Qt 5.11 | Qt Quick | Scene Graph - Rendering FBOs in a thread | main.qml Example File

Qt 5.11.3 Reference Documentation

# main.qml Example File

scenegraph/textureinthread/main.qml

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      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(3.14159265358979323846 * 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."
          }

      }