Qt Quick 3D - Principled Material Example

 /****************************************************************************
 **
 ** Copyright (C) 2022 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the examples 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
 import QtQuick3D

 Item {
     id: root
     required property Node origin
     required property Camera camera

     property real speed: 1
     property real xSpeed: 0.1
     property real ySpeed: 0.1

     property bool xInvert: false
     property bool yInvert: true

     property bool mouseEnabled: true

     readonly property bool inputsNeedProcessing: status.useMouse || status.isPanning

     implicitWidth: parent.width
     implicitHeight: parent.height

     Connections {
         target: camera
         function onZChanged() {
             // Adjust near/far values based on distance
             let distance = camera.z
             if (distance < 1) {
                 camera.clipNear = 0.01
                 camera.clipFar = 100
             } else if (distance < 100) {
                 camera.clipNear = 0.1
                 camera.clipFar = 1000
             } else {
                 camera.clipNear = 1
                 camera.clipFar = 10000
             }
         }
     }

     DragHandler {
         id: dragHandler
         target: null
         enabled: mouseEnabled
         acceptedModifiers: Qt.NoModifier
         onCentroidChanged: {
             mouseMoved(Qt.vector2d(centroid.position.x, centroid.position.y), false);
         }

         onActiveChanged: {
             if (active)
                 mousePressed(Qt.vector2d(centroid.position.x, centroid.position.y));
             else
                 mouseReleased(Qt.vector2d(centroid.position.x, centroid.position.y));
         }
     }

     DragHandler {
         id: ctrlDragHandler
         target: null
         enabled: mouseEnabled
         acceptedModifiers: Qt.ControlModifier
         onCentroidChanged: {
             panEvent(Qt.vector2d(centroid.position.x, centroid.position.y));
         }

         onActiveChanged: {
             if (active)
                 startPan(Qt.vector2d(centroid.position.x, centroid.position.y));
             else
                 endPan();
         }
     }

     PinchHandler {
         id: pinchHandler
         target: null
         enabled: mouseEnabled

         property real distance: 0.0
         onCentroidChanged: {
             panEvent(Qt.vector2d(centroid.position.x, centroid.position.y))
         }

         onActiveChanged: {
             if (active) {
                 startPan(Qt.vector2d(centroid.position.x, centroid.position.y))
                 distance = root.camera.z
             } else {
                 endPan()
                 distance = 0.0
             }
         }
         onScaleChanged: {
             camera.z = distance * (1 / scale)
         }
     }

     TapHandler {
         onTapped: root.forceActiveFocus()
     }

     WheelHandler {
         id: wheelHandler
         orientation: Qt.Vertical
         target: null
         enabled: mouseEnabled
         onWheel: event => {
             let delta = -event.angleDelta.y * 0.01;
             camera.z += camera.z * 0.1 * delta
         }
     }

     function mousePressed(newPos) {
         root.forceActiveFocus()
         status.currentPos = newPos
         status.lastPos = newPos
         status.useMouse = true;
     }

     function mouseReleased(newPos) {
         status.useMouse = false;
     }

     function mouseMoved(newPos: vector2d) {
         status.currentPos = newPos;
     }

     function startPan(pos: vector2d) {
         status.isPanning = true;
         status.currentPanPos = pos;
         status.lastPanPos = pos;
     }

     function endPan() {
         status.isPanning = false;
     }

     function panEvent(newPos: vector2d) {
         status.currentPanPos = newPos;
     }

     function processInputs()
     {
         if (root.inputsNeedProcessing)
             status.processInput();
     }

     Timer {
         id: updateTimer
         interval: 16
         repeat: true
         running: root.inputsNeedProcessing
         onTriggered: {
             processInputs();
         }
     }

     QtObject {
         id: status

         property bool useMouse: false
         property bool isPanning: false

         property vector2d lastPos: Qt.vector2d(0, 0)
         property vector2d lastPanPos: Qt.vector2d(0, 0)
         property vector2d currentPos: Qt.vector2d(0, 0)
         property vector2d currentPanPos: Qt.vector2d(0, 0)

         function negate(vector) {
             return Qt.vector3d(-vector.x, -vector.y, -vector.z)
         }

         function processInput() {
             if (useMouse) {
                 // Get the delta
                 var rotationVector = origin.eulerRotation;
                 var delta = Qt.vector2d(lastPos.x - currentPos.x,
                                         lastPos.y - currentPos.y);
                 // rotate x
                 var rotateX = delta.x * xSpeed
                 if (xInvert)
                     rotateX = -rotateX;
                 rotationVector.y += rotateX;

                 // rotate y
                 var rotateY = delta.y * -ySpeed
                 if (yInvert)
                     rotateY = -rotateY;
                 rotationVector.x += rotateY;
                 origin.setEulerRotation(rotationVector);
                 lastPos = currentPos;
             }
             if (isPanning) {
                 let delta = currentPanPos.minus(lastPanPos);
                 delta.x = -delta.x

                 delta.x = (delta.x / root.width) * camera.z
                 delta.y = (delta.y / root.height) * camera.z

                 let velocity = Qt.vector3d(0, 0, 0)
                 // X Movement
                 let xDirection = origin.right
                 velocity = velocity.plus(Qt.vector3d(xDirection.x * delta.x,
                                                      xDirection.y * delta.x,
                                                      xDirection.z * delta.x));
                 // Y Movement
                 let yDirection = origin.up
                 velocity = velocity.plus(Qt.vector3d(yDirection.x * delta.y,
                                                      yDirection.y * delta.y,
                                                      yDirection.z * delta.y));

                 origin.position = origin.position.plus(velocity)

                 lastPanPos = currentPanPos
             }
         }
     }

 }