/* -*-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 <osgUtil/Optimizer>

#include <osgDB/ReadFile>
#include <osgDB/WriteFile>
#include <osgDB/Registry>

#include <osgViewer/Viewer>

#include <osg/Geode>
#include <osg/Camera>
#include <osg/ShapeDrawable>
#include <osg/Sequence>

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


osg::Group* createHUDText()
{

    osg::Group* rootNode = new osg::Group;

    osgText::Font* font = osgText::readFontFile("fonts/arial.ttf");

    osg::Geode* geode  = new osg::Geode;
    rootNode->addChild(geode);

    float windowHeight = 1024.0f;
    float windowWidth = 1280.0f;
    float margin = 50.0f;


////////////////////////////////////////////////////////////////////////////////////////////////////////
//    
// Examples of how to set up different text layout
//

    osg::Vec4 layoutColor(1.0f,1.0f,0.0f,1.0f);
    float layoutCharacterSize = 20.0f;    
    
    {
        osgText::Text* text = new osgText::Text;
        text->setFont(font);
        text->setColor(layoutColor);
        text->setCharacterSize(layoutCharacterSize);
        text->setPosition(osg::Vec3(margin,windowHeight-margin,0.0f));

        // the default layout is left to right, typically used in languages
        // originating from europe such as English, French, German, Spanish etc..
        text->setLayout(osgText::Text::LEFT_TO_RIGHT);

        text->setText("text->setLayout(osgText::Text::LEFT_TO_RIGHT);");
        geode->addDrawable(text);
    }

    {
        osgText::Text* text = new osgText::Text;
        text->setFont(font);
        text->setColor(layoutColor);
        text->setCharacterSize(layoutCharacterSize);
        text->setPosition(osg::Vec3(windowWidth-margin,windowHeight-margin,0.0f));

        // right to left layouts would be used for hebrew or arabic fonts.
        text->setLayout(osgText::Text::RIGHT_TO_LEFT);
        text->setAlignment(osgText::Text::RIGHT_BASE_LINE);

        text->setText("text->setLayout(osgText::Text::RIGHT_TO_LEFT);");
        geode->addDrawable(text);
    }

    {
        osgText::Text* text = new osgText::Text;
        text->setFont(font);
        text->setColor(layoutColor);
        text->setPosition(osg::Vec3(margin,windowHeight-margin,0.0f));
        text->setCharacterSize(layoutCharacterSize);

        // vertical font layout would be used for asian fonts.
        text->setLayout(osgText::Text::VERTICAL);

        text->setText("text->setLayout(osgText::Text::VERTICAL);");
        geode->addDrawable(text);
    }
    
    
////////////////////////////////////////////////////////////////////////////////////////////////////////
//    
// Examples of how to set up different font resolution
//

    osg::Vec4 fontSizeColor(0.0f,1.0f,1.0f,1.0f);
    float fontSizeCharacterSize = 30;
    
    osg::Vec3 cursor = osg::Vec3(margin*2,windowHeight-margin*2,0.0f);
    
    {
        osgText::Text* text = new osgText::Text;
        text->setFont(font);
        text->setColor(fontSizeColor);
        text->setCharacterSize(fontSizeCharacterSize);
        text->setPosition(cursor);
        
        // use text that uses 10 by 10 texels as a target resolution for fonts.
        text->setFontResolution(10,10); // blocky but small texture memory usage
        
        text->setText("text->setFontResolution(10,10); // blocky but small texture memory usage");
        geode->addDrawable(text);
    }
    
    cursor.y() -= fontSizeCharacterSize;
    {
        osgText::Text* text = new osgText::Text;
        text->setFont(font);
        text->setColor(fontSizeColor);
        text->setCharacterSize(fontSizeCharacterSize);
        text->setPosition(cursor);
        
        // use text that uses 20 by 20 texels as a target resolution for fonts.
        text->setFontResolution(20,20); // smoother but higher texture memory usage (but still quite low).
        
        text->setText("text->setFontResolution(20,20); // smoother but higher texture memory usage (but still quite low).");
        geode->addDrawable(text);
    }
    
    cursor.y() -= fontSizeCharacterSize;
    {
        osgText::Text* text = new osgText::Text;
        text->setFont(font);
        text->setColor(fontSizeColor);
        text->setCharacterSize(fontSizeCharacterSize);
        text->setPosition(cursor);
        
        // use text that uses 40 by 40 texels as a target resolution for fonts.
        text->setFontResolution(40,40); // even smoother but again higher texture memory usage.
        
        text->setText("text->setFontResolution(40,40); // even smoother but again higher texture memory usage.");
        geode->addDrawable(text);
    }


////////////////////////////////////////////////////////////////////////////////////////////////////////
//    
// Examples of how to set up different sized text
//

    osg::Vec4 characterSizeColor(1.0f,0.0f,1.0f,1.0f);
    
    cursor.y() -= fontSizeCharacterSize*2.0f;
    
    {
        osgText::Text* text = new osgText::Text;
        text->setFont(font);
        text->setColor(characterSizeColor);
        text->setFontResolution(20,20);
        text->setPosition(cursor);
        
        // use text that is 20 units high.
        text->setCharacterSize(20); // small
        
        text->setText("text->setCharacterSize(20.0f); // small");
        geode->addDrawable(text);
    }
    
    cursor.y() -= 30.0f;
    {
        osgText::Text* text = new osgText::Text;
        text->setFont(font);
        text->setColor(characterSizeColor);
        text->setFontResolution(30,30);
        text->setPosition(cursor);
        
        // use text that is 30 units high.
        text->setCharacterSize(30.0f); // medium
        
        text->setText("text->setCharacterSize(30.0f); // medium");
        geode->addDrawable(text);
    }
    
    cursor.y() -= 50.0f;
    {
        osgText::Text* text = new osgText::Text;
        text->setFont(font);
        text->setColor(characterSizeColor);
        text->setFontResolution(40,40);
        text->setPosition(cursor);
        
        // use text that is 60 units high.
        text->setCharacterSize(60.0f); // large
        
        text->setText("text->setCharacterSize(60.0f); // large");
        geode->addDrawable(text);
    }


////////////////////////////////////////////////////////////////////////////////////////////////////////
//    
// Examples of how to set up different alignments
//

    osg::Vec4 alignmentSizeColor(0.0f,1.0f,0.0f,1.0f);
    float alignmentCharacterSize = 25.0f;
    cursor.x() = 640;
    cursor.y() = margin*4.0f;
    
    typedef std::pair<osgText::Text::AlignmentType,std::string> AlignmentPair;
    typedef std::vector<AlignmentPair> AlignmentList;
    AlignmentList alignmentList;
    alignmentList.push_back(AlignmentPair(osgText::Text::LEFT_TOP,"text->setAlignment(\nosgText::Text::LEFT_TOP);"));
    alignmentList.push_back(AlignmentPair(osgText::Text::LEFT_CENTER,"text->setAlignment(\nosgText::Text::LEFT_CENTER);"));
    alignmentList.push_back(AlignmentPair(osgText::Text::LEFT_BOTTOM,"text->setAlignment(\nosgText::Text::LEFT_BOTTOM);"));
    alignmentList.push_back(AlignmentPair(osgText::Text::CENTER_TOP,"text->setAlignment(\nosgText::Text::CENTER_TOP);"));
    alignmentList.push_back(AlignmentPair(osgText::Text::CENTER_CENTER,"text->setAlignment(\nosgText::Text::CENTER_CENTER);"));
    alignmentList.push_back(AlignmentPair(osgText::Text::CENTER_BOTTOM,"text->setAlignment(\nosgText::Text::CENTER_BOTTOM);"));
    alignmentList.push_back(AlignmentPair(osgText::Text::RIGHT_TOP,"text->setAlignment(\nosgText::Text::RIGHT_TOP);"));
    alignmentList.push_back(AlignmentPair(osgText::Text::RIGHT_CENTER,"text->setAlignment(\nosgText::Text::RIGHT_CENTER);"));
    alignmentList.push_back(AlignmentPair(osgText::Text::RIGHT_BOTTOM,"text->setAlignment(\nosgText::Text::RIGHT_BOTTOM);"));
    alignmentList.push_back(AlignmentPair(osgText::Text::LEFT_BASE_LINE,"text->setAlignment(\nosgText::Text::LEFT_BASE_LINE);"));
    alignmentList.push_back(AlignmentPair(osgText::Text::CENTER_BASE_LINE,"text->setAlignment(\nosgText::Text::CENTER_BASE_LINE);"));
    alignmentList.push_back(AlignmentPair(osgText::Text::RIGHT_BASE_LINE,"text->setAlignment(\nosgText::Text::RIGHT_BASE_LINE);"));
    alignmentList.push_back(AlignmentPair(osgText::Text::LEFT_BOTTOM_BASE_LINE,"text->setAlignment(\nosgText::Text::LEFT_BOTTOM_BASE_LINE);"));
    alignmentList.push_back(AlignmentPair(osgText::Text::CENTER_BOTTOM_BASE_LINE,"text->setAlignment(\nosgText::Text::CENTER_BOTTOM_BASE_LINE);"));
    alignmentList.push_back(AlignmentPair(osgText::Text::RIGHT_BOTTOM_BASE_LINE,"text->setAlignment(\nosgText::Text::RIGHT_BOTTOM_BASE_LINE);"));


    osg::Sequence* sequence = new osg::Sequence;
    {
        for(AlignmentList::iterator itr=alignmentList.begin();
            itr!=alignmentList.end();
            ++itr)
        {
            osg::Geode* alignmentGeode = new osg::Geode;
            sequence->addChild(alignmentGeode);
            sequence->setTime(sequence->getNumChildren(), 1.0f);

            osgText::Text* text = new osgText::Text;
            text->setFont(font);
            text->setColor(alignmentSizeColor);
            text->setCharacterSize(alignmentCharacterSize);
            text->setPosition(cursor);
            text->setDrawMode(osgText::Text::TEXT|osgText::Text::ALIGNMENT|osgText::Text::BOUNDINGBOX);
            
            text->setAlignment(itr->first);
            text->setText(itr->second);
            
            alignmentGeode->addDrawable(text);


        }
        
    }

    sequence->setMode(osg::Sequence::START);
    sequence->setInterval(osg::Sequence::LOOP, 0, -1);
    sequence->setDuration(1.0f, -1);
    
    rootNode->addChild(sequence);


////////////////////////////////////////////////////////////////////////////////////////////////////////
//    
// Examples of how to set up different fonts...
//

    cursor.x() = margin*2.0f;
    cursor.y() = margin*2.0f;
    
    osg::Vec4 fontColor(1.0f,0.5f,0.0f,1.0f);
    float fontCharacterSize = 20.0f;
    float spacing = 40.0f;
    
    {
        osgText::Text* text = new osgText::Text;
        text->setColor(fontColor);
        text->setPosition(cursor);
        text->setCharacterSize(fontCharacterSize);
        
        text->setFont(0);
        text->setText("text->setFont(0); // inbuilt font.");
        geode->addDrawable(text);

        cursor.x() = text->getBound().xMax() + spacing ;
    }
    
    {
        osgText::Font* arial = osgText::readFontFile("fonts/arial.ttf");

        osgText::Text* text = new osgText::Text;
        text->setColor(fontColor);
        text->setPosition(cursor);
        text->setCharacterSize(fontCharacterSize);
        
        text->setFont(arial);
        text->setText(arial!=0?
                      "text->setFont(\"fonts/arial.ttf\");":
                      "unable to load \"fonts/arial.ttf\"");
        geode->addDrawable(text);

        cursor.x() = text->getBound().xMax() + spacing ;
    }
    
    {
        osgText::Font* times = osgText::readFontFile("fonts/times.ttf");

        osgText::Text* text = new osgText::Text;
        text->setColor(fontColor);
        text->setPosition(cursor);
        text->setCharacterSize(fontCharacterSize);
        
        geode->addDrawable(text);
        text->setFont(times);
        text->setText(times!=0?
                      "text->setFont(\"fonts/times.ttf\");":
                      "unable to load \"fonts/times.ttf\"");

        cursor.x() = text->getBound().xMax() + spacing ;
    }
    
    cursor.x() = margin*2.0f;
    cursor.y() = margin;

    {
        osgText::Font* dirtydoz = osgText::readFontFile("fonts/dirtydoz.ttf");

        osgText::Text* text = new osgText::Text;
        text->setColor(fontColor);
        text->setPosition(cursor);
        text->setCharacterSize(fontCharacterSize);
        
        text->setFont(dirtydoz);
        text->setText(dirtydoz!=0?
                      "text->setFont(\"fonts/dirtydoz.ttf\");":
                      "unable to load \"fonts/dirtydoz.ttf\"");
        geode->addDrawable(text);

        cursor.x() = text->getBound().xMax() + spacing ;
    }
    
    {
        osgText::Font* fudd = osgText::readFontFile("fonts/fudd.ttf");
    
        osgText::Text* text = new osgText::Text;
        text->setColor(fontColor);
        text->setPosition(cursor);
        text->setCharacterSize(fontCharacterSize);
        
        text->setFont(fudd);
        text->setText(fudd!=0?
                      "text->setFont(\"fonts/fudd.ttf\");":
                      "unable to load \"fonts/fudd.ttf\"");
        geode->addDrawable(text);

        cursor.x() = text->getBound().xMax() + spacing ;
    }
            
    return rootNode;    
}




// create text which sits in 3D space such as would be inserted into a normal model
osg::Group* create3DText(const osg::Vec3& center,float radius)
{

    osg::Geode* geode  = new osg::Geode;

////////////////////////////////////////////////////////////////////////////////////////////////////////
//    
// Examples of how to set up axis/orientation alignments
//

    float characterSize=radius*0.2f;
    
    osg::Vec3 pos(center.x()-radius*.5f,center.y()-radius*.5f,center.z()-radius*.5f);

    osgText::Text* text1 = new osgText::Text;
    text1->setFont("fonts/times.ttf");
    text1->setCharacterSize(characterSize);
    text1->setPosition(pos);
    text1->setAxisAlignment(osgText::Text::XY_PLANE);
    text1->setText("XY_PLANE");
    geode->addDrawable(text1);

    osgText::Text* text2 = new osgText::Text;
    text2->setFont("fonts/times.ttf");
    text2->setCharacterSize(characterSize);
    text2->setPosition(pos);
    text2->setAxisAlignment(osgText::Text::YZ_PLANE);
    text2->setText("YZ_PLANE");
    geode->addDrawable(text2);

    osgText::Text* text3 = new osgText::Text;
    text3->setFont("fonts/times.ttf");
    text3->setCharacterSize(characterSize);
    text3->setPosition(pos);
    text3->setAxisAlignment(osgText::Text::XZ_PLANE);
    text3->setText("XZ_PLANE");
    geode->addDrawable(text3);


    osgText::Text* text4 = new osgText::Text;
    text4->setFont("fonts/times.ttf");
    text4->setCharacterSize(characterSize);
    text4->setPosition(center);
    text4->setAxisAlignment(osgText::Text::SCREEN);

    osg::Vec4 characterSizeModeColor(1.0f,0.0f,0.5f,1.0f);

    osgText::Text* text5 = new osgText::Text;
    text5->setColor(characterSizeModeColor);
    text5->setFont("fonts/times.ttf");
    //text5->setCharacterSize(characterSize);
    text5->setCharacterSize(32.0f); // medium
    text5->setPosition(center - osg::Vec3(0.0, 0.0, 0.2));
    text5->setAxisAlignment(osgText::Text::SCREEN);
    text5->setCharacterSizeMode(osgText::Text::SCREEN_COORDS);
    text5->setText("CharacterSizeMode SCREEN_COORDS(size 32.0)");
    geode->addDrawable(text5);

    osgText::Text* text6 = new osgText::Text;
    text6->setColor(characterSizeModeColor);
    text6->setFont("fonts/times.ttf");
    text6->setCharacterSize(characterSize);
    text6->setPosition(center - osg::Vec3(0.0, 0.0, 0.4));
    text6->setAxisAlignment(osgText::Text::SCREEN);
    text6->setCharacterSizeMode(osgText::Text::OBJECT_COORDS_WITH_MAXIMUM_SCREEN_SIZE_CAPPED_BY_FONT_HEIGHT);
    text6->setText("CharacterSizeMode OBJECT_COORDS_WITH_MAXIMUM_SCREEN_SIZE_CAPPED_BY_FONT_HEIGHT");
    geode->addDrawable(text6);

    osgText::Text* text7 = new osgText::Text;
    text7->setColor(characterSizeModeColor);
    text7->setFont("fonts/times.ttf");
    text7->setCharacterSize(characterSize);
    text7->setPosition(center - osg::Vec3(0.0, 0.0, 0.6));
    text7->setAxisAlignment(osgText::Text::SCREEN);
    text7->setCharacterSizeMode(osgText::Text::OBJECT_COORDS);
    text7->setText("CharacterSizeMode OBJECT_COORDS (default)");
    geode->addDrawable(text7);

#if 1
    // reproduce outline bounding box compute problem with backdrop on.
    text4->setBackdropType(osgText::Text::OUTLINE);
    text4->setDrawMode(osgText::Text::TEXT | osgText::Text::BOUNDINGBOX);
#endif

    text4->setText("SCREEN");
    geode->addDrawable(text4);

    osg::ShapeDrawable* shape = new osg::ShapeDrawable(new osg::Sphere(center,characterSize*0.2f));
    shape->getOrCreateStateSet()->setMode(GL_LIGHTING,osg::StateAttribute::ON);
    geode->addDrawable(shape);

    osg::Group* rootNode = new osg::Group;
    rootNode->addChild(geode);

    return rootNode;    
}

int main(int , char **)
{
    // construct the viewer.
    osgViewer::Viewer viewer;

    // prepare scene.
    {
        osg::Vec3 center(0.0f,0.0f,0.0f);
        float radius = 1.0f;
        
        // make sure the root node is group so we can add extra nodes to it.
        osg::Group* group = new osg::Group;
        
        {
            // create the hud.
            osg::Camera* camera = new osg::Camera;
            camera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
            camera->setProjectionMatrixAsOrtho2D(0,1280,0,1024);
            camera->setViewMatrix(osg::Matrix::identity());
            camera->setClearMask(GL_DEPTH_BUFFER_BIT);
            camera->addChild(createHUDText());
            camera->getOrCreateStateSet()->setMode(GL_LIGHTING,osg::StateAttribute::OFF);

            group->addChild(camera);
        }

        group->addChild(create3DText(center,radius));

        // set the scene to render
        viewer.setSceneData(group);
    }

    osgDB::writeNodeFile(*viewer.getSceneData(),"text.osg");

    return viewer.run();
}

