1 files changed, 165 insertions, 0 deletions
diff --git a/src/effects/qgfxsourceproxy.cpp b/src/effects/qgfxsourceproxy.cpp
new file mode 100644
index 0000000000..a05ed9e576
--- /dev/null
+++ b/src/effects/qgfxsourceproxy.cpp
@@ -0,0 +1,165 @@
+// Copyright (C) 2016 Jolla Ltd, author: <gunnar.sletta@jollamobile.com>
+// Copyright (C) 2022 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#include "qgfxsourceproxy_p.h"
+
+#include <private/qquickshadereffectsource_p.h>
+#include <private/qquickitem_p.h>
+#include <private/qquickimage_p.h>
+
+QT_BEGIN_NAMESPACE
+
+QGfxSourceProxy::QGfxSourceProxy(QQuickItem *parentItem)
+    : QQuickItem(parentItem)
+{
+}
+
+QGfxSourceProxy::~QGfxSourceProxy()
+{
+    delete m_proxy;
+}
+
+void QGfxSourceProxy::setInput(QQuickItem *input)
+{
+    if (m_input == input)
+        return;
+
+    if (m_input)
+        disconnect(m_input, nullptr, this, nullptr);
+    m_input = input;
+    polish();
+    if (m_input) {
+        if (QQuickImage *image = qobject_cast<QQuickImage *>(m_input)) {
+            connect(image, &QQuickImage::sourceSizeChanged, this, &QGfxSourceProxy::repolish);
+            connect(image, &QQuickImage::fillModeChanged, this, &QGfxSourceProxy::repolish);
+        }
+        connect(m_input, &QQuickItem::childrenChanged, this, &QGfxSourceProxy::repolish);
+    }
+    Q_EMIT inputChanged();
+}
+
+void QGfxSourceProxy::setOutput(QQuickItem *output)
+{
+    if (m_output == output)
+        return;
+    m_output = output;
+    Q_EMIT activeChanged();
+    Q_EMIT outputChanged();
+}
+
+void QGfxSourceProxy::setSourceRect(const QRectF &sourceRect)
+{
+    if (m_sourceRect == sourceRect)
+        return;
+    m_sourceRect = sourceRect;
+    polish();
+    Q_EMIT sourceRectChanged();
+}
+
+void QGfxSourceProxy::setInterpolation(Interpolation i)
+{
+    if (m_interpolation == i)
+        return;
+    m_interpolation = i;
+    polish();
+    Q_EMIT interpolationChanged();
+}
+
+void QGfxSourceProxy::useProxy()
+{
+    if (!m_proxy)
+        m_proxy = new QQuickShaderEffectSource(this);
+    m_proxy->setSourceRect(m_sourceRect);
+    m_proxy->setSourceItem(m_input);
+    m_proxy->setSmooth(m_interpolation != Interpolation::Nearest);
+    setOutput(m_proxy);
+}
+
+void QGfxSourceProxy::repolish()
+{
+    polish();
+}
+
+QObject *QGfxSourceProxy::findLayer(QQuickItem *item)
+{
+    if (!item)
+        return nullptr;
+    QQuickItemPrivate *d = QQuickItemPrivate::get(item);
+    if (d->extra.isAllocated() && d->extra->layer) {
+        QObject *layer = qvariant_cast<QObject *>(item->property("layer"));
+        if (layer && layer->property("enabled").toBool())
+            return layer;
+    }
+    return nullptr;
+}
+
+void QGfxSourceProxy::updatePolish()
+{
+    if (!m_input) {
+        setOutput(nullptr);
+        return;
+    }
+
+    QQuickImage *image = qobject_cast<QQuickImage *>(m_input);
+    QQuickShaderEffectSource *shaderSource = qobject_cast<QQuickShaderEffectSource *>(m_input);
+    bool childless = m_input->childItems().size() == 0;
+    bool interpOk = m_interpolation == Interpolation::Any
+                    || (m_interpolation == Interpolation::Linear && m_input->smooth() == true)
+                    || (m_interpolation == Interpolation::Nearest && m_input->smooth() == false);
+
+    // Layers can be used in two different ways. Option 1 is when the item is
+    // used as input to a separate ShaderEffect component. In this case,
+    // m_input will be the item itself.
+    QObject *layer = findLayer(m_input);
+    if (!layer && shaderSource) {
+        // Alternatively, the effect is applied via layer.effect, and the
+        // input to the effect will be the layer's internal ShaderEffectSource
+        // item. In this case, we need to backtrack and find the item that has
+        // the layer and configure it accordingly.
+        layer = findLayer(shaderSource->sourceItem());
+    }
+
+    // A bit crude test, but we're only using source rect for
+    // blurring+transparent edge, so this is good enough.
+    bool padded = m_sourceRect.x() < 0 || m_sourceRect.y() < 0;
+
+    bool direct = false;
+
+    if (layer) {
+        // Auto-configure the layer so interpolation and padding works as
+        // expected without allocating additional FBOs. In edgecases, where
+        // this feature is undesiered, the user can simply use
+        // ShaderEffectSource rather than layer.
+        layer->setProperty("sourceRect", m_sourceRect);
+        layer->setProperty("smooth", m_interpolation != Interpolation::Nearest);
+        direct = true;
+
+    } else if (childless && interpOk) {
+        if (shaderSource) {
+            if (shaderSource->sourceRect() == m_sourceRect || m_sourceRect.isEmpty())
+                direct = true;
+
+        } else if (!padded && ((image && image->fillMode() == QQuickImage::Stretch && !image->sourceSize().isNull())
+                                || (!image && m_input->isTextureProvider())
+                              )
+                  ) {
+            direct = true;
+        }
+    }
+
+    if (direct)
+        setOutput(m_input);
+    else
+        useProxy();
+
+    // Remove the proxy if it is not in use..
+    if (m_proxy && m_output == m_input) {
+        delete m_proxy;
+        m_proxy = nullptr;
+    }
+}
+
+QT_END_NAMESPACE
+
+#include "moc_qgfxsourceproxy_p.cpp"