Make relevant effects respect layer.smooth

Currently, source items that set smooth to false will have blurry
effects when using layer.effect. Fix that by setting the interpolation
property of each effect's SourceProxy.

Standalone effects seem to work fine already.

The patch adds a manual testcase: "smooth". This can be used to verify
that the functionality works in the future, as adding an auto test
is not really possible.

This isn't done for all effects, as it doesn't make sense for all of
them (blurs, for example).

Task-number: QTBUG-67382
Change-Id: Ic6f030090cd0579dd4259ebafc9c99a8b9940494
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

8 files changed, 467 insertions, 1 deletions

diff --git a/tests/manual/manual.pro b/tests/manual/manual.pro
index 0e7e6e4..730f489 100644
--- a/tests/manual/manual.pro
+++ b/tests/manual/manual.pro
@@ -1,4 +1,4 @@
 TEMPLATE = subdirs
 OTHER_FILES = testbed/*.qml
-#SUBDIRS += testbed
+SUBDIRS += smooth
 
diff --git a/tests/manual/smooth/CellContainer.qml b/tests/manual/smooth/CellContainer.qml
new file mode 100644
index 0000000..5a04bd3
--- /dev/null
+++ b/tests/manual/smooth/CellContainer.qml
@@ -0,0 +1,9 @@
+import QtQuick 2.9
+import QtQuick.Layouts 1.3
+
+Item {
+    implicitWidth: children[0].implicitWidth * children[0].scale
+    implicitHeight: children[0].implicitHeight * children[0].scale
+
+    Layout.alignment: Qt.AlignHCenter
+}
diff --git a/tests/manual/smooth/SourceImage.qml b/tests/manual/smooth/SourceImage.qml
new file mode 100644
index 0000000..7956190
--- /dev/null
+++ b/tests/manual/smooth/SourceImage.qml
@@ -0,0 +1,8 @@
+import QtQuick 2.0
+
+Image {
+    source: "star.png"
+    smooth: false
+    scale: 4
+    transformOrigin: Item.TopLeft
+}
diff --git a/tests/manual/smooth/main.cpp b/tests/manual/smooth/main.cpp
new file mode 100644
index 0000000..aaca093
--- /dev/null
+++ b/tests/manual/smooth/main.cpp
@@ -0,0 +1,53 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QGuiApplication>
+#include <QQmlApplicationEngine>
+#include <QQuickItem>
+
+int main(int argc, char *argv[])
+{
+    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
+
+    QGuiApplication app(argc, argv);
+
+    QQmlApplicationEngine engine;
+    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
+    if (engine.rootObjects().isEmpty())
+        return -1;
+
+    return app.exec();
+}
diff --git a/tests/manual/smooth/main.qml b/tests/manual/smooth/main.qml
new file mode 100644
index 0000000..36bfb12
--- /dev/null
+++ b/tests/manual/smooth/main.qml
@@ -0,0 +1,358 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.9
+import QtQuick.Window 2.3
+import QtQuick.Layouts 1.3
+import QtGraphicalEffects 1.0
+
+/*
+    A testbench for source items (and effects) that set smooth to false.
+
+    Setting smooth to false doesn't make sense for all effects (like blurs).
+*/
+
+Window {
+    id: window
+    width: 1200
+    height: 1000
+    visible: true
+
+    Flickable {
+        anchors.fill: parent
+        contentWidth: rowLayout.width
+        contentHeight: rowLayout.implicitHeight
+
+        GridLayout {
+            id: rowLayout
+            width: window.width
+            columns: 4
+
+            // Header
+            Text {
+                text: "Plain Image"
+                Layout.alignment: Qt.AlignHCenter
+                Layout.column: 1
+            }
+
+            Text {
+                text: "... with standalone effect"
+                Layout.alignment: Qt.AlignHCenter
+            }
+
+            Text {
+                text: "... with layer effect"
+                Layout.alignment: Qt.AlignHCenter
+            }
+
+            // ColorOverlay
+            Text {
+                text: "ColorOverlay"
+                Layout.fillWidth: true
+            }
+
+            CellContainer {
+                SourceImage {}
+            }
+
+            CellContainer {
+                SourceImage {
+                    visible: false
+                }
+
+                ColorOverlay {
+                    width: parent.children[0].width
+                    height: parent.children[0].height
+                    source: parent.children[0]
+                    color: "#aa0ff000"
+                    scale: parent.children[0].scale
+                    transformOrigin: Item.TopLeft
+                }
+            }
+
+            CellContainer {
+                SourceImage {
+                    layer.enabled: true
+                    layer.effect: ColorOverlay {
+                        width: parent.children[0].width
+                        height: parent.children[0].height
+                        source: parent.children[0]
+                        color: "#aa0ff000"
+                    }
+                }
+            }
+
+            // Colorize
+            Text {
+                text: "Colorize"
+                Layout.fillWidth: true
+            }
+
+            CellContainer {
+                SourceImage {}
+            }
+
+            CellContainer {
+                SourceImage {
+                    visible: false
+                }
+
+                Colorize {
+                    width: parent.children[0].width
+                    height: parent.children[0].height
+                    source: parent.children[0]
+                    hue: 0.5
+                    scale: parent.children[0].scale
+                    transformOrigin: Item.TopLeft
+                }
+            }
+
+            CellContainer {
+                SourceImage {
+                    layer.enabled: true
+                    layer.effect: Colorize {
+                        width: parent.children[0].width
+                        height: parent.children[0].height
+                        source: parent.children[0]
+                        hue: 0.5
+                    }
+                }
+            }
+
+            // BrightnessContrast
+            Text {
+                text: "BrightnessContrast"
+                Layout.fillWidth: true
+            }
+
+            CellContainer {
+                SourceImage {}
+            }
+
+            CellContainer {
+                SourceImage {
+                    visible: false
+                }
+
+                BrightnessContrast {
+                    width: parent.children[0].width
+                    height: parent.children[0].height
+                    source: parent.children[0]
+                    brightness: 0.5
+                    scale: parent.children[0].scale
+                    transformOrigin: Item.TopLeft
+                }
+            }
+
+            CellContainer {
+                SourceImage {
+                    layer.enabled: true
+                    layer.effect: BrightnessContrast {
+                        width: parent.children[0].width
+                        height: parent.children[0].height
+                        source: parent.children[0]
+                        brightness: 0.5
+                    }
+                }
+            }
+
+            // HueSaturation
+            Text {
+                text: "HueSaturation"
+                Layout.fillWidth: true
+            }
+
+            CellContainer {
+                SourceImage {}
+            }
+
+            CellContainer {
+                SourceImage {
+                    visible: false
+                }
+
+                HueSaturation {
+                    width: parent.children[0].width
+                    height: parent.children[0].height
+                    source: parent.children[0]
+                    saturation: 1.0
+                    scale: parent.children[0].scale
+                    transformOrigin: Item.TopLeft
+                }
+            }
+
+            CellContainer {
+                SourceImage {
+                    layer.enabled: true
+                    layer.effect: HueSaturation {
+                        width: parent.children[0].width
+                        height: parent.children[0].height
+                        source: parent.children[0]
+                        saturation: 1.0
+                    }
+                }
+            }
+
+            // Desaturate
+            Text {
+                text: "Desaturate"
+                Layout.fillWidth: true
+            }
+
+            CellContainer {
+                SourceImage {}
+            }
+
+            CellContainer {
+                SourceImage {
+                    visible: false
+                }
+
+                Desaturate {
+                    width: parent.children[0].width
+                    height: parent.children[0].height
+                    source: parent.children[0]
+                    desaturation: 0.85
+                    scale: parent.children[0].scale
+                    transformOrigin: Item.TopLeft
+                }
+            }
+
+            CellContainer {
+                SourceImage {
+                    layer.enabled: true
+                    layer.effect: Desaturate {
+                        width: parent.children[0].width
+                        height: parent.children[0].height
+                        source: parent.children[0]
+                        desaturation: 0.85
+                    }
+                }
+            }
+
+            // GammaAdjust
+            Text {
+                text: "GammaAdjust"
+                Layout.fillWidth: true
+            }
+
+            CellContainer {
+                SourceImage {}
+            }
+
+            CellContainer {
+                SourceImage {
+                    visible: false
+                }
+
+                // doesn't seem to do anything...
+                GammaAdjust {
+                    width: parent.children[0].width
+                    height: parent.children[0].height
+                    source: parent.children[0]
+                    gamma: 10
+                    scale: parent.children[0].scale
+                    transformOrigin: Item.TopLeft
+                }
+            }
+
+            CellContainer {
+                SourceImage {
+                    layer.enabled: true
+                    layer.effect: GammaAdjust {
+                        width: parent.children[0].width
+                        height: parent.children[0].height
+                        source: parent.children[0]
+                        gamma: 10
+                    }
+                }
+            }
+
+            // LevelAdjust
+            Text {
+                text: "LevelAdjust"
+                Layout.fillWidth: true
+            }
+
+            CellContainer {
+                SourceImage {}
+            }
+
+            CellContainer {
+                SourceImage {
+                    visible: false
+                }
+
+                LevelAdjust {
+                    width: parent.children[0].width
+                    height: parent.children[0].height
+                    source: parent.children[0]
+                    minimumOutput: "#00ffffff"
+                    maximumOutput: "#ff000000"
+                    scale: parent.children[0].scale
+                    transformOrigin: Item.TopLeft
+                }
+            }
+
+            CellContainer {
+                SourceImage {
+                    layer.enabled: true
+                    layer.effect: LevelAdjust {
+                        width: parent.children[0].width
+                        height: parent.children[0].height
+                        source: parent.children[0]
+                        minimumOutput: "#00ffffff"
+                        maximumOutput: "#ff000000"
+                    }
+                }
+            }
+        }
+    }
+}
diff --git a/tests/manual/smooth/resources.qrc b/tests/manual/smooth/resources.qrc
new file mode 100644
index 0000000..b2b4653
--- /dev/null
+++ b/tests/manual/smooth/resources.qrc
@@ -0,0 +1,8 @@
+<RCC>
+    <qresource prefix="/">
+        <file>main.qml</file>
+        <file>CellContainer.qml</file>
+        <file>SourceImage.qml</file>
+        <file>star.png</file>
+    </qresource>
+</RCC>
diff --git a/tests/manual/smooth/smooth.pro b/tests/manual/smooth/smooth.pro
new file mode 100644
index 0000000..5e577f4
--- /dev/null
+++ b/tests/manual/smooth/smooth.pro
@@ -0,0 +1,30 @@
+QT += quick
+CONFIG += c++11
+
+# The following define makes your compiler emit warnings if you use
+# any feature of Qt which as been marked deprecated (the exact warnings
+# depend on your compiler). Please consult the documentation of the
+# deprecated API in order to know how to port your code away from it.
+DEFINES += QT_DEPRECATED_WARNINGS
+
+# You can also make your code fail to compile if you use deprecated APIs.
+# In order to do so, uncomment the following line.
+# You can also select to disable deprecated APIs only up to a certain version of Qt.
+#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0
+
+SOURCES += \
+        main.cpp
+
+RESOURCES += \
+    resources.qrc
+
+# Additional import path used to resolve QML modules in Qt Creator's code model
+QML_IMPORT_PATH =
+
+# Additional import path used to resolve QML modules just for Qt Quick Designer
+QML_DESIGNER_IMPORT_PATH =
+
+# Default rules for deployment.
+qnx: target.path = /tmp/$${TARGET}/bin
+else: unix:!android: target.path = /opt/$${TARGET}/bin
+!isEmpty(target.path): INSTALLS += target
diff --git a/tests/manual/smooth/star.png b/tests/manual/smooth/star.png
new file mode 100644
index 0000000..81c9ade
--- /dev/null
+++ b/tests/manual/smooth/star.png