/* osgVisual test. distortionNG, experimental.
*
*  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 "extViewer.h"
#include "distortionNG.h"

#include <osg/PolygonOffset>
#include <osg/Texture2D>
#include <osg/TextureRectangle>
#include <osg/TexMat>
#include <osg/ComputeBoundsVisitor>
#include <osg/Vec2>

#include <osgDB/ReadFile>
#include <osgDB/FileUtils>

#include <osgUtil/SmoothingVisitor>

#include "DistortionManipulator.h"

extViewer::extViewer() : Viewer()
{
}

extViewer::extViewer(osg::ArgumentParser& arguments) : Viewer(arguments)
{
	// Add help for command-line options here
    arguments.getApplicationUsage()->addCommandLineOption("--distort","load distortion file and set up geometrical distortion for viewer. This includes blending");
    arguments.getApplicationUsage()->addCommandLineOption("--blend","Set up viewer vor simple blending CullDrawThreadPerContext threading model for viewer.");

	osgDB::Registry::instance()->addFileExtensionAlias("dist", "osgt");
}

extViewer::extViewer(const osgViewer::Viewer& viewer, const osg::CopyOp& copyop) : Viewer(viewer, copyop)
{

}

extViewer::~extViewer()
{

}

static osg::Geometry* createMesh(const osg::Vec3& origin, const osg::Vec3& widthVector, const osg::Vec3& heightVector, unsigned int columns, unsigned int rows, const osg::Matrix& projectorMatrix)
{
	// Create Quad to render on
	osg::ref_ptr<osg::Geometry> geom = new osg::Geometry;

	geom->setUseDisplayList( false );

	osg::Vec3 xAxis(widthVector);
    float width = widthVector.length();
    xAxis /= width;

    osg::Vec3 yAxis(heightVector);
    float height = heightVector.length();
    yAxis /= height;

	osg::Vec3 dx = xAxis*(width/((float)(columns-1)));
    osg::Vec3 dy = yAxis*(height/((float)(rows-1)));


	// Create vertices and coordinates
	osg::Vec3Array* vertices = new osg::Vec3Array;
    osg::Vec2Array* texcoords0 = new osg::Vec2Array;
    osg::Vec4Array* colors = new osg::Vec4Array;

	geom->getOrCreateStateSet()->setMode(GL_CULL_FACE, osg::StateAttribute::OFF | osg::StateAttribute::PROTECTED);

	for ( unsigned int row=0; row<rows; row++ )
	{
		for ( unsigned int col=0; col<columns; col++ )
		{
			// Create coordinates of the mesh node (geometry).
			vertices->push_back( origin+dy*row+dx*col );

			// Create tex coordinates
			osg::Vec2 texcoord = osg::Vec2((float)col/(float)(columns-1), (float)row/(float)(rows-1));

			// Set Coordinates for RTT-Texture (scene rendering)
			texcoords0->push_back( texcoord );

			// Set Color of the mesh node
			colors->push_back(osg::Vec4(1.0f,1.0f,1.0f,1.0f));
		}
	}

	// Pass the created vertex array to the points geometry object.
	geom->setUseVertexBufferObjects( true );
	geom->setVertexArray(vertices);

	geom->setColorArray(colors);
    geom->setColorBinding(osg::Geometry::BIND_PER_VERTEX);

    geom->setTexCoordArray(0,texcoords0);

	// Quads grid
	for ( unsigned int row=0; row<rows-1; row++ )	// each strip consists of two affected vertex rows, so we need only row-1 strips.
	{
		osg::ref_ptr<osg::DrawElementsUInt> de = new osg::DrawElementsUInt(osg::PrimitiveSet::QUAD_STRIP, columns*2);	// columns*2 = number of involved vertices for this strip.
		for ( unsigned int col=0; col<columns; col++ )
		{
			(*de)[col*2 + 0] = row*columns + col;
			(*de)[col*2 + 1] = (row+1)*columns + col;
		}
		geom->addPrimitiveSet( de.get() );
	}

	//// Triangle grid
	//for ( unsigned int row=0; row<rows-1; row++ )	// each strip consists of two affected vertex rows, so we need only row-1 strips.
	//{
	//	osg::ref_ptr<osg::DrawElementsUInt> de = new osg::DrawElementsUInt(osg::PrimitiveSet::TRIANGLE_STRIP, columns * 2 );	
	//	for ( unsigned int col=0; col<columns; col++ )
	//	{
	//		(*de)[col*2 + 0] = row*columns + col;
	//		(*de)[col*2 + 1] = (row+1)*columns + col;
	//	}
	//	geom->addPrimitiveSet( de.get() );
	//}

	return geom.release();
}


void extViewer::setUpViewForManualDistortion(unsigned int screenNum, osg::Image* intensityMap, const osg::Matrixd& projectorMatrix)
{
	OSG_INFO<<"View::setUpViewForManualDistortion(sn="<<screenNum<<")"<<std::endl;

	// Create DistortionSet
	_distortionSet = new osgViewer::DistortionSet();
	_distortionSet->setIntensityMap( intensityMap );
	_distortionSet->setDistortionMeshRows( 20 );
	_distortionSet->setDistortionMeshColumns( 20 );




    osg::GraphicsContext::WindowingSystemInterface* wsi = osg::GraphicsContext::getWindowingSystemInterface();
    if (!wsi)
    {
        OSG_NOTICE<<"Error, no WindowSystemInterface available, cannot create windows."<<std::endl;
        return;
    }

	osg::GraphicsContext::ScreenIdentifier si;
    si.readDISPLAY();

    // displayNum has not been set so reset it to 0.
    if (si.displayNum<0) si.displayNum = 0;

    si.screenNum = screenNum;

    unsigned int width, height;
    wsi->getScreenResolution(si, width, height);

	osg::ref_ptr<osg::GraphicsContext::Traits> traits = new osg::GraphicsContext::Traits;
    traits->hostName = si.hostName;
    traits->displayNum = si.displayNum;
    traits->screenNum = si.screenNum;
    traits->x = 0;
    traits->y = 0;
    traits->width = width;
    traits->height = height;
    traits->windowDecoration = false;
    traits->doubleBuffer = true;
    traits->sharedContext = 0;

	osg::ref_ptr<osg::GraphicsContext> gc = osg::GraphicsContext::createGraphicsContext(traits.get());
    if (!gc)
    {
        OSG_NOTICE<<"GraphicsWindow has not been created successfully."<<std::endl;
        return;
    }

	// Set up projection Matrix as it is done in View::setUpViewOnSingleScreen(
	double fovy, aspectRatio, zNear, zFar;
	_camera->getProjectionMatrixAsPerspective(fovy, aspectRatio, zNear, zFar);

	double newAspectRatio = double(traits->width) / double(traits->height);
	double aspectRatioChange = newAspectRatio / aspectRatio;
	if (aspectRatioChange != 1.0)
	{
		_camera->getProjectionMatrix() *= osg::Matrix::scale(1.0/aspectRatioChange,1.0,1.0);
	}


    int tex_width = width;
    int tex_height = height;

    int camera_width = tex_width;
    int camera_height = tex_height;

    osg::TextureRectangle* sceneTexture = new osg::TextureRectangle;

    sceneTexture->setTextureSize(tex_width, tex_height);
    sceneTexture->setInternalFormat(GL_RGB);
    sceneTexture->setFilter(osg::Texture::MIN_FILTER,osg::Texture::LINEAR);
    sceneTexture->setFilter(osg::Texture::MAG_FILTER,osg::Texture::LINEAR);
    sceneTexture->setWrap(osg::Texture::WRAP_S,osg::Texture::CLAMP_TO_EDGE);
    sceneTexture->setWrap(osg::Texture::WRAP_T,osg::Texture::CLAMP_TO_EDGE);


#if 0
    osg::Camera::RenderTargetImplementation renderTargetImplementation = osg::Camera::SEPERATE_WINDOW;
    GLenum buffer = GL_FRONT;
#else
    osg::Camera::RenderTargetImplementation renderTargetImplementation = osg::Camera::FRAME_BUFFER_OBJECT;
    GLenum buffer = GL_FRONT;
#endif

	// Scene camera
    {
        osg::ref_ptr<osg::Camera> camera = new osg::Camera;
        camera->setName("Scene cam");
        camera->setGraphicsContext(gc.get());
        camera->setViewport(new osg::Viewport(0,0,camera_width, camera_height));
        camera->setDrawBuffer(buffer);
        camera->setReadBuffer(buffer);
        camera->setAllowEventFocus(false);
        // tell the camera to use OpenGL frame buffer object where supported.
        camera->setRenderTargetImplementation(renderTargetImplementation);
        // attach the texture and use it as the color buffer.
        camera->attach(osg::Camera::COLOR_BUFFER, sceneTexture);

        addSlave(camera.get(), osg::Matrixd(), osg::Matrixd());
    }

    // distortion correction set up.
    {
		osg::Geode* geode = new osg::Geode();

		// new we need to add the scene texture to the mesh, we do so by creating a
        // StateSet to contain the Texture StateAttribute.
	    osg::StateSet* stateset = geode->getOrCreateStateSet();
        stateset->setTextureAttributeAndModes(_distortionSet->getTexUnitScene(), sceneTexture,osg::StateAttribute::ON);
        stateset->setMode(GL_LIGHTING,osg::StateAttribute::OFF);

		osg::TexMat* texmat = new osg::TexMat;
	    texmat->setScaleByTextureRectangleSize(true);
        stateset->setTextureAttributeAndModes(0, texmat, osg::StateAttribute::ON);

		setUpIntensityMapBlending(_distortionSet, stateset, screenNum);

		osg::Geometry* distortionMesh = createMesh(osg::Vec3(0.0f,0.0f,0.0f), osg::Vec3(width,0.0f,0.0f), osg::Vec3(0.0f,height,0.0f), 20, 20, projectorMatrix);
		geode->addDrawable(distortionMesh);

        osg::ref_ptr<osg::Camera> camera = new osg::Camera;
        camera->setGraphicsContext(gc.get());
        camera->setClearMask(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT );
        camera->setClearColor( osg::Vec4(0.0,0.0,0.0,1.0) );
        camera->setViewport(new osg::Viewport(0, 0, width, height));
        GLenum buffer = traits->doubleBuffer ? GL_BACK : GL_FRONT;
        camera->setDrawBuffer(buffer);
        camera->setReadBuffer(buffer);
        camera->setReferenceFrame(osg::Camera::ABSOLUTE_RF);
        camera->setAllowEventFocus(false);
        camera->setInheritanceMask(camera->getInheritanceMask() & ~osg::CullSettings::CLEAR_COLOR & ~osg::CullSettings::COMPUTE_NEAR_FAR_MODE);
        //camera->setComputeNearFarMode(osg::CullSettings::DO_NOT_COMPUTE_NEAR_FAR);

        camera->setProjectionMatrixAsOrtho2D(0,width,0,height);
        camera->setViewMatrix(osg::Matrix::identity());

		// selector
		geode->getOrCreateStateSet()->setMode( GL_LIGHTING, osg::StateAttribute::OFF );
		geode->getOrCreateStateSet()->setAttributeAndModes( new osg::PolygonOffset(1.0f, 1.0f) );
		osg::ref_ptr<distortionHandler> selectorHandler = new distortionHandler( camera, distortionMesh );
		osg::ref_ptr<osg::Group> root = new osg::Group;
		root->addChild(geode);
		osg::Geode* selectorHighlighter = selectorHandler->createVertexHighlighter();
		selectorHighlighter->setCullingActive(false);	// disable the culling for the selector, otherwise the selector is culled away on the edge.
		root->addChild(selectorHighlighter);
		addEventHandler( selectorHandler.get() );
		camera->addChild(root);
		// Avoid that the highlighter is culled away
		osg::CullSettings::CullingMode mode = camera->getCullingMode();
		camera->setCullingMode( mode & (~osg::CullSettings::SMALL_FEATURE_CULLING) );

		// Add the distortionHandler
		osgViewer::DistortionManipulator* distManip = new osgViewer::DistortionManipulator();
		distManip->setDistortionSet(_distortionSet);
		addEventHandler(distManip);


        camera->setName("Dist Cam");

        addSlave(camera.get(), osg::Matrixd(), osg::Matrixd(), false);
    }
}

void extViewer::setUpIntensityMapBlending(osgViewer::DistortionSet* distSet, osg::StateSet* stateset, unsigned int screenNum)
{
	osg::Image* intensityMap = _distortionSet->getIntensityMap();
	if(intensityMap == NULL)	return;

	if(stateset == NULL)
	{
		OSG_NOTICE<<"Error, no intensityMap or stateset for intensityMapBlending specified."<<std::endl;
		return;
	}

	osg::GraphicsContext::WindowingSystemInterface* wsi = osg::GraphicsContext::getWindowingSystemInterface();
    if (!wsi)
    {
        OSG_NOTICE<<"Error, no WindowSystemInterface available, cannot create windows."<<std::endl;
        return;
    }

	osg::GraphicsContext::ScreenIdentifier si;
    si.readDISPLAY();

    // displayNum has not been set so reset it to 0.
    if (si.displayNum<0) si.displayNum = 0;

    si.screenNum = screenNum;

    unsigned int width, height;
    wsi->getScreenResolution(si, width, height);

	// Resize intensityMap if the dimensions are wrong
	if(intensityMap->s()!=width || intensityMap->t()!=height)
		intensityMap->scaleImage(width, height, intensityMap->r());

	osg::TextureRectangle* intensityMapTexture = new osg::TextureRectangle(intensityMap);
	intensityMapTexture->setFilter(osg::Texture::MIN_FILTER,osg::Texture::LINEAR);
	intensityMapTexture->setFilter(osg::Texture::MAG_FILTER,osg::Texture::LINEAR);
	intensityMapTexture->setWrap(osg::Texture::WRAP_S,osg::Texture::CLAMP_TO_EDGE);
	intensityMapTexture->setWrap(osg::Texture::WRAP_T,osg::Texture::CLAMP_TO_EDGE);

    stateset->setTextureAttributeAndModes(_distortionSet->getTexUnitIntensityMap(), intensityMapTexture, osg::StateAttribute::ON);

	// create shaders for blending
	osg::Program* distortProgram = new osg::Program;
	distortProgram->setName( "intensityMapBlending" );
	osg::Shader* fShader = osg::Shader::readShaderFile( osg::Shader::FRAGMENT, "shader.frag" ); 
	fShader->setName("intensityMapFragShader");

	if ( fShader )
	{
		distortProgram->addShader( fShader );
		stateset->addUniform( new osg::Uniform("sceneTexture", (int)_distortionSet->getTexUnitScene()) );
		stateset->addUniform( new osg::Uniform("intensityMapTexture", (int)_distortionSet->getTexUnitIntensityMap()) );
		stateset->setAttributeAndModes(distortProgram, osg::StateAttribute::ON);
	}
}

void extViewer::setUpIntensityMapBlending(std::string intensityMap)
{
	// Try to load intensityMap
	osg::Image* intMap = osgDB::readImageFile(intensityMap);
	if (!intMap)
	{
		osg::notify(osg::WARN) << "Quitting, couldn't find intensity map: " << intensityMap << std::endl;
		return;
	} 

	// Create DistortionSet
	_distortionSet = new osgViewer::DistortionSet();
	_distortionSet->setIntensityMap( intMap );
	_distortionSet->setDistortionMeshRows( 1 );
	_distortionSet->setDistortionMeshColumns( 1 );
	_distortionSet->setTexUnitScene( 0 );
	_distortionSet->setTexUnitIntensityMap( 1 );

	// Todo: call setupDistortion/Blendung to perform the blending
}