/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2010 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 "TextNode.h"
#include "../../src/osgText/GlyphGeometry.h"

#include <osg/PositionAttitudeTransform>
#include <osg/Geode>
#include <osgUtil/SmoothingVisitor>

#include <osg/io_utils>

using namespace osgText;

/////////////////////////////////////////////////////////////////////////////////////////
//
// Layout
//
Layout::Layout()
{
}

Layout::Layout(const Layout& layout, const osg::CopyOp& copyop):
    osg::Object(layout,copyop)
{
}

osg::ref_ptr<Layout>& Layout::getDefaultLayout()
{
    static OpenThreads::Mutex s_DefaultLayoutMutex;
    OpenThreads::ScopedLock<OpenThreads::Mutex> lock(s_DefaultLayoutMutex);

    static osg::ref_ptr<Layout> s_defaultLayout = new Layout;
    return s_defaultLayout;
}

void Layout::layout(TextNode& text) const
{
    OSG_NOTICE<<"Layout::layout"<<std::endl;

    Font* font = text.getActiveFont();
    Style* style = text.getActiveStyle();
    TextTechnique* technique = text.getTextTechnique();
    const String& str = text.getText();

    if (!text.getTextTechnique())
    {
        OSG_NOTICE<<"Warning: no TextTechnique assigned to Layout"<<std::endl;
        return;
    }

    osg::Vec3 pos(0.0f,0.0f,0.0f);
    float characterSize = text.getCharacterSize();
    osg::Vec3 size(characterSize, characterSize, 0.0);
    if (style)
    {
        size.y() = characterSize;
        size.z() = characterSize;
    }


    osgText::FontResolution resolution(32,32);
    if (style)
    {
        resolution.first = static_cast<unsigned int>(static_cast<float>(resolution.first)*style->getSampleDensity());
        resolution.second = static_cast<unsigned int>(static_cast<float>(resolution.second)*style->getSampleDensity());
    }

    float characterWidthScale = 1.0f;

    bool textIs3D = (style && style->getThicknessRatio()!=0.0);
    if (!textIs3D)
    {
        characterWidthScale = 1.0f/static_cast<float>(resolution.first);
    }

    osgText::KerningType kerningType = osgText::KERNING_DEFAULT;

    technique->start();

    unsigned int previousCharcode = 0;
    for(unsigned int i=0; i<str.size(); ++i)
    {
        unsigned int charcode = str[i];

        if (size.z()==0.0f)
        {
            osgText::Glyph* glyph = font->getGlyph(resolution, charcode);
            if (glyph)
            {
                technique->addCharacter(pos, size, glyph, style);
                pos += osg::Vec3(size.x()*(glyph->getHorizontalAdvance()*characterWidthScale), 0.0f ,0.0f);
            }
        }
        else
        {
            osgText::Glyph3D* glyph = font->getGlyph3D(charcode);
            OSG_NOTICE<<"pos = "<<pos<<", charcode="<<charcode<<", glyph="<<glyph<< std::endl;
            if (glyph)
            {
                osg::Vec3 local_scale( size );
                technique->addCharacter(pos, local_scale, glyph, style);
                pos += osg::Vec3(size.x()*glyph->getWidth(), 0.0f ,0.0f);
            }
        }

        if (previousCharcode!=0 && charcode!=0)
        {
            osg::Vec2 offset = font->getKerning(previousCharcode, charcode, kerningType);
            OSG_NOTICE<<"  offset = "<<offset<< std::endl;
            pos.x() += offset.x();
            pos.y() += offset.y();
        }

        previousCharcode = charcode;
    }

    technique->finish();
}


/////////////////////////////////////////////////////////////////////////////////////////
//
// TextTechnique
//
TextTechnique::TextTechnique():
    _textNode(0)
{
}


TextTechnique::TextTechnique(const TextTechnique& technique, const osg::CopyOp& copyop):
    osg::Object(technique, copyop),
    _textNode(0)
{
}

osg::ref_ptr<TextTechnique>& TextTechnique::getDefaultTextTechinque()
{
    static OpenThreads::Mutex s_DefaultTextTechniqueMutex;
    OpenThreads::ScopedLock<OpenThreads::Mutex> lock(s_DefaultTextTechniqueMutex);

    static osg::ref_ptr<TextTechnique> s_defaultTextTechnique = new TextTechnique;
    return s_defaultTextTechnique;
}

void TextTechnique::start()
{
    OSG_NOTICE<<"TextTechnique::start()"<<std::endl;
}

void TextTechnique::addCharacter(const osg::Vec3& position, const osg::Vec3& size, Glyph* glyph, Style* style)
{
    OSG_NOTICE<<"TextTechnique::addCharacter 2D("<<position<<", "<<size<<", "<<glyph<<", "<<style<<")"<<std::endl;
}

void TextTechnique::addCharacter(const osg::Vec3& position, const osg::Vec3& size, Glyph3D* glyph, Style* style)
{
    OSG_NOTICE<<"TextTechnique::addCharacter 3D("<<position<<", "<<size<<", "<<glyph<<", "<<style<<")"<<std::endl;

    osg::ref_ptr<osg::PositionAttitudeTransform> transform = new osg::PositionAttitudeTransform;
    transform->setPosition(position);
    transform->setAttitude(osg::Quat(osg::inDegrees(90.0),osg::Vec3d(1.0,0.0,0.0)));
    transform->setScale(size);

    osg::ref_ptr<osg::Geode> geode = new osg::Geode;

    const Bevel* bevel = style ? style->getBevel() : 0;
    bool outline = style ? style->getOutlineRatio()>0.0f : false;
    float width = style->getThicknessRatio();
    float creaseAngle = 30.0f;
    bool smooth = true;

    if (bevel)
    {
        osg::ref_ptr<osg::Geometry> glyphGeometry = osgText::computeGlyphGeometry(glyph, *bevel, width);
        osg::ref_ptr<osg::Geometry> textGeometry = osgText::computeTextGeometry(glyphGeometry.get(), *bevel, width);
        osg::ref_ptr<osg::Geometry> shellGeometry = outline ? osgText::computeShellGeometry(glyphGeometry.get(), *bevel, width) : 0;
        if (textGeometry.valid()) geode->addDrawable(textGeometry.get());
        if (shellGeometry.valid()) geode->addDrawable(shellGeometry.get());

        // create the normals
        if (smooth && textGeometry.valid())
        {
            osgUtil::SmoothingVisitor::smooth(*textGeometry, osg::DegreesToRadians(creaseAngle));
        }
    }
    else
    {
        osg::ref_ptr<osg::Geometry> textGeometry = osgText::computeTextGeometry(glyph, width);
        if (textGeometry.valid()) geode->addDrawable(textGeometry.get());

        // create the normals
        if (smooth && textGeometry.valid())
        {
            osgUtil::SmoothingVisitor::smooth(*textGeometry, osg::DegreesToRadians(creaseAngle));
        }
    }

    transform->addChild(geode.get());

    _textNode->addChild(transform.get());

    transform->getOrCreateStateSet()->setMode(GL_NORMALIZE, osg::StateAttribute::ON);

}

void TextTechnique::finish()
{
    OSG_NOTICE<<"TextTechnique::finish()"<<std::endl;
}

void TextTechnique::traverse(osg::NodeVisitor& nv)
{
    // OSG_NOTICE<<"TextTechnique::traverse()"<<std::endl;
    if (_textNode) _textNode->osg::Group::traverse(nv);
}

/////////////////////////////////////////////////////////////////////////////////////////
//
// TextNode
//
TextNode::TextNode():
        _characterSize(1.0f)
{
}


TextNode::TextNode(const TextNode& text, const osg::CopyOp& copyop):
    osg::Group(text, copyop)
{
}

TextNode::~TextNode()
{
    setTextTechnique(0);
}

void TextNode::traverse(osg::NodeVisitor& nv)
{
    if (_technique.valid())
    {
        _technique->traverse(nv);
    }
    else
    {
        Group::traverse(nv);
    }
}

void TextNode::setTextTechnique(TextTechnique* technique)
{
    if (_technique==technique) return;

    if (_technique.valid()) _technique->setTextNode(0);

    if (TextTechnique::getDefaultTextTechinque()==technique)
    {
        OSG_NOTICE<<"Warning: Attempt to assign DefaultTextTechnique() prototype to TextNode::setTextTechnique(..), assigning a clone() of it instead."<<std::endl;
        technique = new TextTechnique(*TextTechnique::getDefaultTextTechinque());
    }

    _technique = technique;

    if (_technique.valid()) _technique->setTextNode(this);
}


void TextNode::update()
{
    getActiveLayout()->layout(*this);
}

void TextNode::setText(const std::string& str)
{
    _string.set(str);
}