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

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

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"Redistribution and use in source and binary forms, with or without

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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* 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.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

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

#include "model.h"

#include <QFile>

#include <QFileInfo>

#include <QTextStream>

#include <QVarLengthArray>

#ifndef QT_NO_OPENGL

#if !defined QT_OPENGL_ES_2 && !defined Q_WS_MAC

#include <GL/glew.h>

#endif

#include <QtOpenGL>

#endif

Model::Model(const QString &filePath)

    : m_fileName(QFileInfo(filePath).fileName())

{

    QFile file(filePath);

    if (!file.open(QIODevice::ReadOnly))

        return;

    QVector3D boundsMin( 1e9, 1e9, 1e9);

    QVector3D boundsMax(-1e9,-1e9,-1e9);

    QTextStream in(&file);

    while (!in.atEnd()) {

        QString input = in.readLine();

        if (input.isEmpty() || input[0] == '#')

            continue;

        QTextStream ts(&input);

        QString id;

        ts >> id;

        if (id == "v") {

            QVector3D p;

            for (int i = 0; i < 3; ++i) {

                ts >> ((float *)&p)[i];

                ((float *)&boundsMin)[i] = qMin(((float *)&boundsMin)[i], ((float *)&p)[i]);

                ((float *)&boundsMax)[i] = qMax(((float *)&boundsMax)[i], ((float *)&p)[i]);

            }

            m_points << p;

        } else if (id == "f" || id == "fo") {

            QVarLengthArray<int, 4> p;

            while (!ts.atEnd()) {

                QString vertex;

                ts >> vertex;

                const int vertexIndex = vertex.split('/').value(0).toInt();

                if (vertexIndex)

                    p.append(vertexIndex > 0 ? vertexIndex - 1 : m_points.size() + vertexIndex);

            }

            for (int i = 0; i < p.size(); ++i) {

                const int edgeA = p[i];

                const int edgeB = p[(i + 1) % p.size()];

                if (edgeA < edgeB)

                    m_edgeIndices << edgeA << edgeB;

            }

            for (int i = 0; i < 3; ++i)

                m_pointIndices << p[i];

            if (p.size() == 4)

                for (int i = 0; i < 3; ++i)

                    m_pointIndices << p[(i + 2) % 4];

        }

    }

    const QVector3D bounds = boundsMax - boundsMin;

    const qreal scale = 1 / qMax(bounds.x() / 1, qMax(bounds.y(), bounds.z() / 1));

    for (int i = 0; i < m_points.size(); ++i)

        m_points[i] = (m_points[i] - (boundsMin + bounds * 0.5)) * scale;

    m_size = bounds * scale;

    m_normals.resize(m_points.size());

    for (int i = 0; i < m_pointIndices.size(); i += 3) {

        const QVector3D a = m_points.at(m_pointIndices.at(i));

        const QVector3D b = m_points.at(m_pointIndices.at(i+1));

        const QVector3D c = m_points.at(m_pointIndices.at(i+2));

        const QVector3D normal = QVector3D::crossProduct(b - a, c - a).normalized();

        for (int j = 0; j < 3; ++j)

            m_normals[m_pointIndices.at(i + j)] += normal;

    }

    for (int i = 0; i < m_normals.size(); ++i)

        m_normals[i] = m_normals[i].normalized();

}

QVector3D Model::size() const

{

    return m_size;

}

void Model::render(bool wireframe, bool normals) const

{

#ifdef QT_NO_OPENGL

    Q_UNUSED(wireframe);

    Q_UNUSED(normals);

#else

    glEnable(GL_DEPTH_TEST);

    glDepthFunc(GL_GEQUAL);

    glDepthMask(true);

#ifdef QT_OPENGL_ES_2

    GLenum elementType = GL_UNSIGNED_SHORT;

#else

    GLenum elementType = GL_UNSIGNED_INT;

#endif

    glEnableVertexAttribArray(0);

    glEnableVertexAttribArray(1);

    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, (float *)m_points.data());

    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, (float *)m_normals.data());

    if (wireframe)

        glDrawElements(GL_LINES, m_edgeIndices.size(), elementType, m_edgeIndices.data());

    else

        glDrawElements(GL_TRIANGLES, m_pointIndices.size(), elementType, m_pointIndices.data());

    if (normals) {

        QVector<QVector3D> points;

        QVector<QVector3D> normals;

        for (int i = 0; i < m_normals.size(); ++i) {

            points << m_points.at(i) << (m_points.at(i) + m_normals.at(i) * 0.02f);

            normals << m_normals.at(i) << m_normals.at(i);

        }

        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, (float *)points.data());

        glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, (float *)normals.data());

        glDrawArrays(GL_LINES, 0, points.size());

    }

    glDisableVertexAttribArray(1);

    glDisableVertexAttribArray(0);

    glDisable(GL_DEPTH_TEST);

#endif

}

void Model::render(QPainter *painter, const QMatrix4x4 &matrix, bool normals) const

{

    m_mapped.resize(m_points.size());

    for (int i = 0; i < m_points.size(); ++i)

        m_mapped[i] = matrix.map(m_points.at(i));

    m_lines.clear();

    for (int i = 0; i < m_edgeIndices.size(); i += 2) {

        const QVector3D a = m_mapped.at(m_edgeIndices.at(i));

        const QVector3D b = m_mapped.at(m_edgeIndices.at(i+1));

        if (a.z() > 0 && b.z() > 0)

            m_lines << QLineF(a.toPointF(), b.toPointF());

    }

    if (normals) {

        for (int i = 0; i < m_normals.size(); ++i) {

            const QVector3D a = m_mapped.at(i);

            const QVector3D b = matrix.map(m_points.at(i) + m_normals.at(i) * 0.02f);

            if (a.z() > 0 && b.z() > 0)

                m_lines << QLineF(a.toPointF(), b.toPointF());

        }

    }

    painter->setRenderHint(QPainter::Antialiasing, false);

    painter->drawLines(m_lines);

}