/****************************************************************************
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
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
****************************************************************************/

#include "platform/CCGL.h"

#include "CCParticleSystemQuad.h"
#include "CCSpriteFrame.h"

namespace cocos2d {

//implementation CCParticleSystemQuad

// overriding the init method
bool CCParticleSystemQuad::initWithTotalParticles(int numberOfParticles)
{
	// base initialization
	if( CCParticleSystem::initWithTotalParticles(numberOfParticles) ) 
	{
		// allocating data space
		m_pQuads = new ccV2F_C4F_T2F_Quad[m_nTotalParticles];
		m_pIndices = new GLushort[m_nTotalParticles * 6];

		if( !m_pQuads || !m_pIndices) 
		{
			CCLOG("cocos2d: Particle system: not enough memory");
			if( m_pQuads )
				delete [] m_pQuads;
			if(m_pIndices)
				delete [] m_pIndices;
			this->release();
			return NULL;
		}

		// initialize only once the texCoords and the indices
        if (m_pTexture)
        {
            this->initTexCoordsWithRect(CCRectMake((float)0, (float)0, (float)m_pTexture->getPixelsWide(), (float)m_pTexture->getPixelsHigh()));
        }
        else
        {
            this->initTexCoordsWithRect(CCRectMake((float)0, (float)0, (float)1, (float)1));
        }

		this->initIndices();

#if CC_USES_VBO
		// create the VBO buffer
		glGenBuffers(1, &m_uQuadsID);

		// initial binding
		glBindBuffer(GL_ARRAY_BUFFER, m_uQuadsID);
		glBufferData(GL_ARRAY_BUFFER, sizeof(m_pQuads[0])*m_nTotalParticles, m_pQuads, GL_DYNAMIC_DRAW);	
		glBindBuffer(GL_ARRAY_BUFFER, 0);	
#endif
		return true;
	}
	return false;
}
CCParticleSystemQuad::~CCParticleSystemQuad()
{
	CC_SAFE_DELETE_ARRAY(m_pQuads);
	CC_SAFE_DELETE_ARRAY(m_pIndices);
#if CC_USES_VBO
    glDeleteBuffers(1, &m_uQuadsID);
#endif
}

// rect should be in Texture coordinates, not pixel coordinates
void CCParticleSystemQuad::initTexCoordsWithRect(CCRect pointRect)
{
    // convert to Tex coords

    CCRect rect = CCRectMake(
        pointRect.origin.x * CC_CONTENT_SCALE_FACTOR(),
        pointRect.origin.y * CC_CONTENT_SCALE_FACTOR(),
        pointRect.size.width * CC_CONTENT_SCALE_FACTOR(),
        pointRect.size.height * CC_CONTENT_SCALE_FACTOR());

    GLfloat wide = (GLfloat) pointRect.size.width;
    GLfloat high = (GLfloat) pointRect.size.height;

    if (m_pTexture)
    {
        wide = (GLfloat)m_pTexture->getPixelsWide();
        high = (GLfloat)m_pTexture->getPixelsHigh();
    }

#if CC_FIX_ARTIFACTS_BY_STRECHING_TEXEL
    GLfloat left = (rect.origin.x*2+1) / (wide*2);
    GLfloat bottom = (rect.origin.y*2+1) / (high*2);
    GLfloat right = left + (rect.size.width*2-2) / (wide*2);
    GLfloat top = bottom + (rect.size.height*2-2) / (high*2);
#else
    GLfloat left = rect.origin.x / wide;
    GLfloat bottom = rect.origin.y / high;
    GLfloat right = left + rect.size.width / wide;
    GLfloat top = bottom + rect.size.height / high;
#endif // ! CC_FIX_ARTIFACTS_BY_STRECHING_TEXEL

	// Important. Texture in cocos2d are inverted, so the Y component should be inverted
	CC_SWAP( top, bottom, float);

	for(int i=0; i<m_nTotalParticles; i++) 
	{
		// bottom-left vertex:
		m_pQuads[i].bl.texCoords.u = left;
		m_pQuads[i].bl.texCoords.v = bottom;
		// bottom-right vertex:
		m_pQuads[i].br.texCoords.u = right;
		m_pQuads[i].br.texCoords.v = bottom;
		// top-left vertex:
		m_pQuads[i].tl.texCoords.u = left;
		m_pQuads[i].tl.texCoords.v = top;
		// top-right vertex:
		m_pQuads[i].tr.texCoords.u = right;
		m_pQuads[i].tr.texCoords.v = top;
	}
}
void CCParticleSystemQuad::setTextureWithRect(CCTexture2D *texture, CCRect rect)
{
	// Only update the texture if is different from the current one
	if( !m_pTexture || texture->getName() != m_pTexture->getName() )
	{
		CCParticleSystem::setTexture(texture);
	}

	this->initTexCoordsWithRect(rect);
}
void CCParticleSystemQuad::setTexture(CCTexture2D* var)
{
	this->setTextureWithRect(var, CCRectMake(0, 0, 
        (float)(var->getPixelsWide() / CC_CONTENT_SCALE_FACTOR()), 
        (float)(var->getPixelsHigh() / CC_CONTENT_SCALE_FACTOR())));
}
void CCParticleSystemQuad::setDisplayFrame(CCSpriteFrame *spriteFrame)
{
	CCAssert( CCPoint::CCPointEqualToPoint( spriteFrame->getOffsetInPixels() , CCPointZero ), "QuadParticle only supports SpriteFrames with no offsets");

	// update texture before updating texture rect
	if ( !m_pTexture || spriteFrame->getTexture()->getName() != m_pTexture->getName())
	{
		this->setTexture(spriteFrame->getTexture());
	}
}
void CCParticleSystemQuad::initIndices()
{
	for( int i = 0; i < m_nTotalParticles; ++i)
	{
        const int i6 = i*6;
        const int i4 = i*4;
		m_pIndices[i6+0] = (GLushort) i4+0;
		m_pIndices[i6+1] = (GLushort) i4+1;
		m_pIndices[i6+2] = (GLushort) i4+2;

		m_pIndices[i6+5] = (GLushort) i4+1;
		m_pIndices[i6+4] = (GLushort) i4+2;
		m_pIndices[i6+3] = (GLushort) i4+3;
	}
}
void CCParticleSystemQuad::updateQuadWithParticle(tCCParticle* particle, CCPoint newPosition)
{
	// colors
    ccV2F_C4F_T2F_Quad *quad = &(m_pQuads[m_nParticleIdx]);
	quad->bl.colors = particle->color;
	quad->br.colors = particle->color;
	quad->tl.colors = particle->color;
	quad->tr.colors = particle->color;

	// vertices
	GLfloat size_2 = particle->size/2;
	if( particle->rotation ) 
	{
		GLfloat x1 = -size_2;
		GLfloat y1 = -size_2;

		GLfloat x2 = size_2;
		GLfloat y2 = size_2;
		GLfloat x = newPosition.x;
		GLfloat y = newPosition.y;

		GLfloat r = (GLfloat)-CC_DEGREES_TO_RADIANS(particle->rotation);
		GLfloat cr = cosf(r);
		GLfloat sr = sinf(r);
		GLfloat ax = x1 * cr - y1 * sr + x;
		GLfloat ay = x1 * sr + y1 * cr + y;
		GLfloat bx = x2 * cr - y1 * sr + x;
		GLfloat by = x2 * sr + y1 * cr + y;
		GLfloat cx = x2 * cr - y2 * sr + x;
		GLfloat cy = x2 * sr + y2 * cr + y;
		GLfloat dx = x1 * cr - y2 * sr + x;
		GLfloat dy = x1 * sr + y2 * cr + y;

		// bottom-left
		quad->bl.vertices.x = ax;
		quad->bl.vertices.y = ay;

		// bottom-right vertex:
		quad->br.vertices.x = bx;
		quad->br.vertices.y = by;

		// top-left vertex:
		quad->tl.vertices.x = dx;
		quad->tl.vertices.y = dy;

		// top-right vertex:
		quad->tr.vertices.x = cx;
		quad->tr.vertices.y = cy;
	} else {
		// bottom-left vertex:
		quad->bl.vertices.x = newPosition.x - size_2;
		quad->bl.vertices.y = newPosition.y - size_2;

		// bottom-right vertex:
		quad->br.vertices.x = newPosition.x + size_2;
		quad->br.vertices.y = newPosition.y - size_2;

		// top-left vertex:
		quad->tl.vertices.x = newPosition.x - size_2;
		quad->tl.vertices.y = newPosition.y + size_2;

		// top-right vertex:
		quad->tr.vertices.x = newPosition.x + size_2;
		quad->tr.vertices.y = newPosition.y + size_2;				
	}
}
void CCParticleSystemQuad::postStep()
{
#if CC_USES_VBO
	glBindBuffer(GL_ARRAY_BUFFER, m_uQuadsID);
	glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(m_pQuads[0])*m_nParticleCount, m_pQuads);
	glBindBuffer(GL_ARRAY_BUFFER, 0);
#endif
}

// overriding draw method
void CCParticleSystemQuad::draw()
{	
	// 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_COLOR_ARRAY, GL_TEXTURE_COORD_ARRAY
	// Unneeded states: -
	glBindTexture(GL_TEXTURE_2D, m_pTexture->getName());

#define kQuadSize sizeof(m_pQuads[0].bl)

#if CC_USES_VBO
    glBindBuffer(GL_ARRAY_BUFFER, m_uQuadsID);

#if CC_ENABLE_CACHE_TEXTTURE_DATA
    glBufferData(GL_ARRAY_BUFFER, sizeof(m_pQuads[0])*m_nTotalParticles, m_pQuads, GL_DYNAMIC_DRAW);	
#endif

	glVertexPointer(2,GL_FLOAT, kQuadSize, 0);

	glColorPointer(4, GL_FLOAT, kQuadSize, (GLvoid*) offsetof(ccV2F_C4F_T2F,colors) );

	glTexCoordPointer(2, GL_FLOAT, kQuadSize, (GLvoid*) offsetof(ccV2F_C4F_T2F,texCoords) );
#else   // vertex array list

    int offset = (int) m_pQuads;

    // vertex
    int diff = offsetof( ccV2F_C4F_T2F, vertices);
    glVertexPointer(2,GL_FLOAT, kQuadSize, (GLvoid*) (offset+diff) );

    // color
    diff = offsetof( ccV2F_C4F_T2F, colors);
    glColorPointer(4, GL_FLOAT, kQuadSize, (GLvoid*)(offset + diff));

    // tex coords
    diff = offsetof( ccV2F_C4F_T2F, texCoords);
    glTexCoordPointer(2, GL_FLOAT, kQuadSize, (GLvoid*)(offset + diff));		

#endif // ! CC_USES_VBO

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

    CCAssert( m_nParticleIdx == m_nParticleCount, "Abnormal error in particle quad");

	glDrawElements(GL_TRIANGLES, m_nParticleIdx*6, GL_UNSIGNED_SHORT, m_pIndices);	

	// restore blend state
	if( newBlend )
		glBlendFunc( CC_BLEND_SRC, CC_BLEND_DST );

#if CC_USES_VBO
	glBindBuffer(GL_ARRAY_BUFFER, 0);
#endif

	// restore GL default state
	// -
}

}// namespace cocos2d