This makes no sense!

adamxiii · 2003-08-20T11:47:49

This works: particle.life -= 0.01f * FrameInterval; but this doesn''t? particle.life -= particle.lifeRate * FrameInterval; lifeRate is just a float in the particle struct that is set to 0.01f and FrameInterval is the amount of time between frames. anyone know why this isn''t working for me? Heres the entire class if that helps anyone... #ifndef CPARTICLE_H #define CPARTICLE_H #include "Globals.h" #include "CFrameRate.h" // Helper function to stuff a FLOAT into a DWORD argument inline DWORD FtoDW( FLOAT f ) { return *((DWORD*)&f); } class CParticle : public CObject { public: CParticle(string n); ~CParticle(); HRESULT Create( int num, CFrameRate &fps, string textureName ); void FreeMemory(); HRESULT Update(); void Render(); private: LPDIRECT3DVERTEXBUFFER9 pVB; LPDIRECT3DTEXTURE9 pTexture; CFrameRate *pFPS; struct Particle { D3DXVECTOR3 position; DWORD color; //------------ D3DXVECTOR3 velocity; float life; float lifeRate; }; DWORD D3DFVF_Particle; Particle *particles; int numParticles; void InitializeParticle( Particle &p ); void UpdateParticle( Particle &p ); }; #endif #include "CParticle.h" //---------------------- // Constructor //---------------------- CParticle::CParticle(string n) { //----------------------- // Object Data name = n; type = PARTICLE; //----------------------- pVB = NULL; pTexture = NULL; particles = NULL; numParticles = 0; D3DFVF_Particle = D3DFVF_XYZ | D3DFVF_DIFFUSE; } //---------------------- // Destructor //---------------------- CParticle::~CParticle() { FreeMemory(); } //---------------------- // FreeMemory //---------------------- void CParticle::FreeMemory() { SAFE_RELEASE(pVB); SAFE_RELEASE(pTexture); } //---------------------- // Create //---------------------- HRESULT CParticle::Create( int num, CFrameRate &fps, string textureName ) { numParticles = num; pFPS = &fps; if( FAILED( D3DXCreateTextureFromFile( d3dDevice, textureName.c_str(), &pTexture ) ) ) return E_FAIL; particles = new Particle[numParticles]; // Create the vertex buffer. if( FAILED( d3dDevice->CreateVertexBuffer( numParticles*sizeof(Particle), D3DUSAGE_POINTS | D3DUSAGE_DYNAMIC | D3DUSAGE_WRITEONLY, D3DFVF_Particle, D3DPOOL_DEFAULT, &pVB, NULL ) ) ) { return E_FAIL; } return S_OK; } //---------------------- // Update //---------------------- HRESULT CParticle::Update() { // Fill the vertex buffer. if( FAILED( pVB->Lock( 0, numParticles*sizeof(Particle), (void**)&particles, D3DLOCK_DISCARD ) ) ) return E_FAIL; for(int i=0; i<numParticles; i++) { if( particles[i].life < 0 ) InitializeParticle( particles[i] ); else UpdateParticle( particles[i] ); } pVB->Unlock(); return S_OK; } //---------------------- // InitializeParticle //---------------------- void CParticle::InitializeParticle( Particle &p ) { p.position.x = 0; p.position.y = 0; p.position.z = 0; p.color = 0xFFFFFFFF; p.life = rand() % 1000 / 10000.0f; p.lifeRate = 0.01f; p.velocity.x = ( rand() % 1000 / 1000.0f ) - 0.5f; p.velocity.y = ( rand() % 1000 / 1000.0f ) - 0.5f; p.velocity.z = ( rand() % 1000 / 1000.0f ) - 0.5f; } //---------------------- // UpdateParticle //---------------------- void CParticle::UpdateParticle( Particle &p ) { p.position += p.velocity * pFPS->GetFrameInterval(); // This makes no sense !!!!!!! p.life -= p.lifeRate * pFPS->GetFrameInterval(); } //---------------------- // Render //---------------------- void CParticle::Render() { if( SUCCEEDED( Update() ) ) { d3dDevice->SetRenderState( D3DRS_ALPHABLENDENABLE, TRUE ); d3dDevice->SetRenderState( D3DRS_SRCBLEND, D3DBLEND_SRCALPHA ); d3dDevice->SetRenderState( D3DRS_DESTBLEND, D3DBLEND_ONE ); d3dDevice->SetRenderState( D3DRS_ZENABLE, D3DZB_FALSE ); // Set the render states for using point sprites d3dDevice->SetRenderState( D3DRS_POINTSPRITEENABLE, TRUE ); d3dDevice->SetRenderState( D3DRS_POINTSCALEENABLE, TRUE ); d3dDevice->SetRenderState( D3DRS_POINTSIZE, FtoDW(0.25f) ); d3dDevice->SetRenderState( D3DRS_POINTSIZE_MIN, FtoDW(0.00f) ); d3dDevice->SetRenderState( D3DRS_POINTSCALE_A, FtoDW(0.00f) ); d3dDevice->SetRenderState( D3DRS_POINTSCALE_B, FtoDW(0.00f) ); d3dDevice->SetRenderState( D3DRS_POINTSCALE_C, FtoDW(1.00f) ); d3dDevice->SetTexture( 0, pTexture ); // Render d3dDevice->SetStreamSource( 0, pVB, 0, sizeof(Particle) ); d3dDevice->SetFVF( D3DFVF_Particle ); d3dDevice->DrawPrimitive( D3DPT_POINTLIST, 0, numParticles ); // Reset render states d3dDevice->SetTexture(0,NULL); d3dDevice->SetRenderState( D3DRS_POINTSPRITEENABLE, FALSE ); d3dDevice->SetRenderState( D3DRS_POINTSCALEENABLE, FALSE ); d3dDevice->SetRenderState( D3DRS_ALPHABLENDENABLE, FALSE ); d3dDevice->SetRenderState( D3DRS_ZENABLE, D3DZB_TRUE ); } }

Graphics and GPU Programming Programming

Started by adamxiii August 18, 2003 05:15 PM

12 comments, last by adamxiii 20 years, 8 months ago

adamxiii

122

Author

August 19, 2003 07:55 PM

frameInterval is a float, sorry

Muhammad Haggag

1,358

August 19, 2003 08:14 PM

quote:Original post by adamxiii
frameInterval is a float, sorry

Have you stepped into the code and checked the values before and after the computation yet?

adamxiii

122

Author

August 19, 2003 11:55 PM

I can''t really debug it because I have already rewritten the code so that lifeRate is now a member of the class and not of the particle struct. This way is much better anyways.

I was just curious why the first way wouldn''t work.

Igilima

122

August 20, 2003 11:47 AM

If the code change to go back and test it out isn''t too much, I''d do it and figure out what was going on. Break on that code and look at the values or display them to screen or something just so you can see if they are what you were expecting. There is always a chance that your value in particle.lifeRate was being stomped by something else. If it was, then something else is now being stomped and it could get ugly later.

This makes no sense!

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This makes no sense!

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