canvasrendernode.cpp

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** Copyright (C) 2015 The Qt Company Ltd.
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** This file is part of the QtCanvas3D module of the Qt Toolkit.
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#include "canvasrendernode_p.h"
#include "canvas3d_p.h"
#include <QtGui/QOpenGLContext>
#include <QtGui/QOpenGLFramebufferObject>

QT_BEGIN_NAMESPACE
QT_CANVAS3D_BEGIN_NAMESPACE

CanvasRenderNode::CanvasRenderNode(Canvas *canvas, QQuickWindow *window) :
    QObject(),
    QSGSimpleTextureNode(),
    m_canvas(canvas),
    m_id(0),
    m_size(0,0),
    m_texture(0),
    m_window(window)
{
    qCDebug(canvas3drendering).nospace() << "CanvasRenderNode::" << __FUNCTION__;

    // Our texture node must have a texture, so use the default 0 texture.
    m_texture = m_window->createTextureFromId(0, QSize(1, 1));
    setTexture(m_texture);
    setFiltering(QSGTexture::Linear);
    setTextureCoordinatesTransform(QSGSimpleTextureNode::MirrorVertically);
}

CanvasRenderNode::~CanvasRenderNode()
{
    delete m_texture;
}

void CanvasRenderNode::newTexture(int id, const QSize &size)
{
    qCDebug(canvas3drendering).nospace() << "CanvasRenderNode::" << __FUNCTION__
                                         << "(" << id << ", " << size << ")";
    m_mutex.lock();
    m_id = id;
    m_size = size;
    m_mutex.unlock();

    // We cannot call QQuickWindow::update directly here, as this is only allowed
    // from the rendering thread or GUI thread.
    emit pendingNewTexture();
}

// Before the scene graph starts to render, we update to the pending texture
void CanvasRenderNode::prepareNode()
{
    qCDebug(canvas3drendering).nospace() << "CanvasRenderNode::" << __FUNCTION__;
    m_mutex.lock();
    int newId = m_id;
    QSize size = m_size;
    m_id = 0;
    m_mutex.unlock();

    if (newId) {
        qCDebug(canvas3drendering).nospace() << "CanvasRenderNode::" << __FUNCTION__
                                             << " showing new texture:" << newId
                                             << " size:" << size
                                             << " targetRect:" << rect();
        delete m_texture;
        m_texture = m_window->createTextureFromId(newId, size);
        setTexture(m_texture);
        qCDebug(canvas3drendering).nospace() << "CanvasRenderNode::" << __FUNCTION__
                                             << " SGTexture size:" << m_texture->textureSize()
                                             << " normalizedTextureSubRect:"
                                             << m_texture->normalizedTextureSubRect();

        // This will notify the main thread that the texture is now being rendered
        // and it can start rendering to the other one.
        emit textureInUse();
    } else {
        qCDebug(canvas3drendering).nospace() << "CanvasRenderNode::" << __FUNCTION__
                                             << " showing previous texture";
    }
}

QT_CANVAS3D_END_NAMESPACE
QT_END_NAMESPACE