Qt 5.7 | Qt Quick | Scene Graph - Rendering FBOs in a thread | main.qml Example File

Qt 5.7.1 Reference Documentation

# main.qml Example File

scenegraph/textureinthread/main.qml

      /****************************************************************************
      **
      ** Copyright (C) 2015 The Qt Company Ltd.
      ** Contact: http://www.qt.io/licensing/
      **
      ** This file is part of the examples of the Qt Toolkit.
      **
      ** $QT_BEGIN_LICENSE:BSD$
      ** 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 2.0

      import SceneGraphRendering 1.0

      Item {
          width: 400
          height: 400

          // The checkers background
          ShaderEffect {
              id: tileBackground
              anchors.fill: parent

              property real tileSize: 16
              property color color1: Qt.rgba(0.9, 0.9, 0.9, 1);
              property color color2: Qt.rgba(0.85, 0.85, 0.85, 1);

              property size pixelSize: Qt.size(width / tileSize, height / tileSize);

              fragmentShader:
                  "
                  uniform lowp vec4 color1;
                  uniform lowp vec4 color2;
                  uniform highp vec2 pixelSize;
                  varying highp vec2 qt_TexCoord0;
                  void main() {
                      highp vec2 tc = sign(sin(3.14152 * qt_TexCoord0 * pixelSize));
                      if (tc.x != tc.y)
                          gl_FragColor = color1;
                      else
                          gl_FragColor = color2;
                  }
                  "
          }

          Renderer {
              id: renderer
              anchors.fill: parent
              anchors.margins: 10

              // The transform is just to show something interesting..
              transform: [
                  Rotation { id: rotation; axis.x: 0; axis.z: 0; axis.y: 1; angle: 0; origin.x: renderer.width / 2; origin.y: renderer.height / 2; },
                  Translate { id: txOut; x: -renderer.width / 2; y: -renderer.height / 2 },
                  Scale { id: scale; },
                  Translate { id: txIn; x: renderer.width / 2; y: renderer.height / 2 }
              ]

              Behavior on opacity { NumberAnimation { duration: 500 } }
              opacity: 0
              Component.onCompleted: renderer.opacity = 1;
          }

          // Just to show something interesting
          SequentialAnimation {
              PauseAnimation { duration: 5000 }
              ParallelAnimation {
                  NumberAnimation { target: scale; property: "xScale"; to: 0.6; duration: 1000; easing.type: Easing.InOutBack }
                  NumberAnimation { target: scale; property: "yScale"; to: 0.6; duration: 1000; easing.type: Easing.InOutBack }
              }
              NumberAnimation { target: rotation; property: "angle"; to: 80; duration: 1000; easing.type: Easing.InOutCubic }
              NumberAnimation { target: rotation; property: "angle"; to: -80; duration: 1000; easing.type: Easing.InOutCubic }
              NumberAnimation { target: rotation; property: "angle"; to: 0; duration: 1000; easing.type: Easing.InOutCubic }
              NumberAnimation { target: renderer; property: "opacity"; to: 0.5; duration: 1000; easing.type: Easing.InOutCubic }
              PauseAnimation { duration: 1000 }
              NumberAnimation { target: renderer; property: "opacity"; to: 0.8; duration: 1000; easing.type: Easing.InOutCubic }
              ParallelAnimation {
                  NumberAnimation { target: scale; property: "xScale"; to: 1; duration: 1000; easing.type: Easing.InOutBack }
                  NumberAnimation { target: scale; property: "yScale"; to: 1; duration: 1000; easing.type: Easing.InOutBack }
              }
              running: true
              loops: Animation.Infinite
          }

          Rectangle {
              id: labelFrame
              anchors.margins: -10
              radius: 5
              color: "white"
              border.color: "black"
              opacity: 0.8
              anchors.fill: label
          }

          Text {
              id: label
              anchors.bottom: renderer.bottom
              anchors.left: renderer.left
              anchors.right: renderer.right
              anchors.margins: 20
              wrapMode: Text.WordWrap
              text: "The blue rectangle with the vintage 'Q' is an FBO, rendered by the application in a dedicated background thread. The background thread juggles two FBOs, one that is being rendered to and one for displaying. The texture to display is posted to the scene graph and displayed using a QSGSimpleTextureNode."
          }

      }