/****************************************************************************
Copyright (c) 2010 cocos2d-x.org

http://www.cocos2d-x.org

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
****************************************************************************/
#include "CCRibbon.h"
#include "CCTextureCache.h"
#include "CGPointExtension.h"
namespace cocos2d {

	/*
	* A ribbon is a dynamically generated list of polygons drawn as a single or series
	* of triangle strips. The primary use of Ribbon is as the drawing class of Motion Streak,
	* but it is quite useful on it's own. When manually drawing a ribbon, you can call addPointAt
	* and pass in the parameters for the next location in the ribbon. The system will automatically
	* generate new polygons, texture them accourding to your texture width, etc, etc.
	*
	* Ribbon data is stored in a RibbonSegment class. This class statically allocates enough verticies and
	* texture coordinates for 50 locations (100 verts or 48 triangles). The ribbon class will allocate
	* new segments when they are needed, and reuse old ones if available. The idea is to avoid constantly
	* allocating new memory and prefer a more static method. However, since there is no way to determine
	* the maximum size of some ribbons (motion streaks), a truely static allocation is not possible.
	*
	*/

	//
	// Ribbon
	//
	CCRibbon * CCRibbon::ribbonWithWidth(float w, const char *path, float length, ccColor4B color, float fade)
	{
		CCRibbon *pRet = new CCRibbon();
		if(pRet && pRet->initWithWidth(w, path, length, color, fade))
		{
			pRet->autorelease();
			return pRet;
		}
		CCX_SAFE_DELETE(pRet)
		return NULL;
	}
	bool CCRibbon::initWithWidth(float w, const char *path, float length, ccColor4B color, float fade)
	{
		m_pSegments = new NSMutableArray<CCRibbonSegment*>();
		m_pDeletedSegments = new NSMutableArray<CCRibbonSegment*>();

		/* 1 initial segment */
		CCRibbonSegment* seg = new CCRibbonSegment();
		seg->init();
		m_pSegments->addObject(seg);
		seg->release();

		m_fTextureLength = length;

		m_tColor = color;
		m_fFadeTime = fade;
		m_tLastLocation = CGPointZero;
		m_fLastWidth = w/2;
		m_fTexVPos = 0.0f;

		m_fCurTime = 0;
		m_bPastFirstPoint = false;

		/* XXX:
		Ribbon, by default uses this blend function, which might not be correct
		if you are using premultiplied alpha images,
		but 99% you might want to use this blending function regarding of the texture
		*/
		m_tBlendFunc.src = GL_SRC_ALPHA;
		m_tBlendFunc.dst = GL_ONE_MINUS_SRC_ALPHA;

		m_pTexture = CCTextureCache::sharedTextureCache()->addImage(path);

		/* default texture parameter */
		ccTexParams params = { GL_LINEAR, GL_LINEAR, GL_REPEAT, GL_REPEAT };
		m_pTexture->setTexParameters(&params);
		return true;
	}
	CCRibbon::~CCRibbon()
	{
		m_pSegments->release();
		m_pDeletedSegments->release();
		m_pTexture->release();
	}
	CGPoint CCRibbon::rotatePoint(CGPoint vec, float rotation)
	{
		float xtemp = (vec.x * cosf(rotation)) - (vec.y * sinf(rotation));
		vec.y = (vec.x * sinf(rotation)) + (vec.y * cosf(rotation));
		vec.x = xtemp;
		return vec;
	}
	void CCRibbon::update(ccTime delta)
	{
		m_fCurTime += delta;
		m_fDelta = delta;
	}
	float CCRibbon::sideOfLine(CGPoint p, CGPoint l1, CGPoint l2)
	{
		CGPoint vp = ccpPerp(ccpSub(l1, l2));
		CGPoint vx = ccpSub(p, l1);
		return ccpDot(vx, vp);
	}

	// adds a new segment to the ribbon
	void CCRibbon::addPointAt(CGPoint location, float width)
	{
		width = width * 0.5f;
		// if this is the first point added, cache it and return
		if (!m_bPastFirstPoint)
		{
			m_fLastWidth = width;
			m_tLastLocation = location;
			m_bPastFirstPoint = true;
			return;
		}

		CGPoint sub = ccpSub(m_tLastLocation, location);
		float r = ccpToAngle(sub) + (float)M_PI_2;
		CGPoint p1 = ccpAdd(this->rotatePoint(ccp(-width, 0), r), location);
		CGPoint p2 = ccpAdd(this->rotatePoint(ccp(+width, 0), r), location);
		float len = sqrtf(powf(m_tLastLocation.x - location.x, 2) + powf(m_tLastLocation.y - location.y, 2));
		float tend = m_fTexVPos + len/m_fTextureLength;
		CCRibbonSegment* seg;
		// grab last segment
		seg = m_pSegments->getLastObject();
		// lets kill old segments
		if (m_pSegments && m_pSegments->count()>0)
		{
			NSMutableArray<CCRibbonSegment*>::NSMutableArrayIterator it;
			for (it = m_pSegments->begin(); it != m_pSegments->end(); ++it)
			{
				if (*it != seg && (*it)->m_bFinished)
				{
					m_pDeletedSegments->addObject(*it);
				}
			}
		}
		
		m_pSegments->removeObjectsInArray(m_pDeletedSegments);
		// is the segment full?
		if (seg->m_uEnd >= 50)
		{
			m_pSegments->removeObjectsInArray(m_pDeletedSegments);
		}
		// grab last segment and append to it if it's not full
		seg = m_pSegments->getLastObject();
		// is the segment full?
		if (seg->m_uEnd >= 50)
		{
			CCRibbonSegment* newSeg;
			// grab it from the cache if we can
			if (m_pDeletedSegments->count() > 0)
			{
				newSeg = m_pDeletedSegments->getObjectAtIndex(0);
				newSeg->retain();							// will be released later
				m_pDeletedSegments->removeObject(newSeg);
				newSeg->reset();
			}
			else
			{
				newSeg = new CCRibbonSegment(); // will be released later
				newSeg->init();
			}

			newSeg->m_pCreationTime[0] = seg->m_pCreationTime[seg->m_uEnd- 1];
			int v = (seg->m_uEnd-1)*6;
			int c = (seg->m_uEnd-1)*4;	
			newSeg->m_pVerts[0] = seg->m_pVerts[v];
			newSeg->m_pVerts[1] = seg->m_pVerts[v+1];
			newSeg->m_pVerts[2] = seg->m_pVerts[v+2];
			newSeg->m_pVerts[3] = seg->m_pVerts[v+3];
			newSeg->m_pVerts[4] = seg->m_pVerts[v+4];
			newSeg->m_pVerts[5] = seg->m_pVerts[v+5];

			newSeg->m_pCoords[0] = seg->m_pCoords[c];
			newSeg->m_pCoords[1] = seg->m_pCoords[c+1];
			newSeg->m_pCoords[2] = seg->m_pCoords[c+2];
			newSeg->m_pCoords[3] = seg->m_pCoords[c+3];	  
			newSeg->m_uEnd++;
			seg = newSeg;
			m_pSegments->addObject(seg);
			newSeg->release();// it was retained before
		}  
		if (seg->m_uEnd == 0)
		{
			// first edge has to get rotation from the first real polygon
			CGPoint lp1 = ccpAdd(this->rotatePoint(ccp(-m_fLastWidth, 0), r), m_tLastLocation);
			CGPoint lp2 = ccpAdd(this->rotatePoint(ccp(+m_fLastWidth, 0), r), m_tLastLocation);
			seg->m_pCreationTime[0] = m_fCurTime - m_fDelta;
			seg->m_pVerts[0] = lp1.x;
			seg->m_pVerts[1] = lp1.y;
			seg->m_pVerts[2] = 0.0f;
			seg->m_pVerts[3] = lp2.x;
			seg->m_pVerts[4] = lp2.y;
			seg->m_pVerts[5] = 0.0f;
			seg->m_pCoords[0] = 0.0f;
			seg->m_pCoords[1] = m_fTexVPos;
			seg->m_pCoords[2] = 1.0f;
			seg->m_pCoords[3] = m_fTexVPos;
			seg->m_uEnd++;
		}

		int v = seg->m_uEnd*6;
		int c = seg->m_uEnd*4;
		// add new vertex
		seg->m_pCreationTime[seg->m_uEnd] = m_fCurTime;
		seg->m_pVerts[v] = p1.x;
		seg->m_pVerts[v+1] = p1.y;
		seg->m_pVerts[v+2] = 0.0f;
		seg->m_pVerts[v+3] = p2.x;
		seg->m_pVerts[v+4] = p2.y;
		seg->m_pVerts[v+5] = 0.0f;


		seg->m_pCoords[c] = 0.0f;
		seg->m_pCoords[c+1] = tend;
		seg->m_pCoords[c+2] = 1.0f;
		seg->m_pCoords[c+3] = tend;

		m_fTexVPos = tend;
		m_tLastLocation = location;
		m_tLastPoint1 = p1;
		m_tLastPoint2 = p2;
		m_fLastWidth = width;
		seg->m_uEnd++;
	}
	void CCRibbon::draw()
	{
		if (m_pSegments->count() > 0)
		{
			// Default GL states: GL_TEXTURE_2D, GL_VERTEX_ARRAY, GL_COLOR_ARRAY, GL_TEXTURE_COORD_ARRAY
			// Needed states: GL_TEXTURE_2D, GL_VERTEX_ARRAY, GL_TEXTURE_COORD_ARRAY
			// Unneeded states: GL_COLOR_ARRAY
			glDisableClientState(GL_COLOR_ARRAY);

			glBindTexture(GL_TEXTURE_2D, m_pTexture->getName());

			bool newBlend = false;
			if( m_tBlendFunc.src != CC_BLEND_SRC || m_tBlendFunc.dst != CC_BLEND_DST ) 
			{
				newBlend = true;
				glBlendFunc( m_tBlendFunc.src, m_tBlendFunc.dst );
			}

			if(m_pSegments && m_pSegments->count() > 0)
			{
				CCRibbonSegment* seg;
				NSMutableArray<CCRibbonSegment*>::NSMutableArrayIterator it;
				for( it = m_pSegments->begin(); it != m_pSegments->end(); it++)
				{
					seg = (CCRibbonSegment*)*it;
					seg->draw(m_fCurTime, m_fFadeTime, m_tColor);
				}
			}

			if( newBlend )
			{
				glBlendFunc(CC_BLEND_SRC, CC_BLEND_DST);
			}

			// restore default GL state
			glEnableClientState( GL_COLOR_ARRAY );
		}
	}

	// Ribbon - CocosNodeTexture protocol
	void CCRibbon::setTexture(CCTexture2D* var)
	{
		m_pTexture->release();
		var->retain();
		m_pTexture = var;
		this->setContentSize(m_pTexture->getContentSize());
		/* XXX Don't update blending function in Ribbons */
	}
	CCTexture2D *CCRibbon::getTexture()
	{
		return m_pTexture;
	}
	void CCRibbon::setTextureLength(float var)
	{
		m_fTextureLength = var;
	}
	float CCRibbon::getTextureLength()
	{
		return m_fTextureLength;
	}
	void CCRibbon::setBlendFunc(ccBlendFunc var)
	{
		m_tBlendFunc = var;
	}
	ccBlendFunc CCRibbon::getBlendFunc()
	{
		return m_tBlendFunc;
	}
	void CCRibbon::setColor(ccColor4B var)
	{
		m_tColor = var;
	}
	ccColor4B CCRibbon::getColor()
	{
		return m_tColor;
	} 

	//
	//RibbonSegment
	//
	CCRibbonSegment * CCRibbonSegment::init()
	{
		this->reset();
		return this;
	}
	char * CCRibbonSegment::description()
	{
		char *ret = new char[100] ;
		sprintf_s(ret, 100, "<CCRibbonSegment | end = %u, begin = %>", m_uEnd, m_uBegin);
		return ret;
	}
	CCRibbonSegment::~CCRibbonSegment()
	{
		CCLOGINFO("cocos2d: deallocing.");
	}
	void CCRibbonSegment::reset()
	{
		m_uEnd = 0;
		m_uBegin = 0;
		m_bFinished = false;
	}
	void CCRibbonSegment::draw(float curTime, float fadeTime, ccColor4B color)
	{
		GLubyte r = color.r;
		GLubyte g = color.g;
		GLubyte b = color.b;
		GLubyte a = color.a;

		if (m_uBegin < 50)
		{
			// the motion streak class will call update and cause time to change, thus, if curTime_ != 0
			// we have to generate alpha for the ribbon each frame.
			if (curTime == 0)
			{
				// no alpha over time, so just set the color
				glColor4ub(r,g,b,a);
			}
			else
			{
				// generate alpha/color for each point
				glEnableClientState(GL_COLOR_ARRAY);
				UINT i = m_uBegin;
				for (; i < m_uEnd; ++i)
				{
					int idx = i*8;
					m_pColors[idx] = r;
					m_pColors[idx+1] = g;
					m_pColors[idx+2] = b;
					m_pColors[idx+4] = r;
					m_pColors[idx+5] = g;
					m_pColors[idx+6] = b;
					float alive = ((curTime - m_pCreationTime[i]) / fadeTime);
					if (alive > 1)
					{
						m_uBegin++;
						m_pColors[idx+3] = 0;
						m_pColors[idx+7] = 0;
					}
					else
					{
						m_pColors[idx+3] = (GLubyte)(255.f - (alive * 255.f));
						m_pColors[idx+7] = m_pColors[idx+3];
					}
				}
				glColorPointer(4, GL_UNSIGNED_BYTE, 0, &m_pColors[m_uBegin*8]);
			}
			glVertexPointer(3, GL_FLOAT, 0, &m_pVerts[m_uBegin*6]);
			glTexCoordPointer(2, GL_FLOAT, 0, &m_pCoords[m_uBegin*4]);
			glDrawArrays(GL_TRIANGLE_STRIP, 0, (m_uEnd - m_uBegin) * 2);
		}
		else
		{
			m_bFinished = true;
		}
	}

}// namespace cocos2d