/*
    SPDX-FileCopyrightText: 2015 The Qt Company Ltd. <https://www.qt.io/licensing/>

    This file is part of the demonstration applications of the Qt Toolkit.

    $QT_BEGIN_LICENSE:LGPL21$
    Commercial License Usage
    Licensees holding valid commercial Qt licenses may use this file in
    accordance with the commercial license agreement provided with the
    Software or, alternatively, in accordance with the terms contained in
    a written agreement between you and The Qt Company. For licensing terms
    and conditions see https://www.qt.io/terms-conditions. For further
    information use the contact form at https://www.qt.io/contact-us.

    GNU Lesser General Public License Usage
    Alternatively, this file may be used under the terms of the GNU Lesser
    General Public License version 2.1 or version 3 as published by the Free
    Software Foundation and appearing in the file LICENSE.LGPLv21 and
    LICENSE.LGPLv3 included in the packaging of this file. Please review the
    following information to ensure the GNU Lesser General Public License
    requirements will be met: https://www.gnu.org/licenses/lgpl.html and
    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

    As a special exception, The Qt Company gives you certain additional
    rights. These rights are described in The Qt Company LGPL Exception
    version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

    $QT_END_LICENSE$

*/

#pragma once

#include <qguiapplication.h>

#include <qsgmaterial.h>
#include <qsgnode.h>

#include <qquickitem.h>
#include <qquickview.h>

#include <qsgsimplerectnode.h>

#include <qsgsimplematerial.h>

//! [1]
struct State
{
    QColor color;

    int compare(const State *other) const
    {
        uint rgb      = color.rgba();
        uint otherRgb = other->color.rgba();

        if (rgb == otherRgb)
        {
            return 0;
        }
        else if (rgb < otherRgb)
        {
            return -1;
        }
        else
        {
            return 1;
        }
    }
};
//! [1]

//! [2]
class Shader : public QSGSimpleMaterialShader<State>
{
    QSG_DECLARE_SIMPLE_COMPARABLE_SHADER(Shader, State)
    //! [2] //! [3]
  public:
    const char *vertexShader() const
    {
        return "attribute highp vec4 aVertex;                              \n"
               "attribute highp vec2 aTexCoord;                            \n"
               "uniform highp mat4 qt_Matrix;                              \n"
               "uniform highp mat4 mvp_matrix;                              \n"
               "varying highp vec2 texCoord;                               \n"
               "void main() {                                              \n"
               "    gl_Position = qt_Matrix * aVertex;                     \n"
               "    texCoord = aTexCoord;                                  \n"
               "}";
    }

    const char *fragmentShader() const
    {
        return "uniform lowp float qt_Opacity;                             \n"
               "uniform lowp vec4 color;                                   \n"
               "varying highp vec2 texCoord;                               \n"
               "void main ()                                               \n"
               "{                                                          \n"
               //"if (cos(0.1*abs(distance(vec2(100.0,100.0).xy, texCoord.xy))) + 0.5 > 0.0) { \n"
               "if(texCoord.x < 0.1 || texCoord.x > 0.2 && texCoord.x < 0.3) { \n"
               "    gl_FragColor = vec4(0.0,0.0,0.0,0.0) * qt_Opacity;  \n"
               " } else {\n"
               "    gl_FragColor = texCoord.y * texCoord.x * color * qt_Opacity;  \n"
               "    }\n"
               "}";
    }
    //! [3] //! [4]
    QList<QByteArray> attributes() const
    {
        return QList<QByteArray>() << "aVertex"
                                   << "aTexCoord";
    }
    //! [4] //! [5]
    void updateState(const State *state, const State *) { program()->setUniformValue(id_color, state->color); }
    //! [5] //! [6]
    void resolveUniforms() { id_color = program()->uniformLocation("color"); }

  private:
    int id_color;
    //! [6]
};

//! [7]
class ColorNode : public QSGGeometryNode
{
  public:
    ColorNode() : m_geometry(QSGGeometry::defaultAttributes_TexturedPoint2D(), 4)
    {
        setGeometry(&m_geometry);

        QSGSimpleMaterial<State> *material = Shader::createMaterial();
        material->setFlag(QSGMaterial::Blending);
        setMaterial(material);
        setFlag(OwnsMaterial);
    }

    QSGGeometry m_geometry;
};
//! [7]

//! [8]
class Item : public QQuickItem
{
    Q_OBJECT

    Q_PROPERTY(QColor color READ color WRITE setColor NOTIFY colorChanged)

  public:
    Item() { setFlag(ItemHasContents, true); }

    void setColor(const QColor &color)
    {
        if (m_color != color)
        {
            m_color = color;
            emit colorChanged();
            update();
        }
    }
    QColor color() const { return m_color; }

  signals:
    void colorChanged();

  private:
    QColor m_color;

    //! [8] //! [9]
  public:
    QSGNode *updatePaintNode(QSGNode *node, UpdatePaintNodeData *)
    {
        ColorNode *n = static_cast<ColorNode *>(node);
        if (!node)
            n = new ColorNode();

        QSGGeometry::updateTexturedRectGeometry(n->geometry(), boundingRect(), QRectF(0, 0, 1, 1));
        static_cast<QSGSimpleMaterial<State> *>(n->material())->state()->color = m_color;

        n->markDirty(QSGNode::DirtyGeometry | QSGNode::DirtyMaterial);

        return n;
    }
};

//#include "simplematerial.moc"
//! [11]
