iphone - Calculate angle for rotation in Pie Chart -

-

i want rotate image around center point.the problem facing need angle calculate in touch moved event (i dont want use multi touch).i current using below code

- (void)touchesmoved:(nsset *)touches withevent:(uievent *)event{  nsarray *alltouches = [touches allobjects];  gesturestartpoint = gesturemovedpoint;//i getting gesturestartpoint on touch began event  gesturemovedpoint = [[alltouches objectatindex:0] locationinview:[self superview]];  nslog(@"gesturemovedpoint = %@",nsstringfromcgpoint(gesturemovedpoint));

}

cgfloat previousangle = [self anglebetweenpoints:gesturestartpoint second11:gesturemovedpoint]; // atan2(gesturemovedpoint.y - gesturestartpoint.y, gesturemovedpoint.x - gesturestartpoint.x) * 180 / m_pi; cgfloat currentangle =atan2(self.transform.b, self.transform.a);//atan2(gesturemovedpoint.y - gesturestartpoint.y,gesturemovedpoint.x - gesturestartpoint.x) * 180 / m_pi;    cgfloat angletorotate = currentangle - previousangle;    float xpoint = (((atan2((gesturemovedpoint.x - gesturestartpoint.x) , (gesturemovedpoint.y - gesturestartpoint.y)))*180)/m_pi);      cgaffinetransform transform = cgaffinetransformmakerotation(angletorotate-100);    self.transform = transform;

kindly me find solution stuck here , need complete application there dead line. in advance

glad remember triginometry

 -(void)degreestorotateobjectwithposition:(cgpoint)objpos andtouchpoint:(cgpoint)touchpoint{     float dx = touchpoint.x-objpos.x;        // distance along x    float dy = touchpoint.y-objpos.y;        // distance along y    float radians = atan2(dy, dx);          // tan = opp / adj     //now have convert radians degrees:    float degrees = radians*m_pi/360;     return degrees; }

once have nice method, in touch event method. (i forgot it's called...)

cgaffinetransform current = view.transform;  [view settransform:cgaffinetransformrotate(current,
                 [self degreestorotateobjectwithposition:view.frame.origin 
                                  andtouchpoint:[touch locationinview:parentview]]  //note: parentview = view object rotate sitting in.

this pretty code you'll need.the math right, i'm not sure settransform stuff. i'm @ school writing in browser. should able figure out here.

good luck,

aurum aquila


Comments

Post a Comment

Popular posts from this blog

Javascript line number mapping -

-
magically formatted comments change reported line number of javascript errors in browsers; this: //@line n "f" n line number , f file name. unfortunately, //@line appears ungoogleable. know there documentation on feature, , browsers support it? (i found references here , here .) from can find available in mozilla based browsers. it using js_setoptions command can turn these options on or off depending on values passed. https://developer.mozilla.org/en/js_setoptions
Read more

c# - Is it possible to remove an existing registration from Autofac container builder? -

-
something along lines: builder.registertype<mytype>().as<itype>(); builder.registertype<mytype2>().as<itype>(); builder.deregistertype<mytype>().as<itype>() var container = builder.build(); var types = container.resolve<ienumerable<itype>>(); assert.istrue(types.count == 1); assert.istrue(types[0].gettype == typeof(mytype2)); scenario: go through bunch of assemblies , go register types want make sure have 1 implementation of given type. need before create container. track on own nice if autofac me bit. this cannot done directly using containerbuilder , unless start on new one. mind you, having first built container should able construct new container filtering away unwanted types , reusing registrations first container. this: ... var container = builder.build(); builder = new containerbuilder(); var components = container.componentregistry.registrations .where(cr => cr.activator.limittype != typ...
Read more

php - Mysql PK and FK char(36) vs int(10) -

-
i have read mysql can handle indexes , searches better if tables keys integers rather char(36) uuid's. is worth converting int(10)? note: use 1 server , have have plans use multiple databases concurrently therefore removing 1 of big reasons using uuid. our tables innodb if makes difference. thanks in advance. usually rdbms can handle integer keys pk more efficient, other datatypes. reason how build index column, yes: long dont require string (or other typed) keys, should use integers. however: char(36) , int(10) far away being equal, because int(10) much smaller, char(36). dont know, if require many different keys, should keep in mind. update, complete last paragraph: int(10) 32-bit, char(36) 36 - ^byte^ (= 288-bit). not mean, int consumes less space, means, char(36) has 4 times more different keys.
Read more