I need to make an application where i'm drawing images on a canvas. When there are on the screen its need to be possible to pinch/pan on the canvas.When i try this code it doesn't correctly zoom on my nexus 5. What is the solution for it?
public class ZoomView extends View {
//These two constants specify the minimum and maximum zoom
private static float MIN_ZOOM = 1f;
private static float MAX_ZOOM = 5f;
private float scaleFactor = 1.f;
private ScaleGestureDetector detector;
//These constants specify the mode that we're in
private static int NONE = 0;
private static int DRAG = 1;
private static int ZOOM = 2;
private int mode;
//These two variables keep track of the X and Y coordinate of the finger when it first
//touches the screen
private float startX = 0f;
private float startY = 0f;
//These two variables keep track of the amount we need to translate the canvas along the X
//and the Y coordinate
private float translateX = 0f;
private float translateY = 0f;
//These two variables keep track of the amount we translated the X and Y coordinates, the last time we
//panned.
private float previousTranslateX = 0f;
private float previousTranslateY = 0f;
public ZoomView(Context context) {
super(context);
detector = new ScaleGestureDetector(getContext(), new ScaleListener());
}
#Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
mode = DRAG;
//We assign the current X and Y coordinate of the finger to startX and startY minus the previously translated
//amount for each coordinates This works even when we are translating the first time because the initial
//values for these two variables is zero.
startX = event.getX() - previousTranslateX;
startY = event.getY() - previousTranslateY;
break;
case MotionEvent.ACTION_MOVE:
translateX = event.getX() - startX;
translateY = event.getY() - startY;
//We cannot use startX and startY directly because we have adjusted their values using the previous translation values.
//This is why we need to add those values to startX and startY so that we can get the actual coordinates of the finger.
double distance = Math.sqrt(Math.pow(event.getX() - (startX + previousTranslateX), 2) +
Math.pow(event.getY() - (startY + previousTranslateY), 2)
);
if(distance > 0) {
dragged = true;
}
break;
case MotionEvent.ACTION_POINTER_DOWN:
mode = ZOOM;
break;
case MotionEvent.ACTION_UP:
mode = NONE;
dragged = false;
//All fingers went up, so let's save the value of translateX and translateY into previousTranslateX and
//previousTranslate
previousTranslateX = translateX;
previousTranslateY = translateY;
break;
case MotionEvent.ACTION_POINTER_UP:
mode = DRAG;
//This is not strictly necessary; we save the value of translateX and translateY into previousTranslateX
//and previousTranslateY when the second finger goes up
previousTranslateX = translateX;
previousTranslateY = translateY;
break;
}
detector.onTouchEvent(event);
//We redraw the canvas only in the following cases:
//
// o The mode is ZOOM
// OR
// o The mode is DRAG and the scale factor is not equal to 1 (meaning we have zoomed) and dragged is
// set to true (meaning the finger has actually moved)
if ((mode == DRAG && scaleFactor != 1f && dragged) || mode == ZOOM) {
invalidate();
}
return true;
}
#Override
public void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.save();
//We're going to scale the X and Y coordinates by the same amount
canvas.scale(scaleFactor, scaleFactor);
//If translateX times -1 is lesser than zero, let's set it to zero. This takes care of the left bound
if((translateX * -1) < 0) {
translateX = 0;
}
//This is where we take care of the right bound. We compare translateX times -1 to (scaleFactor - 1) * displayWidth.
//If translateX is greater than that value, then we know that we've gone over the bound. So we set the value of
//translateX to (1 - scaleFactor) times the display width. Notice that the terms are interchanged; it's the same
//as doing -1 * (scaleFactor - 1) * displayWidth
else if((translateX * -1) > (scaleFactor - 1) * displayWidth) {
translateX = (1 - scaleFactor) * displayWidth;
}
if(translateY * -1 < 0) {
translateY = 0;
}
//We do the exact same thing for the bottom bound, except in this case we use the height of the display
else if((translateY * -1) > (scaleFactor - 1) * displayHeight) {
translateY = (1 - scaleFactor) * displayHeight;
}
//We need to divide by the scale factor here, otherwise we end up with excessive panning based on our zoom level
//because the translation amount also gets scaled according to how much we've zoomed into the canvas.
canvas.translate(translateX / scaleFactor, translateY / scaleFactor);
/* The rest of your canvas-drawing code */
canvas.restore();
}
private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
#Override
public boolean onScale(ScaleGestureDetector detector) {
scaleFactor *= detector.getScaleFactor();
scaleFactor = Math.max(MIN_ZOOM, Math.min(scaleFactor, MAX_ZOOM));
return true;
}
}
}
Thx in advance
Related
i have a Problem with my Preview Zoom for the Camera2 API. I am using a TextureView.
I want to zoom only the preview Stream that was showed in the TextureView.
I want to zoom the Area where i use the Zoom Gesture.
I use the SimpleOnScaleGestureListener!
I added following Code. The zoomingFactor and the x and y Position are right.
private void updateTextureViewSize(float xPosi,float yPosi, float scale){
float scaleX = 1.0f;
float scaleY = 1.0f;
float mVideoWidth = mCamcontrol.getmPreviewSize().getWidth();
float mVideoHeight = mCamcontrol.getmPreviewSize().getHeight();
int rotation = getWindowManager().getDefaultDisplay().getRotation();
RectF viewRect = new RectF(0, 0, 1440, 2560);
RectF bufferRect = new RectF(0, 0, mVideoHeight, mVideoWidth);
bufferRect.offset(xPosi - bufferRect.centerX(), yPosi - bufferRect.centerY());
//16:9 faktor
scaleX = ((mScale * scale) / 9f) * 16f;
scaleY = ((mScale * scale) / 16f) * 9f;
Matrix matrix = new Matrix();
matrix.setRectToRect(bufferRect, viewRect, Matrix.ScaleToFit.FILL);
scalefactorView.setText(String.valueOf(xPosi) + " " + String.valueOf(yPosi));
matrix.setScale(scaleY, scaleX, xPosi, yPosi);
matrix.postRotate(90 * (rotation - 2), xPosi, yPosi);
mTextureView.setTransform(matrix);
}
Zooming is Right, but not the Position where i Zoom. For Example! When i zoom on the position right/middle i see only the left/top rectangle of the Stream.
I added the following pictures to unterstand the problem.
Android Camera2 api : Pinch Zoom In/Out
Use this sample code for Camera2Basic from google developers. https://github.com/googlesamples/android-Camera2Basic
Now declare two class variables –
public float finger_spacing = 0;
public int zoom_level = 1;
and update the given onTouch() method.
public boolean onTouch(View v, MotionEvent event) {
try {
Activity activity = getActivity();
CameraManager manager = (CameraManager) activity.getSystemService(Context.CAMERA_SERVICE);
CameraCharacteristics characteristics = manager.getCameraCharacteristics(mCameraId);
float maxzoom = (characteristics.get(CameraCharacteristics.SCALER_AVAILABLE_MAX_DIGITAL_ZOOM))*10;
Rect m = characteristics.get(CameraCharacteristics.SENSOR_INFO_ACTIVE_ARRAY_SIZE);
int action = event.getAction();
float current_finger_spacing;
if (event.getPointerCount() > 1) {
// Multi touch logic
current_finger_spacing = getFingerSpacing(event);
if(finger_spacing != 0){
if(current_finger_spacing > finger_spacing && maxzoom > zoom_level){
zoom_level++;
} else if (current_finger_spacing < finger_spacing && zoom_level > 1){
zoom_level--;
}
int minW = (int) (m.width() / maxzoom);
int minH = (int) (m.height() / maxzoom);
int difW = m.width() - minW;
int difH = m.height() - minH;
int cropW = difW /100 *(int)zoom_level;
int cropH = difH /100 *(int)zoom_level;
cropW -= cropW & 3;
cropH -= cropH & 3;
Rect zoom = new Rect(cropW, cropH, m.width() - cropW, m.height() - cropH);
mPreviewRequestBuilder.set(CaptureRequest.SCALER_CROP_REGION, zoom);
}
finger_spacing = current_finger_spacing;
} else{
if (action == MotionEvent.ACTION_UP) {
//single touch logic
}
}
try {
mCaptureSession
.setRepeatingRequest(mPreviewRequestBuilder.build(), mCaptureCallback, null);
} catch (CameraAccessException e) {
e.printStackTrace();
} catch (NullPointerException ex) {
ex.printStackTrace();
}
} catch (CameraAccessException e) {
throw new RuntimeException("can not access camera.", e);
}
return true;
}
//Determine the space between the first two fingers
#SuppressWarnings("deprecation")
private float getFingerSpacing(MotionEvent event) {
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return (float) Math.sqrt(x * x + y * y);
}
Thanks to #arin 's answer, I made an improved version.
His code is basically working, but there are 2 problems:
1) Readability - actually I don't know what is going on calculating the Rect zoom
2) In my Android 7.1.1 device, the preview will freeze if the zoom is big to a certain extent. Since I solved this problem with the code below, I am pretty sure it is because the original code allowed over-zooming beyond camera's maximum zoom ratio.
(In fact, I don't know why he needs to apply *10 on the ratio returned by CameraCharacteristics)
Below are my codes: (I do this all inside my custom TextureView, which also stores my Camera2 objects and logics):
Related Member variables:
protected CameraCharacteristics cameraCharacteristics;
protected CameraCaptureSession captureSession;
protected CaptureRequest.Builder previewRequestBuilder;
//Zooming
protected float fingerSpacing = 0;
protected float zoomLevel = 1f;
protected float maximumZoomLevel;
protected Rect zoom;
Right after you get CameraCharacteristics from CameraManager, probably in some initial setup:
maximumZoomLevel = cameraCharacteristics.get(CameraCharacteristics.SCALER_AVAILABLE_MAX_DIGITAL_ZOOM);
override onTouchEvent:
#Override
public boolean onTouchEvent(MotionEvent event) {
try {
Rect rect = cameraCharacteristics.get(CameraCharacteristics.SENSOR_INFO_ACTIVE_ARRAY_SIZE);
if (rect == null) return false;
float currentFingerSpacing;
if (event.getPointerCount() == 2) { //Multi touch.
currentFingerSpacing = getFingerSpacing(event);
float delta = 0.05f; //Control this value to control the zooming sensibility
if (fingerSpacing != 0) {
if (currentFingerSpacing > fingerSpacing) { //Don't over zoom-in
if ((maximumZoomLevel - zoomLevel) <= delta) {
delta = maximumZoomLevel - zoomLevel;
}
zoomLevel = zoomLevel + delta;
} else if (currentFingerSpacing < fingerSpacing){ //Don't over zoom-out
if ((zoomLevel - delta) < 1f) {
delta = zoomLevel - 1f;
}
zoomLevel = zoomLevel - delta;
}
float ratio = (float) 1 / zoomLevel; //This ratio is the ratio of cropped Rect to Camera's original(Maximum) Rect
//croppedWidth and croppedHeight are the pixels cropped away, not pixels after cropped
int croppedWidth = rect.width() - Math.round((float)rect.width() * ratio);
int croppedHeight = rect.height() - Math.round((float)rect.height() * ratio);
//Finally, zoom represents the zoomed visible area
zoom = new Rect(croppedWidth/2, croppedHeight/2,
rect.width() - croppedWidth/2, rect.height() - croppedHeight/2);
previewRequestBuilder.set(CaptureRequest.SCALER_CROP_REGION, zoom);
}
fingerSpacing = currentFingerSpacing;
} else { //Single touch point, needs to return true in order to detect one more touch point
return true;
}
captureSession.setRepeatingRequest(previewRequestBuilder.build(), captureCallback, null);
return true;
} catch (final Exception e) {
//Error handling up to you
return true;
}
}
And the getFingerSpacing method:
private float getFingerSpacing(MotionEvent event) {
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return (float) Math.sqrt(x * x + y * y);
}
Finally don't forget to set the crop region when you actually take the photo. My code is base on this Camera2Basic, I do this inside the captureStillPicture() method:
//Zoom
if (zoom != null) {
captureBuilder.set(CaptureRequest.SCALER_CROP_REGION, zoom);
}
#arin Answer is working thank #arin just one thing zoom sensitivity too high.
To control this i make some changes in might be useful to you.
Change zoom_level data type to double
public int zoom_level = 1; to public double zoom_level = 1;
Then increase or decrease zoom_level with low value i use 0.4
if (current_finger_spacing > finger_spacing && maxzoom > zoom_level) {
zoom_level = zoom_level + .4;
//zoom_level++;
} else if (current_finger_spacing < finger_spacing && zoom_level > 1) {
zoom_level = zoom_level - .4;
//zoom_level--;
}
Here is a Pan and Zoom object from Camera2 that I made to work using the OnScaleGestureListener and SimpleOnGestureListener-onScroll outputs. This will only work as expected if you have a camera with support level > LEGACY, as LEGACY only supports crop to center.
Two caveats:
One is that this is currently NOT set up to output to JPEG output, as rectangles for JPEG outputs must have dimensions which are multiple of 16 (See why here). The second is that I've locked my screen to landscape mode, and my camera is locked to landscape as well, but it should be possible to deal with screen rotations after a few tweaks.
You'll need to pass in the screen dimensions
DisplayMetrics displayMetrics = new DisplayMetrics();
((Activity) mView.getContext()).getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
the Maximum Camera Digital Zoom
try {
CameraManager manager = (CameraManager) mView.getContext().getSystemService(Context.CAMERA_SERVICE);
CameraCharacteristics characteristics = manager.getCameraCharacteristics(mCameraID);
float maxZoom = (characteristics.get(CameraCharacteristics.SCALER_AVAILABLE_MAX_DIGITAL_ZOOM));
} catch (CameraAccessException e) {
e.printStackTrace();
}
the Camera Sensor's Active Array Size
try {
CameraManager manager = (CameraManager) mView.getContext().getSystemService(Context.CAMERA_SERVICE);
CameraCharacteristics characteristics = manager.getCameraCharacteristics(mCameraID);
Rect rectInit = characteristics.get(CameraCharacteristics.SENSOR_INFO_ACTIVE_ARRAY_SIZE);
} catch (CameraAccessException e) {
e.printStackTrace();
}
Here is my object initialization
mScaler = new CamScaler(maxZoom, rectInit.width(), rectInit.height(), displayMetrics.heightPixels, displayMetrics.widthPixels);
the CamScaler class
public class CamScaler {
private final float ZOOM_MIN = 1.0f;
private final int X_MIN = 0;
private final int Y_MIN = 0;
private int displayWidth;
private int displayHeight;
private Rect current_rect;
private int xCenter;
private int yCenter;
private int xWidth;
private int yHeight;
private int xMax;
private int yMax;
private float zoomMax;
private float zoomCurrent;
public CamScaler(float zoomMax, int xMax, int yMax, int displayHeight, int displayWidth) {
this.xMax = xMax;
this.yMax = yMax;
this.zoomMax = zoomMax;
current_rect = new Rect(X_MIN,Y_MIN, xMax, yMax); //(0,0,xMax,yMax) as the starting rectangle
zoomCurrent = ZOOM_MIN;
xWidth = current_rect.width();
yHeight = current_rect.height();
xCenter = current_rect.centerX();
yCenter = current_rect.centerY();
this.displayHeight = displayHeight;
this.displayWidth = displayWidth;
}
public void pan(float distanceX, float distanceY){
//calculate the shift in the we want to take on the camera sensor with respect to the distance moved on the screen
int xShift = Math.round((distanceX/displayWidth)*xWidth); //scales down to a percentage of the current view width->converts to a pixel shift
int yShift = Math.round((distanceY/displayHeight)*yHeight); //scales down to a percentage of the current view height->converts to a pixel shift
//check if the shift will push us pass our maximums, this should account for both negative and positive values of xShift and yShift correctly
if ( !((xCenter + Math.round(xWidth/2.0) + xShift < xMax) && (xCenter - Math.round(xWidth/2.0) + xShift > 0))) { //if not within xBounds, set xShift to 0
xShift = 0;
}
if ( !((yCenter + Math.round(yHeight/2) + yShift < yMax) && (yCenter - Math.round(yHeight/2.0) + yShift > 0))) { //if not within yBounds, set yShift to 0
yShift = 0;
}
Log.d("Scaler", "pan: xShift" + xShift + " yShift " + yShift);
current_rect.offset(xShift,yShift);
Log.d("Scaler", "pan: current_rect" + current_rect.toString());
xCenter = current_rect.centerX(); //update center
yCenter = current_rect.centerY(); //update center
}
public void zoom(float scale_change){
if ( (zoomCurrent*scale_change < zoomMax) && (zoomCurrent*scale_change > ZOOM_MIN) ){ //if we are within zoom bounds
zoomCurrent *= scale_change; //update the zoom factor
int newWidthHalf = (int)Math.floor(xMax/zoomCurrent/2.0);
int newHeightHalf = (int)Math.floor(yMax/zoomCurrent/2.0);
int xTempCenter = xCenter;
int yTempCenter = yCenter;
//if at edge we need to shift and scale
if (xCenter + newWidthHalf > xMax) { //if at right edge
xTempCenter = xMax - newWidthHalf; //shift center to the left
} else if (xCenter - newWidthHalf < 0) { //if at left edge
xTempCenter = newWidthHalf; //shift center to the right
}
if (yCenter + newHeightHalf > yMax) { //if at bottom
yTempCenter = yMax - newHeightHalf; //shift center up
} else if (yCenter - newHeightHalf < 0) { //if at top
yTempCenter = newHeightHalf; //shift center down
}
Log.d("Scaler", "zoom: " + zoomCurrent);
Log.d(TAG, "current center(x,y) " + xTempCenter + " " + yTempCenter + "current halfwidths(x,y) " + newWidthHalf + " " + newHeightHalf);
current_rect.set(xTempCenter - newWidthHalf, yTempCenter - newHeightHalf,xTempCenter + newWidthHalf, yTempCenter + newHeightHalf);
Log.d("Scaler", "zoom: current_rect" + current_rect.toString());
xWidth = current_rect.width();
yHeight = current_rect.height();
xCenter = current_rect.centerX(); //update center
yCenter = current_rect.centerY(); //update center
} //if not in digital zoom bounds, do nothing
}
public Rect getCurrentView() {
return current_rect;
}
}
And how to use it
public void pan(float distanceX, float distanceY){
if (mScaler != null) {
synchronized (mScaler) {
mScaler.pan(distanceX, distanceY);
try {
mPreviewRequestBuilder.set(CaptureRequest.SCALER_CROP_REGION, mScaler.getCurrentView());
mCaptureSession.setRepeatingRequest(mPreviewRequestBuilder.build(), mCaptureCallback, mBackgroundHandler);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
}
}
public void zoom(float scale_factor) {
if (mScaler!= null) {
synchronized (mScaler) {
mScaler.zoom(scale_factor);
try {
mPreviewRequestBuilder.set(CaptureRequest.SCALER_CROP_REGION, mScaler.getCurrentView());
mCaptureSession.setRepeatingRequest(mPreviewRequestBuilder.build(), mCaptureCallback, mBackgroundHandler);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
}
}
The inputs to these functions are directly passed through from the gesture listeners
I hope this helps someone!
In addition to arin answer,Need to add captureBuilder.set(CaptureRequest.SCALER_CROP_REGION, zoom);
To captureStillPicture() method to let zoom take effect on capture
I'm working in a spaceship first person view game. I have a joystick, and when i move the joystick i can move all the objects (asteroids) of the screen simulating that the spaceship is being moved with the joystick.
The game works fine, but now i have a problem. If you are pressing the joystick in the max left position and then you do ACTION_UP and then instantly ACTION_DOWN in the joystick again but in the max right position, the spaceship starts moving to the right at max speed. It is hard to explain it. For example, If you press the joystick in max left position the spaceship is moving -20px per frame to the left and if you press the joystick in the max right position, the spaceship moves to the right +20px per frame.
So, now, if i do a fast max left and max right touch on the joystick, the spaceship does this movement: -20....+20
It is not reallistic movement.
I want to get this movement: -20 -17 -14 -9 -5 0 +5 +9 +14 +17 +20.... I mean a more reallistic spaceship movement. But the problem is that i am not a math or physics expert, and i dont have any idea of how to get that kind of functionality in this joystick... any help will be very grateful.
Here you can find a demo project with the joystick: https://mega.co.nz/#!cp5FhYIT!dM88qx_xQdyhED9fX_4xeJ9ciQYJirUlNzEi-KOzU2k
This is the joystick code, i found it in google and works very well except for the non realistic movement that i described before:
public class Joystick extends View {
public static final int INVALID_POINTER = -1;
private JoystickMovedListener moveListener;
//# of pixels movement required between reporting to the listener
private float moveResolution;
//Max range of movement in user coordinate system
private float movementRange;
//Last touch point in view coordinates
private int pointerId = INVALID_POINTER;
private float touchX;
private float touchY;
private float touchXDelayedMovement;
private float touchYDelayedMovement;
//Handle center in view coordinates
private float handleX;
private float handleY;
//Last reported position in view coordinates (allows different reporting sensitivities)
private float reportX;
private float reportY;
//Center of the view in view coordinates
private int cX;
private int cY;
//Size of the view in view coordinates
private int dimX;
private int dimY;
private int innerPadding;
private int bgRadius;
private int handleRadius;
private int movementRadius;
private int handleInnerBoundaries;
//Cartesian coordinates of last touch point - joystick center is (0,0)
private int cartX;
private int cartY;
//User coordinates of last touch point
private int userX;
private int userY;
//Offset co-ordinates (used when touch events are received from parent's coordinate origin)
private int offsetX;
private int offsetY;
private Paint bgPaint;
private Paint handlePaint;
boolean disabled;
Handler handler;
Handler handlerDelayedMovement;
public Joystick(Context context) {
super(context);
initJoystickView();
}
private void initJoystickView() {
setFocusable(true);
handlePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
handlePaint.setColor(Color.RED);
handlePaint.setStrokeWidth(1);
handlePaint.setStyle(Paint.Style.FILL_AND_STROKE);
bgPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
bgPaint.setColor(Color.DKGRAY);
bgPaint.setStrokeWidth(1);
bgPaint.setStyle(Paint.Style.FILL_AND_STROKE);
this.moveResolution = 1.0f;
handler = new Handler();
handlerDelayedMovement = new Handler();
}
public void setMovementRange(float movementRange) {
this.movementRange = movementRange;
}
public void setOnJostickMovedListener(JoystickMovedListener listener) {
this.moveListener = listener;
}
#Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
super.onLayout(changed, left, top, right, bottom);
int d = Math.min(getMeasuredWidth(), getMeasuredHeight());
dimX = d;
dimY = d;
cX = d / 2;
cY = d / 2;
bgRadius = dimX/2 - innerPadding;
handleRadius = (int)(d * 0.2);
handleInnerBoundaries = handleRadius;
movementRadius = Math.min(cX, cY) - handleInnerBoundaries;
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// Here we make sure that we have a perfect circle
int measuredWidth = measure(widthMeasureSpec);
int measuredHeight = measure(heightMeasureSpec);
setMeasuredDimension(measuredWidth, measuredHeight);
}
private int measure(int measureSpec) {
int result = 0;
// Decode the measurement specifications.
int specMode = MeasureSpec.getMode(measureSpec);
int specSize = MeasureSpec.getSize(measureSpec);
if (specMode == MeasureSpec.UNSPECIFIED) {
result = 200; // Return a default size of 200 if no bounds are specified.
} else {
result = specSize; // As you want to fill the available space always return the full available bounds.
}
return result;
}
#Override
protected void onDraw(Canvas canvas) {
canvas.save();
// Draw the background
canvas.drawCircle(cX, cY, bgRadius, bgPaint);
// Draw the handle
handleX = touchX + cX;
handleY = touchY + cY;
canvas.drawCircle(handleX, handleY, handleRadius, handlePaint);
canvas.restore();
}
public void setPointerId(int id) {
this.pointerId = id;
}
public int getPointerId() {
return pointerId;
}
#Override
public boolean onTouchEvent(MotionEvent ev) {
final int action = ev.getAction();
switch (action & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_MOVE: {
if (disabled==true)
break;
return processMoveEvent(ev);
}
case MotionEvent.ACTION_CANCEL:
case MotionEvent.ACTION_UP: {
if ( pointerId != INVALID_POINTER ) {
returnHandleToCenter();
returnHandleToCenterDelayedMovement();
setPointerId(INVALID_POINTER);
}
break;
}
case MotionEvent.ACTION_POINTER_UP: {
if ( pointerId != INVALID_POINTER ) {
final int pointerIndex = (action & MotionEvent.ACTION_POINTER_INDEX_MASK) >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
final int pointerId = ev.getPointerId(pointerIndex);
if ( pointerId == this.pointerId ) {
returnHandleToCenter();
returnHandleToCenterDelayedMovement();
setPointerId(INVALID_POINTER);
return true;
}
}
break;
}
case MotionEvent.ACTION_DOWN: {
handlerDelayedMovement.removeCallbacksAndMessages(null);
if ( pointerId == INVALID_POINTER ) {
int x = (int) ev.getX();
if ( x >= offsetX && x < offsetX + dimX ) {
setPointerId(ev.getPointerId(0));
if (disabled==true){
return true;
}
return processMoveEvent(ev);
}
}
break;
}
case MotionEvent.ACTION_POINTER_DOWN: {
if ( pointerId == INVALID_POINTER ) {
final int pointerIndex = (action & MotionEvent.ACTION_POINTER_INDEX_MASK) >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
final int pointerId = ev.getPointerId(pointerIndex);
int x = (int) ev.getX(pointerId);
if ( x >= offsetX && x < offsetX + dimX ) {
setPointerId(pointerId);
return true;
}
}
break;
}
}
return false;
}
private boolean processMoveEvent(MotionEvent ev) {
if ( pointerId != INVALID_POINTER ) {
final int pointerIndex = ev.findPointerIndex(pointerId);
// Translate touch position to center of view
float x = ev.getX(pointerIndex);
touchX = x - cX - offsetX;
float y = ev.getY(pointerIndex);
touchY = y - cY - offsetY;
reportOnMoved();
invalidate();
return true;
}
return false;
}
private void reportOnMoved() {
//constraint circle
float diffX = touchX;
float diffY = touchY;
double radial = Math.sqrt((diffX*diffX) + (diffY*diffY));
if ( radial > movementRadius ) {
touchX = (int)((diffX / radial) * movementRadius);
touchY = (int)((diffY / radial) * movementRadius);
}
//We calc user coordinates
//First convert to cartesian coordinates
cartX = (int)(touchX / movementRadius * movementRange);
cartY = (int)(touchY / movementRadius * movementRange);
//Cartesian Coordinates
userX = cartX;
userY = cartY;
if (moveListener != null) {
boolean rx = Math.abs(touchX - reportX) >= moveResolution;
boolean ry = Math.abs(touchY - reportY) >= moveResolution;
if (rx || ry) {
this.reportX = touchX;
this.reportY = touchY;
moveListener.OnMoved(userX, userY);
}
}
}
private void reportOnMovedDelayedMovement() {
//constraint circle
float diffX = touchXDelayedMovement;
float diffY = touchYDelayedMovement;
double radial = Math.sqrt((diffX*diffX) + (diffY*diffY));
if ( radial > movementRadius ) {
touchXDelayedMovement = (int)((diffX / radial) * movementRadius);
touchYDelayedMovement = (int)((diffY / radial) * movementRadius);
}
//We calc user coordinates
//First convert to cartesian coordinates
cartX = (int)(touchXDelayedMovement / movementRadius * movementRange);
cartY = (int)(touchYDelayedMovement / movementRadius * movementRange);
//Cartesian Coordinates
userX = cartX;
userY = cartY;
if (moveListener != null) {
boolean rx = Math.abs(touchXDelayedMovement - reportX) >= moveResolution;
boolean ry = Math.abs(touchYDelayedMovement - reportY) >= moveResolution;
if (rx || ry) {
this.reportX = touchXDelayedMovement;
this.reportY = touchYDelayedMovement;
moveListener.OnMoved(userX, userY);
}
}
}
private void returnHandleToCenter() {
final int numberOfFrames = 5;
final double intervalsX = (0 - touchX) / numberOfFrames;
final double intervalsY = (0 - touchY) / numberOfFrames;
handler.removeCallbacksAndMessages(null);
for (int i = 0; i < numberOfFrames; i++) {
final int j = i;
handler.postDelayed(new Runnable() {
#Override
public void run() {
touchX += intervalsX;
touchY += intervalsY;
//reportOnMoved();
invalidate();
if (moveListener != null && j == numberOfFrames - 1) {
moveListener.OnReturnedToCenter();
}
}
}, i * 10);
}
if (moveListener != null) {
moveListener.OnReleased();
}
}
private void returnHandleToCenterDelayedMovement() {
final int numberOfFrames = 25;
touchXDelayedMovement=touchX;
touchYDelayedMovement=touchY;
final double intervalsX = (0 - touchXDelayedMovement) / numberOfFrames;
final double intervalsY = (0 - touchYDelayedMovement) / numberOfFrames;
handlerDelayedMovement.removeCallbacksAndMessages(null);
for (int i = 0; i < numberOfFrames; i++) {
handlerDelayedMovement.postDelayed(new Runnable() {
#Override
public void run() {
touchXDelayedMovement += intervalsX;
touchYDelayedMovement += intervalsY;
reportOnMovedDelayedMovement();
}
}, i * 50);
}
}
public void setInnerPadding(int innerPadding){
this.innerPadding=innerPadding;
}
public void disable(){
disabled=true;
}
public void enable(){
disabled=false;
}
public interface JoystickMovedListener {
public void OnMoved(int pan, int tilt);
public void OnReleased();
public void OnReturnedToCenter();
}
}
You must do this in the class that will use the joystick:
private JoystickMovedListener joystickListener = new JoystickMovedListener() {
#Override
public void OnMoved(int pan, int tilt) {
//here i move the objects in the game
}
}
#Override
public void OnReleased() {}
public void OnReturnedToCenter() {};
};
joystickOnScreen = new Joystick(this);
joystickOnScreen.setMovementRange(screenHeight/50);
joystickOnScreen.setInnerPadding(screenHeight/30);
joystickOnScreen.setOnJostickMovedListener(joystickListener);
RelativeLayout.LayoutParams joystickParams = new RelativeLayout.LayoutParams(sh/3, sh/3);
joystickParams.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
joystickParams.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
joystickParams.setMargins(sh/100, 0, 0, sh/100);
joystickOnScreen.setLayoutParams(joystickParams);
joystickOnScreen.setAlpha(0.3f);
I will not implement the changes for you but hopefully this answer can help you towards implementing this on your own.
With your current implementation you are updating the object position (x, y) each frame. To get the more realistic physics that you want, you need to store and update velocity as well (vx, vy).
Add two new variables, vx and vy (with initial values of zero) in the objects that you are currently updating the position for. The joystick should control the change of the velocity instead of the position. Change the code that updates the positions x and y, to update the velocities vx and vy instead. When the joystick is max left, you can for example set vx = vx - 3.
After the velocity is updated, you need to update the position using the velocity variables. For example, set the position x = x + vx. Ideally you want this to happen in a different method that runs even if you don't move the joystick, but to keep it simple you can do this update right after the update of the velocity variables.
With this implementation you will get a more realistic game physics. As a next step you might want to add limits on the velocity to not move too fast. This can be done with an if-statement where you check that the value is not too big before adding more to it, or too smal before subtracting from it. Good luck!
I am trying to freely translate Bitmap inside an imageView.
I have ImageView with MATRIX scaletype and width and height match_parent
Here is my code for Touch listener
Following is my code for touch
public class Touch implements OnTouchListener
{
// These matrices will be used to move and zoom image
public Matrix matrix = new Matrix();
Matrix savedMatrix = new Matrix();
// We can be in one of these 3 states
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
int mode = NONE;
// Remember some things for zooming
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1f;
float[] lastEvent = null;
float d = 0f;
float newRot = 0f;
private float dx; // postTranslate X distance
private float dy; // postTranslate Y distance
private float[] matrixValues = new float[9];
float matrixX = 0; // X coordinate of matrix inside the ImageView
float matrixY = 0; // Y coordinate of matrix inside the ImageView
float width = 0; // width of drawable
float height = 0; // height of drawable
View mainView;
#Override
public boolean onTouch(View v, MotionEvent event)
{
ImageView view = (ImageView) v;
switch (event.getAction() & MotionEvent.ACTION_MASK)
{
case MotionEvent.ACTION_DOWN:
savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
mode = DRAG;
lastEvent = null;
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
if (oldDist > 10f)
{
//savedMatrix.set(matrix);
//midPoint(mid, event);
//mode = ZOOM;
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
lastEvent = null;
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG)
{
matrix.set(savedMatrix);
matrix.getValues(matrixValues);
matrixX = matrixValues[2];
matrixY = matrixValues[5];
width = matrixValues[0] * (((ImageView) view).getDrawable()
.getIntrinsicWidth());
height = matrixValues[4] * (((ImageView) view).getDrawable()
.getIntrinsicHeight());
dx = event.getX() - start.x;
dy = event.getY() - start.y;
//if image will go outside left bound
if (matrixX + dx < 0){
dx = -matrixX;
}
//if image will go outside right bound
if(matrixX + dx + width > view.getWidth()){
dx = view.getWidth() - matrixX - width;
}
//if image will go oustside top bound
if (matrixY + dy < 0){
dy = -matrixY;
}
//if image will go outside bottom bound
if(matrixY + dy + height > view.getHeight()){
dy = view.getHeight() - matrixY - height;
}
matrix.postTranslate(dx, dy);
}
break;
}
view.setImageMatrix(matrix);
return true; // indicate event was handled
}
public void updateValues(ImageView view)
{
matrix = view.getImageMatrix();
matrix.postTranslate(dx, dy);
view.setImageMatrix(matrix);
}
/** Determine the space between the first two fingers */
#SuppressLint("FloatMath")
private float spacing(MotionEvent event) {
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return FloatMath.sqrt(x * x + y * y);
}
}
It works perfect, however when i try to attach another Bitmap, it loses its current position and bitmap is moved to its original 0,0 state. However after setting bitmap if i call updateValues(ImageView view) it retains its current dragged positon. But when i try to drag again it suddenly goes to 0,0
How can i fix this. I want the new bitmap to start at the same position as before
Also how can i set the image to appear in Center at first place , currently it shows at top left corner
Try this to make it center on load
vTranslate.x = (getWidth()/2) - (scale * (sWidth()/2));
vTranslate.y = (getHeight()/2) - (scale * (sHeight()/2));
I created a method that would move a sprite in any direction to a point at a constant speed. I then added a queuing system for each point to move to.
My problem is that if a point becomes queued, usually only the first movement will be correct, then the sprite will seem to move to random locations for other points. The weird part is if I add a
if((int) x != (int) moveInfo.getTargetX() && (int) y != moveInfo.getTargetY()){
...
}else{
this.setPosition(moveInfo.getTargetX(), moveInfo.getTargetY());
...
}
the sprite corrects itself to its target position after it finishes moving to its random point. I created a debugger and it wasn't the sprites image offsetting either as the x and y values were real.
Here is some code I created that may cause the problem...
x and y are doubles.
Movement to point queuing constructor:
Queue<MoveInfo> moveTo = new LinkedList<MoveInfo>();
MoveTo class
private class MoveInfo{
private double targetX, targetY;
private double deltaX, deltaY;
private double direction;
private double speed;
private boolean ai;
public MoveInfo(double targetX, double targetY, double speed){
this.targetX = targetX;
this.targetY = targetY;
this.speed = speed;
this.deltaX = targetX - x;
this.deltaY = targetY - y;
calculateDirection();
ai = false;
}
public void calculateDirection(){
this.direction = Math.atan2(deltaX, deltaY);
}
... //Setters and getters.
}
Called every game update:
private void moveToUpdate(){
if(!spriteMoving && !moveTo.isEmpty()){
if(!moveTo.peek().isAi()){
moveInfo = moveTo.poll();
spriteMoving = true;
System.out.println("Next X"+moveInfo.targetX+" Y"+moveInfo.targetY);
}
}else if(spriteMoving && moveInfo != null){
if((int) x != (int) moveInfo.getTargetX() && (int) y != moveInfo.getTargetY()){
double nextY = y + (moveInfo.getSpeed() * Math.cos(moveInfo.getDirection()));
double nextX = x + (moveInfo.getSpeed() * Math.sin(moveInfo.getDirection()));
setPosition(nextX, nextY);
}else{
this.setPosition(moveInfo.getTargetX(), moveInfo.getTargetY());
spriteMoving = false;
moveInfo = null;
}
}
}
If you wish to see other parts of the code, let me know in the comments.
I am creating a custom view which is a kind of arc slider progress view.I can draw more or less of the arc based on where the user touches(on the x axis) by calculating the sweep, i do this by first calculating the percetage where the user touched along the x axis..0% would be all the way to the left and 100% would be all the way to the right.
I want to take this a step further, instead off drawing the arc based on the x coordinate that the user presses, I want to make it move only when the user touches on the actual arc draw path, so its more realistic. I am still new to custom views and my maths is limited but if I get some tips I would be grateful thanks
class ArcProgress extends View {
Context cx;
float width;
float height;
float center_x, center_y;
final RectF oval = new RectF();
final RectF touchArea = new RectF();
float sweep = 0;
float left, right;
int percent = 0;
public ArcProgress(Context context) {
super(context);
cx = context;
}
public int getPercentage() {
return percent;
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
setBackgroundColor(0xfff0ebde);
width = (float) getWidth();
height = (float) getHeight();
float radius;
if (width > height) {
radius = height / 3;
} else {
radius = width / 3;
}
Paint paint = new Paint();
paint.setAntiAlias(true);
paint.setColor(0xffd2c8b6);
paint.setStrokeWidth(35);
paint.setStyle(Paint.Style.STROKE);
center_x = width / 2;
center_y = height / 2;
left = center_x - radius;
float top = center_y - radius;
right = center_x + radius;
float bottom = center_y + radius;
oval.set(left, top, right, bottom);
//this is the background arc, it remains constant
canvas.drawArc(oval, 180, 180, false, paint);
paint.setStrokeWidth(10);
paint.setColor(0xffe0524d);
//this is the red arc whichhas its sweep argument manipulated by on touch
canvas.drawArc(oval, 180, sweep, false, paint);
}
#Override
public boolean onTouchEvent(MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_MOVE) {
float xPosition = event.getX();
float yPosition = event.getY();
if (oval.contains(xPosition, yPosition)) {
float x = xPosition - left;
float s = x * 100;
float b = s / oval.width();
percent = Math.round(b);
sweep = (180 / 100.0f) * (float) percent;
invalidate();
} else {
if (xPosition < left) {
percent = 0;
sweep = (180 / 100.0f) * (float) percent;
invalidate();
}
if (xPosition > right) {
percent = 100;
sweep = (180 / 100.0f) * (float) percent;
invalidate();
}
}
}
return true;
}
}
I want to make it move only when the user touches on the actual arc
draw path
At the beginning of onTouchEvent() you need to check whether xPosition and yPosition are fulfilling some condition. If yes, you do the stuff, which you are doing now. If no, return true.
Condition:
We want to check whether x, y are in that grey arc background:
Let's calculate a distance from (x, y) to that point (a, b) in the center:
final dist = distance(x, y, a, b)
distance() is a simple Euclidean distance between points (x,y) and (a,b):
double distance(int x, int y, int a, int b)
{
return Math.sqrt((x - a) * (x - a) + (y - b) * (y - b));
}
x, y are in that grey arc background, if y > Y && dist >= r && dist <= R.
Does this work for you?
You don't need a lot of Maths. You can calculate the distance of the touch point from the center of your arc (it's a circle so it's easy) and the compare that with the radius you are using. That will tell you if the point is on the arc (almost, see below for full case).
Point touchEv = ...;
Point circleCenter = ...;
//the radius of the circle you used to draw the arc
float circleRadius = ...;
//how far from the arc should a touch point treated as it's on the arc
float maxDiff = getResources().getDimension(R.dimen.max_diff_dp);
//calculate the distance of the touch point from the center of your circle
float dist = Math.pow(touchEv.x-circleCenter.x,2) + Math.pow(touchEv.y- circleCenter.y,2)
dist = Math.sqrt(dist);
//We also need the bounding rect of the top half of the circle (the visible arc)
Rect topBoundingRect = new Rect(circleCenter.x - circleRadius,
circleCenter.y - circleRadius,
circleCenter.x + circleRadius,
circleCenter.y);
if (Math.abs(dist - circleRadius) <= maxDiff &&
topBoundingRect.contains(touchEv.x, touchEv.y)) {
// the user is touching the arc
}