shadereffectsource.cpp

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#include "shadereffectsource.h"
#include "shadereffectbuffer.h"
#include "shadereffect.h"
#include "glfunctions.h"

#include <QtOpenGL>

ShaderEffectSource::ShaderEffectSource(QDeclarativeItem *parent)
    : QDeclarativeItem(parent)
    , m_sourceItem(0)
    , m_wrapMode(ClampToEdge)
    , m_sourceRect(0, 0, 0, 0)
    , m_textureSize(0, 0)
    , m_format(RGBA)
    , m_size(0, 0)
    , m_fbo(0)
    , m_multisampledFbo(0)
    , m_refs(0)
    , m_dirtyTexture(true)
    , m_dirtySceneGraph(true)
    , m_multisamplingSupported(false)
    , m_checkedForMultisamplingSupport(false)
    , m_live(true)
    , m_hideSource(false)
    , m_mirrored(false)
{
}

ShaderEffectSource::~ShaderEffectSource()
{
    if (m_refs && m_sourceItem)
        detachSourceItem();

    delete m_fbo;
    delete m_multisampledFbo;
}

void ShaderEffectSource::setSourceItem(QDeclarativeItem *item)
{
    if (item == m_sourceItem)
        return;

    if (m_sourceItem) {
        disconnect(m_sourceItem, SIGNAL(widthChanged()), this, SLOT(markSourceSizeDirty()));
        disconnect(m_sourceItem, SIGNAL(heightChanged()), this, SLOT(markSourceSizeDirty()));

        if (m_refs)
            detachSourceItem();
    }

    m_sourceItem = item;

    if (m_sourceItem) {

        // Must have some item as parent
        if (m_sourceItem->parentItem() == 0)
            m_sourceItem->setParentItem(this);

        if (m_refs)
            attachSourceItem();

        connect(m_sourceItem, SIGNAL(widthChanged()), this, SLOT(markSourceSizeDirty()));
        connect(m_sourceItem, SIGNAL(heightChanged()), this, SLOT(markSourceSizeDirty()));
    }

    updateSizeAndTexture();
    emit sourceItemChanged();
    emit repaintRequired();
}

void ShaderEffectSource::setSourceRect(const QRectF &rect)
{
    if (rect == m_sourceRect)
        return;
    m_sourceRect = rect;
    updateSizeAndTexture();
    emit sourceRectChanged();
    emit repaintRequired();

    m_dirtyTexture = true;
    markSourceItemDirty();
}

void ShaderEffectSource::setTextureSize(const QSize &size)
{
    if (size == m_textureSize)
        return;

    m_textureSize = size;
    updateSizeAndTexture();
    emit textureSizeChanged();
    emit repaintRequired();

    m_dirtyTexture = true;
    markSourceItemDirty();
}

void ShaderEffectSource::setLive(bool s)
{
    if (s == m_live)
        return;

    m_live = s;

    emit liveChanged();
    emit repaintRequired();
}

void ShaderEffectSource::setHideSource(bool hide)
{
    if (hide == m_hideSource)
        return;

    m_hideSource = hide;

    emit hideSourceChanged();
    emit repaintRequired();
}

void ShaderEffectSource::setWrapMode(WrapMode mode)
{
    if (mode == m_wrapMode)
        return;

    m_wrapMode = mode;
    emit wrapModeChanged();

    m_dirtyTexture = true;
    markSourceItemDirty();
}

void ShaderEffectSource::grab()
{
    m_dirtyTexture = true;
    emit repaintRequired();
}

void ShaderEffectSource::bind()
{
    GLint filtering = smooth() ? GL_LINEAR : GL_NEAREST;
    GLuint hwrap = (m_wrapMode == Repeat || m_wrapMode == RepeatHorizontally) ? GL_REPEAT : GL_CLAMP_TO_EDGE;
    GLuint vwrap = (m_wrapMode == Repeat || m_wrapMode == RepeatVertically) ? GL_REPEAT : GL_CLAMP_TO_EDGE;

#if !defined(QT_OPENGL_ES_2)
    glEnable(GL_TEXTURE_2D);
#endif

    if (m_fbo && m_fbo->isValid()) {
        glBindTexture(GL_TEXTURE_2D, m_fbo->texture());
    } else {
        m_dirtyTexture = true;
        emit repaintRequired();
        markSourceItemDirty();
        glBindTexture(GL_TEXTURE_2D, 0);
    }

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, filtering);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, smooth() ? GL_LINEAR : GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, hwrap);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, vwrap);
}

void ShaderEffectSource::refFromEffectItem()
{
    if (m_refs++ == 0) {
        attachSourceItem();
        emit activeChanged();
    }
}

void ShaderEffectSource::derefFromEffectItem()
{
    if (--m_refs == 0) {
        detachSourceItem();
        emit activeChanged();
    }
    Q_ASSERT(m_refs >= 0);
}

void ShaderEffectSource::updateBackbuffer()
{
    if (!m_sourceItem || !QGLContext::currentContext())
        return;

    // Multisampling is not (for now) supported.
    QSize size = QSize(m_sourceItem->width(), m_sourceItem->height());
    if (!m_textureSize.isEmpty())
        size = m_textureSize;

    if (size.height() > 0 && size.width() > 0) {
        QGLFramebufferObjectFormat format;
        format.setAttachment(QGLFramebufferObject::CombinedDepthStencil);
        format.setInternalTextureFormat(m_format);

        if (!m_fbo) {
            m_fbo =  new ShaderEffectBuffer(size, format);
        } else {
            if (!m_fbo->isValid() || m_fbo->size() != size || m_fbo->format().internalTextureFormat() != GLenum(m_format)) {
                delete m_fbo;
                m_fbo = 0;
                m_fbo =  new ShaderEffectBuffer(size, format);
            }
        }
    }

    // Note that real update for the source content happens in shadereffect.cpp
    m_dirtyTexture = false;
}

void ShaderEffectSource::markSceneGraphDirty()
{
    m_dirtySceneGraph = true;
    emit repaintRequired();
}

void ShaderEffectSource::markSourceSizeDirty()
{
    Q_ASSERT(m_sourceItem);
    if (m_textureSize.isEmpty())
        updateSizeAndTexture();
    if (m_refs)
        emit repaintRequired();
}

void ShaderEffectSource::markSourceItemDirty()
{
    m_dirtyTexture = true;
    if (m_sourceItem) {
        ShaderEffect* effect = qobject_cast<ShaderEffect*> (m_sourceItem->graphicsEffect());
        if (effect)
            effect->m_changed = true;
    }
}

void ShaderEffectSource::updateSizeAndTexture()
{
    if (m_sourceItem) {
        QSize size = m_textureSize;
        if (size.isEmpty())
            size = QSize(m_sourceItem->width(), m_sourceItem->height());
        if (size.width() < 1)
            size.setWidth(1);
        if (size.height() < 1)
            size.setHeight(1);
        if (m_fbo && (m_fbo->size() != size || !m_fbo->isValid())) {
            delete m_fbo;
            m_fbo = 0;
            delete m_multisampledFbo;
            m_fbo = m_multisampledFbo = 0;
        }
        if (m_size.width() != size.width()) {
            m_size.setWidth(size.width());
            emit widthChanged();
        }
        if (m_size.height() != size.height()) {
            m_size.setHeight(size.height());
            emit heightChanged();
        }
        m_dirtyTexture = true;
    } else {
        if (m_size.width() != 0) {
            m_size.setWidth(0);
            emit widthChanged();
        }
        if (m_size.height() != 0) {
            m_size.setHeight(0);
            emit heightChanged();
        }
    }
}

void ShaderEffectSource::attachSourceItem()
{
    if (!m_sourceItem)
        return;

    ShaderEffect *effect = qobject_cast<ShaderEffect*> (m_sourceItem->graphicsEffect());

    if (!effect) {
        effect = new ShaderEffect();
        m_sourceItem->setGraphicsEffect(effect);
    }

    if (effect)
        effect->addRenderTarget(this);

    m_sourceItem->update();
}

void ShaderEffectSource::detachSourceItem()
{
    if (!m_sourceItem)
        return;

    ShaderEffect* effect = qobject_cast<ShaderEffect*> (m_sourceItem->graphicsEffect());

    if (effect)
        effect->removeRenderTarget(this);

    delete m_fbo;
    m_fbo = 0;

    delete m_multisampledFbo;
    m_multisampledFbo = 0;

    m_dirtyTexture = true;
}