I want to collide 2 sprites using Physics Engine.
But my contact listener is not responding. and no warning/error on log or runtime.
So here is what i did :
Declaration
1)cocos2d::PhysicsWorld* m_world;
2)void setPhyWorld(cocos2d::PhysicsWorld* world){m_world = world;}
3)bool onContactBegin(cocos2d::PhysicsContact& contact);
Implementation
For PhysicsWorld:
Scene ->
Scene* HelloWorld::createScene()
{
// 'scene' is an autorelease object
auto scene = Scene::createWithPhysics();
scene->getPhysicsWorld()->setDebugDrawMask(PhysicsWorld::DEBUGDRAW_ALL);
auto layer = HelloWorld::create();
layer->setPhyWorld(scene->getPhysicsWorld());
// add layer as a child to scene
scene->addChild(layer);
// return the scene
return scene;
}
PhysicsWorld->
void HelloWorld::createPhysicsWorld(){
auto body = PhysicsBody::createEdgeBox(visibleSize, PHYSICSBODY_MATERIAL_DEFAULT, 3);
auto edgeNode = Node::create();
edgeNode->setPosition(Point(visibleSize.width/2,visibleSize.height/2));
edgeNode->setPhysicsBody(body);
this->addChild(edgeNode);
}
Creating Sprite->
void HelloWorld::createCar(){
car = Sprite::create("car.png");
auto body3 = PhysicsBody::createBox(car->getContentSize());
body3->setDynamic(false);
body3->setCategoryBitmask(2);
body3->setCollisionBitmask(2);
body3->setContactTestBitmask(true);
car->setPhysicsBody(body3);
// position the sprite on the center of the screen
car->setPosition(Vec2(visibleSize.width/2 + origin.x, visibleSize.height/2 + origin.y));
// add the sprite as a child to this layer
this->addChild(car, 1);
car->setAnchorPoint(Vec2(0.5, 0));
car->setFlippedX(true);
}
void HelloWorld::createRocket(){
rocket = Sprite::create("rocket.png");
auto body2 = PhysicsBody::createBox(rocket->getContentSize());
body2->setDynamic(false);
body2->setCategoryBitmask(1);
body2->setCollisionBitmask(1);
body2->setContactTestBitmask(true);
rocket->setPhysicsBody(body2);
// position the sprite on the center of the screen
rocket->setPosition(Vec2(visibleSize.width/2 + origin.x,origin.y));
// add the sprite as a child to this layer
this->addChild(rocket, 1);
}
Collision->
auto contactListener = EventListenerPhysicsContact::create();
contactListener->onContactBegin = CC_CALLBACK_1(HelloWorld::onContactBegin, this);
this->getEventDispatcher()->addEventListenerWithSceneGraphPriority(contactListener,this);
ContactListner->
bool HelloWorld::onContactBegin(cocos2d::PhysicsContact& contact)
{
CCLOG("onContactBegin -------> ");
return true;
}
Well it is tricky thing that you miss in your code.one body should be setDynamic to true.
body->setDynamic(true);
cheers!
Well, it turned out that it was bit ugly mistake.
body3->setContactTestBitmask(true);
this method's argument is a bitmask not 'true'/'false' field, so your 'true' mask was treated as it was 1 while your bodies mask is 2. The solution is:
body3->setCategoryBitmask(1);
body3->setCollisionBitmask(3);
body3->setContactTestBitmask(1);
body2->setCategoryBitmask(3);
body2->setCollisionBitmask(1);
body2->setContactTestBitmask(1);
I Just Comment out body2->setDynamic(false); inside createRocket Method and setGravityEnable(false); and it works now.
void HelloWorld::createRocket(){
rocket = Sprite::create("rocket.png");
rocket->setPosition(Vec2(visibleSize.width/2 + origin.x,origin.y - 50));
rocket->setTag(3);
auto body2 = PhysicsBody::createBox(rocket->getContentSize());
//body2->setDynamic(false);
body2->setTag(3);
body2->setGravityEnable(false);
body2->setCollisionBitmask(3);
body2->setContactTestBitmask(true);
rocket->setPhysicsBody(body2);
this->addChild(rocket, 1);
}
Related
first of all, i'm not a native english speaker but, still, i'll try my best to be understandable and as clear as possible.
So, in my programming class, I need to make a Tile based game (like zelda, for exemple) with animate cc (flash). On a map, I want to make a dance floor with tiles that changes on the rhythm of a music. these tiles are movieclip with two frame, one white and one red.
This is how the tiles are generated:
private function createGrid(): void {
grid = new MovieClip();
addChild(grid);
for (var r: int = 0; r < nbRow; r++) {
for (var c: int = 0; c < nbCol; c++) {
var t: Tiles = new Tiles();
t.x = t.width * c;
t.y = t.height * r;
grid.addChild(t);
}
}
grid.x = 15; //center the grid on x
grid.y = 35; //center the grid on y
}
This is the Tiles Class :
package {
import flash.display.MovieClip;
import flash.events.*;
public class Tiles extends MovieClip {
private var rand:int;
public function Tiles() {
// constructor code
getTiles();
}
public function getTiles():void {
random();
setColor();
}
private function random() : void{
rand = Math.floor(Math.random()*100)+1;
}
private function setColor() : void{
if(rand<=30){
gotoAndStop(8); //red frame
}else{
gotoAndStop(7); //white frame
}
}
}
}
createGrid() place the tiles as soon as the map is placed on the stage and stock every tiles in the MovieClip grid. Now, I want the tiles to change randomly between red and white on the beat of a streamed music (and keep the ratio of 30% red tiles and 70% white tiles)
var s: Sound = new Sound();
var sc: SoundChannel;
s.load(new URLRequest("GameSong_mixdown.mp3"));
sc = s.play(0, 1000);
I know i need the leftpeek properties of my soundchannel to achieve that but,for now, I do my test with a button that trigger this function:
private function setTiles(e: Event): void {
// loop through all child element of a movieclip
for (var i: int = 0; i < grid.numChildren; i++) {
grid.getChildAt(i).getTiles();
}
}
Right now, the problem is : I'm unable to acces my Tiles method. I did a trace on grid,getChildAt(i), and saw all instances of my tiles in the console. So, i know for sure that every instances of my tiles are stored in grid. But, I don't know why, grid.getChildAt(i).getTiles(); doesn't work (and every other method from Tiles). The error message is: Call to a possibly udefined method getTiles through a reference with static type flash.display:DisplayObject
Does someone know what i'm doing wrong ?
ps: I translated all my class name, var name, etc from french to
english to make the code clearer.
Your mistake is that getChildAt(...) method has a return type of DisplayObject which is neither dynamic (will not let you access random properties) nor it have DisplayObject.getTiles() method.
All you need is to tell the program that this object is actually of Tiles class:
private function setTiles(e:Event):void
{
// loop through all child element of a movieclip
for (var i: int = 0; i < grid.numChildren; i++)
{
// Cast display objects to Tiles class.
var aTiles:Tiles = grid.getChildAt(i) as Tiles;
// Call the method.
aTiles.getTiles();
}
}
Really a basic question, but I am moving a sprite A with a physics body over another kind of sprites B having another physics body. I expect the collision callback oncontact to be called for these bodies. They have their respective category bitmasks set using setCategoryBitmask() and also respectively have each other's categories set using setContactTestBitmask().
The collision works as long as I do not move sprite A. I assume the problem is that I move sprite A using cocos2d actions, and I need to do something else. But using cocos2d actions for scripting things like these look so much simpler to me than anything else I can think of.
Move sprite A using physics calls. (looks like a lot of work, and it looks like it's hard to achieve exact scripting perfection)
Do my own collision detection in update() instead. (looks like a bunch of work too, especially if the sprites are rotated etc)
Is there any other shortcut? Or did I miss something else?
I ended up doing "Do my own collision detection in update() instead". It wasn't too problematic.
Something like this in update()...
const Rect RECT_A = spriteA->getBoundingBox();
for (auto spriteB : someparent->getChildren()) {
const Rect RECT_B = spriteB->getBoundingBox();
if (RECT_A.intersectsRect(RECT_B)) {
// Hit
}
}
Contaction detection should be fine while collion doesn't work.
Scene* HelloWorld::createScene()
{
// 'scene' is an autorelease object
auto scene = Scene::createWithPhysics();
// 'layer' is an autorelease object
auto layer = HelloWorld::create();
// add layer as a child to scene
scene->addChild(layer);
scene->getPhysicsWorld()->setDebugDrawMask(PhysicsWorld::DEBUGDRAW_ALL);
scene->getPhysicsWorld()->setGravity(Vec2::ZERO);
// return the scene
return scene;
}
bool HelloWorld::init()
{
if ( !Layer::init() )
{
return false;
}
auto createSprite = [this](const Vec2& pos) {
auto sprite = Sprite::create();
auto bodyA = PhysicsBody::createCircle(20);
sprite->setPhysicsBody(bodyA);
sprite->setPosition(pos);
bodyA->setCollisionBitmask(0xff);
bodyA->setCategoryBitmask(0xff);
bodyA->setContactTestBitmask(0xff);
return sprite;
};
auto spriteA = createSprite(Vec2(300, 300));
auto moveBy = MoveBy::create(1.f, Vec2(200, 200));
spriteA->runAction(moveBy);
auto spriteB = createSprite(Vec2(350, 350));
addChild(spriteA);
addChild(spriteB);
auto contactListener = EventListenerPhysicsContact::create();
contactListener->onContactBegin = [=](PhysicsContact& contact) {
auto a = contact.getShapeA()->getBody()->getNode();
auto b = contact.getShapeB()->getBody()->getNode();
assert((a == spriteA && b == spriteB) || (a == spriteB && b == spriteA));
log("It is working");
return false;
};
_eventDispatcher->addEventListenerWithSceneGraphPriority(contactListener, this);
return true;
}
I have a gun child inside of a movieclip called "player" and "player" is inside another movieclip called "level one".
So inside the gun class, the code spawns a bullet. Which has to spawn in the parent's parent. So the bullet can shoot into the level.
private function fire(m: MouseEvent)
{
//when bullet fired
var b = new Bullet;
MovieClip(MovieClip(parent).parent).addChild(b);
}
However, the bullet never appears in the parent's parent. What could be the issue here?
UPDATED CODE:
In gun class:
function fire(e:MouseEvent):void
{
dispatchEvent(new Event('fire!', true));
}
In player class:
protected function fire(e: Event)
{
var b: Bullet = new Bullet();
// bullet must be in same position and angle as player.gun
b.rotation = player.gun.rotation;
b.x = player.gun.x; + player.gun.width * Math.cos(player.gun.rotation / 180 * Math.PI);
b.y = player.gun.y + player.gun.width * Math.sin(player.gun.rotation / 180 * Math.PI);
addChild(b);
}
You missed to strong typing the variable and add parentheses
Try
var b:Bullet = new Bullet();
Why don't you keep a reference to the parent.parent?
var b:Bullet = new Bullet(parent)
...
public function Bullet(spawnTarget:MovieClip)
{
_spawnTarget = spawnTarget;
}
private function fire(m: MouseEvent)
{
//when bullet fired
var b = new Bullet;
_spawnTarget.addChild(b);
}
Using parent.parent is risky because you'd always need to make sure that the gun class is instantiated in a child of the game class. Also, you can't create guns in any other position in the hierarchy which can be a problem if your game grows bigger.
You can solve this with listeners (as the comments state, and this is an example of passing a game reference. Each instance receives a reference to game, so each instance can call public function on game:
Game.as
myPlayer = new Player(this);
public function addBulletToWorld(){
}
Player.as
public function Player(game){
myGun = new Gun(game);
}
Gun.as
public function Gun(game){
game.addBulletToWorld();
}
If you absolutely insist on using the parent.parent thing, just set a break point at that line and see what parent.parent actually is, then adjust as needed to match your actual structure. But aside from the fact that this is just bad practice, it's going to limit you to where you can't use this Class anywhere but at that one depth.
I'd recommend just generating a custom event when you want to fire the bullet, and letting the grandparent handle it.
In Gun:
function fire(e:MoudeEvent):void {
dispatchEvent(new Event('fire!', true));//setting it true lets it bubble up to the parent
}
In Game
protected var bullets:Vector. = new Vector();
public function Game() {
addEventListener('fire!', fire);
}
//note I worked with Flex too long to use private methods very often
protected function fire(e:Event) {
var bullet:Bullet = new Bullet();
bullet.x = MoveClip(e.target).x);
bullet.y = MoveClip(e.target).y);
addChild(bullet);
bullets.push(bullet);//I assume you're going to want to move this or something, so we need to store it to manage it
}
I wanted to mask some nodes of my DisplayObject tree. I couldn't make masking work in my big project. So I build a simple example for me and I saw it works actually pretty good. But I can't figure out why it doesn't work in my big project. All my visible objects are Sprites or from classes that extend Sprite.
masking in big project doesn't work
I can see the normal state of my nodeToBeMasked
when I add the mask to this node I can see the mask
but when I set the mask to be the mask, I continue to see everything (pure nodeToBeMasked is masked but not the children - which would be much more important)
masking in simple example works fine
How can masking stop working ?
Code: (that doesn't work, big project)
// custom class extends Sprite
override protected function onAddToStage(event:Event):void
{
trace(stage); // stage exists
var maskSprite:Sprite = new Sprite();
maskSprite.graphics.beginFill(0xffff00, 1);
maskSprite.graphics.drawCircle(0, 0, 64);
maskSprite.graphics.endFill();
maskSprite.x = 64;
maskSprite.y = 64;
if (true)
{
this.addChild(maskSprite); // doesn't help
this.mask = maskSprite; // I can see EVERYTHING here, inside and outside the cirle
}
else
addChild(maskSprite); // I can see the mask here
}
Code: (that works)
[SWF(frameRate="60",backgroundColor="0xffffff",width="128",height="128")]
public class MaskTest extends Sprite
{
public function MaskTest()
{
addEventListener(Event.ADDED_TO_STAGE, onAddedToStage);
}
private function onAddedToStage(event: Event): void
{
trace(stage);
// this
graphics.beginFill(0x00ff00, 1);
graphics.drawRect(8, 8, 112, 112);
graphics.endFill();
// extra childs <- ^^
for (var i: int = 0; i < 100; i++)
{
var child: Sprite = new Sprite();
child.graphics.beginFill(uint(Math.random() * 0x1000000), 1);
child.graphics.drawRect(Math.random() * 64, Math.random() * 64, 64, 64);
child.graphics.endFill();
addChild(child);
}
// mask
var maskSprite: Sprite = new Sprite();
maskSprite.graphics.beginFill(0xffff00, 1);
maskSprite.graphics.drawCircle(0, 0, 64);
maskSprite.graphics.endFill();
maskSprite.x = 64;
maskSprite.y = 64;
// switch to check the mask
if (true)
this.mask = maskSprite;
else
addChild(maskSprite);
}
}
Update:
I found out that my custom class (that is the root and is only responsible for Event.ENTER_FRAME updates) was causing the problem. I don't know why but by disabling the z update in all my project solved the children of my maskedNode not being masked.
The mask MUST be added to the parent to work, not only used as
obj.mask = myMask; //This will not work alone
To make it work, it must be added to the parent object display list
obj.addChild(myMask);
obj.mask = myMask;
//this wasthe problem in my big project
maskSprite.z = 0; // avoid this with masks
Just a wild guess from me:if you use the properties z, rotationX, rotationY, rotationZ (maybe some more) the sprite is shifted to the 3D space and the masking is only working in 2D.
I have experimented with Flash 3D a bit. The transition from 2D to 3D seemed very smooth. You can't see when they "turn".
i created my own Button which simply extends from Sprite.
Its able to show 3 different text fading in and out using a timer.
In my draw function i first draw a rectangle with the Sprites graphics object representing the background of the button.
I added a function to set the button width. This property is used to draw the rectangle. I know that the sprites's size is updated after the rectangle drawing. But for some reason the sprite's width is always more than what i have set via my "setButtonWidth" function.
Now i have a simple sprite acting as a button having a graphics.drawRectangle part drawing a simple rect. with lets say 500px width. But when i trace the width of that button it is always about 10% more. Where are these 10% coming from?
I read about calling validateNow(). But this is only for Labels, or Checkboxes. For some reason i cannot access the library for Label. This must work somehow with TextFields. But how?
// this function is part of MyButtonClass.as file
function drawButton()
{
this.graphics.clear();
this.graphics.beginFill( currentBackColor);
this.graphics.drawRoundRect(0, 0, int(this.buttonWidth)+20, 30, 10, 10);
this.graphics.endFill();
}
// this code is in main action code frame
// the buttonWidth is set this way
stage.addEventListener( Event.RESIZE, updateBtn);
function updateBtn( event:Event)
{
// access the container in which the buttons are in like ...
for( var i = 0; i < buttonContainer.numChildren; i++) {
var btn = buttonContainer.getChildAt( i) as MyButtonClass;
// MyButtonClass is the class which extends from Sprite drawing my button
// and using buttonWidth to draw the backgrounds width.
btn.setButtonWidth( (stage.stageWidth / 2) - 20);
// i set half of stageWidth because i have two columns with a list of buttons
// after setButtonWidth is called in MyButtonClass, the draw function is called
// which does the graphics stuff above.
}
}
this.buttonWidth is set to 500. There is nothing special done on that sprite. No children to be added, only this drawing stuff. But this sets the sprite's width to 550 or something.
Define Button like this
package {
import flash.display.Sprite;
public class Button extends Sprite {
private var _buttonWith: int = 0;
private var _buttonHeight: int = 0;
public function Button() {
// constructor code
}
public function set buttonWidth(w: int): void {
_buttonWith = w;
updateButton();
}
public function get buttonWidth(): int {
return _buttonWith;
}
public function set buttonHeight(h: int): void {
_buttonHeight = h;
updateButton();
}
public function get buttonHeight(): int {
return _buttonHeight;
}
protected function updateButton() {
graphics.clear();
graphics.beginFill(0xff00ff);
graphics.drawRoundRect(0, 0, buttonWidth, buttonHeight, 10, 10);
graphics.endFill();
}
}
}
And create instance like this
var button:Button = new Button();
addChild(button);
button.buttonWidth = 100;
button.buttonHeight = 30;