glc_viewport.cpp

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/****************************************************************************

 This file is part of the GLC-lib library.
 Copyright (C) 2005-2008 Laurent Ribon (laumaya@users.sourceforge.net)
 Version 2.0.0 Beta 1, packaged on April 2010.

 http://glc-lib.sourceforge.net

 GLC-lib is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; either version 2 of the License, or
 (at your option) any later version.

 GLC-lib 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
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with GLC-lib; if not, write to the Free Software
 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

*****************************************************************************/



#include "glc_viewport.h"
#include "../glc_openglexception.h"
#include "../glc_ext.h"
#include "../shading/glc_selectionmaterial.h"
#include "../glc_state.h"
#include "../sceneGraph/glc_3dviewinstance.h"

#include <QtDebug>

using namespace glc;
// Constructor Destructor

GLC_Viewport::GLC_Viewport(QGLWidget *GLWidget)
// Camera definition
: m_pViewCam(new GLC_Camera())                          // Camera
, m_dCamDistMax(500.0)                  // Camera Maximum distance
, m_dCamDistMin(0.01)                   // Camera Minimum distance
, m_dFov(35)                                    // Camera angle of view
, m_ViewTangent(tan(glc::toRadian(m_dFov)))
, m_pImagePlane(NULL)                   // Background image
// OpenGL Window size
, m_nWinHSize(0)                                // Horizontal OpenGL viewport size
, m_nWinVSize(0)                                // Vertical OpenGL viewport size
, m_AspectRatio(1.0)
, m_pQGLWidget(GLWidget)                // Attached QGLWidget
// the default backgroundColor
, m_BackgroundColor(Qt::black)
, m_SelectionSquareSize(4)
, m_ProjectionMatrix()
, m_Frustum()
, m_ClipPlane()
, m_UseClipPlane(false)
, m_3DWidget()
, m_UseOrtho(false)
{

}

GLC_Viewport::~GLC_Viewport()
{
        delete m_pViewCam;

        // delete background image
        deleteBackGroundImage();

        // Delete clip planes
        QHash<GLenum, GLC_Plane*>::iterator iClip= m_ClipPlane.begin();
        while (m_ClipPlane.constEnd() != iClip)
        {
                delete iClip.value();
                ++iClip;
        }
}

// Get Functions

GLC_Vector3d GLC_Viewport::mapPosMouse( GLdouble Posx, GLdouble Posy) const
{
        // Change the window origin (Up Left -> centred)
        Posx= Posx - static_cast<double>(m_nWinHSize)  / 2.0;
        Posy= static_cast<double>(m_nWinVSize) / 2.0 - Posy;

        GLC_Vector3d VectMouse(Posx, Posy,0);

        // Compute the length of camera's field of view
        const double ChampsVision = m_pViewCam->distEyeTarget() *  m_ViewTangent;

        // the side of camera's square is mapped on Vertical length of window
        // Ratio OpenGL/Pixel = dimend GL / dimens Pixel
        const double Ratio= ChampsVision / static_cast<double>(m_nWinVSize);

        VectMouse= VectMouse * Ratio;

        return VectMouse;
}

// Public OpenGL Functions

void GLC_Viewport::initGl()
{
        // OpenGL initialisation from NEHE production
        m_pQGLWidget->qglClearColor(m_BackgroundColor);       // Background
        glClearDepth(1.0f);                                   // Depth Buffer Setup
        glShadeModel(GL_SMOOTH);                              // Enable Smooth Shading
        glEnable(GL_DEPTH_TEST);                              // Enables Depth Testing
        glDepthFunc(GL_LEQUAL);                               // The Type Of Depth Testing To Do
        glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);    // Really Nice Perspective Calculation
        glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);

        // Init GLC_State
        GLC_State::init();
}

void GLC_Viewport::glExecuteCam(void)
{
        m_pViewCam->glExecute();
        glExecuteImagePlane();
}

void GLC_Viewport::updateProjectionMat(void)
{
        // Make opengl context attached the current One
        m_pQGLWidget->makeCurrent();

        glMatrixMode(GL_PROJECTION);                                            // select The Projection Matrix
        glLoadIdentity();                                                                       // Reset The Projection Matrix

        if (m_UseOrtho)
        {
                const double ChampsVision = m_pViewCam->distEyeTarget() * m_ViewTangent;
                const double height= ChampsVision;
                const double with= ChampsVision * m_AspectRatio;
                const double left= -with * 0.5;
                const double right=  -left;
                const double bottom= - height * 0.5;
                const double top= -bottom;
                glOrtho(left, right, bottom, top, m_dCamDistMin, m_dCamDistMax);
        }
        else
        {
                gluPerspective(m_dFov, m_AspectRatio, m_dCamDistMin, m_dCamDistMax);
        }

        // Save the projection matrix
        glGetDoublev(GL_PROJECTION_MATRIX, m_ProjectionMatrix.data());

        glMatrixMode(GL_MODELVIEW);                                                     // select The Modelview Matrix
        glLoadIdentity();                                                                       // Reset The Modelview Matrix
}

void GLC_Viewport::forceAspectRatio(double ratio)
{
        m_AspectRatio= ratio;
        updateProjectionMat();
}

void GLC_Viewport::updateAspectRatio()
{
        // Update The Aspect Ratio Of The Window
        m_AspectRatio= static_cast<double>(m_nWinHSize)/static_cast<double>(m_nWinVSize);
}
GLC_Frustum GLC_Viewport::selectionFrustum(int x, int y) const
{
        const int halfSize= m_SelectionSquareSize / 2;
        // Calculate the 4 points of the selection
        //p1->p2
        //
        //p0  p3
        QList<int> coordinates;
        // Point 0
        coordinates << (x - halfSize) << (y + halfSize);
        // Point 1
        coordinates << (x - halfSize) << (y - halfSize);
        // Point 2
        coordinates << (x + halfSize) << (y - halfSize);
        // Point 3
        coordinates << (x + halfSize) << (y + halfSize);

        // Unproject the 4 point
        QList<GLC_Point3d> listOfPoint= unproject(coordinates);

        Q_ASSERT(4 == listOfPoint.size());
        // Create the four frustum planes
        GLC_Point3d eye= m_pViewCam->eye();
        const GLC_Plane leftPlane(listOfPoint.at(0), listOfPoint.at(1), eye);
        const GLC_Plane rightPlane(listOfPoint.at(3), eye , listOfPoint.at(2));
        const GLC_Plane upPlane(listOfPoint.at(2), eye, listOfPoint.at(1));
        const GLC_Plane bottomPlane(listOfPoint.at(0), eye, listOfPoint.at(3));

        GLC_Frustum selectionFrustum(m_Frustum);
        selectionFrustum.setLeftClippingPlane(leftPlane);
        selectionFrustum.setRightClippingPlane(rightPlane);
        selectionFrustum.setTopClippingPlane(upPlane);
        selectionFrustum.setBottomClippingPlane(bottomPlane);

        return selectionFrustum;
}

GLC_Point3d GLC_Viewport::unProject(int x, int y) const
{
        // Z Buffer component of the given coordinate is between 0 and 1
        GLfloat Depth;
        // read selected point
        glReadPixels(x, m_nWinVSize - y , 1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, &Depth);

        // The current viewport opengl definition
        GLint Viewport[4];
        glGetIntegerv(GL_VIEWPORT, Viewport);

        // OpenGL ccordinate of selected point
        GLdouble pX, pY, pZ;
        gluUnProject((GLdouble) x, (GLdouble) (m_nWinVSize - y) , Depth
                , m_pViewCam->modelViewMatrix().data(), m_ProjectionMatrix.data(), Viewport, &pX, &pY, &pZ);

        return GLC_Point3d(pX, pY, pZ);
}

QList<GLC_Point3d> GLC_Viewport::unproject(const QList<int>& list)const
{
        const int size= list.size();
        Q_ASSERT((size % 2) == 0);

        // The current viewport opengl definition
        GLint Viewport[4];
        glGetIntegerv(GL_VIEWPORT, Viewport);

        // Z Buffer component of the given coordinate is between 0 and 1
        GLfloat Depth;

        // Coordinate of readed points
        GLdouble pX, pY, pZ;
        QList<GLC_Point3d> unprojectedPoints;
        for (int i= 0; i < size; i+= 2)
        {
                const int x= list.at(i);
                const int y= m_nWinVSize - list.at(i + 1);
                glReadPixels(x, y , 1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, &Depth);

                gluUnProject(static_cast<GLdouble>(x), static_cast<GLdouble>(y) , Depth , m_pViewCam->modelViewMatrix().data()
                                , m_ProjectionMatrix.data(), Viewport, &pX, &pY, &pZ);
                unprojectedPoints.append(GLC_Point3d(pX, pY, pZ));
        }

        return unprojectedPoints;
}

// Private OpenGL Functions

void GLC_Viewport::glExecuteImagePlane()
{

        if(!GLC_State::isInSelectionMode())
        {
                if (m_pImagePlane != NULL)
                {
                        m_pImagePlane->render();
                }
        }
}

void GLC_Viewport::render3DWidget()
{
        m_3DWidget.render(0, glc::WireRenderFlag);
        m_3DWidget.render(0, glc::TransparentRenderFlag);
}
// Set Functions

void GLC_Viewport::setWinGLSize(int HSize, int VSize)
{
        m_nWinHSize= HSize;
        m_nWinVSize= VSize;

        // from NeHe's Tutorial 3
        if (m_nWinVSize == 0)                                                           // Prevent A Divide By Zero By
        {
                m_nWinVSize= 1;                                                                 // Making Height Equal One
        }

        glViewport(0,0,m_nWinHSize,m_nWinVSize);                        // Reset The Current Viewport

        updateAspectRatio();

        updateProjectionMat();

}

GLC_uint GLC_Viewport::renderAndSelect(int x, int y)
{

        m_pQGLWidget->qglClearColor(Qt::black);
        GLC_State::setSelectionMode(true);
        // Draw the scene
        m_pQGLWidget->updateGL();
        GLC_State::setSelectionMode(false);

        return selectOnPreviousRender(x, y);
}

GLC_uint GLC_Viewport::selectOnPreviousRender(int x, int y)
{
        GLsizei width= m_SelectionSquareSize;
        GLsizei height= width;
        GLint newX= x - width / 2;
        GLint newY= (m_pQGLWidget->size().height() - y) - height / 2;
        if (newX < 0) newX= 0;
        if (newY < 0) newY= 0;

        return meaningfulIdInsideSquare(newX, newY, width, height);
}
GLC_uint GLC_Viewport::selectBody(GLC_3DViewInstance* pInstance, int x, int y)
{
        m_pQGLWidget->qglClearColor(Qt::black);
        GLC_State::setSelectionMode(true);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
        glLoadIdentity();

        glExecuteCam();

        // Draw the scene
        glDisable(GL_BLEND);
        glDisable(GL_LIGHTING);
        glDisable(GL_TEXTURE_2D);

        pInstance->renderForBodySelection();
        GLC_State::setSelectionMode(false);

        GLsizei width= 6;
        GLsizei height= width;
        GLint newX= x - width / 2;
        GLint newY= (m_pQGLWidget->size().height() - y) - height / 2;
        if (newX < 0) newX= 0;
        if (newY < 0) newY= 0;

        return meaningfulIdInsideSquare(newX, newY, width, height);
}

QPair<int, GLC_uint> GLC_Viewport::selectPrimitive(GLC_3DViewInstance* pInstance, int x, int y)
{
        QPair<int, GLC_uint> result;

        m_pQGLWidget->qglClearColor(Qt::black);
        GLC_State::setSelectionMode(true);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
        glLoadIdentity();

        glExecuteCam();

        // Draw the scene
        glDisable(GL_BLEND);
        glDisable(GL_LIGHTING);
        glDisable(GL_TEXTURE_2D);

        pInstance->renderForBodySelection();


        GLsizei width= 6;
        GLsizei height= width;
        GLint newX= x - width / 2;
        GLint newY= (m_pQGLWidget->size().height() - y) - height / 2;
        if (newX < 0) newX= 0;
        if (newY < 0) newY= 0;

        GLC_uint bodyId= meaningfulIdInsideSquare(newX, newY, width, height);
        if (bodyId == 0)
        {
                result.first= -1;
                result.second= 0;
        }
        else
        {
                glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

                result.first= pInstance->renderForPrimitiveSelection(bodyId);
                result.second= meaningfulIdInsideSquare(newX, newY, width, height);
        }
        GLC_State::setSelectionMode(false);
        return result;
}

QSet<GLC_uint> GLC_Viewport::selectInsideSquare(int x1, int y1, int x2, int y2)
{
        if (x1 > x2)
        {
                int xTemp= x1;
                x1= x2;
                x2= xTemp;
        }
        if (y2 > y1)
        {
                int yTemp= y1;
                y1= y2;
                y2= yTemp;
        }
        m_pQGLWidget->qglClearColor(Qt::black);
        GLC_State::setSelectionMode(true);
        // Draw the scene
        m_pQGLWidget->updateGL();
        GLC_State::setSelectionMode(false);

        GLsizei width= x2 - x1;
        GLsizei height= y1 - y2;
        GLint newX= x1;
        GLint newY= (m_pQGLWidget->size().height() - y1);
        if (newX < 0) newX= 0;
        if (newY < 0) newY= 0;

        return listOfIdInsideSquare(newX, newY, width, height);
}

GLC_uint GLC_Viewport::meaningfulIdInsideSquare(GLint x, GLint y, GLsizei width, GLsizei height)
{
        const int squareSize= width * height;
        const GLsizei arraySize= squareSize * 4; // 4 -> R G B A
        QVector<GLubyte> colorId(arraySize);

        // Get the array of pixels
        glReadPixels(x, y, width, height, GL_RGBA, GL_UNSIGNED_BYTE, colorId.data());

        // Restore Background color
        m_pQGLWidget->qglClearColor(m_BackgroundColor);

        QHash<GLC_uint, int> idHash;
        QList<int> idWeight;

        // Find the most meaningful color
        GLC_uint returnId= 0;
        // There is nothing at the center
        int maxWeight= 0;
        int currentIndex= 0;
        for (int i= 0; i < squareSize; ++i)
        {
                GLC_uint id= glc::decodeRgbId(&colorId[i * 4]);
                if (idHash.contains(id))
                {
                        const int currentWeight= ++(idWeight[idHash.value(id)]);
                        if (maxWeight < currentWeight)
                        {
                                returnId= id;
                                maxWeight= currentWeight;
                        }
                }
                else if (id != 0)
                {
                        idHash.insert(id, currentIndex++);
                        idWeight.append(1);
                        if (maxWeight < 1)
                        {
                                returnId= id;
                                maxWeight= 1;
                        }
                }
        }

        return returnId;
}

QSet<GLC_uint> GLC_Viewport::listOfIdInsideSquare(GLint x, GLint y, GLsizei width, GLsizei height)
{
        const int squareSize= width * height;
        const GLsizei arraySize= squareSize * 4; // 4 -> R G B A
        QVector<GLubyte> colorId(arraySize);

        // Get the array of pixels
        glReadPixels(x, y, width, height, GL_RGBA, GL_UNSIGNED_BYTE, colorId.data());

        // Restore Background color
        m_pQGLWidget->qglClearColor(m_BackgroundColor);

        QSet<GLC_uint> idSet;

        // get the color inside square
        for (int i= 0; i < squareSize; ++i)
        {
                GLC_uint id= glc::decodeRgbId(&colorId[i * 4]);
                idSet << id;
        }

        return idSet;
}

void GLC_Viewport::loadBackGroundImage(const QString& ImageFile)
{
        delete m_pImagePlane;
        m_pImagePlane= new GLC_ImagePlane(m_pQGLWidget->context(), ImageFile);
}

void GLC_Viewport::loadBackGroundImage(const QImage& image)
{
        delete m_pImagePlane;
        m_pImagePlane= new GLC_ImagePlane(m_pQGLWidget->context(), image);
}

void GLC_Viewport::deleteBackGroundImage()
{
        delete m_pImagePlane;
        m_pImagePlane= NULL;
}

void GLC_Viewport::setToOrtho(bool useOrtho)
{
        if (m_UseOrtho != useOrtho)
        {
                m_UseOrtho= useOrtho;
                updateProjectionMat();
        }

}

void GLC_Viewport::reframe(const GLC_BoundingBox& box)
{
        Q_ASSERT(!box.isEmpty());

        // Center view on the BoundingBox
        const GLC_Vector3d deltaVector(box.center() - m_pViewCam->target());
        m_pViewCam->translate(deltaVector);

        double cameraCover= box.boundingSphereRadius() * 2.0;

        // Compute Camera distance
        const double distance = cameraCover / m_ViewTangent;

        // Update Camera position
        m_pViewCam->setDistEyeTarget(distance);
}

bool GLC_Viewport::setDistMin(double DistMin)
{
        DistMin= fabs(DistMin);
        if (DistMin < m_dCamDistMax)
        {
                m_dCamDistMin= DistMin;

                updateProjectionMat();  // Update OpenGL projection matrix

                return true;
        }
        else
        {
                qDebug("GLC_Viewport::SetDistMin : KO");
                return false;
        }

}

bool GLC_Viewport::setDistMax(double DistMax)
{
        DistMax= fabs(DistMax);
        if (DistMax > m_dCamDistMin)
        {
                m_dCamDistMax= DistMax;

                // Update OpenGL projection matrix
                updateProjectionMat();

                return true;
        }
        else
        {
                qDebug("GLC_Viewport::SetDistMax : KO");
                return false;
        }
}

void GLC_Viewport::setDistMinAndMax(const GLC_BoundingBox& bBox)
{
        if(!bBox.isEmpty())
        {
                // The scene is not empty
                GLC_Matrix4x4 matComp(m_pViewCam->modelViewMatrix());

                // The bounding Box in Camera coordinate
                GLC_BoundingBox boundingBox(bBox);
                boundingBox.transform(matComp);

                // Increase size of the bounding box
                const double increaseFactor= 1.1;
                // Convert box distance in sphere distance
                const double center= fabs(boundingBox.center().z());
                const double radius= boundingBox.boundingSphereRadius();
                const double min= center - radius * increaseFactor;
                const double max= center + radius * increaseFactor;

                GLC_Point3d camEye(m_pViewCam->eye());
                camEye= matComp * camEye;

                if (min > 0.0)
                {
                        // Outside bounding Sphere
                        m_dCamDistMin= min;
                        m_dCamDistMax= max;
                        //qDebug() << "distmin" << m_dCamDistMin;
                        //qDebug() << "distmax" << m_dCamDistMax;
                }
                else
                {
                        // Inside bounding Sphere
                        m_dCamDistMin= qMin(0.01 * radius, m_pViewCam->distEyeTarget() / 4.0);
                        m_dCamDistMax= max;
                        //qDebug() << "inside distmin" << m_dCamDistMin;
                        //qDebug() << "inside distmax" << m_dCamDistMax;
                }
        }
        else
        {
                // The scene is empty
                m_dCamDistMin= m_pViewCam->distEyeTarget() / 2.0;
                m_dCamDistMax= m_pViewCam->distEyeTarget();
        }

        // Update OpenGL projection matrix
        updateProjectionMat();
}

void GLC_Viewport::setBackgroundColor(QColor setColor)
{
        m_BackgroundColor= setColor;
        m_pQGLWidget->qglClearColor(m_BackgroundColor);
}

void GLC_Viewport::addClipPlane(GLenum planeGlEnum,GLC_Plane* pPlane)
{
        if (m_ClipPlane.contains(planeGlEnum))
        {
                delete m_ClipPlane.value(planeGlEnum);
                m_ClipPlane.remove(planeGlEnum);
        }
        m_ClipPlane.insert(planeGlEnum, pPlane);
}

void GLC_Viewport::removeClipPlane(GLenum planeGlEnum)
{
        if (m_ClipPlane.contains(planeGlEnum))
        {
                delete m_ClipPlane.value(planeGlEnum);
                m_ClipPlane.remove(planeGlEnum);
        }
        else
        {
                qDebug() << "GLC_Viewport::removeClipPlane Clipp plane " << planeGlEnum << " Not found";
        }
}

void GLC_Viewport::useClipPlane(bool flag)
{
        m_UseClipPlane= flag;
        if (m_UseClipPlane)
        {
                QHash<GLenum, GLC_Plane*>::iterator iClip= m_ClipPlane.begin();
                while (m_ClipPlane.constEnd() != iClip)
                {
                        GLenum planeKey= iClip.key();
                        GLC_Plane* pPlane= iClip.value();

                        glClipPlane (planeKey, pPlane->data());
                        glEnable (planeKey);
                        ++iClip;
                }
        }
        else
        {
                QHash<GLenum, GLC_Plane*>::iterator iClip= m_ClipPlane.begin();
                while (m_ClipPlane.constEnd() != iClip)
                {
                        glDisable(iClip.key());
                        ++iClip;
                }
        }

}