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unknown problem with particle engine

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Hi all, I am working on my graphics engine. Have skybox, meshes displaying properly. Currently working on the particle engine. I have completed coding it and feel it should work. No errors, but nothing displayed. I adapted this from an example from a book, and it looks solid. Don't know why it's not displaying anything. Anyone see anything? I feel it's something small I'm forgetting. I've only included the primary methods, any q's plz ask.
void cParticleCollection::PreRender()
{
//TODO: move some of these one-time settings to constructor.. not sure which ones

//general settings
Graphics->p_device->SetRenderState(D3DRS_LIGHTING, false);
Graphics->p_device->SetRenderState(D3DRS_POINTSPRITEENABLE, true);
Graphics->p_device->SetRenderState(D3DRS_POINTSCALEENABLE, true);
Graphics->p_device->SetRenderState(D3DRS_POINTSIZE, FloatToDWORD(2.5f) );
Graphics->p_device->SetRenderState(D3DRS_POINTSIZE_MIN, FloatToDWORD(0.1f) );

//set the size of the particle relative to distance
Graphics->p_device->SetRenderState(D3DRS_POINTSCALE_A, FloatToDWORD(0.0f) );
Graphics->p_device->SetRenderState(D3DRS_POINTSCALE_B, FloatToDWORD(0.0f) );
Graphics->p_device->SetRenderState(D3DRS_POINTSCALE_C, FloatToDWORD(1.0f) );

//use alpha from texture
Graphics->p_device->SetTextureStageState(0, D3DTSS_ALPHAARG1, D3DTA_TEXTURE);
Graphics->p_device->SetTextureStageState(0, D3DTSS_ALPHAOP, D3DTOP_SELECTARG1);

Graphics->p_device->SetRenderState(D3DRS_ALPHABLENDENABLE, true);
Graphics->p_device->SetRenderState(D3DRS_SRCBLEND, D3DBLEND_SRCALPHA);
Graphics->p_device->SetRenderState(D3DRS_DESTBLEND, D3DBLEND_INVSRCALPHA);

//set vertex format
Graphics->p_device->SetFVF(D3DFVF_XYZ | D3DFVF_DIFFUSE | D3DFVF_PSIZE);
//set stream source
Graphics->p_device->SetStreamSource(0, ParticleBuffer, 0, sizeof(cVertex));

}
void cParticleCollection::PostRender()
{
Graphics->p_device->SetRenderState(D3DRS_LIGHTING, true);
Graphics->p_device->SetRenderState(D3DRS_POINTSPRITEENABLE, false);
Graphics->p_device->SetRenderState(D3DRS_POINTSCALEENABLE, false);
Graphics->p_device->SetRenderState(D3DRS_ALPHABLENDENABLE, false);
}
void cParticleCollection::Render()
{
	if (Particles.size() > 0) //if there are entries
	{
	PreRender();				//prepare to render

	//render collection:
	cVertex *v = 0;
	int iCurrentVertex = 0;

		//counter number of particles that are on
		for (int i = 0; i <= Particles.size(); i++) 	//loop thru all
		{
			if (Particles[i].fLifeTime > 0)				//if on
			{	
				//RENDER THIS PARTICLE

				//lock a slot
				ParticleBuffer->Lock(iCurrentVertex * sizeof(cVertex),							//beginning of lock
									 sizeof(cVertex),											//size of lock range
									 (void**)&v,												//address of vertex
									 iCurrentVertex ? D3DLOCK_NOOVERWRITE : D3DLOCK_DISCARD);	//flags
				//fill info
				v->d3dColor = d3d::GREEN;						//sould ba var
				v->fSize	= 50.0f;								//should be a var
				v->vPos		= Particles[i].vPos;
				//set texture
				Graphics->p_device->SetTexture(0, Graphics->Textures[10]); //30 should be a variable
				
				//unlock and render
				ParticleBuffer->Unlock();
				Graphics->p_device->DrawPrimitive(D3DPT_POINTLIST,
												  iCurrentVertex,
												  1);
				//move to next slot
				iCurrentVertex++;
					if ( iCurrentVertex > iVBsize-1 ) { iCurrentVertex = 0; }


			}
		}


	PostRender();			//reset after render
	}
}
void cParticleCollection::Init()
{
	r = Graphics->p_device->CreateVertexBuffer(iVBsize * sizeof(cVertex),
												D3DUSAGE_DYNAMIC | D3DUSAGE_POINTS | D3DUSAGE_WRITEONLY,
												D3DFVF_XYZ | D3DFVF_DIFFUSE,
												D3DPOOL_DEFAULT,
												&ParticleBuffer,
												0);
}

[Edited by - alundgren on May 3, 2007 12:51:47 PM]

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Could you please re-format the code and put it into [source] [/source] tags? That would help a lot with trying to read it.

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Since you say you code hangs, it's likely that running it in the debugger and breaking when it hangs will show you where it hangs, which should help find the problem.

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Sorry was using [code ] tags. I worded the problem poorly - it doesn't hang up, it just doesn't display anything. There are no errors and it runs fine, just nothing's displayed.

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You don't seem to be checking for errors. Always check return codes for errors.

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