org.flixel.FlxGroup Maven / Gradle / Ivy
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package org.flixel;
import java.util.Comparator;
import com.badlogic.gdx.utils.Array;
import com.badlogic.gdx.utils.reflect.ClassReflection;
/**
* This is an organizational class that can update and render a bunch of FlxBasics.
* NOTE: Although FlxGroup extends FlxBasic, it will not automatically
* add itself to the global collisions quad tree, it will only add its members.
*
* @author Ka Wing Chin
* @author Thomas Weston
*/
public class FlxGroup extends FlxBasic
{
/**
* Use with sort() to sort in ascending order.
*/
static public final int ASCENDING = -1;
/**
* Use with sort() to sort in descending order.
*/
static public final int DESCENDING = 1;
/**
* Array of all the FlxBasics that exist in this group.
*/
public Array members;
/**
* The number of entries in the members array.
* For performance and safety you should check this variable
* instead of members.length unless you really know what you're doing!
*/
public int length;
/**
* Internal tracker for the maximum capacity of the group.
* Default is 0, or no max capacity.
*/
protected int _maxSize;
/**
* Internal helper variable for recycling objects a la FlxEmitter.
*/
protected int _marker;
/**
* Helper for sort.
*/
protected String _sortIndex;
/**
* Helper for sort.
*/
protected int _sortOrder;
/**
* Constructor
*/
public FlxGroup(int MaxSize)
{
super();
members = new Array(MaxSize);
length = 0;
_maxSize = MaxSize;
_marker = 0;
_sortIndex = null;
}
/**
* Constructor
*/
public FlxGroup()
{
this(0);
}
/**
* Override this function to handle any deleting or "shutdown" type operations you might need,
* such as removing traditional Flash children like Sprite objects.
*/
@Override
public void destroy()
{
if(members != null)
{
FlxBasic basic;
int i = 0;
while(i < length)
{
basic = members.get(i++);
if(basic != null)
basic.destroy();
}
members.clear();
members = null;
}
_sortIndex = null;
}
/**
* Just making sure we don't increment the active objects count.
*/
@Override
public void preUpdate()
{
}
/**
* Automatically goes through and calls update on everything you added.
*/
@Override
public void update()
{
FlxBasic basic;
int i = 0;
while(i < length)
{
basic = members.get(i++);
if((basic != null) && basic.exists && basic.active)
{
basic.preUpdate();
basic.update();
basic.postUpdate();
}
}
}
/**
* Automatically goes through and calls render on everything you added.
*/
@Override
public void draw()
{
FlxBasic basic;
int i = 0;
while(i < length)
{
basic = members.get(i++);
if((basic != null) && basic.exists && basic.visible)
basic.draw();
}
}
/**
* The maximum capacity of this group. Default is 0, meaning no max capacity, and the group can just grow.
*/
public int getMaxSize()
{
return _maxSize;
}
/**
* The maximum capacity of this group. Default is 0, meaning no max capacity, and the group can just grow.
*/
public void setMaxSize(int Size)
{
_maxSize = Size;
if(_marker >= _maxSize)
_marker = 0;
if((_maxSize == 0) || (members == null) || (_maxSize >= members.size))
return;
//If the max size has shrunk, we need to get rid of some objects
FlxBasic basic;
int i = _maxSize;
int l = members.size;
while(i < l)
{
basic = members.get(i++);
if(basic != null)
basic.destroy();
}
members.truncate(length = _maxSize);
}
/**
* Adds a new FlxBasic subclass (FlxBasic, FlxSprite, Enemy, etc) to the group.
* FlxGroup will try to replace a null member of the array first.
* Failing that, FlxGroup will add it to the end of the member array,
* assuming there is room for it, and doubling the size of the array if necessary.
*
* WARNING: If the group has a maxSize that has already been met,
* the object will NOT be added to the group!
*
* @param Object The object you want to add to the group.
*
* @return The same FlxBasic object that was passed in.
*/
public FlxBasic add(FlxBasic Object)
{
if(Object == null)
{
FlxG.log("WARNING: Cannot add 'null' object to a FlxGroup.");
return null;
}
//Don't bother adding an object twice.
if(members.indexOf(Object, true) >= 0)
return Object;
//First, look for a null entry where we can add the object.
int i = 0;
int l = members.size;
while(i < l)
{
if(members.get(i) == null)
{
members.set(i, Object);
if(i >= length)
length = i+1;
return Object;
}
i++;
}
//Failing that, expand the array (if we can) and add the object.
if(_maxSize > 0)
{
if(members.size >= _maxSize)
return Object;
}
//If we made it this far, then we successfully grew the group,
//and we can go ahead and add the object at the first open slot.
members.add(Object);
length = i+1;
return Object;
}
/**
* Recycling is designed to help you reuse game objects without always re-allocating or "newing" them.
*
* If you specified a maximum size for this group (like in FlxEmitter),
* then recycle will employ what we're calling "rotating" recycling.
* Recycle() will first check to see if the group is at capacity yet.
* If group is not yet at capacity, recycle() returns a new object.
* If the group IS at capacity, then recycle() just returns the next object in line.
*
* If you did NOT specify a maximum size for this group,
* then recycle() will employ what we're calling "grow-style" recycling.
* Recycle() will return either the first object with exists == false,
* or, finding none, add a new object to the array,
* doubling the size of the array if necessary.
*
* WARNING: If this function needs to create a new object,
* and no object class was provided, it will return null
* instead of a valid object!
*
* @param ObjectClass The class type you want to recycle (e.g. FlxSprite, EvilRobot, etc). Do NOT "new" the class in the parameter!
*
* @return A reference to the object that was created. Don't forget to cast it back to the Class you want (e.g. myObject = (myObjectClass) myGroup.recycle(myObjectClass);).
*/
public FlxBasic recycle(Class ObjectClass)
{
FlxBasic basic;
if(_maxSize > 0)
{
if(length < _maxSize)
{
if(ObjectClass == null)
return null;
try
{
return add(ClassReflection.newInstance(ObjectClass));
}
catch(Exception e)
{
throw new RuntimeException(e);
}
}
else
{
basic = members.get(_marker++);
if(_marker >= _maxSize)
_marker = 0;
return basic;
}
}
else
{
basic = getFirstAvailable(ObjectClass);
if(basic != null)
return basic;
if(ObjectClass == null)
return null;
try
{
return add(ClassReflection.newInstance(ObjectClass));
}
catch(Exception e)
{
throw new RuntimeException(e);
}
}
}
/**
* Recycling is designed to help you reuse game objects without always re-allocating or "newing" them.
*
* If you specified a maximum size for this group (like in FlxEmitter),
* then recycle will employ what we're calling "rotating" recycling.
* Recycle() will first check to see if the group is at capacity yet.
* If group is not yet at capacity, recycle() returns a new object.
* If the group IS at capacity, then recycle() just returns the next object in line.
*
* If you did NOT specify a maximum size for this group,
* then recycle() will employ what we're calling "grow-style" recycling.
* Recycle() will return either the first object with exists == false,
* or, finding none, add a new object to the array,
* doubling the size of the array if necessary.
*
* WARNING: If this function needs to create a new object,
* and no object class was provided, it will return null
* instead of a valid object!
*
* @param ObjectClass The class type you want to recycle (e.g. FlxSprite, EvilRobot, etc). Do NOT "new" the class in the parameter!
*
* @return A reference to the object that was created. Don't forget to cast it back to the Class you want (e.g. myObject = (myObjectClass) myGroup.recycle(myObjectClass);).
*/
public FlxBasic recycle()
{
return recycle(null);
}
/**
* Removes an object from the group.
*
* @param Object The FlxBasic you want to remove.
* @param Splice Whether the object should be cut from the array entirely or not.
*
* @return The removed object.
*/
public FlxBasic remove(FlxBasic Object,boolean Splice)
{
int index = members.indexOf(Object, true);
if((index < 0) || (index >= members.size))
return null;
if(Splice)
{
members.removeIndex(index);
length--;
}
else
members.set(index, null);
return Object;
}
/**
* Removes an object from the group.
*
* @param Object The FlxBasic you want to remove.
*
* @return The removed object.
*/
public FlxBasic remove(FlxBasic Object)
{
return remove(Object,false);
}
/**
* Replaces an existing FlxBasic with a new one.
*
* @param OldObject The object you want to replace.
* @param NewObject The new object you want to use instead.
*
* @return The new object.
*/
public FlxBasic replace(FlxBasic OldObject,FlxBasic NewObject)
{
int index = members.indexOf(OldObject, true);
if((index < 0) || (index >= members.size))
return null;
members.set(index, NewObject);
return NewObject;
}
/**
* Call this function to sort the group according to a particular value and order.
* For example, to sort game objects for Zelda-style overlaps you might call
* myGroup.sort("y",ASCENDING) at the bottom of your
* FlxState.update() override. To sort all existing objects after
* a big explosion or bomb attack, you might call myGroup.sort("exists",DESCENDING).
*
* @param Index The String name of the member variable you want to sort on. Default value is "y".
* @param Order A FlxGroup constant that defines the sort order. Possible values are ASCENDING and DESCENDING. Default value is ASCENDING.
*/
public void sort(String Index,int Order)
{
_sortIndex = Index;
_sortOrder = Order;
members.sort(sortHandler);
}
/**
* Call this function to sort the group according to a particular value and order.
* For example, to sort game objects for Zelda-style overlaps you might call
* myGroup.sort("y",ASCENDING) at the bottom of your
* FlxState.update() override. To sort all existing objects after
* a big explosion or bomb attack, you might call myGroup.sort("exists",DESCENDING).
*
* @param Index The String name of the member variable you want to sort on. Default value is "y".
*/
public void sort(String Index)
{
sort(Index,ASCENDING);
}
/**
* Call this function to sort the group according to a particular value and order.
* For example, to sort game objects for Zelda-style overlaps you might call
* myGroup.sort("y",ASCENDING) at the bottom of your
* FlxState.update() override. To sort all existing objects after
* a big explosion or bomb attack, you might call myGroup.sort("exists",DESCENDING).
*
*/
public void sort()
{
sort("y",ASCENDING);
}
/**
* Go through and set the specified variable to the specified value on all members of the group.
*
* @param VariableName The string representation of the variable name you want to modify, for example "visible" or "scrollFactor".
* @param Value The value you want to assign to that variable.
* @param Recurse Default value is true, meaning if setAll() encounters a member that is a group, it will call setAll() on that group rather than modifying its variable.
*/
public void setAll(String VariableName,Object Value,boolean Recurse)
{
FlxBasic basic;
int i = 0;
while(i < length)
{
basic = members.get(i++);
if(basic != null)
{
if(Recurse && (basic instanceof FlxGroup))
((FlxGroup) basic).setAll(VariableName,Value,Recurse);
else
{
try
{
ClassReflection.getField(basic.getClass(), VariableName).set(basic, Value);
}
catch(Exception e)
{
throw new RuntimeException(e);
}
}
}
}
}
/**
* Go through and set the specified variable to the specified value on all members of the group.
*
* @param VariableName The string representation of the variable name you want to modify, for example "visible" or "scrollFactor".
* @param Value The value you want to assign to that variable.
*/
public void setAll(String VariableName,Object Value)
{
setAll(VariableName,Value,true);
}
/**
* Go through and call the specified function on all members of the group.
* Currently only works on functions that have no required parameters.
*
* @param FunctionName The string representation of the function you want to call on each object, for example "kill()" or "init()".
* @param Recurse Default value is true, meaning if callAll() encounters a member that is a group, it will call callAll() on that group rather than calling the group's function.
*/
public void callAll(String FunctionName,boolean Recurse)
{
FlxBasic basic;
int i = 0;
while(i < length)
{
basic = members.get(i++);
if(basic != null)
{
if(Recurse && (basic instanceof FlxGroup))
((FlxGroup) basic).callAll(FunctionName, Recurse);
else
{
try
{
ClassReflection.getMethod(basic.getClass(), FunctionName).invoke(basic);
}
catch(Exception e)
{
throw new RuntimeException(e);
}
}
}
}
}
/**
* Go through and call the specified function on all members of the group.
* Currently only works on functions that have no required parameters.
*
* @param FunctionName The string representation of the function you want to call on each object, for example "kill()" or "init()".
*/
public void callAll(String FunctionName)
{
callAll(FunctionName,true);
}
/**
* Call this function to retrieve the first object with exists == false in the group.
* This is handy for recycling in general, e.g. respawning enemies.
*
* @param ObjectClass An optional parameter that lets you narrow the results to instances of this particular class.
*
* @return A FlxBasic currently flagged as not existing.
*/
public FlxBasic getFirstAvailable(Class ObjectClass)
{
FlxBasic basic;
int i = 0;
while(i < length)
{
basic = members.get(i++);
if((basic != null) && !basic.exists && ((ObjectClass == null) || (ClassReflection.isInstance(ObjectClass, basic))))
return basic;
}
return null;
}
/**
* Call this function to retrieve the first object with exists == false in the group.
* This is handy for recycling in general, e.g. respawning enemies.
*
* @return A FlxBasic currently flagged as not existing.
*/
public FlxBasic getFirstAvailable()
{
return getFirstAvailable(null);
}
/**
* Call this function to retrieve the first index set to 'null'.
* Returns -1 if no index stores a null object.
*
* @return An int indicating the first null slot in the group.
*/
public int getFirstNull()
{
int i = 0;
int l = members.size;
while(i < l)
{
if(members.get(i) == null)
return i;
else
i++;
}
return -1;
}
/**
* Call this function to retrieve the first object with exists == true in the group.
* This is handy for checking if everything's wiped out, or choosing a squad leader, etc.
*
* @return A FlxBasic currently flagged as existing.
*/
public FlxBasic getFirstExtant()
{
FlxBasic basic;
int i = 0;
while(i < length)
{
basic = members.get(i++);
if((basic != null) && basic.exists)
return basic;
}
return null;
}
/**
* Call this function to retrieve the first object with alive == true in the group.
* This is handy for checking if everything's wiped out, or choosing a squad leader, etc.
*
* @return A FlxBasic currently flagged as not dead.
*/
public FlxBasic getFirstAlive()
{
FlxBasic basic;
int i = 0;
while(i < length)
{
basic = members.get(i++);
if((basic != null) && basic.exists && basic.alive)
return basic;
}
return null;
}
/**
* Call this function to retrieve the first object with alive == false in the group.
* This is handy for checking if everything's wiped out, or choosing a squad leader, etc.
*
* @return A FlxBasic currently flagged as dead.
*/
public FlxBasic getFirstDead()
{
FlxBasic basic;
int i = 0;
while(i < length)
{
basic = members.get(i++);
if((basic != null) && !basic.alive)
return basic;
}
return null;
}
/**
* Call this function to find out how many members of the group are not dead.
*
* @return The number of FlxBasics flagged as not dead. Returns -1 if group is empty.
*/
public int countLiving()
{
int count = -1;
FlxBasic basic;
int i = 0;
while(i < length)
{
basic = members.get(i++);
if(basic != null)
{
if(count < 0)
count = 0;
if(basic.exists && basic.alive)
count++;
}
}
return count;
}
/**
* Call this function to find out how many members of the group are dead.
*
* @return The number of FlxBasics flagged as dead. Returns -1 if group is empty.
*/
public int countDead()
{
int count = -1;
FlxBasic basic;
int i = 0;
while(i < length)
{
basic = members.get(i++);
if(basic != null)
{
if(count < 0)
count = 0;
if(!basic.alive)
count++;
}
}
return count;
}
/**
* Returns a member at random from the group.
*
* @param StartIndex Optional offset off the front of the array. Default value is 0, or the beginning of the array.
* @param Length Optional restriction on the number of values you want to randomly select from.
*
* @return A FlxBasic from the members list.
*/
public FlxBasic getRandom(int StartIndex,int Length)
{
if(Length == 0)
Length = length;
return FlxU.getRandom(members,StartIndex,Length);
}
/**
* Returns a member at random from the group.
*
* @param StartIndex Optional offset off the front of the array. Default value is 0, or the beginning of the array.
*
* @return A FlxBasic from the members list.
*/
public FlxBasic getRandom(int StartIndex)
{
return getRandom(StartIndex,0);
}
/**
* Returns a member at random from the group.
*
* @return A FlxBasic from the members list.
*/
public FlxBasic getRandom()
{
return getRandom(0,0);
}
/**
* Remove all instances of FlxBasic subclass (FlxSprite, FlxBlock, etc) from the list.
* WARNING: does not destroy() or kill() any of these objects!
*/
public void clear()
{
length = 0;
members.clear();
}
/**
* Calls kill on the group's members and then on the group itself.
*/
@Override
public void kill()
{
FlxBasic basic;
int i = 0;
while(i < length)
{
basic = members.get(i++);
if((basic != null) && basic.exists)
basic.kill();
}
super.kill();
}
/**
* Helper function for the sort process.
*
* @param Obj1 The first object being sorted.
* @param Obj2 The second object being sorted.
*
* @return An integer value: -1 (Obj1 before Obj2), 0 (same), or 1 (Obj1 after Obj2).
*/
// TODO: sortHandler only works with floats
protected Comparator sortHandler = new Comparator()
{
@Override
public int compare(FlxBasic Obj1,FlxBasic Obj2)
{
try
{
if((Float) ClassReflection.getField(Obj1.getClass(), _sortIndex).get(Obj1) < (Float) ClassReflection.getField(Obj2.getClass(), _sortIndex).get(Obj2))
return _sortOrder;
else if((Float) ClassReflection.getField(Obj1.getClass(), _sortIndex).get(Obj1) > (Float) ClassReflection.getField(Obj2.getClass(), _sortIndex).get(Obj2))
return -_sortOrder;
}
catch(Exception e)
{
throw new RuntimeException(e);
}
return 0;
}
};
}
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