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

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Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).*

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modification, are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice,

* this list of conditions and the following disclaimer.

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* this list of conditions and the following disclaimer in the documentation

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* Neither the name of Nokia Corporation and its Subsidiary(-ies) nor the

* names of its contributors may be used to endorse or promote products

* derived from this software without specific prior written permission.

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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

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

#include "modelitem.h"

#include "model.h"

#include <QtGui>

#include "mazescene.h"

#ifndef QT_NO_OPENGL

#if !defined QT_OPENGL_ES_2 && !defined Q_WS_MAC

#include <GL/glew.h>

#endif

#include <QtOpenGL>

#ifndef GL_MULTISAMPLE

#define GL_MULTISAMPLE  0x809D

#endif

#endif

#include <QVector2D>

void ModelItem::updateTransform(const Camera &camera)

{

    QPointF pos(3, 7);

    QVector2D toCamera = QVector2D(camera.pos() - pos).normalized();

    QPointF delta(toCamera.y(), -toCamera.x());

    setPosition(pos - delta, pos + delta);

    ProjectedItem::updateTransform(camera);

    setTransform(QTransform());

    m_matrix = camera.viewMatrix();

    m_matrix.translate(3, 0, 7);

}

QRectF ModelItem::boundingRect() const

{

    if (!scene()->views().isEmpty()) {

        QGraphicsView *view = scene()->views().at(0);

        return view->mapToScene(view->rect()).boundingRect();

    }

    return scene()->sceneRect();

}

void ModelItem::updateItem()

{

    ProjectedItem::update();

}

const char *vertexProgram =

    "attribute highp    vec4    vertexCoordsArray;"

    "attribute highp    vec4    normalCoordsArray;"

    "varying   highp    vec4    normal;"

    "uniform   highp    mat4    pmvMatrix;"

    "uniform   highp    mat4    modelMatrix;"

    "void main(void)"

    "{"

    "        normal = modelMatrix * vec4(normalCoordsArray.xyz, 0);"

    "        gl_Position = pmvMatrix * vertexCoordsArray;"

    "}";

const char *fragmentProgram =

    "uniform   lowp     vec4    color;"

    "varying   highp    vec4    normal;"

    "void main() {"

    "   lowp vec3 toLight = normalize(vec3(-0.9, -1, 0.6));"

    "   gl_FragColor = color * (0.4 + 0.6 * max(dot(normalize(normal).xyz, toLight), 0.0));"

    "}";

QMatrix4x4 fromProjection(float fov);

QMatrix4x4 fromRotation(float angle, Qt::Axis axis);

void ModelItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget *)

{

    if (!m_model || isObscured())

        return;

    QMatrix4x4 projectionMatrix = QMatrix4x4(painter->transform()) * fromProjection(70);

    const int delta = m_time.elapsed() - m_lastTime;

    m_rotation += m_angularMomentum * (delta / 1000.0);

    m_lastTime += delta;

    QVector3D size = m_model->size();

    float extent = qSqrt(2.0);

    float scale = 1 / qMax(size.y(), qMax(size.x() / extent, size.z() / extent));

    QMatrix4x4 modelMatrix;

    modelMatrix.scale(scale, -scale, scale);

    modelMatrix = fromRotation(m_rotation.z(), Qt::ZAxis) * modelMatrix;

    modelMatrix = fromRotation(m_rotation.y(), Qt::YAxis) * modelMatrix;

    modelMatrix = fromRotation(m_rotation.x(), Qt::XAxis) * modelMatrix;

    QTimer::singleShot(10, this, SLOT(updateItem()));

#ifndef QT_NO_OPENGL

    if (painter->paintEngine()->type() != QPaintEngine::OpenGL

        && painter->paintEngine()->type() != QPaintEngine::OpenGL2) {

#endif

        m_wireframe->setEnabled(false);

        m_wireframe->setChecked(false);

        m_wireframeEnabled = false;

        painter->setTransform(QTransform());

        painter->setPen(m_modelColor);

        m_model->render(painter, projectionMatrix * m_matrix * modelMatrix, m_normalsEnabled);

        return;

#ifndef QT_NO_OPENGL

    }

    m_wireframe->setEnabled(true);

    painter->beginNativePainting();

#ifdef QT_OPENGL_ES_2

    glClearDepthf(0);

#else

    glClearDepth(0);

#endif

    glClear(GL_DEPTH_BUFFER_BIT);

    if (!m_program) {

#if !defined QT_OPENGL_ES_2 && !defined Q_WS_MAC

        glewInit();

#endif

        m_program = new QGLShaderProgram;

        m_program->addShaderFromSourceCode(QGLShader::Fragment, fragmentProgram);

        m_program->addShaderFromSourceCode(QGLShader::Vertex, vertexProgram);

        m_program->bindAttributeLocation("vertexCoordsArray", 0);

        m_program->bindAttributeLocation("normalCoordsArray", 1);

        m_program->link();

        if (!m_program->isLinked())

            qDebug() << m_program->log();

    }

    qreal ortho[] = {

        2.0f / painter->device()->width(), 0, 0, -1,

        0, -2.0f / painter->device()->height(), 0, 1,

        0, 0, -1, 0,

        0, 0, 0, 1

    };

    m_program->bind();

    m_program->setUniformValue("color", m_modelColor);

    m_program->setUniformValue("pmvMatrix", QMatrix4x4(ortho) * projectionMatrix * m_matrix * modelMatrix);

    m_program->setUniformValue("modelMatrix", modelMatrix);

    m_model->render(m_wireframeEnabled, m_normalsEnabled);

    m_program->release();

    painter->endNativePainting();

#endif

}

ModelItem::ModelItem()

    : ProjectedItem(QRectF(), false, false)

    , m_wireframeEnabled(false)

    , m_normalsEnabled(false)

    , m_modelColor(153, 255, 0)

    , m_model(0)

    , m_lastTime(0)

    , m_distance(1.4f)

    , m_angularMomentum(0, 40, 0)

#ifndef QT_NO_OPENGL

    , m_program(0)

#endif

{

    setLayout(new QVBoxLayout);

    m_modelButton = new QPushButton(tr("Load model"));

    connect(m_modelButton, SIGNAL(clicked()), this, SLOT(loadModel()));

#ifndef QT_NO_CONCURRENT

    connect(&m_modelLoader, SIGNAL(finished()), this, SLOT(modelLoaded()));

#endif

    layout()->addWidget(m_modelButton);

    m_wireframe = new QCheckBox(tr("Render as wireframe"));

    connect(m_wireframe, SIGNAL(toggled(bool)), this, SLOT(enableWireframe(bool)));

    layout()->addWidget(m_wireframe);

    QCheckBox *normals = new QCheckBox(tr("Display normals vectors"));

    connect(normals, SIGNAL(toggled(bool)), this, SLOT(enableNormals(bool)));

    layout()->addWidget(normals);

    QPushButton *colorButton = new QPushButton(tr("Choose model color"));

    connect(colorButton, SIGNAL(clicked()), this, SLOT(setModelColor()));

    layout()->addWidget(colorButton);

    loadModel(QLatin1String("qt.obj"));

    m_time.start();

}

static Model *loadModel(const QString &filePath)

{

    return new Model(filePath);

}

void ModelItem::loadModel()

{

    loadModel(QFileDialog::getOpenFileName(0, tr("Choose model"), QString(), QLatin1String("*.obj")));

}

void ModelItem::loadModel(const QString &filePath)

{

    if (filePath.isEmpty())

        return;

    m_modelButton->setEnabled(false);

    QApplication::setOverrideCursor(Qt::BusyCursor);

#ifndef QT_NO_CONCURRENT

    m_modelLoader.setFuture(QtConcurrent::run(::loadModel, filePath));

#else

    setModel(::loadModel(filePath));

    modelLoaded();

#endif

}

void ModelItem::modelLoaded()

{

#ifndef QT_NO_CONCURRENT

    setModel(m_modelLoader.result());

#endif

    m_modelButton->setEnabled(true);

    QApplication::restoreOverrideCursor();

}

void ModelItem::setModel(Model *model)

{

    delete m_model;

    m_model = model;

    ProjectedItem::update();

}

void ModelItem::enableWireframe(bool enabled)

{

    m_wireframeEnabled = enabled;

    ProjectedItem::update();

}

void ModelItem::enableNormals(bool enabled)

{

    m_normalsEnabled = enabled;

    ProjectedItem::update();

}

void ModelItem::setModelColor()

{

    const QColor color = QColorDialog::getColor(m_modelColor);

    if (color.isValid()) {

        m_modelColor = color;

        ProjectedItem::update();

    }

}