void Render(double time)
{
// update the particle positions, ages and directions
GLuint i = 0;
float time_diff = (time - prev_time);
float age_mult = 0.2f;
while(i != positions.size())
{
float drag = 0.1f * (time_diff);
if((ages[i] += time_diff * age_mult) < 1.0f)
{
directions[i] *= (1.0f - drag);
positions[i] += directions[i]*time_diff;
}
else
{
ages[i] = 0.0f;
directions[i] = NewDirection();
positions[i] = Vec3f();
}
++i;
}
// if there are not enough particles yet
if(i != particle_count)
{
float spawn_interval = 1.0f/(age_mult*particle_count);
if(prev_spawn + spawn_interval < time)
{
directions.push_back(NewDirection());
positions.push_back(Vec3f());
ages.push_back(0.0f);
prev_spawn = time;
}
}
prev_time = time;
assert(positions.size() == directions.size());
assert(positions.size() == ages.size());
// upload the particle positions
pos_buf.Bind(Buffer::Target::Array);
Buffer::Data(Buffer::Target::Array, positions);
// upload the particle ages
age_buf.Bind(Buffer::Target::Array);
Buffer::Data(Buffer::Target::Array, ages);
gl.Clear().ColorBuffer().DepthBuffer();
//
// set the matrix for camera orbiting the origin
camera_matrix.Set(
CamMatrixf::Orbiting(
Vec3f(),
18.0f,
FullCircles(time * 0.5),
Degrees(45)
)
);
gl.DrawArrays(PrimitiveType::Points, 0, positions.size());
}
void Player::CheckDirections()
{
if (mDirection == FORWARD && mNode->Front!=NULL)
{
if (!mNode->Front->GhostNode)
{NewDirection(mNode->Front);}
}
else if (mDirection == BACKWARD && mNode->Back!=NULL)
{
if (!mNode->Back->GhostNode)
{NewDirection(mNode->Back);}
}
else if (mDirection == LEFT && mNode->Left!=NULL)
{
if (!mNode->Left->GhostNode)
{NewDirection(mNode->Left);}
}
else if (mDirection == RIGHT && mNode->Right!=NULL)
{
if (!mNode->Right->GhostNode)
{NewDirection(mNode->Right);}
}
else mDirection = PAUSE;
}
// Spawns a new particle if the time is right
bool SpawnParticle(
double time,
Vec3f& position,
Vec3f& direction,
float& age
)
{
float new_age = time - spawn_time - spawn_interval;
if(new_age >= 0.0f)
{
spawn_time += spawn_interval;
direction = NewDirection();
Vec3f emitter_pos = path.Position(spawn_time/cycle_time);
position = emitter_pos + direction;
age = new_age;
return true;
}
return false;
}