iOS Development expanded Chapter-uidynamic (Gravity Behavior + collision detection)

iOS Development expanded Chapter-uidynamic (Gravity Behavior + collision detection)

First, gravity behavior

Description: Given gravity direction, acceleration, let the object fall toward the gravity direction

1. Methods

(1) Initialization of Uigravitybehavior

-(Instancetype) Initwithitems: (Nsarray *) items;

Item parameter: A physical simulation element is stored inside

(2) Common methods of Uigravitybehavior

-(void) AddItem: (ID <UIDynamicItem>) item;

Add 1 physical emulation elements

-(void) RemoveItem: (ID <UIDynamicItem>) item;

Remove 1 Physical simulation elements

2.UIGravityBehavior Common Properties

@property (nonatomic, readonly, copy) nsarray* items;

All the physical simulation elements added to the gravity behavior

@property (ReadWrite, nonatomic) Cgvector gravitydirection;

Gravity direction (is a two-dimensional vector)

@property (ReadWrite, nonatomic) cgfloat angle;

Gravity direction (is an angle, the positive direction of the X axis is 0°, clockwise positive, counterclockwise negative)

@property (ReadWrite, nonatomic) cgfloat magnitude;

Magnitude (used to control acceleration, 1.0 means acceleration is points/second²)

Second, the collision behavior

1. Introduction

Description: Can be used to achieve collision between objects

Physical collisions can be confined to a space by adding boundaries (boundary)

2.UICollisionBehavior boundary-related methods

-(void) Addboundarywithidentifier: (ID <NSCopying>) identifier Forpath: (uibezierpath*) Bezierpath;

-(void) Addboundarywithidentifier: (ID <NSCopying>) identifier frompoint: (Cgpoint) P1 topoint: (cgpoint) P2;

-(uibezierpath*) Boundarywithidentifier: (id <NSCopying>) identifier;

-(void) Removeboundarywithidentifier: (id <NSCopying>) identifier;

@property (nonatomic, readonly, copy) nsarray* boundaryidentifiers;

-(void) removeallboundaries;

3.UICollisionBehavior Common usage

@property (nonatomic, ReadWrite) BOOL translatesreferenceboundsintoboundary;

　　Whether to use the bounds of the reference view as the boundary

-(void) Settranslatesreferenceboundsintoboundarywithinsets: (uiedgeinsets) insets;

　　Set the bounds of the reference view to the boundary, and set the padding

@property (nonatomic, ReadWrite) Uicollisionbehaviormode Collisionmode;

　　Collision Mode (divided into 3 types, elemental collisions, boundary collisions, all collisions)

@property (nonatomic, assign, ReadWrite) ID <UICollisionBehaviorDelegate> collisiondelegate;

　　Proxy object (can listen for element collision process)

Third, code example

Drag and drop several controls in the storyboard for testing.

Test code:

YYVIEWCONTROLLER.M file

////YYVIEWCONTROLLER.M//12-gravity Behavior and collision behavior////Created by Apple on 14-8-6.//Copyright (c) 2014 Yangyong. All rights reserved.//#import"YYViewController.h"@interface Yyviewcontroller () @property (weak, nonatomic) Iboutlet UIView*Redview, @property (weak, nonatomic) Iboutlet Uiprogressview*Block1, @property (weak, nonatomic) Iboutlet Uisegmentedcontrol*Block2, @property (nonatomic,strong) Uidynamicanimator*animator, @end @implementation Yyviewcontroller-(Uidynamicanimator *) animator{if(_animator==Nil) {        //Create a physical emulator (Referenceview: Reference view, setting emulation range)Self.animator=[[Uidynamicanimator Alloc]initwithreferenceview:self.view]; }    return_animator;}- (void) viewdidload{[Super Viewdidload]; //set the angle of the red viewself.redview.transform=cgaffinetransformmakerotation (m_pi_4);}-(void) Touchesbegan: (Nsset *) touches withevent: (Uievent *)Event{    //1. Gravity Behavior//[self testgravity]; //2. Gravity Behavior + Collision detection//[self testgravityandcollsion]; //3. Test some properties of gravity[self testGravityAndCollsion2]; //using 2 lines as the boundary//[self testGravityAndCollision3]; //4. Use circles as boundaries//[self testGravityAndCollision4];}/** * Gravity behavior*/-(void) testgravity{//1. Create simulation behavior (what is the simulation effect?) )//Gravity BehaviorUigravitybehavior *gravity=[[Uigravitybehavior alloc]init]; //2. Adding physical emulation elements[Gravity AddItem:self.redView]; //3. Perform simulation to allow physical simulation elements to perform simulation behavior[Self.animator addbehavior:gravity];}/** * Gravity behavior + Collision detection*/-(void) testgravityandcollsion{//1. Gravity BehaviorUigravitybehavior *gravity=[[Uigravitybehavior alloc]init];        [Gravity AddItem:self.redView]; //2 Collision Detection BehaviorUicollisionbehavior *collision=[[Uicollisionbehavior alloc]init];    [Collision AddItem:self.redView];    [Collision AddItem:self.block1];        [Collision AddItem:self.block2]; //make the bounding rectangle of the reference view the boundary of the collision detectioncollision.translatesreferenceboundsintoboundary=YES; //3. Perform the simulation[Self.animator addbehavior:gravity]; [Self.animator addbehavior:collision];}/** * Test properties of gravity behavior*/-(void) testgravityandcollsion2{//1. Gravity BehaviorUigravitybehavior *gravity=[[Uigravitybehavior alloc]init]; //(1) Set the direction of gravity (is an angle)//gravity.angle= (m_pi_2-m_pi_4); //(2) Set the acceleration of gravity, the greater the acceleration of gravity, the greater the collisionGravity.magnitude= -; //(3) set the direction of gravity (is a two-dimensional vector)Gravity.gravitydirection=cgvectormake (0,1);        [Gravity AddItem:self.redView]; //2 Collision Detection BehaviorUicollisionbehavior *collision=[[Uicollisionbehavior alloc]init];    [Collision AddItem:self.redView];    [Collision AddItem:self.block1];        [Collision AddItem:self.block2]; //make the bounding rectangle of the reference view the boundary of the collision detectioncollision.translatesreferenceboundsintoboundary=YES; //3. Perform the simulation[Self.animator addbehavior:gravity];    [Self.animator addbehavior:collision]; }/** Use circles as boundaries*/- (void) testgravityandcollision4{//1. Gravity BehaviorUigravitybehavior *gravity =[[Uigravitybehavior alloc] init];        [Gravity AddItem:self.redView]; //2. Collision Detection BehaviorUicollisionbehavior *collision =[[Uicollisionbehavior alloc] init];        [Collision AddItem:self.redView]; //add an ellipse as a collision boundaryUibezierpath *path = [Uibezierpath bezierpathwithovalinrect:cgrectmake (0,0, the, the)]; [Collision Addboundarywithidentifier:@"Circle"Forpath:path]; //3. Start Simulation[Self.animator addbehavior:gravity]; [Self.animator addbehavior:collision];}/** * with 2 lines as the boundary*/- (void) testgravityandcollision3{//1. Gravity BehaviorUigravitybehavior *gravity =[[Uigravitybehavior alloc] init];        [Gravity AddItem:self.redView]; //2. Collision Detection BehaviorUicollisionbehavior *collision =[[Uicollisionbehavior alloc] init];    [Collision AddItem:self.redView]; Cgpoint STARTP= Cgpointmake (0, the); Cgpoint ENDP= Cgpointmake ( the, -); [Collision Addboundarywithidentifier:@"line1"FROMPOINT:STARTP TOPOINT:ENDP]; Cgpoint startP1= Cgpointmake ( the,0); [Collision Addboundarywithidentifier:@"line2"FROMPOINT:STARTP1 TOPOINT:ENDP];//collision.translatesreferenceboundsintoboundary = YES; //3. Start Simulation[Self.animator addbehavior:gravity]; [Self.animator addbehavior:collision];} @end

Some test results:

Code Supplement Description:

(1) Acceleration

Speed: point/s

Acceleration: point/s²

1\2 * Acceleration * t²

Gravity.magnitude = 1000; The greater the gravitational acceleration, the greater the collision.

(2) Direction of gravity

The coordinates are as follows:

Gravity direction (two-dimensional vector)

Description : A point within a given coordinate plane. Then the origin (0,0) is used to connect it, which forms a vector.

Note : In iOS, the upper-left corner is the coordinate origin, the right x is increased, and the lower y is larger.

1     // (3) set the direction of gravity (is a two-dimensional vector) 2     Gravity.gravitydirection=cgvectormake (-11);

The gravity direction is the lower left (southwest) direction

(3) Collision detection behavior

Uicollisionbehavior *collision =[[Uicollisionbehavior alloc] init];    [Collision AddItem:self.redView]; Cgpoint STARTP= Cgpointmake (0, the); Cgpoint ENDP= Cgpointmake ( the, -); [Collision Addboundarywithidentifier:@"line1"FROMPOINT:STARTP TOPOINT:ENDP]; Cgpoint startP1= Cgpointmake ( the,0); [Collision Addboundarywithidentifier:@"line2"FROMPOINT:STARTP1 TOPOINT:ENDP];

Note : Identifiers cannot be written empty. You can write a string because the identifier needs to conform to the Nscopying protocol, and the string satisfies the requirement.

(4) Bezier curve

Tip: Here the path is a circle, setting the width of the height is not the same, then it is an ellipse.

iOS Development expanded Chapter-uidynamic (Gravity Behavior + collision detection)