/* -*-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.
*/

#include <osgText/Font>
#include <osgText/Text>

#include <osg/State>
#include <osg/Notify>
#include <osg/GLU>

#include <osgUtil/SmoothingVisitor>

#include <string.h>
#include <stdlib.h>

#include "GlyphGeometry.h"

using namespace osgText;
using namespace std;

GlyphTexture::GlyphTexture():
    _margin(1),
    _marginRatio(0.02f),
    _usedY(0),
    _partUsedX(0),
    _partUsedY(0)
{
    setWrap(WRAP_S, CLAMP_TO_EDGE);
    setWrap(WRAP_T, CLAMP_TO_EDGE);
}

GlyphTexture::~GlyphTexture() 
{
}

// return -1 if *this < *rhs, 0 if *this==*rhs, 1 if *this>*rhs.
int GlyphTexture::compare(const osg::StateAttribute& rhs) const
{
    if (this<&rhs) return -1;
    else if (this>&rhs) return 1;
    return 0;
}


bool GlyphTexture::getSpaceForGlyph(Glyph* glyph, int& posX, int& posY)
{
    int maxAxis = std::max(glyph->s(), glyph->t());
    int margin = _margin + (int)((float)maxAxis * _marginRatio);
    
    int width = glyph->s()+2*margin;
    int height = glyph->t()+2*margin;

    // first check box (_partUsedX,_usedY) to (width,height)
    if (width <= (getTextureWidth()-_partUsedX) &&
        height <= (getTextureHeight()-_usedY))
    {
        // can fit in existing row.

        // record the position in which the texture will be stored.
        posX = _partUsedX+margin;
        posY = _usedY+margin;        

        // move used markers on.
        _partUsedX += width;
        if (_usedY+height>_partUsedY) _partUsedY = _usedY+height;
        
        return true;
    }
    
    // start an new row.
    if (width <= getTextureWidth() &&
        height <= (getTextureHeight()-_partUsedY))
    {
        // can fit next row.
        _partUsedX = 0;
        _usedY = _partUsedY;

        posX = _partUsedX+margin;
        posY = _usedY+margin;        

        // move used markers on.
        _partUsedX += width;
        if (_usedY+height>_partUsedY) _partUsedY = _usedY+height;
        
        return true;
    }

    // doesn't fit into glyph.
    return false;
}

void GlyphTexture::addGlyph(Glyph* glyph, int posX, int posY)
{
    OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_mutex);

    _glyphs.push_back(glyph);
    for(unsigned int i=0;i<_glyphsToSubload.size();++i)
    {
        _glyphsToSubload[i].push_back(glyph);
    }

    // set up the details of where to place glyph's image in the texture.
    glyph->setTexture(this);
    glyph->setTexturePosition(posX,posY);

    glyph->setMinTexCoord( osg::Vec2( static_cast<float>(posX)/static_cast<float>(getTextureWidth()),
                                      static_cast<float>(posY)/static_cast<float>(getTextureHeight()) ) );
    glyph->setMaxTexCoord( osg::Vec2( static_cast<float>(posX+glyph->s())/static_cast<float>(getTextureWidth()),
                                      static_cast<float>(posY+glyph->t())/static_cast<float>(getTextureHeight()) ) );
}

void GlyphTexture::apply(osg::State& state) const
{
    // get the contextID (user defined ID of 0 upwards) for the 
    // current OpenGL context.
    const unsigned int contextID = state.getContextID();

    if (contextID>=_glyphsToSubload.size())
    {
        OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_mutex);

        // graphics context is beyond the number of glyphsToSubloads, so
        // we must now copy the glyph list across, this is a potential
        // threading issue though is multiple applies are happening the
        // same time on this object - to avoid this condition number of
        // graphics contexts should be set before create text.
        for(unsigned int i=_glyphsToSubload.size();i<=contextID;++i)
        {
            GlyphPtrList& glyphPtrs = _glyphsToSubload[i];
            for(GlyphRefList::const_iterator itr=_glyphs.begin();
                itr!=_glyphs.end();
                ++itr)
            {
                glyphPtrs.push_back(itr->get());
            }
        }
    }


    const Extensions* extensions = getExtensions(contextID,true);
    bool generateMipMapSupported = extensions->isGenerateMipMapSupported();

    // get the texture object for the current contextID.
    TextureObject* textureObject = getTextureObject(contextID);
    
    bool newTextureObject = (textureObject == 0);

    if (newTextureObject)
    {
        GLint maxTextureSize = 256;
        glGetIntegerv(GL_MAX_TEXTURE_SIZE, &maxTextureSize);
        if (maxTextureSize < getTextureWidth() || maxTextureSize < getTextureHeight())
        {
            OSG_WARN<<"Warning: osgText::Font texture size of ("<<getTextureWidth()<<", "<<getTextureHeight()<<") too large, unable to create font texture."<<std::endl;
            OSG_WARN<<"         Maximum supported by hardward by native OpenGL implementation is ("<<maxTextureSize<<","<<maxTextureSize<<")."<<std::endl;
            OSG_WARN<<"         Please set OSG_MAX_TEXTURE_SIZE lenvironment variable to "<<maxTextureSize<<" and re-run application."<<std::endl;
            return;
        }
        
        // being bound for the first time, need to allocate the texture

        _textureObjectBuffer[contextID] = textureObject = osg::Texture::generateTextureObject(
                this, contextID,GL_TEXTURE_2D,1,GL_ALPHA,getTextureWidth(), getTextureHeight(),1,0);

        textureObject->bind();


        applyTexParameters(GL_TEXTURE_2D,state);

        
        // need to look at generate mip map extension if mip mapping required.
        switch(_min_filter)
        {
        case NEAREST_MIPMAP_NEAREST:
        case NEAREST_MIPMAP_LINEAR:
        case LINEAR_MIPMAP_NEAREST:
        case LINEAR_MIPMAP_LINEAR:
            if (generateMipMapSupported)
            {
                glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP_SGIS,GL_TRUE);
            }
            else glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, LINEAR);
            break;
        default:
            // not mip mapping so no problems.
            break;
        }
        
        unsigned int imageDataSize = getTextureHeight()*getTextureWidth();
        unsigned char* imageData = new unsigned char[imageDataSize];
        for(unsigned int i=0; i<imageDataSize; ++i)
        {
            imageData[i] = 0;
        }
        

//        OSG_NOTICE<<"Texture width = "<<getTextureWidth()<<std::endl;
//        OSG_NOTICE<<"Texture height = "<<getTextureHeight()<<std::endl;
               
        // allocate the texture memory.
        glTexImage2D( GL_TEXTURE_2D, 0, GL_ALPHA,
                getTextureWidth(), getTextureHeight(), 0,
                GL_ALPHA,
                GL_UNSIGNED_BYTE,
                imageData );
                
        delete [] imageData;
    
    }
    else
    {
        // reuse texture by binding.
        textureObject->bind();
        
        if (getTextureParameterDirty(contextID))
        {
            applyTexParameters(GL_TEXTURE_2D,state);
        }


    }
    
    static const GLubyte* s_renderer = 0;
    static bool s_subloadAllGlyphsTogether = false;
    if (!s_renderer)
    {
        OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_mutex);

        s_renderer = glGetString(GL_RENDERER);
        OSG_INFO<<"glGetString(GL_RENDERER)=="<<s_renderer<<std::endl;
        if (s_renderer && strstr((const char*)s_renderer,"IMPACT")!=0)
        {
            // we're running on an Octane, so need to work around its
            // subloading bugs by loading all at once.
            s_subloadAllGlyphsTogether = true;
        }
        
        if (s_renderer && 
            ((strstr((const char*)s_renderer,"Radeon")!=0) || 
            (strstr((const char*)s_renderer,"RADEON")!=0) ||
            (strstr((const char*)s_renderer,"ALL-IN-WONDER")!=0)))
        {
            // we're running on an ATI, so need to work around its
            // subloading bugs by loading all at once.
            s_subloadAllGlyphsTogether = true;
        }

        if (s_renderer && strstr((const char*)s_renderer,"Sun")!=0)
        {
            // we're running on an solaris x server, so need to work around its
            // subloading bugs by loading all at once.
            s_subloadAllGlyphsTogether = true;
        }

        const char* str = getenv("OSG_TEXT_INCREMENTAL_SUBLOADING");
        if (str)
        {
            s_subloadAllGlyphsTogether = strcmp(str,"OFF")==0 || strcmp(str,"Off")==0 || strcmp(str,"off")==0;
        }
    }


    // now subload the glyphs that are outstanding for this graphics context.
    GlyphPtrList& glyphsWereSubloading = _glyphsToSubload[contextID];

    if (!glyphsWereSubloading.empty() || newTextureObject)
    {
        OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_mutex);

        if (!s_subloadAllGlyphsTogether)
        {
            if (newTextureObject)
            {
                for(GlyphRefList::const_iterator itr=_glyphs.begin();
                    itr!=_glyphs.end();
                    ++itr)
                {
                    (*itr)->subload();
                }
            }
            else // just subload the new entries.
            {            
                // default way of subloading as required.
                //std::cout<<"subloading"<<std::endl;
                for(GlyphPtrList::iterator itr=glyphsWereSubloading.begin();
                    itr!=glyphsWereSubloading.end();
                    ++itr)
                {
                    (*itr)->subload();
                }
            }
            
            // clear the list since we have now subloaded them.
            glyphsWereSubloading.clear();
            
        }
        else
        {
            OSG_INFO<<"osgText::Font loading all glyphs as a single subload."<<std::endl;

            // Octane has bugs in OGL driver which mean that subloads smaller
            // than 32x32 produce errors, and also cannot handle general alignment,
            // so to get round this copy all glyphs into a temporary image and
            // then subload the whole lot in one go.

            int tsize = getTextureHeight() * getTextureWidth();
            unsigned char *local_data = new unsigned char[tsize];
            memset( local_data, 0L, tsize);

            for(GlyphRefList::const_iterator itr=_glyphs.begin();
                itr!=_glyphs.end();
                ++itr)
            {
                //(*itr)->subload();

                // Rather than subloading to graphics, we'll write the values
                // of the glyphs into some intermediate data and subload the
                // whole thing at the end
                for( int t = 0; t < (*itr)->t(); t++ )
                {
                    for( int s = 0; s < (*itr)->s(); s++ )
                    {
                        int sindex = (t*(*itr)->s()+s);
                        int dindex =  
                            ((((*itr)->getTexturePositionY()+t) * getTextureWidth()) +
                            ((*itr)->getTexturePositionX()+s));

                        const unsigned char *sptr = &(*itr)->data()[sindex];
                        unsigned char *dptr       = &local_data[dindex];

                        (*dptr)   = (*sptr);
                    }
                }
            }

            // clear the list since we have now subloaded them.
            glyphsWereSubloading.clear();

            // Subload the image once
            glTexSubImage2D( GL_TEXTURE_2D, 0, 0, 0, 
                    getTextureWidth(),
                    getTextureHeight(),
                    GL_ALPHA, GL_UNSIGNED_BYTE, local_data );

            delete [] local_data;

        }
    }
    else
    {
//        OSG_INFO << "no need to subload "<<std::endl;
    }



//     if (generateMipMapTurnedOn)
//     {
//         glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP_SGIS,GL_FALSE);
//     }


}

void GlyphTexture::setThreadSafeRefUnref(bool threadSafe)
{
    osg::Texture2D::setThreadSafeRefUnref(threadSafe);
}

void GlyphTexture::resizeGLObjectBuffers(unsigned int maxSize)
{
    osg::Texture2D::resizeGLObjectBuffers(maxSize);
    _glyphsToSubload.resize(maxSize);
}


// all the methods in Font::Glyph have been made non inline because VisualStudio6.0 is STUPID, STUPID, STUPID PILE OF JUNK.
Glyph::Glyph(Font* font, unsigned int glyphCode):
    _font(font),
    _glyphCode(glyphCode),
    _horizontalBearing(0.0f,0.f),
    _horizontalAdvance(0.f),
    _verticalBearing(0.0f,0.f),
    _verticalAdvance(0.f),
    _texture(0),
    _texturePosX(0),
    _texturePosY(0),
    _minTexCoord(0.0f,0.0f),
    _maxTexCoord(0.0f,0.0f)
{
    setThreadSafeRefUnref(true);
}

Glyph::~Glyph()
{
}

void Glyph::setHorizontalBearing(const osg::Vec2& bearing) {  _horizontalBearing=bearing; }
const osg::Vec2& Glyph::getHorizontalBearing() const { return _horizontalBearing; }

void Glyph::setHorizontalAdvance(float advance) { _horizontalAdvance=advance; }
float Glyph::getHorizontalAdvance() const { return _horizontalAdvance; }

void Glyph::setVerticalBearing(const osg::Vec2& bearing) {  _verticalBearing=bearing; }
const osg::Vec2& Glyph::getVerticalBearing() const { return _verticalBearing; }

void Glyph::setVerticalAdvance(float advance) {  _verticalAdvance=advance; }
float Glyph::getVerticalAdvance() const { return _verticalAdvance; }

void Glyph::setTexture(GlyphTexture* texture) { _texture = texture; }
GlyphTexture* Glyph::getTexture() { return _texture; }
const GlyphTexture* Glyph::getTexture() const { return _texture; }

void Glyph::setTexturePosition(int posX,int posY) { _texturePosX = posX; _texturePosY = posY; }
int Glyph::getTexturePositionX() const { return _texturePosX; }
int Glyph::getTexturePositionY() const { return _texturePosY; }

void Glyph::setMinTexCoord(const osg::Vec2& coord) { _minTexCoord=coord; }
const osg::Vec2& Glyph::getMinTexCoord() const { return _minTexCoord; }

void Glyph::setMaxTexCoord(const osg::Vec2& coord) { _maxTexCoord=coord; }
const osg::Vec2& Glyph::getMaxTexCoord() const { return _maxTexCoord; }

void Glyph::subload() const
{
    GLenum errorNo = glGetError();
    if (errorNo!=GL_NO_ERROR)
    {
        const GLubyte* msg = osg::gluErrorString(errorNo);
        if (msg) { OSG_WARN<<"before Glyph::subload(): detected OpenGL error: "<<msg<<std::endl; }
        else  { OSG_WARN<<"before Glyph::subload(): detected OpenGL error number: "<<errorNo<<std::endl; }
    }

    if(s() <= 0 || t() <= 0)
    {
        OSG_INFO<<"Glyph::subload(): texture sub-image width and/or height of 0, ignoring operation."<<std::endl;
        return;
    }

    glPixelStorei(GL_UNPACK_ALIGNMENT,getPacking());

    glTexSubImage2D(GL_TEXTURE_2D,0,
                    _texturePosX,_texturePosY,
                    s(),t(),
                    (GLenum)getPixelFormat(),
                    (GLenum)getDataType(),
                    data());
                    
    errorNo = glGetError();
    if (errorNo!=GL_NO_ERROR)
    {


        const GLubyte* msg = osg::gluErrorString(errorNo);
        if (msg) { OSG_WARN<<"after Glyph::subload() : detected OpenGL error: "<<msg<<std::endl; }
        else { OSG_WARN<<"after Glyph::subload() : detected OpenGL error number: "<<errorNo<<std::endl; }

        OSG_WARN<< "\tglTexSubImage2D(0x"<<hex<<GL_TEXTURE_2D<<dec<<" ,"<<0<<"\t"<<std::endl<<
                                 "\t                "<<_texturePosX<<" ,"<<_texturePosY<<std::endl<<
                                 "\t                "<<s()<<" ,"<<t()<<std::endl<<hex<<
                                 "\t                0x"<<(GLenum)getPixelFormat()<<std::endl<<
                                 "\t                0x"<<(GLenum)getDataType()<<std::endl<<
                                 "\t                0x"<<(unsigned long)data()<<");"<<dec<<std::endl;
    }                    
}

Glyph3D::Glyph3D(Font* font, unsigned int glyphCode):
    osg::Referenced(true),
    _font(font),
    _glyphCode(glyphCode),
    _horizontalBearing(0,0),
    _horizontalAdvance(0),
    _verticalBearing(0,0),
    _verticalAdvance(0)
    {}

void Glyph3D::setThreadSafeRefUnref(bool threadSafe)
{
    GlyphGeometries _glyphGeometries;
    for(GlyphGeometries::iterator itr = _glyphGeometries.begin();
        itr != _glyphGeometries.end();
        ++itr)
    {
        (*itr)->setThreadSafeRefUnref(threadSafe);
    }
}

GlyphGeometry* Glyph3D::getGlyphGeometry(const Style* style)
{

    for(GlyphGeometries::iterator itr = _glyphGeometries.begin();
        itr != _glyphGeometries.end();
        ++itr)
    {
        GlyphGeometry* glyphGeometry = itr->get();
        if (glyphGeometry->match(style))
        {
            OSG_INFO<<"Glyph3D::getGlyphGeometry(Style* style) found matching GlyphGeometry."<<std::endl;
            return glyphGeometry;
        }
    }

    OSG_INFO<<"Glyph3D::getGlyphGeometry(Style* style) could not find matching GlyphGeometry, creating a new one."<<std::endl;

    osg::ref_ptr<GlyphGeometry> glyphGeometry = new GlyphGeometry();
    glyphGeometry->setup(this, style);
    _glyphGeometries.push_back(glyphGeometry);

    return glyphGeometry.get();
}


GlyphGeometry::GlyphGeometry()
{
}

void GlyphGeometry::setThreadSafeRefUnref(bool threadSafe)
{
    if (_geode.valid()) _geode->setThreadSafeRefUnref(threadSafe);
}

void GlyphGeometry::setup(const Glyph3D* glyph, const Style* style)
{
    float creaseAngle = 30.0f;
    bool smooth = true;
    osg::ref_ptr<osg::Geometry> shellGeometry;

    if (!style)
    {
        OSG_INFO<<"GlyphGeometry::setup(const Glyph* glyph, NULL) creating default glyph geometry."<<std::endl;

        float width = 0.1f;

        _geometry = osgText::computeTextGeometry(glyph, width);
    }
    else
    {
        OSG_INFO<<"GlyphGeometry::setup(const Glyph* glyph, NULL) create glyph geometry with custom Style."<<std::endl;

        // record the style
        _style = dynamic_cast<Style*>(style->clone(osg::CopyOp::DEEP_COPY_ALL));

        const Bevel* bevel = style ? style->getBevel() : 0;
        bool outline = style ? style->getOutlineRatio()>0.0f : false;
        float width = style->getThicknessRatio();

        if (bevel)
        {
            float thickness = bevel->getBevelThickness();

            osg::ref_ptr<osg::Geometry> glyphGeometry = osgText::computeGlyphGeometry(glyph, thickness, width);

            _geometry = osgText::computeTextGeometry(glyphGeometry.get(), *bevel, width);
            shellGeometry = outline ? osgText::computeShellGeometry(glyphGeometry.get(), *bevel, width) : 0;
        }
        else
        {
            _geometry = osgText::computeTextGeometry(glyph, width);
        }
    }

    if (!_geometry)
    {
        OSG_INFO<<"Warning: GlyphGeometry::setup(const Glyph* glyph, const Style* style) failed."<<std::endl;
        return;
    }

    _geode = new osg::Geode;
    _geode->addDrawable(_geometry.get());
    if (shellGeometry.valid()) _geode->addDrawable(shellGeometry.get());

    // create the normals
    if (smooth)
    {
        osgUtil::SmoothingVisitor::smooth(*_geometry, osg::DegreesToRadians(creaseAngle));
    }

    _vertices = dynamic_cast<osg::Vec3Array*>(_geometry->getVertexArray());
    _normals = dynamic_cast<osg::Vec3Array*>(_geometry->getNormalArray());

    for(osg::Geometry::PrimitiveSetList::iterator itr = _geometry->getPrimitiveSetList().begin();
        itr != _geometry->getPrimitiveSetList().end();
        ++itr)
    {
        osg::PrimitiveSet* prim = itr->get();
        if (prim->getName()=="front") _frontPrimitiveSetList.push_back(prim);
        else if (prim->getName()=="back") _backPrimitiveSetList.push_back(prim);
        else if (prim->getName()=="wall") _wallPrimitiveSetList.push_back(prim);
    }
}

bool GlyphGeometry::match(const Style* style) const
{
    if (_style == style) return true;
    if (!_style || !style) return false;

    return (*_style==*style);
}