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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:

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