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#include "qsgshadereffectsource_p.h"

#include "qsgitem_p.h"
#include "qsgcanvas_p.h"
#include <private/qsgadaptationlayer_p.h>
#include <private/qsgrenderer_p.h>

#include "qglframebufferobject.h"
#include "qmath.h"
#include <private/qsgtexture_p.h>

QT_BEGIN_NAMESPACE

DEFINE_BOOL_CONFIG_OPTION(qmlFboOverlay, QML_FBO_OVERLAY)

QSGShaderEffectTexture::QSGShaderEffectTexture(QSGItem *shaderSource)
    : QSGDynamicTexture()
    , m_item(0)
    , m_format(GL_RGBA)
    , m_shaderSource(shaderSource)
    , m_renderer(0)
    , m_fbo(0)
    , m_multisampledFbo(0)
#ifdef QSG_DEBUG_FBO_OVERLAY
    , m_debugOverlay(0)
#endif
    , m_live(true)
    , m_dirtyTexture(true)
    , m_multisamplingSupportChecked(false)
    , m_multisampling(false)
{
}

QSGShaderEffectTexture::~QSGShaderEffectTexture()
{
    delete m_renderer;
    delete m_fbo;
    delete m_multisampledFbo;
#ifdef QSG_DEBUG_FBO_OVERLAY
    delete m_debugOverlay;
#endif
}


int QSGShaderEffectTexture::textureId() const
{
    return m_fbo->texture();
}

bool QSGShaderEffectTexture::hasAlphaChannel() const
{
    return m_format != GL_RGB;
}

bool QSGShaderEffectTexture::hasMipmaps() const
{
    return m_mipmapFiltering;
}


void QSGShaderEffectTexture::bind()
{
    glBindTexture(GL_TEXTURE_2D, m_fbo->texture());
    updateBindOptions();
}

bool QSGShaderEffectTexture::updateTexture()
{
    if (m_dirtyTexture) {
        grab();
        return true;
    }
    return false;
}

void QSGShaderEffectTexture::setHasMipmaps(QSGTexture::Filtering filtering)
{
    if (filtering == m_mipmapFiltering)
        return;
    m_mipmapFiltering = filtering;
    if (filtering != None && m_fbo && !m_fbo->format().mipmap())
        markDirtyTexture();
}


void QSGShaderEffectTexture::setItem(QSGNode *item)
{
    if (item == m_item)
        return;
    m_item = item;
    markDirtyTexture();
}

void QSGShaderEffectTexture::setRect(const QRectF &rect)
{
    if (rect == m_rect)
        return;
    m_rect = rect;
    markDirtyTexture();
}

void QSGShaderEffectTexture::setSize(const QSize &size)
{
    if (size == m_size)
        return;
    m_size = size;
    markDirtyTexture();
}

void QSGShaderEffectTexture::setFormat(GLenum format)
{
    if (format == m_format)
        return;
    m_format = format;
    markDirtyTexture();
}

void QSGShaderEffectTexture::setLive(bool live)
{
    if (live == m_live)
        return;
    m_live = live;
    markDirtyTexture();
}

void QSGShaderEffectTexture::markDirtyTexture()
{
    if (m_live) {
        m_dirtyTexture = true;
        emit textureChanged();
    }
}

void QSGShaderEffectTexture::grab()
{
    Q_ASSERT(m_item);
    QSGNode *root = m_item;
    while (root->childCount() && root->type() != QSGNode::RootNodeType)
        root = root->childAtIndex(0);
    if (root->type() != QSGNode::RootNodeType)
        return;

    if (m_size.isEmpty()) {
        delete m_fbo;
        delete m_multisampledFbo;
        m_multisampledFbo = m_fbo = 0;
        return;
    }

    QSGContext *context = QSGItemPrivate::get(m_shaderSource)->sceneGraphContext();

    if (!m_renderer) {
        m_renderer = context->createRenderer();
        connect(m_renderer, SIGNAL(sceneGraphChanged()), this, SLOT(markDirtyTexture()), Qt::DirectConnection);
    }
    m_renderer->setRootNode(static_cast<QSGRootNode *>(root));

    bool mipmap = m_mipmapFiltering != None;
    if (!m_fbo || m_fbo->size() != m_size || m_fbo->format().internalTextureFormat() != m_format
        || (!m_fbo->format().mipmap() && mipmap))
    {
        if (!m_multisamplingSupportChecked) {
            QList<QByteArray> extensions = QByteArray((const char *)glGetString(GL_EXTENSIONS)).split(' ');
            m_multisampling = extensions.contains("GL_EXT_framebuffer_multisample")
                            && extensions.contains("GL_EXT_framebuffer_blit");
            m_multisamplingSupportChecked = true;
        }
        if (m_multisampling) {
            delete m_fbo;
            delete m_multisampledFbo;
            QGLFramebufferObjectFormat format;

            format.setAttachment(QGLFramebufferObject::CombinedDepthStencil);
            format.setInternalTextureFormat(m_format);
            format.setSamples(8);
            m_multisampledFbo = new QGLFramebufferObject(m_size, format);

            format.setAttachment(QGLFramebufferObject::NoAttachment);
            format.setMipmap(m_mipmapFiltering);
            format.setSamples(0);
            m_fbo = new QGLFramebufferObject(m_size, format);

        } else {
            delete m_fbo;
            QGLFramebufferObjectFormat format;
            format.setAttachment(QGLFramebufferObject::CombinedDepthStencil);
            format.setInternalTextureFormat(m_format);
            format.setMipmap(m_mipmapFiltering);
            m_fbo = new QGLFramebufferObject(m_size, format);
        }
    }

    // Render texture.
    QSGNode::DirtyFlags dirty = root->dirtyFlags();
    root->markDirty(QSGNode::DirtyNodeAdded); // Force matrix and clip update.
    m_renderer->nodeChanged(root, QSGNode::DirtyNodeAdded); // Force render list update.

#ifdef QSG_DEBUG_FBO_OVERLAY
    if (qmlFboOverlay()) {
        if (!m_debugOverlay)
            m_debugOverlay = context->createRectangleNode();
        m_debugOverlay->setRect(QRectF(0, 0, m_size.width(), m_size.height()));
        m_debugOverlay->setColor(QColor(0xff, 0x00, 0x80, 0x40));
        m_debugOverlay->setPenColor(QColor());
        m_debugOverlay->setPenWidth(0);
        m_debugOverlay->setRadius(0);
        m_debugOverlay->update();
        root->appendChildNode(m_debugOverlay);
    }
#endif

    m_dirtyTexture = false;

    const QGLContext *ctx = QGLContext::currentContext();
    m_renderer->setDeviceRect(m_size);
    m_renderer->setViewportRect(m_size);
    QRectF mirrored(m_rect.left(), m_rect.bottom(), m_rect.width(), -m_rect.height());
    m_renderer->setProjectMatrixToRect(mirrored);
    m_renderer->setClearColor(Qt::transparent);

    if (m_multisampling) {
        m_renderer->renderScene(BindableFbo(m_multisampledFbo));
        QRect r(0, 0, m_fbo->width(), m_fbo->height());
        QGLFramebufferObject::blitFramebuffer(m_fbo, r, m_multisampledFbo, r);
    } else {
        m_renderer->renderScene(BindableFbo(m_fbo));
    }

    if (mipmap) {
        glBindTexture(GL_TEXTURE_2D, textureId());
        ctx->functions()->glGenerateMipmap(GL_TEXTURE_2D);
    }

    root->markDirty(dirty | QSGNode::DirtyNodeAdded); // Force matrix, clip and render list update.

#ifdef QSG_DEBUG_FBO_OVERLAY
    if (qmlFboOverlay())
        root->removeChildNode(m_debugOverlay);
#endif
}


QSGShaderEffectSource::QSGShaderEffectSource(QSGItem *parent)
    : QSGItem(parent)
    , m_wrapMode(ClampToEdge)
    , m_sourceItem(0)
    , m_textureSize(0, 0)
    , m_format(RGBA)
    , m_live(true)
    , m_hideSource(false)
    , m_mipmap(false)
{
    setFlag(ItemHasContents);
    m_texture = new QSGShaderEffectTexture(this);
    connect(m_texture, SIGNAL(textureChanged()), this, SIGNAL(textureChanged()), Qt::DirectConnection);
}

QSGShaderEffectSource::~QSGShaderEffectSource()
{
    delete m_texture;
    if (m_sourceItem)
        QSGItemPrivate::get(m_sourceItem)->derefFromEffectItem(m_hideSource);
}

QSGShaderEffectSource::WrapMode QSGShaderEffectSource::wrapMode() const
{
    return m_wrapMode;
}

void QSGShaderEffectSource::setWrapMode(WrapMode mode)
{
    if (mode == m_wrapMode)
        return;
    m_wrapMode = mode;
    update();
    emit wrapModeChanged();
}

QSGItem *QSGShaderEffectSource::sourceItem() const
{
    return m_sourceItem;
}

void QSGShaderEffectSource::setSourceItem(QSGItem *item)
{
    if (item == m_sourceItem)
        return;
    if (m_sourceItem)
        QSGItemPrivate::get(m_sourceItem)->derefFromEffectItem(m_hideSource);
    m_sourceItem = item;
    if (m_sourceItem) {
        // TODO: Find better solution.
        // 'm_sourceItem' needs a canvas to get a scenegraph node.
        // The easiest way to make sure it gets a canvas is to
        // make it a part of the same item tree as 'this'.
        if (m_sourceItem->parentItem() == 0) {
            m_sourceItem->setParentItem(this);
            m_sourceItem->setVisible(false);
        }
        QSGItemPrivate::get(m_sourceItem)->refFromEffectItem(m_hideSource);
    }
    update();
    emit sourceItemChanged();
}

QRectF QSGShaderEffectSource::sourceRect() const
{
    return m_sourceRect;
}

void QSGShaderEffectSource::setSourceRect(const QRectF &rect)
{
    if (rect == m_sourceRect)
        return;
    m_sourceRect = rect;
    update();
    emit sourceRectChanged();
}

QSize QSGShaderEffectSource::textureSize() const
{
    return m_textureSize;
}

void QSGShaderEffectSource::setTextureSize(const QSize &size)
{
    if (size == m_textureSize)
        return;
    m_textureSize = size;
    update();
    emit textureSizeChanged();
}

QSGShaderEffectSource::Format QSGShaderEffectSource::format() const
{
    return m_format;
}

void QSGShaderEffectSource::setFormat(QSGShaderEffectSource::Format format)
{
    if (format == m_format)
        return;
    m_format = format;
    update();
    emit formatChanged();
}

bool QSGShaderEffectSource::live() const
{
    return m_live;
}

void QSGShaderEffectSource::setLive(bool live)
{
    if (live == m_live)
        return;
    m_live = live;
    update();
    emit liveChanged();
}

bool QSGShaderEffectSource::hideSource() const
{
    return m_hideSource;
}

void QSGShaderEffectSource::setHideSource(bool hide)
{
    if (hide == m_hideSource)
        return;
    if (m_sourceItem) {
        QSGItemPrivate::get(m_sourceItem)->refFromEffectItem(hide);
        QSGItemPrivate::get(m_sourceItem)->derefFromEffectItem(m_hideSource);
    }
    m_hideSource = hide;
    update();
    emit hideSourceChanged();
}

bool QSGShaderEffectSource::mipmap() const
{
    return m_mipmap;
}

void QSGShaderEffectSource::setMipmap(bool enabled)
{
    if (enabled == m_mipmap)
        return;
    printf("setting mipmap to: %d\n", enabled);
    m_mipmap = enabled;
    update();
    emit mipmapChanged();
}

void QSGShaderEffectSource::grab()
{
    if (!m_sourceItem)
        return;
    QSGCanvas *canvas = m_sourceItem->canvas();
    if (!canvas)
        return;
    QSGCanvasPrivate::get(canvas)->updateDirtyNodes();
    QGLContext *glctx = const_cast<QGLContext *>(canvas->context());
    glctx->makeCurrent();
    qobject_cast<QSGShaderEffectTexture *>(m_texture)->grab();
}

static void get_wrap_mode(QSGShaderEffectSource::WrapMode mode, QSGTexture::WrapMode *hWrap, QSGTexture::WrapMode *vWrap)
{
    switch (mode) {
    case QSGShaderEffectSource::RepeatHorizontally:
        *hWrap = QSGTexture::Repeat;
        *vWrap = QSGTexture::ClampToEdge;
        break;
    case QSGShaderEffectSource::RepeatVertically:
        *vWrap = QSGTexture::Repeat;
        *hWrap = QSGTexture::ClampToEdge;
        break;
    case QSGShaderEffectSource::Repeat:
        *hWrap = *vWrap = QSGTexture::Repeat;
        break;
    default:
        break;
    }
}


QSGTexture *QSGShaderEffectSource::texture() const
{
    m_texture->setMipmapFiltering(m_mipmap ? QSGTexture::Linear : QSGTexture::None);
    m_texture->setFiltering(QSGItemPrivate::get(this)->smooth ? QSGTexture::Linear : QSGTexture::Nearest);
    QSGTexture::WrapMode h, v;
    get_wrap_mode(m_wrapMode, &h, &v);
    m_texture->setHorizontalWrapMode(h);
    m_texture->setVerticalWrapMode(v);
    return m_texture;
}

QSGNode *QSGShaderEffectSource::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *)
{
    if (!m_sourceItem) {
        delete oldNode;
        return 0;
    }

    QSGImageNode *node = static_cast<QSGImageNode *>(oldNode);
    if (!node) {
        node = QSGItemPrivate::get(this)->sceneGraphContext()->createImageNode();
        node->setFlag(QSGNode::UsePreprocess, true);
        node->setTexture(m_texture);
    }

    QSGShaderEffectTexture *tex = qobject_cast<QSGShaderEffectTexture *>(m_texture);

    tex->setItem(QSGItemPrivate::get(m_sourceItem)->itemNode());
    QRectF sourceRect = m_sourceRect.isNull()
                      ? QRectF(0, 0, m_sourceItem->width(), m_sourceItem->height())
                      : m_sourceRect;
    tex->setRect(sourceRect);
    QSize textureSize = m_textureSize.isEmpty()
                      ? QSize(qCeil(qAbs(sourceRect.width())), qCeil(qAbs(sourceRect.height())))
                      : m_textureSize;
    tex->setSize(textureSize);
    tex->setLive(m_live);
    tex->setFormat(GLenum(m_format));

    QSGTexture::Filtering filtering = QSGItemPrivate::get(this)->smooth
                                            ? QSGTexture::Linear
                                            : QSGTexture::Nearest;
    QSGTexture::Filtering mmFiltering = m_mipmap ? filtering : QSGTexture::None;
    tex->setHasMipmaps(mmFiltering);
    node->setMipmapFiltering(mmFiltering);
    node->setFiltering(filtering);

    QSGTexture::WrapMode hWrap, vWrap;
    get_wrap_mode(m_wrapMode, &hWrap, &vWrap);

    node->setHorizontalWrapMode(hWrap);
    node->setVerticalWrapMode(vWrap);
    node->setTargetRect(QRectF(0, 0, width(), height()));
    node->setSourceRect(QRectF(0, 0, 1, 1));
    node->update();

    return node;
}

QT_END_NAMESPACE