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#include "qphongalphamaterial.h"
#include "qphongalphamaterial_p.h"
#include <Qt3DRender/qfilterkey.h>
#include <Qt3DRender/qmaterial.h>
#include <Qt3DRender/qeffect.h>
#include <Qt3DRender/qtechnique.h>
#include <Qt3DRender/qshaderprogram.h>
#include <Qt3DRender/qparameter.h>
#include <Qt3DRender/qrenderpass.h>
#include <Qt3DRender/qgraphicsapifilter.h>
#include <Qt3DRender/qblendequation.h>
#include <Qt3DRender/qblendequationarguments.h>
#include <Qt3DRender/qnodepthmask.h>
#include <QUrl>
#include <QVector3D>
#include <QVector4D>

QT_BEGIN_NAMESPACE

using namespace Qt3DRender;

namespace Qt3DExtras {

QPhongAlphaMaterialPrivate::QPhongAlphaMaterialPrivate()
    : QMaterialPrivate()
    , m_phongEffect(new QEffect())
    , m_ambientParameter(new QParameter(QStringLiteral("ka"), QColor::fromRgbF(0.05f, 0.05f, 0.05f, 1.0f)))
    , m_diffuseParameter(new QParameter(QStringLiteral("kd"), QColor::fromRgbF(0.7f, 0.7f, 0.7f, 1.0f)))
    , m_specularParameter(new QParameter(QStringLiteral("ks"), QColor::fromRgbF(0.01f, 0.01f, 0.01f, 1.0f)))
    , m_shininessParameter(new QParameter(QStringLiteral("shininess"), 150.0f))
    , m_alphaParameter(new QParameter(QStringLiteral("alpha"), 0.5f))
    , m_phongAlphaGL3Technique(new QTechnique())
    , m_phongAlphaGL2Technique(new QTechnique())
    , m_phongAlphaES2Technique(new QTechnique())
    , m_phongAlphaGL3RenderPass(new QRenderPass())
    , m_phongAlphaGL2RenderPass(new QRenderPass())
    , m_phongAlphaES2RenderPass(new QRenderPass())
    , m_phongAlphaGL3Shader(new QShaderProgram())
    , m_phongAlphaGL2ES2Shader(new QShaderProgram())
    , m_noDepthMask(new QNoDepthMask())
    , m_blendState(new QBlendEquationArguments())
    , m_blendEquation(new QBlendEquation())
    , m_filterKey(new QFilterKey)
{
}

// TODO: Define how lights are properties are set in the shaders. Ideally using a QShaderData
void QPhongAlphaMaterialPrivate::init()
{
    connect(m_ambientParameter, &Qt3DRender::QParameter::valueChanged,
            this, &QPhongAlphaMaterialPrivate::handleAmbientChanged);
    connect(m_diffuseParameter, &Qt3DRender::QParameter::valueChanged,
            this, &QPhongAlphaMaterialPrivate::handleDiffuseChanged);
    connect(m_specularParameter, &Qt3DRender::QParameter::valueChanged,
            this, &QPhongAlphaMaterialPrivate::handleSpecularChanged);
    connect(m_shininessParameter, &Qt3DRender::QParameter::valueChanged,
            this, &QPhongAlphaMaterialPrivate::handleShininessChanged);
    connect(m_alphaParameter, &Qt3DRender::QParameter::valueChanged,
            this, &QPhongAlphaMaterialPrivate::handleAlphaChanged);

    m_phongAlphaGL3Shader->setVertexShaderCode(QShaderProgram::loadSource(QUrl(QStringLiteral("qrc:/shaders/gl3/phong.vert"))));
    m_phongAlphaGL3Shader->setFragmentShaderCode(QShaderProgram::loadSource(QUrl(QStringLiteral("qrc:/shaders/gl3/phongalpha.frag"))));
    m_phongAlphaGL2ES2Shader->setVertexShaderCode(QShaderProgram::loadSource(QUrl(QStringLiteral("qrc:/shaders/es2/phong.vert"))));
    m_phongAlphaGL2ES2Shader->setFragmentShaderCode(QShaderProgram::loadSource(QUrl(QStringLiteral("qrc:/shaders/es2/phongalpha.frag"))));

    m_phongAlphaGL3Technique->graphicsApiFilter()->setApi(QGraphicsApiFilter::OpenGL);
    m_phongAlphaGL3Technique->graphicsApiFilter()->setMajorVersion(3);
    m_phongAlphaGL3Technique->graphicsApiFilter()->setMinorVersion(1);
    m_phongAlphaGL3Technique->graphicsApiFilter()->setProfile(QGraphicsApiFilter::CoreProfile);

    m_phongAlphaGL2Technique->graphicsApiFilter()->setApi(QGraphicsApiFilter::OpenGL);
    m_phongAlphaGL2Technique->graphicsApiFilter()->setMajorVersion(2);
    m_phongAlphaGL2Technique->graphicsApiFilter()->setMinorVersion(0);
    m_phongAlphaGL2Technique->graphicsApiFilter()->setProfile(QGraphicsApiFilter::NoProfile);

    m_phongAlphaES2Technique->graphicsApiFilter()->setApi(QGraphicsApiFilter::OpenGLES);
    m_phongAlphaES2Technique->graphicsApiFilter()->setMajorVersion(2);
    m_phongAlphaES2Technique->graphicsApiFilter()->setMinorVersion(0);
    m_phongAlphaES2Technique->graphicsApiFilter()->setProfile(QGraphicsApiFilter::NoProfile);

    Q_Q(QPhongAlphaMaterial);
    m_filterKey->setParent(q);
    m_filterKey->setName(QStringLiteral("renderingStyle"));
    m_filterKey->setValue(QStringLiteral("forward"));

    m_phongAlphaGL3Technique->addFilterKey(m_filterKey);
    m_phongAlphaGL2Technique->addFilterKey(m_filterKey);
    m_phongAlphaES2Technique->addFilterKey(m_filterKey);

    m_blendState->setSourceRgb(QBlendEquationArguments::SourceAlpha);
    m_blendState->setDestinationRgb(QBlendEquationArguments::OneMinusSourceAlpha);
    m_blendEquation->setBlendFunction(QBlendEquation::Add);

    m_phongAlphaGL3RenderPass->setShaderProgram(m_phongAlphaGL3Shader);
    m_phongAlphaGL2RenderPass->setShaderProgram(m_phongAlphaGL2ES2Shader);
    m_phongAlphaES2RenderPass->setShaderProgram(m_phongAlphaGL2ES2Shader);

    m_phongAlphaGL3RenderPass->addRenderState(m_noDepthMask);
    m_phongAlphaGL3RenderPass->addRenderState(m_blendState);
    m_phongAlphaGL3RenderPass->addRenderState(m_blendEquation);

    m_phongAlphaGL2RenderPass->addRenderState(m_noDepthMask);
    m_phongAlphaGL2RenderPass->addRenderState(m_blendState);
    m_phongAlphaGL2RenderPass->addRenderState(m_blendEquation);

    m_phongAlphaES2RenderPass->addRenderState(m_noDepthMask);
    m_phongAlphaES2RenderPass->addRenderState(m_blendState);
    m_phongAlphaES2RenderPass->addRenderState(m_blendEquation);

    m_phongAlphaGL3Technique->addRenderPass(m_phongAlphaGL3RenderPass);
    m_phongAlphaGL2Technique->addRenderPass(m_phongAlphaGL2RenderPass);
    m_phongAlphaES2Technique->addRenderPass(m_phongAlphaES2RenderPass);

    m_phongEffect->addTechnique(m_phongAlphaGL3Technique);
    m_phongEffect->addTechnique(m_phongAlphaGL2Technique);
    m_phongEffect->addTechnique(m_phongAlphaES2Technique);

    m_phongEffect->addParameter(m_ambientParameter);
    m_phongEffect->addParameter(m_diffuseParameter);
    m_phongEffect->addParameter(m_specularParameter);
    m_phongEffect->addParameter(m_shininessParameter);
    m_phongEffect->addParameter(m_alphaParameter);

    q->setEffect(m_phongEffect);
}

void QPhongAlphaMaterialPrivate::handleAmbientChanged(const QVariant &var)
{
    Q_Q(QPhongAlphaMaterial);
    emit q->ambientChanged(var.value<QColor>());
}

void QPhongAlphaMaterialPrivate::handleDiffuseChanged(const QVariant &var)
{
    Q_Q(QPhongAlphaMaterial);
    emit q->diffuseChanged(var.value<QColor>());
}

void QPhongAlphaMaterialPrivate::handleSpecularChanged(const QVariant &var)
{
    Q_Q(QPhongAlphaMaterial);
    emit q->specularChanged(var.value<QColor>());
}

void QPhongAlphaMaterialPrivate::handleShininessChanged(const QVariant &var)
{
    Q_Q(QPhongAlphaMaterial);
    emit q->shininessChanged(var.toFloat());
}

void QPhongAlphaMaterialPrivate::handleAlphaChanged(const QVariant &var)
{
    Q_Q(QPhongAlphaMaterial);
    emit q->alphaChanged(var.toFloat());
}

/*!
    \class Qt3DRender::QPhongAlphaMaterial

    \brief The QPhongAlphaMaterial class provides a default implementation of
    the phong lighting effect with alpha.
    \inmodule Qt3DRenderer
    \since 5.5

    The phong lighting effect is based on the combination of 3 lighting components ambient, diffuse and specular.
    The relative strengths of these components is controlled by means of their reflectivity coefficients which are modelled as RGB triplets:

    \list
    \li Ambient is the color that is emitted by an object without any other light source.
    \li Diffuse is the color that is emitted for rought surface reflections with the lights.
    \li Specular is the color emitted for shiny surface reflections with the lights.
    \li The shininess of a surface is controlled by a float property.
    \li Alpha is the transparency of the surface between 0 (fully transparent) and 1 (opaque).
    \endlist

    This material uses an effect with a single render pass approach and performs per fragment lighting.
    Techniques are provided for OpenGL 2, OpenGL 3 or above as well as OpenGL ES 2.
*/

/*!
    \fn Qt3DRender::QPhongAlphaMaterial::QPhongAlphaMaterial(Qt3DCore::QNode *parent)

    Constructs a new QPhongAlphaMaterial instance with parent object \a parent.
*/
QPhongAlphaMaterial::QPhongAlphaMaterial(QNode *parent)
    : QMaterial(*new QPhongAlphaMaterialPrivate, parent)
{
    Q_D(QPhongAlphaMaterial);
    d->init();
}

/*!
   Destroys the QPhongAlphaMaterial.
*/
QPhongAlphaMaterial::~QPhongAlphaMaterial()
{
}

/*!
    \property Qt3DRender::QPhongAlphaMaterial::ambient

    Holds the ambient color.
*/
QColor QPhongAlphaMaterial::ambient() const
{
    Q_D(const QPhongAlphaMaterial);
    return d->m_ambientParameter->value().value<QColor>();
}

/*!
    \property Qt3DRender::QPhongAlphaMaterial::diffuse

    Holds the diffuse color.
*/
QColor QPhongAlphaMaterial::diffuse() const
{
    Q_D(const QPhongAlphaMaterial);
    return d->m_diffuseParameter->value().value<QColor>();
}

/*!
    \property Qt3DRender::QPhongAlphaMaterial::specular

    Holds the specular color.
*/
QColor QPhongAlphaMaterial::specular() const
{
    Q_D(const QPhongAlphaMaterial);
    return d->m_specularParameter->value().value<QColor>();
}

/*!
    \property Qt3DRender::QPhongAlphaMaterial::shininess

    Holds the shininess exponent.
*/
float QPhongAlphaMaterial::shininess() const
{
    Q_D(const QPhongAlphaMaterial);
    return d->m_shininessParameter->value().toFloat();
}

/*!
    \property Qt3DRender::QPhongAlphaMaterial::alpha

    Holds the alpha component of the object which varies between 0 and 1.

    \note: default value is 0.5f
*/
float QPhongAlphaMaterial::alpha() const
{
    Q_D(const QPhongAlphaMaterial);
    return d->m_alphaParameter->value().toFloat();
}

void QPhongAlphaMaterial::setAmbient(const QColor &ambient)
{
    Q_D(QPhongAlphaMaterial);
    d->m_ambientParameter->setValue(ambient);
}

void QPhongAlphaMaterial::setDiffuse(const QColor &diffuse)
{
    Q_D(QPhongAlphaMaterial);
    d->m_diffuseParameter->setValue(diffuse);
}

void QPhongAlphaMaterial::setSpecular(const QColor &specular)
{
    Q_D(QPhongAlphaMaterial);
    d->m_specularParameter->setValue(specular);
}

void QPhongAlphaMaterial::setShininess(float shininess)
{
    Q_D(QPhongAlphaMaterial);
    d->m_shininessParameter->setValue(shininess);
}

void QPhongAlphaMaterial::setAlpha(float alpha)
{
    Q_D(QPhongAlphaMaterial);
    d->m_alphaParameter->setValue(alpha);
}

} // namespace Qt3DExtras

QT_END_NAMESPACE