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#include "qsgvideonode_rgb.h"
#include <QtQuick/qsgtexturematerial.h>
#include <QtQuick/qsgmaterial.h>
#include <QtCore/qmutex.h>
#include <QtGui/QOpenGLContext>
#include <QtGui/QOpenGLFunctions>
#include <QtGui/QOpenGLShaderProgram>

QList<QVideoFrame::PixelFormat> QSGVideoNodeFactory_RGB::supportedPixelFormats(
                                        QAbstractVideoBuffer::HandleType handleType) const
{
    QList<QVideoFrame::PixelFormat> pixelFormats;

    if (handleType == QAbstractVideoBuffer::NoHandle) {
        pixelFormats.append(QVideoFrame::Format_RGB565);
        pixelFormats.append(QVideoFrame::Format_RGB32);
        pixelFormats.append(QVideoFrame::Format_ARGB32);
        pixelFormats.append(QVideoFrame::Format_BGR32);
        pixelFormats.append(QVideoFrame::Format_BGRA32);
    }

    return pixelFormats;
}

QSGVideoNode *QSGVideoNodeFactory_RGB::createNode(const QVideoSurfaceFormat &format)
{
    if (supportedPixelFormats(format.handleType()).contains(format.pixelFormat()))
        return new QSGVideoNode_RGB(format);

    return 0;
}


class QSGVideoMaterialShader_RGB : public QSGMaterialShader
{
public:
    QSGVideoMaterialShader_RGB(QVideoFrame::PixelFormat pixelFormat)
        : QSGMaterialShader(),
          m_id_matrix(-1),
          m_id_rgbTexture(-1),
          m_id_opacity(-1),
          m_pixelFormat(pixelFormat)
    {
    }

    void updateState(const RenderState &state, QSGMaterial *newMaterial, QSGMaterial *oldMaterial);

    virtual char const *const *attributeNames() const {
        static const char *names[] = {
            "qt_VertexPosition",
            "qt_VertexTexCoord",
            0
        };
        return names;
    }

protected:

    virtual const char *vertexShader() const {
        const char *shader =
        "uniform highp mat4 qt_Matrix;                      \n"
        "attribute highp vec4 qt_VertexPosition;            \n"
        "attribute highp vec2 qt_VertexTexCoord;            \n"
        "varying highp vec2 qt_TexCoord;                    \n"
        "void main() {                                      \n"
        "    qt_TexCoord = qt_VertexTexCoord;               \n"
        "    gl_Position = qt_Matrix * qt_VertexPosition;   \n"
        "}";
        return shader;
    }

    virtual const char *fragmentShader() const {
        static const char *shader =
        "uniform sampler2D rgbTexture;"
        "uniform lowp float opacity;"
        ""
        "varying highp vec2 qt_TexCoord;"
        ""
        "void main()"
        "{"
        "    gl_FragColor = texture2D(rgbTexture, qt_TexCoord) * opacity;"
        "}";

        static const char *colorsSwapShader =
        "uniform sampler2D rgbTexture;"
        "uniform lowp float opacity;"
        ""
        "varying highp vec2 qt_TexCoord;"
        ""
        "void main()"
        "{"
        "    gl_FragColor =  vec4(texture2D(rgbTexture, qt_TexCoord).bgr, 1.0) * opacity;"
        "}";


        switch (m_pixelFormat) {
            case QVideoFrame::Format_RGB32:
            case QVideoFrame::Format_ARGB32:
                return colorsSwapShader;
            default:
                return shader;
        }
    }

    virtual void initialize() {
        m_id_matrix = program()->uniformLocation("qt_Matrix");
        m_id_rgbTexture = program()->uniformLocation("rgbTexture");
        m_id_opacity = program()->uniformLocation("opacity");
    }

    int m_id_matrix;
    int m_id_rgbTexture;
    int m_id_opacity;
    QVideoFrame::PixelFormat m_pixelFormat;
};


class QSGVideoMaterial_RGB : public QSGMaterial
{
public:
    QSGVideoMaterial_RGB(const QVideoSurfaceFormat &format) :
        m_format(format),
        m_textureId(0),
        m_opacity(1.0)
    {
        setFlag(Blending, false);
    }

    ~QSGVideoMaterial_RGB()
    {
        if (m_textureId)
            glDeleteTextures(1, &m_textureId);
    }

    virtual QSGMaterialType *type() const {
        static QSGMaterialType theType;
        return &theType;
    }

    virtual QSGMaterialShader *createShader() const {
        return new QSGVideoMaterialShader_RGB(m_format.pixelFormat());
    }

    virtual int compare(const QSGMaterial *other) const {
        const QSGVideoMaterial_RGB *m = static_cast<const QSGVideoMaterial_RGB *>(other);
        return m_textureId - m->m_textureId;
    }

    void updateBlending() {
        setFlag(Blending, qFuzzyCompare(m_opacity, qreal(1.0)) ? false : true);
    }

    void setVideoFrame(const QVideoFrame &frame) {
        QMutexLocker lock(&m_frameMutex);
        m_frame = frame;
    }

    void bind()
    {
        QOpenGLFunctions *functions = QOpenGLContext::currentContext()->functions();

        QMutexLocker lock(&m_frameMutex);
        if (m_frame.isValid()) {
            if (m_frame.map(QAbstractVideoBuffer::ReadOnly)) {
                if (m_textureSize != m_frame.size()) {
                    if (!m_textureSize.isEmpty())
                        glDeleteTextures(1, &m_textureId);
                    glGenTextures(1, &m_textureId);
                    m_textureSize = m_frame.size();
                }

                GLint dataType = GL_UNSIGNED_BYTE;
                GLint dataFormat = GL_RGBA;

                if (m_frame.pixelFormat() == QVideoFrame::Format_RGB565) {
                    dataType = GL_UNSIGNED_SHORT_5_6_5;
                    dataFormat = GL_RGB;
                }

                functions->glActiveTexture(GL_TEXTURE0);
                glBindTexture(GL_TEXTURE_2D, m_textureId);
                glTexImage2D(GL_TEXTURE_2D, 0, dataFormat,
                             m_textureSize.width(), m_textureSize.height(),
                             0, dataFormat, dataType, m_frame.bits());

                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

                m_frame.unmap();
            }
            m_frame = QVideoFrame();
        } else {
            functions->glActiveTexture(GL_TEXTURE0);
            glBindTexture(GL_TEXTURE_2D, m_textureId);
        }
    }

    QVideoFrame m_frame;
    QMutex m_frameMutex;
    QSize m_textureSize;
    QVideoSurfaceFormat m_format;
    GLuint m_textureId;
    qreal m_opacity;
};


QSGVideoNode_RGB::QSGVideoNode_RGB(const QVideoSurfaceFormat &format) :
    m_format(format)
{
    setFlag(QSGNode::OwnsMaterial);
    m_material = new QSGVideoMaterial_RGB(format);
    setMaterial(m_material);
}

QSGVideoNode_RGB::~QSGVideoNode_RGB()
{
}

void QSGVideoNode_RGB::setCurrentFrame(const QVideoFrame &frame)
{
    m_material->setVideoFrame(frame);
    markDirty(DirtyMaterial);
}

void QSGVideoMaterialShader_RGB::updateState(const RenderState &state,
                                                QSGMaterial *newMaterial,
                                                QSGMaterial *oldMaterial)
{
    Q_UNUSED(oldMaterial);
    QSGVideoMaterial_RGB *mat = static_cast<QSGVideoMaterial_RGB *>(newMaterial);
    program()->setUniformValue(m_id_rgbTexture, 0);

    mat->bind();

    if (state.isOpacityDirty()) {
        mat->m_opacity = state.opacity();
        mat->updateBlending();
        program()->setUniformValue(m_id_opacity, GLfloat(mat->m_opacity));
    }

    if (state.isMatrixDirty())
        program()->setUniformValue(m_id_matrix, state.combinedMatrix());
}
