InfiniteScrollNode.cpp

//
//  InfiniteScrollNode.cpp
//  InfiniteScrollNodeTest
//
//  Created by Jason Marziani on 3/26/12
//  Copyright (c) 2012 Little Wins LLC. All rights reserved.
//
//  Made compatible with Cocos2d-x 2.x by Stefan Nguyen on 7/30/12 (as CCParallaxScrollNode).
//  Made compatible with Axmol Engine 2.x by Daniel Alias on 23/12/09 (yy/mm/dd)
//

#include "InfiniteScrollNode.h"

#ifndef SIGN
#define SIGN(x) ((x < 0) ? -1 : (x > 0))
#endif

USING_NS_AX;

bool InfiniteScrollNode::init()
{
	if ( !Layer::init() ) return false;
  
  Size screen = Director::getInstance()->getWinSize();
  _range = Size(screen.width, screen.height);
  this->setAnchorPoint(Point(0,0));
  
  return true;
}

// Used with box2d style velocity (m/s where m = 32 pixels), but box2d is not required
void InfiniteScrollNode::updateWithVelocity(Point vel, float dt)
{
	vel = vel * PTM_RATIO;
  
  for (int i = 0; i < _scrollOffsets.size(); i ++)
  {
    InfiniteScrollOffset *scrollOffset = (InfiniteScrollOffset*) _scrollOffsets.at(i);
		Point relVel = scrollOffset->getRelVelocity() * PTM_RATIO;
		Point totalVel = vel + relVel;
        Point offset = ((totalVel * dt) * scrollOffset->getRatio());
    
    Node *child = scrollOffset->getTheChild();
		child->setPosition(child->getPosition() + offset);
		
		if ( (offset.x < 0 && child->getPosition().x + child->getContentSize().width < 0) ||
        (offset.x > 0 && child->getPosition().x > _range.width) ) {
			child->setPosition((child->getPosition() + Point(-SIGN(offset.x) * fabs(scrollOffset->getScrollOffset().x), 0)));
		}
		
		// Positive y indicates upward movement in cocos2d
		if ( (offset.y < 0 && child->getPosition().y + child->getContentSize().height < 0) ||
        (offset.y > 0 && child->getPosition().y > _range.height) ) {
			child->setPosition((child->getPosition() + Point(0, -SIGN(offset.y) * fabs(scrollOffset->getScrollOffset().y))));
		}
	}
}


void InfiniteScrollNode::updateWithYPosition(float y, float dt)
{
  for (int i = 0; i < _scrollOffsets.size(); i ++)
  {
    InfiniteScrollOffset *scrollOffset = (InfiniteScrollOffset*) _scrollOffsets.at(i);

		Node *child = scrollOffset->getTheChild();
		float offset = y * scrollOffset->getRatio().y;
		child->setPosition(Point(child->getPosition().x, scrollOffset->getOrigPosition().y + offset));
	}
}


void InfiniteScrollNode::addChild(Sprite *node, int z, Point r, Point p, Point so, Point v)
{
	node->setAnchorPoint(Point(0,0));
  
	InfiniteScrollOffset *obj = InfiniteScrollOffset::scrollWithNode(node, r, p, so, v);
	_scrollOffsets.pushBack(obj);
  this->ax::Node::addChild(node, z);
}

void InfiniteScrollNode::addChild(Sprite *node, int z, Point r, Point p, Point so){
	this->addChild(node,z,r,p,so,Point(0,0));
}

void InfiniteScrollNode::removeChild(Sprite *node, bool cleanup)
{
	ax::Vector < InfiniteScrollOffset * > tobeDeleted;

  for (int i = 0; i < _scrollOffsets.size(); i ++)
  {
    InfiniteScrollOffset *scrollOffset = (InfiniteScrollOffset*) _scrollOffsets.at(i);

		if( scrollOffset->getTheChild() == node){
			tobeDeleted.pushBack(scrollOffset);
			break;
		}
	}

  for (int i = 0; i < tobeDeleted.size(); i ++)
  {
    _scrollOffsets.eraseObject(tobeDeleted.at(i));
  }
}

void InfiniteScrollNode::addInfiniteScrollWithObjects(const ax::Vector<Sprite *>& objects, int z, Point ratio, Point pos, Point dir, Point relVel, Point padding)
{
	// NOTE: corrects for 1 pixel at end of each sprite to avoid thin lines appearing
	
	// Calculate total width and height
	float totalWidth = 0;
	float totalHeight = 0;
  
  for (int i = 0; i < objects.size(); i ++)
  {
    Sprite *object = (Sprite*) objects.at(i);
		totalWidth += object->getContentSize().width * object->getScaleX() + dir.x * padding.x;
		totalHeight += object->getContentSize().height * object->getScaleY() + dir.y * padding.y;
	}
  
	// Position objects, add to parallax
	Point currPos = pos;
  for (int i = 0; i < objects.size(); i ++)
  {
    Sprite *object = (Sprite*) objects.at(i);
		this->addChild(object, z, ratio, currPos, Point(totalWidth, totalHeight), relVel);
		Point nextPosOffset = Point(dir.x * (object->getContentSize().width * object->getScaleX() + padding.x),
                                dir.y * (object->getContentSize().height * object->getScaleY() + padding.y));
		currPos = currPos + nextPosOffset;
	}
}

void InfiniteScrollNode::addInfiniteScrollWithObjects(const ax::Vector<Sprite *>& objects, int z, Point ratio, Point pos, Point dir, Point relVel)
{
	this->addInfiniteScrollWithObjects(objects, z, ratio, pos, dir, relVel, Point(-1,-1));
}

void InfiniteScrollNode::addInfiniteScrollWithObjects(const ax::Vector<Sprite *>& objects, int z, Point ratio, Point pos, Point dir)
{
	this->addInfiniteScrollWithObjects(objects, z, ratio, pos, dir, Point(0,0));
}

void InfiniteScrollNode::addInfiniteScrollXWithZ(int z, Point ratio, Point pos, Sprite* firstObject, ...)
{
  ax::Vector<Sprite *> objects;
  
	va_list args;
  va_start(args, firstObject);
	
	for (Sprite *arg = firstObject; arg != NULL; arg = va_arg(args, Sprite*)) {
		objects.pushBack(arg);
	}
	va_end(args);
  
	
	this->addInfiniteScrollWithObjects(objects, z, ratio, pos, Point(1,0));
}

void InfiniteScrollNode::addInfiniteScrollYWithZ(int z, Point ratio, Point pos, Sprite* firstObject, ...)
{
  ax::Vector<Sprite *> objects;

	va_list args;
  va_start(args, firstObject);
	
	for (Sprite *arg = firstObject; arg != NULL; arg = va_arg(args, Sprite*)) {
		objects.pushBack(arg);
	}
	va_end(args);
	
	this->addInfiniteScrollWithObjects(objects, z, ratio, pos, Point(0,1));
}