pxt-common-packages
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Microsoft MakeCode (PXT) common packages
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text/typescript
namespace pxsim.input {
export function onGesture(gesture: number, handler: RefAction) {
let b = accelerometer();
b.accelerometer.activate();
if (gesture == DAL.ACCELEROMETER_EVT_SHAKE && !b.useShake) {
b.useShake = true;
runtime.queueDisplayUpdate();
}
pxtcore.registerWithDal(DAL.DEVICE_ID_GESTURE, gesture, handler);
}
export function rotation(kind: number): number {
let b = accelerometer();
let acc = b.accelerometer;
acc.activate();
let x = acc.getX(MicroBitCoordinateSystem.NORTH_EAST_DOWN);
let y = acc.getY(MicroBitCoordinateSystem.NORTH_EAST_DOWN);
let z = acc.getZ(MicroBitCoordinateSystem.NORTH_EAST_DOWN);
let roll = Math.atan2(y, z);
let pitch = Math.atan(-x / (y * Math.sin(roll) + z * Math.cos(roll)));
let r = 0;
switch (kind) {
case 0: r = pitch; break;
case 1: r = roll; break;
}
return Math.floor(r / Math.PI * 180);
}
export function setAccelerometerRange(range: number) {
let b = accelerometer();
b.accelerometer.setSampleRange(range);
}
export function acceleration(dimension: number): number {
let b = accelerometer();
let acc = b.accelerometer;
acc.activate();
switch (dimension) {
case 0: return acc.getX();
case 1: return acc.getY();
case 2: return acc.getZ();
default: return Math.floor(Math.sqrt(acc.instantaneousAccelerationSquared()));
}
}
}
namespace pxsim {
interface AccelerometerSample {
x: number;
y: number;
z: number;
}
interface ShakeHistory {
x: boolean;
y: boolean;
z: boolean;
count: number;
shaken: number;
timer: number;
}
/**
* Co-ordinate systems that can be used.
* RAW: Unaltered data. Data will be returned directly from the accelerometer.
*
* SIMPLE_CARTESIAN: Data will be returned based on an easy to understand alignment, consistent with the cartesian system taught in schools.
* When held upright, facing the user:
*
* /
* +--------------------+ z
* | |
* | ..... |
* | * ..... * |
* ^ | ..... |
* | | |
* y +--------------------+ x-->
*
*
* NORTH_EAST_DOWN: Data will be returned based on the industry convention of the North East Down (NED) system.
* When held upright, facing the user:
*
* z
* +--------------------+ /
* | |
* | ..... |
* | * ..... * |
* ^ | ..... |
* | | |
* x +--------------------+ y-->
*
*/
export enum MicroBitCoordinateSystem {
RAW,
SIMPLE_CARTESIAN,
NORTH_EAST_DOWN
}
export class Accelerometer {
private sigma: number = 0; // the number of ticks that the instantaneous gesture has been stable.
private lastGesture: number = 0; // the last, stable gesture recorded.
private currentGesture: number = 0 // the instantaneous, unfiltered gesture detected.
private sample: AccelerometerSample = { x: 0, y: 0, z: -1023 }
private shake: ShakeHistory = { x: false, y: false, z: false, count: 0, shaken: 0, timer: 0 }; // State information needed to detect shake events.
private pitch: number;
private roll: number;
private id: number;
public isActive = false;
public sampleRange = 2;
constructor(public runtime: Runtime) {
this.id = DAL.DEVICE_ID_ACCELEROMETER;
}
public setSampleRange(range: number) {
this.activate();
this.sampleRange = Math.max(1, Math.min(8, range));
}
public activate() {
if (!this.isActive) {
this.isActive = true;
this.runtime.queueDisplayUpdate();
}
}
/**
* Reads the acceleration data from the accelerometer, and stores it in our buffer.
* This is called by the tick() member function, if the interrupt is set!
*/
public update(x: number, y: number, z: number) {
// read MSB values...
this.sample.x = Math.floor(x);
this.sample.y = Math.floor(y);
this.sample.z = Math.floor(z);
// Update gesture tracking
this.updateGesture();
// Indicate that a new sample is available
board().bus.queue(this.id, DAL.ACCELEROMETER_EVT_DATA_UPDATE)
}
public instantaneousAccelerationSquared() {
// Use pythagoras theorem to determine the combined force acting on the device.
return this.sample.x * this.sample.x + this.sample.y * this.sample.y + this.sample.z * this.sample.z;
}
/**
* Service function. Determines the best guess posture of the device based on instantaneous data.
* This makes no use of historic data (except for shake), and forms this input to the filter implemented in updateGesture().
*
* @return A best guess of the current posture of the device, based on instantaneous data.
*/
private instantaneousPosture(): number {
let force = this.instantaneousAccelerationSquared();
let shakeDetected = false;
// Test for shake events.
// We detect a shake by measuring zero crossings in each axis. In other words, if we see a strong acceleration to the left followed by
// a string acceleration to the right, then we can infer a shake. Similarly, we can do this for each acxis (left/right, up/down, in/out).
//
// If we see enough zero crossings in succession (MICROBIT_ACCELEROMETER_SHAKE_COUNT_THRESHOLD), then we decide that the device
// has been shaken.
if ((this.getX() < -DAL.ACCELEROMETER_SHAKE_TOLERANCE && this.shake.x) || (this.getX() > DAL.ACCELEROMETER_SHAKE_TOLERANCE && !this.shake.x)) {
shakeDetected = true;
this.shake.x = !this.shake.x;
}
if ((this.getY() < -DAL.ACCELEROMETER_SHAKE_TOLERANCE && this.shake.y) || (this.getY() > DAL.ACCELEROMETER_SHAKE_TOLERANCE && !this.shake.y)) {
shakeDetected = true;
this.shake.y = !this.shake.y;
}
if ((this.getZ() < -DAL.ACCELEROMETER_SHAKE_TOLERANCE && this.shake.z) || (this.getZ() > DAL.ACCELEROMETER_SHAKE_TOLERANCE && !this.shake.z)) {
shakeDetected = true;
this.shake.z = !this.shake.z;
}
if (shakeDetected && this.shake.count < DAL.ACCELEROMETER_SHAKE_COUNT_THRESHOLD && ++this.shake.count == DAL.ACCELEROMETER_SHAKE_COUNT_THRESHOLD)
this.shake.shaken = 1;
if (++this.shake.timer >= DAL.ACCELEROMETER_SHAKE_DAMPING) {
this.shake.timer = 0;
if (this.shake.count > 0) {
if (--this.shake.count == 0)
this.shake.shaken = 0;
}
}
if (this.shake.shaken)
return DAL.ACCELEROMETER_EVT_SHAKE;
let sq = (n: number) => n * n
if (force < sq(DAL.ACCELEROMETER_FREEFALL_TOLERANCE))
return DAL.ACCELEROMETER_EVT_FREEFALL;
if (force > sq(DAL.ACCELEROMETER_3G_TOLERANCE))
return DAL.ACCELEROMETER_EVT_3G;
if (force > sq(DAL.ACCELEROMETER_6G_TOLERANCE))
return DAL.ACCELEROMETER_EVT_6G;
if (force > sq(DAL.ACCELEROMETER_8G_TOLERANCE))
return DAL.ACCELEROMETER_EVT_8G;
// Determine our posture.
if (this.getX() < (-1000 + DAL.ACCELEROMETER_TILT_TOLERANCE))
return DAL.ACCELEROMETER_EVT_TILT_LEFT;
if (this.getX() > (1000 - DAL.ACCELEROMETER_TILT_TOLERANCE))
return DAL.ACCELEROMETER_EVT_TILT_RIGHT;
if (this.getY() < (-1000 + DAL.ACCELEROMETER_TILT_TOLERANCE))
return DAL.ACCELEROMETER_EVT_TILT_UP;
if (this.getY() > (1000 - DAL.ACCELEROMETER_TILT_TOLERANCE))
return DAL.ACCELEROMETER_EVT_TILT_DOWN;
if (this.getZ() < (-1000 + DAL.ACCELEROMETER_TILT_TOLERANCE))
return DAL.ACCELEROMETER_EVT_FACE_UP;
if (this.getZ() > (1000 - DAL.ACCELEROMETER_TILT_TOLERANCE))
return DAL.ACCELEROMETER_EVT_FACE_DOWN;
return 0;
}
updateGesture() {
// Determine what it looks like we're doing based on the latest sample...
let g = this.instantaneousPosture();
// Perform some low pass filtering to reduce jitter from any detected effects
if (g == this.currentGesture) {
if (this.sigma < DAL.ACCELEROMETER_GESTURE_DAMPING)
this.sigma++;
}
else {
this.currentGesture = g;
this.sigma = 0;
}
// If we've reached threshold, update our record and raise the relevant event...
if (this.currentGesture != this.lastGesture && this.sigma >= DAL.ACCELEROMETER_GESTURE_DAMPING) {
this.lastGesture = this.currentGesture;
board().bus.queue(DAL.DEVICE_ID_GESTURE, this.lastGesture);
}
}
/**
* Reads the X axis value of the latest update from the accelerometer.
* @param system The coordinate system to use. By default, a simple cartesian system is provided.
* @return The force measured in the X axis, in milli-g.
*
* Example:
* @code
* uBit.accelerometer.getX();
* uBit.accelerometer.getX(RAW);
* @endcode
*/
public getX(system: MicroBitCoordinateSystem = MicroBitCoordinateSystem.SIMPLE_CARTESIAN): number {
this.activate();
let val: number;
switch (system) {
case MicroBitCoordinateSystem.SIMPLE_CARTESIAN:
val = -this.sample.x;
case MicroBitCoordinateSystem.NORTH_EAST_DOWN:
val = this.sample.y;
//case MicroBitCoordinateSystem.SIMPLE_CARTESIAN.RAW:
default:
val = this.sample.x;
}
return (board() as AccelerometerBoard).invertAccelerometerXAxis ? val * -1 : val;
}
/**
* Reads the Y axis value of the latest update from the accelerometer.
* @param system The coordinate system to use. By default, a simple cartesian system is provided.
* @return The force measured in the Y axis, in milli-g.
*
* Example:
* @code
* uBit.accelerometer.getY();
* uBit.accelerometer.getY(RAW);
* @endcode
*/
public getY(system: MicroBitCoordinateSystem = MicroBitCoordinateSystem.SIMPLE_CARTESIAN): number {
this.activate();
let val: number;
switch (system) {
case MicroBitCoordinateSystem.SIMPLE_CARTESIAN:
val = -this.sample.y;
case MicroBitCoordinateSystem.NORTH_EAST_DOWN:
val = -this.sample.x;
//case RAW:
default:
val = this.sample.y;
}
return (board() as AccelerometerBoard).invertAccelerometerYAxis ? val * -1 : val;
}
/**
* Reads the Z axis value of the latest update from the accelerometer.
* @param system The coordinate system to use. By default, a simple cartesian system is provided.
* @return The force measured in the Z axis, in milli-g.
*
* Example:
* @code
* uBit.accelerometer.getZ();
* uBit.accelerometer.getZ(RAW);
* @endcode
*/
public getZ(system: MicroBitCoordinateSystem = MicroBitCoordinateSystem.SIMPLE_CARTESIAN): number {
this.activate();
let val: number;
switch (system) {
case MicroBitCoordinateSystem.NORTH_EAST_DOWN:
val = -this.sample.z;
//case MicroBitCoordinateSystem.SIMPLE_CARTESIAN:
//case MicroBitCoordinateSystem.RAW:
default:
val = this.sample.z;
}
return (board() as AccelerometerBoard).invertAccelerometerZAxis ? val * -1 : val;
}
/**
* Provides a rotation compensated pitch of the device, based on the latest update from the accelerometer.
* @return The pitch of the device, in degrees.
*
* Example:
* @code
* uBit.accelerometer.getPitch();
* @endcode
*/
public getPitch(): number {
this.activate();
return Math.floor((360 * this.getPitchRadians()) / (2 * Math.PI));
}
getPitchRadians(): number {
this.recalculatePitchRoll();
return this.pitch;
}
/**
* Provides a rotation compensated roll of the device, based on the latest update from the accelerometer.
* @return The roll of the device, in degrees.
*
* Example:
* @code
* uBit.accelerometer.getRoll();
* @endcode
*/
public getRoll(): number {
this.activate();
return Math.floor((360 * this.getRollRadians()) / (2 * Math.PI));
}
getRollRadians(): number {
this.recalculatePitchRoll();
return this.roll;
}
/**
* Recalculate roll and pitch values for the current sample.
* We only do this at most once per sample, as the necessary trigonemteric functions are rather
* heavyweight for a CPU without a floating point unit...
*/
recalculatePitchRoll() {
let x = this.getX(MicroBitCoordinateSystem.NORTH_EAST_DOWN);
let y = this.getY(MicroBitCoordinateSystem.NORTH_EAST_DOWN);
let z = this.getZ(MicroBitCoordinateSystem.NORTH_EAST_DOWN);
this.roll = Math.atan2(y, z);
this.pitch = Math.atan(-x / (y * Math.sin(this.roll) + z * Math.cos(this.roll)));
}
}
export class AccelerometerState {
accelerometer: Accelerometer;
useShake = false;
private tiltDecayer: any = 0;
private element: HTMLElement | SVGElement;
constructor(runtime: Runtime) {
this.accelerometer = new Accelerometer(runtime);
}
attachEvents(element: HTMLElement | SVGElement) {
this.element = element;
this.tiltDecayer = 0;
this.element.addEventListener(pointerEvents.move, (ev: MouseEvent) => {
if (!this.accelerometer.isActive) return;
if (this.tiltDecayer) {
clearInterval(this.tiltDecayer);
this.tiltDecayer = 0;
}
let bbox = element.getBoundingClientRect();
let ax = (ev.clientX - bbox.width / 2) / (bbox.width / 3);
let ay = (ev.clientY - bbox.height / 2) / (bbox.height / 3);
let x = - Math.max(- 1023, Math.min(1023, Math.floor(ax * 1023)));
let y = Math.max(- 1023, Math.min(1023, Math.floor(ay * 1023)));
let z2 = 1023 * 1023 - x * x - y * y;
let z = Math.floor((z2 > 0 ? -1 : 1) * Math.sqrt(Math.abs(z2)));
this.accelerometer.update(-x, y, z);
this.updateTilt();
}, false);
this.element.addEventListener(pointerEvents.leave, (ev: MouseEvent) => {
if (!this.accelerometer.isActive) return;
if (!this.tiltDecayer) {
this.tiltDecayer = setInterval(() => {
let accx = this.accelerometer.getX();
accx = Math.floor(Math.abs(accx) * 0.85) * (accx > 0 ? 1 : -1);
let accy = this.accelerometer.getY();
accy = Math.floor(Math.abs(accy) * 0.85) * (accy > 0 ? 1 : -1);
let accz = -Math.sqrt(Math.max(0, 1023 * 1023 - accx * accx - accy * accy));
if (Math.abs(accx) <= 24 && Math.abs(accy) <= 24) {
clearInterval(this.tiltDecayer);
this.tiltDecayer = 0;
accx = 0;
accy = 0;
accz = -1023;
}
this.accelerometer.update(accx, accy, accz);
this.updateTilt();
}, 50)
}
}, false);
}
private updateTilt() {
if (!this.accelerometer.isActive || !this.element) return;
const x = this.accelerometer.getX();
const y = this.accelerometer.getY();
const af = 8 / 1023;
const s = 1 - Math.min(0.1, Math.pow(Math.max(Math.abs(x), Math.abs(y)) / 1023, 2) / 35);
this.element.style.transform = `perspective(30em) rotateX(${y * af}deg) rotateY(${x * af}deg) scale(${s}, ${s})`
this.element.style.perspectiveOrigin = "50% 50% 50%";
this.element.style.perspective = "30em";
}
}
}