Method initGrid

cpp/5_Domain_Specific/smokeParticles/ParticleSystem.cpp:193–220

initialize in regular grid

// initialize in regular grid
void ParticleSystem::initGrid(vec3f start,
                              uint3 size,
                              vec3f spacing,
                              float jitter,
                              vec3f vel,
                              uint  numParticles,
                              float lifetime)
{
    srand(1973);

    float4 *posPtr = m_pos.getHostPtr();
    float4 *velPtr = m_vel.getHostPtr();

    for (uint z = 0; z < size.z; z++) {
        for (uint y = 0; y < size.y; y++) {
            for (uint x = 0; x < size.x; x++) {
                uint i = (z * size.y * size.x) + (y * size.x) + x;

                if (i < numParticles) {
                    vec3f pos = start + spacing * vec3f((float)x, (float)y, (float)z) + svrand() * jitter;

                    posPtr[i] = make_float4(pos.x, pos.y, pos.z, 0.0f);
                    velPtr[i] = make_float4(vel.x, vel.y, vel.z, lifetime);
                }
            }
        }
    }
}

// initialize in random positions within cube
void ParticleSystem::initCubeRandom(vec3f origin, vec3f size, vec3f vel, float lifetime)