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#include "view.h"

#include "teapot.h"

#include "cube.h"

#include <QtCore/qdebug.h>

#include <QtCore/qtimer.h>

#include <stdio.h>

#include "qaccelerometer.h"

#if defined(QT_OPENGL_ES)

#define USE_BUFFERS 1

#endif

class smoothedaccelerometerfilter : public QObject, public QAccelerometerFilter

{

    qreal prevX;

    qreal prevY;

    qreal prevZ;

    bool havePrev;

public:

    smoothedaccelerometerfilter(QObject *parent = 0)

        : QObject(parent)

        , QAccelerometerFilter()

        , prevX(0)

        , prevY(0)

        , prevZ(0)

        , havePrev(false)

    {

    }

    bool filter(QAccelerometerReading *reading)

    {

        // Smooth out the reported values.  Large changes are applied as-is,

        // and small jitters smooth to the rest position.

        if (havePrev) {

            qreal xdiff = reading->x() - prevX;

            qreal ydiff = reading->y() - prevY;

            qreal zdiff = reading->z() - prevZ;

#define threshold 0.196133f

            if (qAbs(xdiff) < threshold && qAbs(ydiff) < threshold && qAbs(zdiff) < threshold) {

                reading->setX(prevX + xdiff * 0.1f);

                reading->setY(prevY + ydiff * 0.1f);

                reading->setZ(prevZ + zdiff * 0.1f);

            }

        }

        prevX = reading->x();

        prevY = reading->y();

        prevZ = reading->z();

        havePrev = true;

        return true;

    }

};

View::View(QWidget *parent)

    : QGLWidget(parent),

      sensitivity(0.1f),

      painter(0),

      showFrameRate(false)

{

    mainCamera = new Camera(this);

    roomCamera = new Camera(this);

    roomCamera->setAdjustForAspectRatio(false);

    sensor = new QAccelerometer(this);

    connect(sensor, SIGNAL(readingChanged()), this, SLOT(accelerometerTimeout()));

    sensor->addFilter(new smoothedaccelerometerfilter(this));

    sensor->start();

    time.start();

    vertexBuffer = 0;

    indexBuffer = 0;

}

View::~View()

{

    delete painter;

}

void View::resizeGL(int width, int height)

{

    glViewport(0, 0, width, height);

}

void View::initializeGL()

{

#if defined(QT_OPENGL_ES_2)

    painter = new ShaderPainter();

#else

    painter = new FixedFunctionPainter();

#endif

    glEnable(GL_DEPTH_TEST);

    roomMaterialBack = new Material();

    roomMaterialBack->setDiffuseColor(QColor(128, 100, 0));

    roomMaterialLeftRight = new Material();

    roomMaterialLeftRight->setDiffuseColor(Qt::cyan);

    roomMaterialTopBottom = new Material();

    roomMaterialTopBottom->setDiffuseColor(Qt::yellow);

    cubeMaterial = new Material();

    cubeMaterial->setColor(QColor(170, 202, 0));

    teapotMaterial = new Material();

    teapotMaterial->setAmbientColor(QColor(192, 150, 128));

    teapotMaterial->setSpecularColor(QColor(60, 60, 60));

    teapotMaterial->setShininess(128);

    roomModel = new LightModel(this);

    roomModel->setAmbientSceneColor(Qt::white);

    roomModel->setViewerPosition(LightModel::LocalViewer);

    normalModel = new LightModel(this);

    Light *light = new Light(this);

    light->setPosition(QVector3D(0.0f, 0.0f, 3.0f));

    painter->setLight(light);

    texture = bindTexture(QImage(QLatin1String(":/qtlogo.png")));

#ifdef USE_BUFFERS

    // Upload the teapot data into GL buffers for quicker rendering.

    glGenBuffers(1, &vertexBuffer);

    glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);

    glBufferData(GL_ARRAY_BUFFER,

                 teapotVertexCount * teapotVertexStride * sizeof(float),

                 teapotVertexData, GL_STATIC_DRAW);

    glBindBuffer(GL_ARRAY_BUFFER, 0);

    glGenBuffers(1, &indexBuffer);

    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBuffer);

    glBufferData(GL_ELEMENT_ARRAY_BUFFER,

                 teapotTriangleCount * 3 * sizeof(ushort),

                 teapotTriangleData, GL_STATIC_DRAW);

    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);

#endif

}

void View::paintGL()

{

    if (showFrameRate)

        qWarning("time since last frame: %d ms", time.restart());

    qreal aspectRatio = qreal(width()) / qreal(height());

    QMatrix4x4 mv, mv2;

    QMatrix4x4 proj;

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    mv = roomCamera->modelViewMatrix();

    proj = roomCamera->projectionMatrix(aspectRatio);

    painter->setLightModel(roomModel);

    painter->setMatrices(mv, proj);

    painter->selectMaterial(roomMaterialBack);

    painter->drawQuad(QVector3D(-3.0f, -3.0f, -15.0f),

                      QVector3D( 3.0f, -3.0f, -15.0f),

                      QVector3D( 3.0f,  3.0f, -15.0f),

                      QVector3D(-3.0f,  3.0f, -15.0f),

                      QVector3D(0.0f, 0.0f, 1.0f));

    painter->selectMaterial(roomMaterialLeftRight);

    painter->drawQuad(QVector3D(-3.0f, -3.0f, -15.0f),

                      QVector3D(-3.0f,  3.0f, -15.0f),

                      QVector3D(-3.0f,  3.0f, 0.0f),

                      QVector3D(-3.0f, -3.0f, 0.0f),

                      QVector3D(1.0f, 0.0f, 0.0f));

    painter->drawQuad(QVector3D(3.0f,  3.0f, -15.0f),

                      QVector3D(3.0f, -3.0f, -15.0f),

                      QVector3D(3.0f, -3.0f, 0.0f),

                      QVector3D(3.0f,  3.0f, 0.0f),

                      QVector3D(-1.0f, 0.0f, 0.0f));

    painter->selectMaterial(roomMaterialTopBottom);

    painter->drawQuad(QVector3D(-3.0f,  3.0f, -15.0f),

                      QVector3D( 3.0f,  3.0f, -15.0f),

                      QVector3D( 3.0f,  3.0f, 0.0f),

                      QVector3D(-3.0f,  3.0f, 0.0f),

                      QVector3D(0.0f, -1.0f, 0.0f));

    painter->drawQuad(QVector3D(-3.0f, -3.0f, -15.0f),

                      QVector3D(-3.0f, -3.0f, 0.0f),

                      QVector3D( 3.0f, -3.0f, 0.0f),

                      QVector3D( 3.0f, -3.0f, -15.0f),

                      QVector3D(0.0f, 1.0f, 0.0f));

    mv = mv2 = mainCamera->modelViewMatrix();

    proj = mainCamera->projectionMatrix(aspectRatio);

    mv.translate(1.0f, -0.5f, 0.0f);

    mv.rotate(45.0f, 1.0f, 1.0f, 1.0f);

    painter->setMatrices(mv, proj);

    painter->setLightModel(normalModel);

    painter->selectTexturedMaterial(cubeMaterial);

    painter->setVertices(cubeVertices, 8);

    painter->setNormals(cubeVertices + 3, 8);

    painter->setTexCoords(cubeVertices + 6, 8);

    glDrawArrays(GL_TRIANGLES, 0, 36);

    mv2.translate(-0.8f, -1.5f, -3.0f);

    painter->setMatrices(mv2, proj);

    painter->selectMaterial(teapotMaterial);

#ifdef USE_BUFFERS

    glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);

    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBuffer);

    painter->setVertices(0, 8);

    painter->setNormals(reinterpret_cast<float *>(3 * sizeof(float)), 8);

    painter->setTexCoords(reinterpret_cast<float *>(6 * sizeof(float)), 8);

    glDrawElements(GL_TRIANGLES, teapotTriangleCount * 3,

                   GL_UNSIGNED_SHORT, 0);

    glBindBuffer(GL_ARRAY_BUFFER, 0);

    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);

#else

    painter->setVertices(teapotVertexData, 8);

    painter->setNormals(teapotVertexData + 3, 8);

    painter->setTexCoords(teapotVertexData + 6, 8);

    glDrawElements(GL_TRIANGLES, teapotTriangleCount * 3,

                   GL_UNSIGNED_SHORT, teapotTriangleData);

#endif

}

void View::accelerometerTimeout()

{

    QVector3D g = gravity();

    mainCamera->setMotionAdjustment(g);

    roomCamera->setMotionAdjustment(g);

    update();

}

#define ACCEL_TO_G(v) (v / 9.80665)

QVector3D View::gravity() const

{

    qreal x = ACCEL_TO_G(sensor->reading()->x()) * sensitivity;

    qreal y = ACCEL_TO_G(sensor->reading()->y()) * sensitivity;

    qreal z = ACCEL_TO_G(sensor->reading()->z());

    return QVector3D(x, y, z);

}