- Qt 5.5
- Qt Sensors
- Qt Sensors - Maze QML Example
- Qt 5.5.1 Reference Documentation

# Qt Sensors - Maze QML Example

### Maze in QML

To write a QML application that will use the TiltSensor QML sensors type you need to do the following steps:

Import the QtSensors 5.x declarative plugin:

    import QtSensors 5.0

Add the Sensor QML types into your qml file.

In this example we use the TiltSensor with values based in degrees and an accuracy of 5 degree:

        TiltSensor {
            id: tiltSensor
            active: true
        }

Starting the sensor can be done by setting the 'enabled' property to true:

            onTriggered: {
                if (!tiltSensor.enabled)
                    tiltSensor.active = true;

The mouse should move by a factor of the tilt value:

                    var xstep = 0;
                    xstep = tiltSensor.reading.yRotation * 0.1 //acceleration

                    var ystep = 0;
                    ystep = tiltSensor.reading.xRotation * 0.1 //acceleration

The walk direction of the mouse takes into account some collision detection:

                    if (xstep < 1 && xstep > 0)
                        xstep = 0
                    else if (xstep > -1 && xstep < 0)
                        xstep = 0

                    if (ystep < 1 && ystep > 0)
                        ystep = 0;
                    else if (ystep > -1 && ystep < 0)
                        ystep = 0;

                    if ((xstep < 0 && mouseCtrl.x > 0
                         && Lib.canMove(mouseCtrl.x + xstep,mouseCtrl.y))) {
                        xval = mouseCtrl.x + xstep;

                    } else if (xstep > 0 && mouseCtrl.x < (Lib.cellDimension * (Lib.dimension - 1))
                        && Lib.canMove(mouseCtrl.x + xstep,mouseCtrl.y)) {
                        xval = mouseCtrl.x + xstep;
                    } else
                        xval = mouseCtrl.x;

                    if (ystep < 0 && mouseCtrl.y > 0
                         && Lib.canMove(mouseCtrl.x, mouseCtrl.y + ystep)) {
                        yval = mouseCtrl.y + ystep;
                    } else if (ystep > 0 && (mouseCtrl.y < (Lib.cellDimension * (Lib.dimension - 1)))
                             && Lib.canMove(mouseCtrl.x, mouseCtrl.y + ystep)) {
                        yval = mouseCtrl.y + ystep;
                    } else
                        yval = mouseCtrl.y

                    mouseCtrl.move(xval, yval);

The rotation of the mouse image is determined according to the angle that the mouse is moving.

            var a = newy - mouse.y
            var b = newx - mouse.x
            var c = distance(mouse.x, mouse.y, newx, newy)
            var radians_to_degrees = 57.2957795

            if (a > 0)
                angle = -Math.acos(a / b) * radians_to_degrees
            else
                angle = -Math.asin(b / c) * radians_to_degrees
            if (b > 0)
                 angle = -Math.acos(a / c) * radians_to_degrees
            else
                angle = Math.acos(a / c) * radians_to_degrees

            if (angle < 0)
                angle = 360 + angle

            img.rotation = angle
            mouse.x = newx;
            mouse.y = newy;

Files:

- maze/Congratulation.qml
- maze/LabyrinthSquare.qml
- maze/Mouse.qml
- maze/lib.js
- maze/maze.qml
- maze/android/AndroidManifest.xml
- maze/components/ApplicationWindow.qml
- maze/components/Button.qml
- maze/main.cpp
- maze/maze.pro
- maze/maze.qrc