/* OpenSceneGraph example, osgtext.
*
*  Permission is hereby granted, free of charge, to any person obtaining a copy
*  of this software and associated documentation files (the "Software"), to deal
*  in the Software without restriction, including without limitation the rights
*  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
*  copies of the Software, and to permit persons to whom the Software is
*  furnished to do so, subject to the following conditions:
*
*  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
*  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
*  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
*  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
*  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
*  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
*  THE SOFTWARE.
*/

#include <iostream>
#include <osgDB/ReadFile>

#include <osgGA/StateSetManipulator>
#include <osgViewer/Viewer>
#include <osgViewer/ViewerEventHandlers>
#include <osgViewer/config/SingleWindow>

#include <osg/Camera>
#include <osg/MatrixTransform>

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

osgText::Text* createText(const std::string& textString, float xPosition)
{
    osgText::Text* returnValue = new osgText::Text;
    returnValue->setDataVariance(osg::Object::DYNAMIC);
    returnValue->setFont("fonts/times.ttf");
    returnValue->setCharacterSize(32.f);
    returnValue->setCharacterSizeMode(osgText::Text::SCREEN_COORDS);
    returnValue->setPosition(osg::Vec3(xPosition, -0.05, 0.0));
    returnValue->setAlignment(osgText::TextBase::CENTER_CENTER);
    returnValue->setAutoRotateToScreen(true);
    returnValue->setText(textString);

    // Note that adding a drop shadow makes text's alignment pretty far off.  This does
    // not seem to have a huge negative impact in my app, but was noticed during the copy
    // over to this demo.  Probably just an artifact of only having text in the scene?
    //returnValue->setBackdropType(osgText::Text::DROP_SHADOW_BOTTOM_RIGHT);
    return returnValue;
}

class TextWidthPrinter : public osgGA::GUIEventHandler
{
public:
    TextWidthPrinter(osgText::Text* text)
      : text_(text)
    {
    }

    virtual bool handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa)
    {
      if (ea.getEventType() == ea.KEYDOWN && ea.getKey() == 't')
      {
        // Matrix has -1 as left side as window, +1 as right side of window.  So one
        // would expect that this would be approximately 0.44 (~1/4 of screen)
        std::cout << "Text width before setText(): " << getTextWidth() << "\n";

        // Change the text string, then change it back to old text
        const osgText::String oldText = text_->getText();
        text_->setText("Anything else");
        text_->setText(oldText);

        // Demonstrate that the bounding box units are drastically different.  This appears
        // to be the actual on-screen text width, not in the model coordinates.
        std::cout << "Text width after setText(): " << getTextWidth() << "\n";
        return true;
      }
      return false;
    }

    /** Returns the bounding box's size in X coordinates */
    float getTextWidth() const
    {
      const osg::BoundingBox bb = text_->getBoundingBox();
      return bb.xMax() - bb.xMin();
    }

private:
    osgText::Text* text_;
};

int main(int argc, char** argv)
{
    osg::ArgumentParser arguments(&argc, argv);

    // construct the viewer.
    osgViewer::Viewer viewer(arguments);

    // make sure the root node is group so we can add extra nodes to it.
    osg::Group* group = new osg::Group;
    osgText::Text* testText = createText("Press 't' to test", 0.0);
    group->addChild(testText);

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

    viewer.addEventHandler(new osgGA::StateSetManipulator(viewer.getCamera()->getOrCreateStateSet()));
    viewer.addEventHandler(new osgViewer::StatsHandler());
    viewer.addEventHandler(new osgViewer::WindowSizeHandler());
    viewer.addEventHandler(new TextWidthPrinter(testText));

    int width = 800;
    int height = 600;
    viewer.setUpViewInWindow(100, 100, width, height);

    // Configure an ortho-2D projection, using -1 and +1 as bounds
    osg::Camera* camera = viewer.getCamera();
    camera->getOrCreateStateSet()->setGlobalDefaults();
    camera->setProjectionMatrixAsOrtho2D(-1.f, 1.f, -1.f, 1.f);
    camera->setProjectionResizePolicy(osg::Camera::FIXED);
    camera->setViewMatrixAsLookAt(
      osg::Vec3d(0, 0, 100),
      osg::Vec3d(0, 0, 0),
      osg::Y_AXIS);

    viewer.run();

    return 0;
}