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 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
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 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
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#ifndef __PARTICLESYSTEM_H__
#define __PARTICLESYSTEM_H__

#include <helper_functions.h>

#include "GpuArray.h"
#include "nvMath.h"
#include "particles_kernel.cuh"
#include "vector_functions.h"

using namespace nv;

// CUDA BodySystem: runs on the GPU
class ParticleSystem
{
public:
    ParticleSystem(uint numParticles, bool bUseVBO = true, bool bUseGL = true);
    ~ParticleSystem();

    enum ParticleConfig { CONFIG_RANDOM, CONFIG_GRID, _NUM_CONFIGS };

    void step(float deltaTime);
    void depthSort();
    void reset(ParticleConfig config);

    uint getNumParticles() { return m_numParticles; }

    uint  getPosBuffer() { return m_pos.getVbo(); }
    uint  getVelBuffer() { return m_vel.getVbo(); }
    uint  getColorBuffer() { return 0; }
    uint  getSortedIndexBuffer() { return m_indices.getVbo(); }
    uint *getSortedIndices();

    float getParticleRadius() { return m_particleRadius; }

    SimParams &getParams() { return m_params; }

    void setSorting(bool x) { m_doDepthSort = x; }
    void setModelView(float *m);
    void setSortVector(float3 v) { m_sortVector = v; }

    void addSphere(uint &index, vec3f pos, vec3f vel, int r, float spacing, float jitter, float lifetime);
    void discEmitter(uint &index,
                     vec3f pos,
                     vec3f vel,
                     vec3f vx,
                     vec3f vy,
                     float r,
                     int   n,
                     float lifetime,
                     float lifetimeVariance);
    void sphereEmitter(uint &index,
                       vec3f pos,
                       vec3f vel,
                       vec3f spread,
                       float r,
                       int   n,
                       float lifetime,
                       float lifetimeVariance);

    void dumpParticles(uint start, uint count);
    void dumpBin(float4 **posData, float4 **velData);

protected: // methods
    ParticleSystem() {}

    void _initialize(int numParticlesm, bool bUseGL = true);
    void _free();

    void initGrid(vec3f start,
                  uint3 size,
                  vec3f spacing,
                  float jitter,
                  vec3f vel,
                  uint  numParticles,
                  float lifetime = 100.0f);
    void initCubeRandom(vec3f origin, vec3f size, vec3f vel, float lifetime = 100.0f);

protected: // data
    bool m_bInitialized;
    bool m_bUseVBO;
    uint m_numParticles;

    float m_particleRadius;

    GpuArray<float4> m_pos;
    GpuArray<float4> m_vel;

    // params
    SimParams m_params;

    float4x4 m_modelView;
    float3   m_sortVector;
    bool     m_doDepthSort;

    GpuArray<float> m_sortKeys;
    GpuArray<uint>  m_indices; // sorted indices for rendering

    StopWatchInterface *m_timer;
    float               m_time;
};

#endif // __PARTICLESYSTEM_H__
