I've just made a quick system that has two joysticks (one for movement, one for shooting) and they work with multitouch.
However, when you use both at the same time they interfere with each other (You slow down, turn weirdly, etc) and am wondering whether this is an issue with my phone (Nexus One, 2.3.6) or an issue with the code:
public void handleEvent(MotionEvent event) {
final int action = event.getAction();
switch(action & MotionEvent.ACTION_MASK){
case MotionEvent.ACTION_DOWN: {
pointerID = event.getPointerId(0);
int tx = (int) event.getX(event.findPointerIndex(pointerID));
int ty = (int) event.getY(event.findPointerIndex(pointerID));
boolean reset = true;
if(tx >= (x - radius * 2) && (tx <= (x + radius * 2))) {
if(ty >= (y - radius * 2) && (ty <= (y + radius * 2))) {
dx = (tx - x);
dy = (ty - y);
reset = false;
}
}
if(reset) pointerID = -1;
break;
}
case MotionEvent.ACTION_POINTER_DOWN: {
if(pointerID == -1) {
final int pointerIndex = event.getActionIndex();
pointerID = event.getPointerId(pointerIndex);
int tx = (int) event.getX(pointerIndex);
int ty = (int) event.getY(pointerIndex);
if(tx >= (x - radius * 2) && (tx <= (x + radius * 2))) {
if(ty >= (y - radius * 2) && (ty <= (y + radius * 2))) {
dx = (tx - x);
dy = (ty - y);
}
}
}
break;
}
case MotionEvent.ACTION_MOVE: {
if(pointerID != -1) {
final int pointerIndex = event.findPointerIndex(pointerID);
int tx = (int) event.getX(pointerIndex);
int ty = (int) event.getY(pointerIndex);
if(tx >= (x - radius * 2) && (tx <= (x + radius * 2))) {
if(ty >= (y - radius * 2) && (ty <= (y + radius * 2))) {
dx = (tx - x);
dy = (ty - y);
}
}
}
break;
}
case MotionEvent.ACTION_POINTER_UP: {
final int pointerIndex = event.getActionIndex();
final int id = event.getPointerId(pointerIndex);
if(id == pointerID) {
dy = 0;
dx = 0;
pointerID = -1;
}
break;
}
case MotionEvent.ACTION_UP: {
if(-1 != pointerID) {
dy = 0;
dx = 0;
pointerID = -1;
}
break;
}
}
}
Important notes:
Each joystick is a class, and the handleEvent method is called for each joystick.
pointerID is an int belonging to each joystick
dy and dx are just the distance from the center of the joystick.
What you are missing is that if there are multiple touches happening at the same time, that one MotionEvent contains them all (and if one of the touches is of the type ACTION_MOVE, it also contains a history of that movement).
Use a loop over event.getPointerCount() (if it is >1) as indexes to get ID's for each touchpoint, which you can then use to track the touch and get the touch's x/y/other information.
Now the thing to realise is that the pointerID not only tracks the touch ... but it also can change if a touch point goes away (finishing with an ACTION_UP event); a POINTER_DOWN event will always add that touch with an ID at the end (so if you have two touches it will get the ID 2), but on a POINTER_UP (or POINTER_2_UP if it''s the second touch point), the points with a higher ID change ID by moving down.
So if you have touches with ID 0, 1 and 2, and the second touch (ID 1) goes POINTER_UP, you have to realise that pointerID 2 will change into ID 1. And if you have two touches (0 and 1), if ID 0 goes up, all of the sudden ID 1 becomes ID 0!
The trick is to keep track of this with some global variables (leftJoyStickID and rightJoyStickID) and some code in action_down and action_up. With just two touchpoints, the ternary operator is your friend:
if (IDofActionUpEvent == leftJoyStickID)
{
rightJoyStickID = IDofActionUpEvent == 0 ? 1 : 0;
}
Related
I am developing a Tetris for Android using C++ taking advantage of SDL2 portability, the thing is that i have a lot of delays when i get events from the touch interface, is like the the function SDL_PollEvent() doesn't work like on PC, i have wrote this on my getting events method.
float x = 0, y = 0;
while (SDL_PollEvent(&event)){
switch (event.type) {
case SDL_QUIT: { gameState = false; break;}
case SDL_FINGERDOWN: {
x = event.tfinger.x;
y = event.tfinger.y;
SDL_Log("\nDesplazamiento x: %f desplazamiento y: %f.\n", x, y);
window.get_AbsPixels(&x, &y);
if (x >= keys->U.getX() && x <= (keys->U.getX() + keys->U.getW()) &&
y >= keys->U.getY() && x <= keys->U.getY() + keys->U.getH())
return Up;
if (x >= keys->D.getX() && x <= (keys->D.getX() + keys->D.getW()) &&
y >= keys->D.getY() && x <= keys->D.getY() + keys->D.getH())
return Down;
if (x >= keys->L.getX() && x <= (keys->L.getX() + keys->L.getW()) &&
y >= keys->L.getY() && x <= keys->L.getY() + keys->L.getH())
return Left;
if (x >= keys->R.getX() && x <= (keys->R.getX() + keys->R.getW()) &&
y >= keys->R.getY() && x <= keys->R.getY() + keys->R.getH())
return Right;
break;
}
default: break;
}
return None;
}
but when i debug my app on android the events act delayed despite they should have been returned and should be received before animation, so i guess if they are treated in another thread in Android or something because they act like independient to the animation.
Tried before with this:
float x = 0, y = 0, tmpx = 0, tmpy = 0;
while (SDL_PollEvent(&event)){
if (event.type == SDL_QUIT){ gameState = false; }
switch (event.type) {
case SDL_FINGERMOTION: {
tmpx = event.tfinger.dx;
tmpy = event.tfinger.dy;
window.get_AbsPixels(&tmpx, &tmpy);
x += tmpx; y += tmpy;
tmpx = tmpy = 0;
SDL_Log("\nDesplazamiento x: %f desplazamiento y: %f.\n", x, y);
break;
}
default: break;
}
if ((x > 70 || x < -70) || (y > 70 || y < -70))
return window.process_Dplcmnt(x, y);
}
return None;
..but it gave me also a lot of delays than the new one.
So to have it all clear and could act acording to, could someone explain me how the touch events should be processed using SDL on Android? Thanks in advance.
I already solve it, after every case:, even when no one fit on a condition there was always a returning so the pending events that didn't match kept there not flushing right, just moved the state return None; outside the while. Now it works like on PC.
float x = 0, y = 0;
while (SDL_PollEvent(&event)){
switch (event.type) {
case SDL_QUIT: { board->setGameState(false); break;}
case SDL_FINGERDOWN: {
x = event.tfinger.x;
y = event.tfinger.y;
SDL_Log("\nDesplazamiento x: %f desplazamiento y: %f.\n", x, y);
window.get_AbsPixels(&x, &y);
if (x > keys->U.getX() && x < (keys->U.getX() + keys->U.getW()) &&
y > keys->U.getY() && y < keys->U.getY() + keys->U.getH()) {
SDL_Log("\nRetornado Up\n");
return Up;
}
if (x > keys->D.getX() && x < (keys->D.getX() + keys->D.getW()) &&
y > keys->D.getY() && y < keys->D.getY() + keys->D.getH()) {
SDL_Log("\nRetornado Down\n");
return Down;
}
if (x > keys->L.getX() && x < (keys->L.getX() + keys->L.getW()) &&
y > keys->L.getY() && y < keys->L.getY() + keys->L.getH()) {
SDL_Log("\nRetornado Left\n");
return Left;
}
if (x > keys->R.getX() && x < (keys->R.getX() + keys->R.getW()) &&
y > keys->R.getY() && y < keys->R.getY() + keys->R.getH()) {
SDL_Log("\nRetornado Right\n");
return Right;
}
break;
}
default:
//SDL_PumpEvents();
//SDL_FlushEvent(SDL_FINGERDOWN);
break;
}
}
return None;
I need to move, rotate and resize edittext based on user's touch gestures.
Here is what I am doing.
1. Listen for ACTION_DOWN event to detect single finger touch and then use that for movement.
Listen for ACTION_POINTER_DOWN, and get the index count to detect two finger touch and then use ACTION_MOVE for rotation.
I need to make resize work such that only the width gets decreased on resize by touch.
Problem I am facing
Movement is working perfectly fine. But when I apply rotation using the ACTION_POINTER_DOWN, rotation goes all sorts of haywire. Any suggestions on how to make the view movement and rotation work together?
Here is the code for touchListener I have applied
tvMain.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
moving = true;
break;
case MotionEvent.ACTION_POINTER_DOWN:
Log.d("ActionPointerIndex", "" + event.getActionIndex());
int index = event.getActionIndex();
moving = false;
//FOR ROTATION DETAILS
xc = tvMain.getWidth() / 2;
yc = tvMain.getHeight() / 2;
x_ = event.getX();
y_ = event.getY();
Log.d("currentAnglePD", ": " + x_ + "," + y_);
if (index == 1) {
rotate = true;
mCurrAngle = Math.toDegrees(Math.atan2(x_ - xc, yc - y_));
moving = false;
}
break;
case MotionEvent.ACTION_MOVE:
if (moving) {
leftBound = rootView.getX();
topBound = rootView.getY();
rightBound = rootView.getX() + 1280;
bottomBound = rootView.getY() + 618;
x = event.getRawX() - tvMain.getWidth() / 2;
y = event.getRawY() - tvMain.getHeight();
dx = Float.valueOf(rootView.getWidth() - tvMain.getWidth());
dy = Float.valueOf(rootView.getHeight() - tvMain.getHeight());
bottomBound_ = tvMain.getY() + tvMain.getHeight();
rightBound_ = tvMain.getX() + tvMain.getWidth();
if (x >= leftBound && y >= topBound && x <= dx && y <= dy) {
tvMain.setX(x);
tvMain.setY(y);
}
}
if (rotate) {
Log.d("currentAngleMove", ": " + x_ + "," + y_);
mPrevAngle = mCurrAngle;
mCurrAngle = Math.toDegrees(Math.atan2(x_ - event.getX(), yc - event.getY()));
animate(mPrevAngle, mCurrAngle, 0);
System.out.println(mCurrAngle);
}
break;
case MotionEvent.ACTION_POINTER_UP:
rotate = false;
break;
case MotionEvent.ACTION_UP:
rotate = false;
moving = false;
//tvMain.clearAnimation();
break;
}
return true;
}
});
Movement is working fine, but once I move the view, rotation goes haywire, and it does not rotate along its center. Once I stop rotating, the view stops listening for any more touch gestures.
For example, I move my finger down the screen and then back up. So, this should count as two drags, the last movement before I paused for a split second and after that when I moved back up. I basically count every time I make a new movement without lifting my finger off the screen. So, how do I get the last movement before I stop movement without lifting my finger?
I'm using motion event. Here is the code in action_move:
case MotionEvent.ACTION_MOVE:
posY = event.getY();
posX = event.getX();
diffPosY = posY - oldY;
diffPosX = posX - oldX;
if (checkMovement(posY, oldY)){
if (diffPosY > 0 || diffPosY < 0){
count +=1;
}
}
public boolean checkMovement(float posY, float oldY) {
int newY = Math.round(posY);
double distance = Math.abs(newY - oldY);
oldY = newY;
if (distance < 25)
return false;
return true;
}
Simple like this
private int mLastMovY = 0;
case MotionEvent.ACTION_MOVE:
posY = event.getY();
posX = event.getX();
diffPosY = posY - oldY;
diffPosX = posX - oldX;
if(diffPosY > 0){//up
if(mLastMovY != 0){//if have any drag down before, the value will != 0
count +=1;
//could save value of mLastMovY before reset it, this is last position when user drag down
mLastMovY = 0;//reset it to avoid 'count' be increased
}
}
else{//down
mLastMovY = posY;//drag down will assign value to mLastMovY
}
I want the user to be able to drag the edges of a square around the canvas. With my current solution it works but has glitches, sometimes an edge cannot be selected. Is there a clean way to tell if a line has been clicked (e.g. passes through a coordinate)? This is how I'm currently testing:
// check edge pressed, edge is the line between to
// coords e.g. (i) & (i = 1)
for (int i = 0; i < coords.size(); i++) {
p1 = coords.get(i);
if ((i + 1) > (coords.size() - 1)) p2 = coords.get(0);
else p2 = coords.get(i + 1);
// is this the line pressed
if (p1.x <= event.getX() + 5 && event.getX() - 5 <= p2.x && p1.y <= event.getY() + 5 && event.getY() - 5 <= p2.y) {
// points found, set to non temp
// variable for use in ACTION_MOVE
point1 = p1;
point2 = p2;
break;
} else if (p1.x >= event.getX() + 5 && event.getX() - 5 >= p2.x && p1.y >= event.getY() + 5 && event.getY() - 5 >= p2.y) {
// points found, set to non temp
// variable for use in ACTION_MOVE
point1 = p1;
point2 = p2;
break;
}
}
The code bellow //is this the line pressed is the most important and also most likely the issue. The +5 and -5 are used to give the use a larger area to click on.
Here is the whole on click event:
public void EditEdge() {
//TODO this works like shit
// Detect the two coordinates along the edge pressed and drag
// them
scene.setOnTouchListener(new View.OnTouchListener() {
private int startX;
private int startY;
private Point point1 = new Point(0, 0);
private Point point2 = new Point(0, 0);
#Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
startX = (int) event.getX();
startY = (int) event.getY();
Point p1;
Point p2;
// check edge pressed, edge is the line between to
// coords e.g. (i) & (i = 1)
for (int i = 0; i < coords.size(); i++) {
p1 = coords.get(i);
if ((i + 1) > (coords.size() - 1)) p2 = coords.get(0);
else p2 = coords.get(i + 1);
// is this the line pressed
if (p1.x <= event.getX() + 5 && event.getX() - 5 <= p2.x && p1.y <= event.getY() + 5 && event.getY() - 5 <= p2.y) {
// points found, set to non temp
// variable for use in ACTION_MOVE
point1 = p1;
point2 = p2;
break;
} else if (p1.x >= event.getX() + 5 && event.getX() - 5 >= p2.x && p1.y >= event.getY() + 5 && event.getY() - 5 >= p2.y) {
// points found, set to non temp
// variable for use in ACTION_MOVE
point1 = p1;
point2 = p2;
break;
}
}
break;
case MotionEvent.ACTION_UP:
point1 = new Point(0, 0);
point2 = new Point(0, 0);
// scene.setOnTouchListener(scene.editModeOnTouchListener);
break;
case MotionEvent.ACTION_MOVE:
for (Point p: new Point[] {
point1, point2
}) {
int modX = (int)(p.x + (event.getX() - startX));
int modY = (int)(p.y + (event.getY() - startY));
p.set(modX, modY);
}
SetCoords(coords);
startX = (int) event.getX();
startY = (int) event.getY();
break;
default:
return false;
}
return true;
}
});
}
So is there a easier way to tell is a line is clicked/ passes through a point or is that not the issue?
Thanks
use the line equation y = mx + b to find out if the point is on a line
float EPSILON = 0.001f;
public boolean isPointOnLine(Point linePointA, Point linePointB, Point point) {
float m = (linePointB.y - linePointA.y) / (linePointB.x - linePointA.x);
float b = linePointA.y - m * linePointA.x;
return Math.abs(point.y - (m*point.x+b)) < EPSILON);
}
Great piece of code by #tyczj !
I added a use-case to handle vertical lines, which gives me the following code fragment:
public boolean isPointOnLine(PointF lineStaPt, PointF lineEndPt, PointF point) {
final float EPSILON = 0.001f;
if (Math.abs(staPt.x - endPt.x) < EPSILON) {
// We've a vertical line, thus check only the x-value of the point.
return (Math.abs(point.x - lineStaPt.x) < EPSILON);
} else {
float m = (lineEndPt.y - lineStaPt.y) / (lineEndPt.x - lineStaPt.x);
float b = lineStaPt.y - m * lineStaPt.x;
return (Math.abs(point.y - (m * point.x + b)) < EPSILON);
}
}
Also a piece of code to check if a point lies on a line-segment:
public boolean isPointOnLineSegment(PointF staPt, PointF endPt, PointF point) {
final float EPSILON = 0.001f;
if (isPointOnLine(staPt, endPt, point)) {
// Create lineSegment bounding-box.
RectF lb = new RectF(staPt.x, staPt.y, endPt.x, endPt.y);
// Extend bounds with epsilon.
RectF bounds = new RectF(lb.left - EPSILON, lb.top - EPSILON, lb.right + EPSILON, lb.bottom + EPSILON);
// Check if point is contained within lineSegment-bounds.
return bounds.contains(point.x, point.y);
}
return false;
}
You could define 8 Rect to check against - the 4 sides and 4 corners (so you can move 2 edges at once). The lines of the edge should have a width for the touchable area.
Define a Point centred on your touch event, there are then methods for checking if a rect contains a point.
So I have a custom view widget I am allowing a user to drag around by their finger. They are dragging it in a custom scrolling view based on a FrameLayout (code here: http://blog.gorges.us/2010/06/android-two-dimensional-scrollview/) that contains a RelativeLayout, so that they can place it where they want and have plenty of space that is not visible on screen to place the item as well.
What I would like to happen is if the user is moving the widget near the edge of the visible scroll area is to scroll the area in the appropriate direction until they either let go (ACTION_UP, in which case no more events would take place anyway) or have moved away from the edge. The code right now has two problems:
1) My phone (T-Mobile G2) continues to trigger ACTION_MOVE even when my finger is still where as my Nexus 7 tablet does not continue to trigger until it has moved. I need to reliably continue to trigger this event until ACTION_UP.
2) The area scrolls but only as I move my finger towards the edge of the screen. In otherwords, I'd like for a finger that is staying still to continue to scroll and move the object when it is near the edge, but this is not happening.
What am I missing? Here is the onTouchEvent that handles the moving of the widget
#Override
public boolean onTouchEvent(MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_MOVE
&& this.getParent() != null) {
getParent().requestDisallowInterceptTouchEvent(true);
}
// mScrollParent gets set in a setter and points to the TwoDScrollView
// mOffsetX/Y is based on where the user touches versus the position of the custom view
// mWidth/mHeight gets set once in the GestureDetector based on the custom view's getWidth()/getHeight()
// mTitleBarHeight gets set once in the GestureDetctor onDown event
// lp is a ViewGroup.LayoutParams type
if (!mGestureDetector.onTouchEvent(event)) {
if (event.getAction() == MotionEvent.ACTION_MOVE) {
int finalX = (int) (event.getRawX() - mOffsetX);
int finalY = (int) (event.getRawY() - mOffsetY - (mTitleBarHeight > 0 ? mTitleBarHeight * 2
: 0));
if (finalX < 0 || finalY < 0)
return false;
int scrollLeft = (int) Math.ceil(mScrollParent.getScrollX() * 1.05);
int scrollTop = (int) Math.ceil(mScrollParent.getScrollY() * 1.05);
int scrollRight = (int) Math.floor((scrollLeft + mScrollParent.getRight()) * 0.95);
int scrollBottom = (int) Math.floor((scrollTop + mScrollParent.getBottom()) * 0.95);
int scrollX = 0;
int scrollY = 0;
if (scrollLeft > finalX)
scrollX = finalX - scrollLeft;
if (scrollRight < (finalX + mWidth))
scrollX = (finalX + mWidth)- scrollRight;
if (scrollTop > finalY)
scrollY = finalY - scrollTop;
if (scrollBottom < (finalY + mHeight))
scrollY = (finalY + mHeight) - scrollBottom;
if (scrollX != 0 || scrollY != 0)
mScrollParent.scrollBy(scrollX * 4, scrollY * 4);
lp.setMargins(finalX + scrollX, finalY + scrollY, 0, 0);
setLayoutParams(lp);
return true;
}
} else if (event.getAction() == MotionEvent.ACTION_UP) {
return true;
} else {
return super.onTouchEvent(event);
}
} else {
return true;
}
}