i am working on game in which i want to move CCSprite in direction of accelerometer tilt.i have referred this tutorial http://www.raywenderlich.com/457/intro-to-box2d-with-cocos2d-tutorial-bouncing-balls but i am not clear with it. Please can any one help me.
Thanks in Advance.
Refer this solution. I used same for moving sprite from left to right in landscape game.: See answer here
Only change for landscape mode is use accelerometer y in place of x.
-(void) accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration
{
if(self.isGamePaused || self.isGameOver)
return;
float deceleration = 1.0f, sensitivity = 15.0f, maxVelocity = 450;
if(sGame.IsIpad)
{
sensitivity = 14.0f;
maxVelocity = 850;
deceleration = 1.5f;
}
// adjust velocity based on current accelerometer acceleration
// vel.x = vel.x * deceleration + acceleration.x * sensitivity;
AppController *app = (AppController*)[UIApplication sharedApplication].delegate;
float velocity_x = self.gameActor.velocity.x ;
self.gameActor.accelVal = ABS(acceleration.y);
if(app.orient == UIInterfaceOrientationLandscapeLeft)
{
velocity_x = velocity_x * deceleration + acceleration.y * sensitivity;
}
else
{
velocity_x = velocity_x * deceleration + (-acceleration.y) * sensitivity;
}
//limit the maximum velocity of the player sprite, in both directions (positive & negative values)
velocity_x = fmaxf(fminf(velocity_x, maxVelocity), -maxVelocity);
self.gameActor.velocity = ccp(velocity_x, self.gameActor.velocity.y);
}
Related
I'm using accelerometer in my first Cocos2D game and it work fine, i'm able to move the sprite using the below code however, when i change the orientation from landscapeLeft to landscapeRight, the sprite stops responding to Y coordination, and the sprite goes to the top of the screen and doesn't properly respond... I believe it's because of changing the device orientation, but i'm not sure since i'm pretty new to App Development, any help will be appreciated.
Here is the sample code i'm using...
- (void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration
{
//this determines how sensitive the accelerometer reacts (higher = more sensitive)
NSUserDefaults *defaulObj = [NSUserDefaults standardUserDefaults];
float sensitivity = [defaulObj floatForKey:#"Sensitivity"]; //10.0f
if (!sensitivity) {
sensitivity = 6;
}
// this controls how quickly the velocity decelerates (lower = quicker to change direction)
float deceleration = 0.4f;
static float xVal = 0;
if (!self.isFlag) {
xVal = -acceleration.x;
self.isFlag = TRUE;
}
playerVelocity.x = playerVelocity.x * deceleration + (xVal + acceleration.x) * sensitivity;
playerVelocity.y = playerVelocity.y * deceleration + acceleration.y * sensitivity;
playerVelocity.y = playerVelocity.y*-1;
}
Perhaps this helps out, flips Y along your current device orientation.
float rotatedY = acceleration.y;
if ([UIApplication sharedApplication].statusBarOrientation==UIInterfaceOrientationLandscapeLeft) {
rotatedY *= -1;
}
then use rotatedY insteat of acceleration.y
I m start learning game development. As a beginner i create one demo game in which one cannon hit bullets to the enemies (coming toward cannon from different direction).
Now i stuck on cannon sprite image rotation anywhere user touch on the screen or enemies. How i do that, My initial code as following,
void HelloWorld:: ccTouchesBegan(CCSet *touches, CCEvent * event)
{
CCSize winSize = CCDirector::sharedDirector()->getWinSize();
CCTouch* touch = (CCTouch*)( touches->anyObject() );
CCPoint location = touch->locationInView(touch->view());
location = CCDirector::sharedDirector()->convertToGL(location);
//Rotate cannon direction toward touch point
CCPoint diffPoint = ccpSub(_cannonImage->getPosition(), location);
float angleRadians = atanf((float)diffPoint.y/(float)diffPoint.x);
float angleOffset = CC_DEGREES_TO_RADIANS(180);
if(diffPoint.x < 0){
angleRadians += angleOffset;
}else{
angleRadians -= angleOffset;
}
CCLog("angle to be rotate = %f", angleRadians);
_cannonImage->runAction(CCRotateBy::actionWithDuration(0.1, angleRadians));
}
The code is written in cocos2d-x . I also accepting answer by someone who written in plain cocos2d.
Thanks
iHungry
The perfect answer as follows,
float HelloWorld::changingAngleAccordingToCoordinateSystem(CCPoint imageCenter, CCPoint touchLocation, float calculatedAngle){
//Consideration :- all Angles is in Degree
if((calculatedAngle >= 0 && calculatedAngle <= 90) || (calculatedAngle >= 90 && calculatedAngle <= 180)){
//Ist quardant
calculatedAngle = calculatedAngle;
}
else if(calculatedAngle < 0 && calculatedAngle >= -90){
//IInd quardant
calculatedAngle = 270 + (90 + calculatedAngle);
}
else if(calculatedAngle < -90 && calculatedAngle >= -180){
calculatedAngle = 180 + (180 + calculatedAngle);
}
return calculatedAngle;
}
//Rotate cannon direction toward touch point
float diff_X = touchLocation.x - myImage->getPosition().x;
float diff_Y = touchLocation.y - myImage->getPosition().y;
CCPoint diffPoint = CCPoint(diff_X, diff_Y);
float angleRadians = atan2f(diffPoint.y,diffPoint.x);
angleRadians = CC_RADIANS_TO_DEGREES(angleRadians);
angleRadians = HelloWorld::changingAngleAccordingToCoordinateSystem(myImage->getPosition(), touchLocation, angleRadians);
myImage->setRotation(-angleRadians);
i used this code to rotate my sprite. i Was moving the sprite according to my accelerometer reading.
float angleRadians =-accelX;
float angleDegrees = CC_RADIANS_TO_DEGREES(angleRadians);
objGlider->sprite_Glider.rotation = cocosAngle;
Check it. The reason of slow may be that you may be using CClog or NSLog in the code.
Here goes the complete code.
if(!boolPlayerDied)
{
static float prevX=0, prevY=0;
#define kFilterFactor 1.0f// don't use filter. the code is here just as an example
float accelX = (float) acceleration.x * kFilterFactor + (1- kFilterFactor)*prevX;
float accelY = (float) acceleration.y * kFilterFactor + (1- kFilterFactor)*prevY;
prevX = accelX;
prevY = accelY;
accelX = accelX-0.5;// Angle check fot tgfor the player to play
float angleRadians =-accelX;
float angleDegrees = CC_RADIANS_TO_DEGREES(angleRadians);
if(accelX>0)
{
cocosAngle = 1.1 * angleDegrees;
}
else
{
if(accelX<-0.5)
accelX=-0.5;
cocosAngle = 1.1 * angleDegrees;
}
objGlider->sprite_Glider.rotation = cocosAngle;
}
objGlider is the object of the class which creates glider sprite and sprite_Glider is the sprite used in glider class.
you can use rotation property with your sprite to be rotated. In cocos2Dx it might be setRotation.
First of all, replace
float angleRadians = atanf((float)diffPoint.y/(float)diffPoint.x);
float angleOffset = CC_DEGREES_TO_RADIANS(180);
if(diffPoint.x < 0){
angleRadians += angleOffset;
}else{
angleRadians -= angleOffset;
}
by
float angleRadians = atan2f(diffPoint.y, diffPoint.x);
Then it would be better to set rotation immediately (without actions) to process multiple frequent touches.
_cannonImage->setRotation(angleRadians);
Maybe you will need to adjust rotation like setRotation(-angleRadians) or setRotation(angleRadians+90) - it depends on your coordinate system.
I made a space game where you use the accelerometer to move a spaceship, When I try the game on my devices (iPad, iPhone) it work well with no errors or incorrect behavior.
I upload my game to the App Store and it was approved, but when I downloaded the game from the App Store, the accelerometer wasn't working and my spaceship was stuck in one direction.
I tried many devices and they all have same problem.
Note: I used the cocos2d and box2d frameworks.
If anybody have any idea, please help!
Use UIAccelerometerDelegate
UIAccelerometer *accelerometer;
In .m file
# pragma mark To Enable Acceleromete
self.isAccelerometerEnabled = YES;
self.accelerometer = [UIAccelerometer sharedAccelerometer];
self.accelerometer.updateInterval = 0.025;
self.accelerometer.delegate = self;
Use these delegates methods
#pragma Mark Accelerometer
-(void) accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration
{
// Set up variables
CGSize winSize = [CCDirector sharedDirector].winSize;
#define kFilteringFactor 0.5
#define kShipMaxPointsPerSec (winSize.height*0.5)
#define kRestAccelX (xCallib)
#define kMaxDiff 0.2
#define kRestAccelY (yCallib)
#define kMaxDiffY 0.1
UIAccelerationValue rollingX=0;
float accelX;
// High pass filter for reducing jitter
rollingX = (acceleration.x * kFilteringFactor) + (rollingX * (1.0 - kFilteringFactor));
accelX = acceleration.x - rollingX;
// Calculate movement for x and y axis
float accelDiffX = accelX - kRestAccelX;///
float accelFractionX = accelDiffX / kMaxDiff;//
movementX = kShipMaxPointsPerSec * accelFractionX;
// Thresh holds for x and y axis movement
willMoveX = YES;
if (((movementX < 45.0f) && (movementX > -45.0f)))
willMoveX = NO;
}
#pragma Mark Accelerometer Update Methods
-(void) update:(ccTime)dt
{
CCSprite *player =(CCSprite *) [self getChildByTag:objPlayerShipTag];
CGSize screenSize = [[CCDirector sharedDirector]winSize];
float oldX = [player position].x;
float newX;
if (willMoveX) {
newX = [player position].x + (movementX * dt);
} else newX = oldX;
if ((newX > (screenSize.width -45)) || newX < 45.0f ) {
newX = oldX;
}
[player setPosition:ccp(newX,90)];
// ++++++++ To generate Bullet and Bomb Power +++++++
[self checkForCollisionWithPowersBullets]; //NEW
[self checkForCollisionWithPowersBomb];
}
I am new in Box2D....
I have ball image in CCSprite. I want to move ball in whole screen using accelerometer...
tell me
How to use accelerometer in box2d??
Thanks...in advance
The standard cocos2d-box2d template file moves boxes using the accelerometer by applying gravity relative to the accelerometer value.
- (void)accelerometer:(UIAccelerometer*)accelerometer didAccelerate:(UIAcceleration*)acceleration
{
static float prevX=0, prevY=0;
//#define kFilterFactor 0.05f
#define kFilterFactor 1.0f // don't use filter. the code is here just as an example
float accelX = (float) acceleration.x * kFilterFactor + (1- kFilterFactor)*prevX;
float accelY = (float) acceleration.y * kFilterFactor + (1- kFilterFactor)*prevY;
prevX = accelX;
prevY = accelY;
// accelerometer values are in "Portrait" mode. Change them to Landscape left
// multiply the gravity by 10
b2Vec2 gravity( -accelY * 10, accelX * 10);
world->SetGravity( gravity );
}
You need to be more specific on what you want the ball to do dependent on how you move the phone. Your question is difficult to answer in its current form.
Get the accelerometer measurements and say Force = coefficient*measurements. The apply this force to your b2Body
Let your Ball Sprite having tag is 1.
Replace this code with your Accelerometer delegate,
I test it on device, its working.
and your ball will move with accelerometer.
-(void)accelerometer:(UIAccelerometer*)accelerometer didAccelerate:(UIAcceleration*)acceleration
{
#define kFilterFactor 0.75
accelerometer.updateInterval = 1.0f/60.0f;
static UIAccelerationValue rollingX = 0, rollingY = 0;
for (b2Body *b = world->GetBodyList(); b; b = b->GetNext())
{
if (b->GetUserData() != NULL)
{
CCSprite *sprite = (CCSprite*)b->GetUserData();
if (sprite.tag == 1) {
rollingX = (acceleration.x * kFilterFactor) + (rollingX * 0.25);
rollingY = (acceleration.y * kFilterFactor) + (rollingY * 0.25);
float accelX = rollingX;
float accelY = rollingY;
CGPoint moveNewPosition = sprite.position;
if (accelX > 0.1) {
moveNewPosition.y += 2;
} if (accelX < 0.1) {
moveNewPosition.y -= 2;
}
if (accelY > 0.1) {
moveNewPosition.x -= 2;
} if (accelY < -0.1) {
moveNewPosition.x += 2;
}
b->SetLinearVelocity(b2Vec2(2,2));
sprite.position = ccp(moveNewPosition.x , moveNewPosition.y );
sprite.rotation = -1 * CC_RADIANS_TO_DEGREES(b->GetAngle());
}
}
}
}
I hope it'll work.
i use following code to move my Box2D object into screen, but because gravity of my world or something else i dont know why my objects is forced to move down, i am new to box2d.
i want to move my object in entire world without gravity.
-(void) tick:(NSTimer *)timer {
int32 velocityIterations = 8;
int32 positionIterations = 1;
world->Step(1.0f/60.0f, velocityIterations, positionIterations);
for (b2Body* b = world->GetBodyList(); b; b = b->GetNext())
{
if (b->GetUserData() != NULL)
{
UIView *oneView = (UIView *)b->GetUserData();
CGPoint newCenter = CGPointMake(b->GetPosition().x * PTM_RATIO,self.view.bounds.size.height - b->GetPosition().y * PTM_RATIO);
oneView.center = newCenter;
CGAffineTransform transform = CGAffineTransformMakeRotation(- b->GetAngle());
oneView.transform = transform;
}
}
}
my accelerometer code is as follow.
- (void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration {
b2Vec2 gravity;
gravity.Set( acceleration.x * 1.81, acceleration.y * 1.81 );
world->SetGravity(gravity);
}
pleas if any one work around.
Thanks.
As i understand you want to move your object setting it's position. It's a bad idea because it will provide non-physical behavior of the bodies colliding with your object. That's because if you will only change the position of your body it's velocity for physics engine will be still zero and collision will be processed according to zero speed of your object.
A better solution is to use b2_kinematicBody type for your object. Then you will be able to control it's motion specifying it's velocity vector and physics will behave as expected. Also the gravity (and no other forces) will not be applied to your object because of it's type.
EDIT
//creation
b2BodyDef bDef;
bDef.type = b2_kinematicBody;
bDef.position.Set(5, 6);
b2Body *body = physWorld->CreateBody(&bDef);
//control
body->SetLinearVelocity(b2Vec2(3, 4));