeInBytes()*_r; }

        /** Return the number of bytes the whole row/image/volume of pixels occupies, including all mip maps if included. */
        unsigned int getTotalSizeInBytesIncludingMipmaps() const;

        /** Return true if the Image represent a valid and usable imagery.*/
        bool valid() const { return _s!=0 && _t!=0 && _r!=0 && _data!=0 && _dataType!=0; }

        /** Raw image data.
          * Note, data in successive rows may not be contiguous, isDataContiguous() return false then you should
          * take care to access the data per row rather than treating the whole data as a single block. */
        inline unsigned char* data() { return _data; }

        /** Raw const image data.
          * Note, data in successive rows may not be contiguous, isDataContiguous() return false then you should
          * take care to access the data per row rather than treating the whole data as a single block. */
        inline const unsigned char* data() const { return _data; }

        inline unsigned char* data(int column, int row=0,int image=0)
        {
            if (!_data) return NULL;
            return _data+(column*getPixelSizeInBits())/8+row*getRowStepInBytes()+image*getImageSizeInBytes();
        }

        inline const unsigned char* data(int column, int row=0,int image=0) const
        {
            if (!_data) return NULL;
            return _data+(column*getPixelSizeInBits())/8+row*getRowStepInBytes()+image*getImageSizeInBytes();
        }

        /** return true if the data stored in the image is a contiguous block of data.*/
        bool isDataContiguous() const { return _rowLength==0 || _rowLength==_s; }

        /** Convenience class for assisting the copying of image data when the image data isn't contiguous.*/
        class OSG_EXPORT DataIterator
        {
        public:
            DataIterator(const Image* image);
            DataIterator(const DataIterator& ri);
            ~DataIterator() {}

            /** advance iterator to next block of data.*/
            void operator ++ ();

            /** is iterator valid.*/
            bool valid() const { return _currentPtr!=0; }

            /** data pointer of current block to copy.*/
            const unsigned char* data() const { return _currentPtr; }

            /** Size of current block to copy.*/
            unsigned int size() const { return _currentSize; }

        protected:


            void assign();

            const osg::Image*                   _image;
            int                                 _rowNum;
            int                                 _imageNum;
            unsigned int                        _mipmapNum;
            const unsigned char*                _currentPtr;
            unsigned int                        _currentSize;
        };

        /** Get the color value for specified texcoord.*/
        Vec4 getColor(unsigned int s,unsigned t=0,unsigned r=0) const;

        /** Get the color value for specified texcoord.*/
        Vec4 getColor(const Vec2& texcoord) const { return getColor(Vec3(texcoord.x(),texcoord.y(),0.0f)); }

        /** Get the color value for specified texcoord.*/
        Vec4 getColor(const Vec3& texcoord) const;


        /** Flip the image horizontally, around s dimension. */
        void flipHorizontal();

        /** Flip the image vertically, around t dimension. */
        void flipVertical();

        /** Flip the image around the r dimension. Only relevent for 3D textures. */
        void flipDepth();

        /** Ensure image dimensions are a power of two.
          * Mipmapped textures require the image dimensions to be
          * power of two and are within the maxiumum texture size for
          * the host machine.
        */
        void ensureValidSizeForTexturing(GLint maxTextureSize);

        static bool isPackedType(GLenum type);
        static GLenum computePixelFormat(GLenum pixelFormat);
        static GLenum computeFormatDataType(GLenum pixelFormat);
        static unsigned int computeBlockSize(GLenum pixelFormat, GLenum packing);
        static unsigned int computeNumComponents(GLenum pixelFormat);
        static unsigned int computePixelSizeInBits(GLenum pixelFormat,GLenum type);
        static unsigned int computeRowWidthInBytes(int width,GLenum pixelFormat,GLenum type,int packing);
        static unsigned int computeImageSizeInBytes(int width,int height, int depth, GLenum pixelFormat, GLenum type, int packing = 1, int slice_packing = 1, int image_packing = 1);
        static int computeNearestPowerOfTwo(int s,float bias=0.5f);
        static int computeNumberOfMipmapLevels(int s,int t = 1, int r = 1);

        /** Precomputed mipmaps stuff. */
        typedef std::vector< unsigned int > MipmapDataType;

        inline bool isMipmap() const {return !_mipmapData.empty();};

        unsigned int getNumMipmapLevels() const
        {
            return static_cast<unsigned int>(_mipmapData.size())+1;
        };

        /** Send offsets into data. It is assumed that first mipmap offset (index 0) is 0.*/
        inline void setMipmapLevels(const MipmapDataType& mipmapDataVector) { _mipmapData = mipmapDataVector; }

        inline const MipmapDataType& getMipmapLevels() const { return _mipmapData; }

        inline unsigned int getMipmapOffset(unsigned int mipmapLevel) const
        {
            if(mipmapLevel == 0)
                return 0;
            else if (mipmapLevel < getNumMipmapLevels())
               return _mipmapData[mipmapLevel-1];
            return 0;
        };

        inline unsigned char* getMipmapData(unsigned int mipmapLevel)
        {
           return _data+getMipmapOffset(mipmapLevel);
        }

        inline const unsigned char* getMipmapData(unsigned int mipmapLevel) const
        {
           return _data+getMipmapOffset(mipmapLevel);
        }

        /** returns false for texture formats that do not support texture subloading */
        bool supportsTextureSubloading() const;

        /** Return true if this image is translucent - i.e. it has alpha values that are less 1.0 (when normalized). */
        virtual bool isImageTranslucent() const;

        /** Set the optional PixelBufferObject used to map the image memory efficiently to graphics memory. */
        void setPixelBufferObject(PixelBufferObject* buffer) { setBufferObject(buffer); }

        /** Get the PixelBufferObject.*/
        PixelBufferObject* getPixelBufferObject() { return dynamic_cast<PixelBufferObject*>(getBufferObject()); }

        /** Get the const PixelBufferObject.*/
        const PixelBufferObject* getPixelBufferObject() const { return dynamic_cast<const PixelBufferObject*>(getBufferObject()); }

        /** Return whether the update(NodeVisitor* nv) should be required on each frame to enable proper working of osg::Image.*/
        virtual bool requiresUpdateCall() const { return false; }

        /** update method for osg::Image subclasses that update themselves during the update traversal.*/
        virtual void update(NodeVisitor* /*nv*/) {}

        /** Convenience update callback class that can be attached to a StateAttribute (such as Textures) to ensure
          * that the Image::update(NodeVisitor*) method is called during the update traversal.  This callback
          * is automatically attached when Image::requiresUpdateCall() is true (it's false by default.)
          */
        struct OSG_EXPORT UpdateCallback : public osg::StateAttributeCallback
        {
            virtual void operator () (osg::StateAttribute* attr, osg::NodeVisitor* nv);
        };

        /** Hint whether to enable or disable focus to images acting as front ends to interactive surfaces such as a vnc or browser window.  Return true if handled. */
        virtual bool sendFocusHint(bool /*focus*/) { return false; }

        /** Send pointer events to images that are acting as front ends to interactive surfaces such as a vnc or browser window.  Return true if handled. */
        virtual bool sendPointerEvent(int /*x*/, int /*y*/, int /*buttonMask*/) { return false; }

        /** Send key events to images that are acting as front ends to interactive surfaces such as a vnc or browser window.  Return true if handled.*/
        virtual bool sendKeyEvent(int /*key*/, bool /*keyDown*/) { return false; }

        /** Pass frame information to the custom Image classes, to be called only when objects associated with imagery are not culled.*/
        virtual void setFrameLastRendered(const osg::FrameStamp* /*frameStamp*/) {}
        
        class DimensionsChangedCallback : public osg::Referenced {
        public:
            DimensionsChangedCallback() : osg::Referenced() {}
            virtual void operator()(osg::Image* image) = 0;
        };
        
        typedef std::vector< osg::ref_ptr<DimensionsChangedCallback> > DimensionsChangedCallbackVector;
        
        void addDimensionsChangedCallback(DimensionsChangedCallback* cb);
        void removeDimensionsChangedCallback(DimensionsChangedCallback* cb);

    protected :

        virtual ~Image();

        Image& operator = (const Image&) { return *this; }
        
        void handleDimensionsChangedCallbacks() 
        {
            for(DimensionsChangedCallbackVector::iterator i = _dimensionsChangedCallbacks.begin(); i != _dimensionsChangedCallbacks.end(); ++i)
            {
                (*i)->operator()(this);
            }
        }

        std::string _fileName;
        WriteHint   _writeHint;

        Origin _origin;

        int _s, _t, _r;
        int _rowLength;
        GLint _internalTextureFormat;
        GLenum _pixelFormat;
        GLenum _dataType;
        unsigned int _packing;
        float _pixelAspectRatio;

        AllocationMode _allocationMode;
        unsigned char* _data;

        void deallocateData();

        void setData(unsigned char* data,AllocationMode allocationMode);

        MipmapDataType _mipmapData;
        
        DimensionsChangedCallbackVector _dimensionsChangedCallbacks;
};

class Geode;

/** Convenience function to be used by image loaders to generate a valid geode
  * to return for readNode().
  * Use the image's s and t values to scale the dimensions of the image.
*/
extern OSG_EXPORT Geode* createGeodeForImage(Image* image);
/** Convenience function to be used by image loaders to generate a valid geode
  * to return for readNode().
  * Use the specified s and t values to scale the dimensions of the image.
*/
extern OSG_EXPORT Geode* createGeodeForImage(Image* image,float s,float t);

}

#endif                                            // __SG_IMAGE_H
