PathItem example: add super- and multisample example

Change-Id: Iefd1a2656161b69de73e66e0bcefc36a49f733e2
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

6 files changed, 194 insertions, 69 deletions

diff --git a/examples/quick/pathitem/content/pathitem.qml b/examples/quick/pathitem/content/pathitem.qml
index c4a86ff8b1..b82d51a13c 100644
--- a/examples/quick/pathitem/content/pathitem.qml
+++ b/examples/quick/pathitem/content/pathitem.qml
@@ -57,7 +57,7 @@ Item {
         anchors.fill: parent
         Component.onCompleted: {
             addExample("PathItem Gallery", "Simple path rendering examples", Qt.resolvedUrl("pathitemgallery.qml"))
-            addExample("Interactive paths", "Dynamic path examples", Qt.resolvedUrl("pathiteminteract.qml"))
+            addExample("Super- and multisampling", "Improving quality", Qt.resolvedUrl("pathitemsampling.qml"))
             addExample("Clip My Tiger!", "Clip examples, a.k.a. What Not To Do", Qt.resolvedUrl("pathitemtigers.qml"))
         }
     }
diff --git a/examples/quick/pathitem/content/pathiteminteract.qml b/examples/quick/pathitem/content/pathiteminteract.qml
deleted file mode 100644
index 78b3b25b55..0000000000
--- a/examples/quick/pathitem/content/pathiteminteract.qml
+++ /dev/null
@@ -1,65 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtQuick module 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 // to get PathItem
-
-Rectangle {
-    id: root
-    width: 1024
-    height: 768
-
-    property color col: "lightsteelblue"
-    gradient: Gradient {
-        GradientStop { position: 0.0; color: Qt.tint(root.col, "#20FFFFFF") }
-        GradientStop { position: 0.1; color: Qt.tint(root.col, "#20AAAAAA") }
-        GradientStop { position: 0.9; color: Qt.tint(root.col, "#20666666") }
-        GradientStop { position: 1.0; color: Qt.tint(root.col, "#20000000") }
-    }
-}
diff --git a/examples/quick/pathitem/content/pathitemsampling.qml b/examples/quick/pathitem/content/pathitemsampling.qml
new file mode 100644
index 0000000000..15c9cbe323
--- /dev/null
+++ b/examples/quick/pathitem/content/pathitemsampling.qml
@@ -0,0 +1,191 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQuick module 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 // to get PathItem
+
+Rectangle {
+    id: root
+    width: 1024
+    height: 768
+
+    property color col: "lightsteelblue"
+    gradient: Gradient {
+        GradientStop { position: 0.0; color: Qt.tint(root.col, "#20FFFFFF") }
+        GradientStop { position: 0.1; color: Qt.tint(root.col, "#20AAAAAA") }
+        GradientStop { position: 0.9; color: Qt.tint(root.col, "#20666666") }
+        GradientStop { position: 1.0; color: Qt.tint(root.col, "#20000000") }
+    }
+
+    Row {
+        anchors.fill: parent
+        anchors.margins: 20
+        spacing: 40
+
+        Column {
+            spacing: 40
+
+            Text {
+                text: "Original"
+            }
+
+            // A simple PathItem without anything special.
+            Rectangle {
+                color: "lightGray"
+                width: 400
+                height: 200
+
+                PathItem {
+                    x: 30
+                    y: 20
+                    width: 50
+                    height: 50
+                    scale: 2
+
+                    VisualPath {
+                        strokeColor: "green"
+                        NumberAnimation on strokeWidth { from: 1; to: 20; duration: 5000 }
+                        fillColor: "transparent"
+                        capStyle: VisualPath.RoundCap
+
+                        Path {
+                            startX: 40; startY: 30
+                            PathQuad { x: 50; y: 80; controlX: 0; controlY: 80 }
+                            PathLine { x: 150; y: 80 }
+                            PathQuad { x: 160; y: 30; controlX: 200; controlY: 80 }
+                        }
+                    }
+                }
+            }
+
+            Text {
+                text: "Supersampling (2x)"
+            }
+
+            // Now let's use 2x supersampling via layers. This way the entire subtree
+            // is rendered into an FBO twice the size and then drawn with linear
+            // filtering. This allows having some level of AA even when there is no
+            // support for multisample framebuffers.
+            Rectangle {
+                id: supersampledItem
+                color: "lightGray"
+                width: 400
+                height: 200
+
+                layer.enabled: true
+                layer.smooth: true
+                layer.textureSize: Qt.size(supersampledItem.width * 2, supersampledItem.height * 2)
+
+                PathItem {
+                    x: 30
+                    y: 20
+                    width: 50
+                    height: 50
+                    scale: 2
+
+                    VisualPath {
+                        strokeColor: "green"
+                        NumberAnimation on strokeWidth { from: 1; to: 20; duration: 5000 }
+                        fillColor: "transparent"
+                        capStyle: VisualPath.RoundCap
+
+                        Path {
+                            startX: 40; startY: 30
+                            PathQuad { x: 50; y: 80; controlX: 0; controlY: 80 }
+                            PathLine { x: 150; y: 80 }
+                            PathQuad { x: 160; y: 30; controlX: 200; controlY: 80 }
+                        }
+                    }
+                }
+            }
+        }
+
+        Column {
+            spacing: 40
+
+            Text {
+                text: "Multisampling (4x)"
+            }
+
+            // Now let's use 4x MSAA, again via layers. This needs support for
+            // multisample renderbuffers and framebuffer blits.
+            Rectangle {
+                color: "lightGray"
+                width: 400
+                height: 200
+
+                layer.enabled: true
+                layer.smooth: true
+                layer.samples: 4
+
+                PathItem {
+                    x: 30
+                    y: 20
+                    width: 50
+                    height: 50
+                    scale: 2
+
+                    VisualPath {
+                        strokeColor: "green"
+                        NumberAnimation on strokeWidth { from: 1; to: 20; duration: 5000 }
+                        fillColor: "transparent"
+                        capStyle: VisualPath.RoundCap
+
+                        Path {
+                            startX: 40; startY: 30
+                            PathQuad { x: 50; y: 80; controlX: 0; controlY: 80 }
+                            PathLine { x: 150; y: 80 }
+                            PathQuad { x: 160; y: 30; controlX: 200; controlY: 80 }
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
diff --git a/examples/quick/pathitem/content/pathitemtigers.qml b/examples/quick/pathitem/content/pathitemtigers.qml
index 6c8e3a19ce..36bff891c6 100644
--- a/examples/quick/pathitem/content/pathitemtigers.qml
+++ b/examples/quick/pathitem/content/pathitemtigers.qml
@@ -108,7 +108,6 @@ Rectangle {
     // instead of scissoring, this is more expensive. It may also trigger a
     // slower code path for PathItems, depending on the path rendering backend
     // in use, and may affect rendering quality as well.
-    // So in short: do not do this.
     Rectangle {
         id: stencilRect
         width: 300
diff --git a/examples/quick/pathitem/pathitem.pro b/examples/quick/pathitem/pathitem.pro
index 3c12f35fd2..333b84176d 100644
--- a/examples/quick/pathitem/pathitem.pro
+++ b/examples/quick/pathitem/pathitem.pro
@@ -5,7 +5,7 @@ SOURCES += main.cpp
 RESOURCES += pathitem.qrc
 OTHER_FILES += content/pathitem.qml \
                content/pathitemgallery.qml \
-               content/pathiteminteract.qml \
+               content/pathitemsampling.qml \
                content/pathitemtigers.qml \
                content/tiger.qml \
                content/item1.qml \
diff --git a/examples/quick/pathitem/pathitem.qrc b/examples/quick/pathitem/pathitem.qrc
index d67c918faf..83984b5e87 100644
--- a/examples/quick/pathitem/pathitem.qrc
+++ b/examples/quick/pathitem/pathitem.qrc
@@ -6,7 +6,7 @@
         <file alias="images/back.png">../shared/images/back.png</file>
         <file alias="pathitem.qml">content/pathitem.qml</file>
         <file alias="pathitemgallery.qml">content/pathitemgallery.qml</file>
-        <file alias="pathiteminteract.qml">content/pathiteminteract.qml</file>
+        <file alias="pathitemsampling.qml">content/pathitemsampling.qml</file>
         <file alias="pathitemtigers.qml">content/pathitemtigers.qml</file>
         <file alias="tiger.qml">content/tiger.qml</file>
         <file alias="item1.qml">content/item1.qml</file>