i have implementing moving image using UIAccelerometer.I have used below code.
code:
float gravX = (acceleration. x * kFilteringFactor) + (gravX * (1 - kFilteringFactor));
float gravY = (acceleration. y * kFilteringFactor) + (gravY * (1 - kFilteringFactor));
float moveX = acceleration. x - gravX;
float moveY = acceleration. y - gravY;
CGPoint MoveCenter = [moveImage center];
float Movex = moveX * 30 + MoveCenter. x;
float Movey = moveY * 30 + MoveCenter. y;
moveImage.center = CGPointMake(Movex, Movey);
In this code there is one problem.If i move device on top side then image is moving on left side,if device is move left side then image is moving top side.can you give me advice.
Maybe is a problem of the coordinates. I'm not sure this is the problem but in Quartz the (0,0) is on bottom left while on UIKit is on top left.
Try to change the coordinates with frame.origin.x and frame.origin.y instead of using CGPoint.
Related
I'm rotating a UIView based on the accelerometer data, and it works fine except that the UIView is deformed. I'm not sure how to fix the issue. Here's the code in my didAccelerate method:
float kFilteringFactor = 0.175;
CGFloat x = acceleration.x * kFilteringFactor + acceleration.x * (1.0 - kFilteringFactor);
CGFloat y = acceleration.y * kFilteringFactor + acceleration.y * (1.0 - kFilteringFactor);
float radians = M_PI - atan2(y, x);
[_horizonView setTransform:CGAffineTransformMakeRotation(radians)];
Am I performing the rotation incorrectly? I've changed the origin point in Xcode, but that appears to have no effect.
what kind of deformation occures? I think the the rotation is fine.
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'm trying to calculate the angle of the click i am making in relationship to the middle of the screen. But maybe i am confused on how atanf is suppsoed to work.
CGPoint pt = [self convertTouchToNodeSpace:[touches anyObject]];
float adj = pt.x - 512;
float opposite = pt.y - 384;
float combined = opposite / adj;
float tan = atanf(combined);
but when i try to NSLog Tan, i just get some giant number like 0.1253649
thoughts?
The right way to convert vector to angle is through atan2 function:
float angle = atan2f (pt.y - 384, pt.x - 512) * 180 / PI;
PS: Are you using cocos2d engine? It has ccpToAngle(...) function.
I'm having a heck of a time calculating points on a circle in Objective-C. Even after reading TONS of other code samples my circle is still way off center. (And that's taking into consideration "center" vs "origin" and adjusting for the size of the UIView, in this case a UIButton.)
Here's the code I'm using. The circle is formed correctly, it's just off center. I'm not sure if this is a radians vs degrees problem or something else. This is a helper function in a ViewController that programmatically creates the UIButtons and adds them to the view:
- (CGPoint)pointOnCircle:(int)thisPoint withTotalPointCount:(int)totalPoints {
CGPoint centerPoint = CGPointMake(self.view.frame.size.width / 2, self.view.frame.size.height / 2);
float radius = 100.0;
float angle = ( 2 * M_PI / (float)totalPoints ) * (float)thisPoint;
CGPoint newPoint;
newPoint.x = (centerPoint.x / 2) + (radius * cosf(angle));
newPoint.y = (centerPoint.y / 2) + (radius * sinf(angle));
return newPoint;
}
Thanks for the help!
The center of your buttons (i.e. points on the circle) is
newPoint.x = (centerPoint.x) + (radius * cosf(angle)); // <= removed / 2
newPoint.y = (centerPoint.y) + (radius * sinf(angle)); // <= removed / 2
Please note that if you place buttons (i.e. rectangles) on these points you have to make sure that their center lies at this point (i.e. subtract buttonWidth/2 from newPoint.x and buttonHeight/2 from newPoint.y to get the top left corner).
Not sure why you divide by 2 a second time newPoint coordinates...
What about this:
newPoint.x = centerPoint.x + (radius * cosf(angle));
newPoint.y = centerPoint.y + (radius * sinf(angle));
return newPoint;
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.