Smoke/Gas effect

#define max_alpha skill1
#define max_fog 150

var cam_fog = 100; // needs to be a variable so it can get closer and further away to the camera as needed
VECTOR wind;

void set_alpha() 
{
	var fade_speed = 0.5;
	// fade model in
	my.alpha=70;
	my.max_alpha = integer(random(30));
	if(my.max_alpha < 10){ my.max_alpha = 25; }
	
	while(my.alpha < my.max_alpha)
	{
		my.alpha += fade_speed*time_step;
		wait(1);
	}
	my.alpha = my.max_alpha;
}

void fog_wind()
{
	while(1)
	{
		// new wind direction...
		vec_set(wind.x, vector((random(1) - .5)*1.5, (random(1) - .5)*1.5, random(1)*.4));
		wait(-5 + random(3));
	}
}

void move_fog()
{
	var roll_speed;
	var fade_distance = cam_fog+(cam_fog/6);
	var fog_speed = 20;
	
	roll_speed = random(2)-1; 
	
	while(me)
	{
		my.roll += roll_speed*time_step; //roll this sprite
		
		// update position globally
		c_move(my, nullvector, vector(random(fog_speed)*wind.x*time_step, random(fog_speed)*wind.y*time_step, 0), IGNORE_PASSABLE);
		
		// fade sprite when close to camera
		if(vec_dist(my.x, camera.x) < fade_distance) 
		{
			my.alpha = minv(my.max_alpha, vec_dist(camera.x, my.x) * my.max_alpha / fade_distance);
		}
		
		wait(1);
	}
}

void autofog()
{
	VECTOR cam_pos;
	var randint;
	
	vec_scale(my.scale_x, 0.8);
	set(my, PASSABLE | TRANSLUCENT); // can add BRIGHT, but slows FPS down
	
	//fade in slowly
	set_alpha();
	move_fog();
	
	while(me)
	{
		if(my.alpha < my.max_alpha) { my.alpha += time_step; }
		
		vec_set(cam_pos, camera.x);
		cam_pos.z = my.z;
		
		if(vec_dist(my.x, cam_pos) >= cam_fog)
		{
			// fade the fog out
			while(my.alpha > 0) { my.alpha -= time_step; wait(1); }
			
			// set on new position at edge of fog distance
			vec_set(my.x, vector(cycle(my.x, camera.x - cam_fog, camera.x + cam_fog), cycle(my.y, camera.y - cam_fog, camera.y + cam_fog), camera.z - random(100) + random (200)));
		}
		
		wait(5);
	}
}

void generate_fog()
{
	var randint; // random fog sprite
	var fogcount;
	
	VECTOR pos_place;
	
	fog_wind(); // sets a random fog position every so often
	
	for(fogcount=0; fogcount<max_fog; fogcount++)
	{
		// set random position around camera
		vec_set(pos_place.x, vector(((camera.x - random(cam_fog)) + (camera.x + random(cam_fog))), ((camera.y - random(cam_fog)) + (camera.y + random(cam_fog))), ((camera.z - random(cam_fog/4)) + random(cam_fog/2))));
		//		vec_set(pos_place.x, nullvector);
		
		// get a random number
		randint = integer(random(2));
		// create different fog, based on random number
		if(randint == 0){ ent_create("Dust_1.tga", pos_place, autofog); }
		if(randint == 1){ ent_create("Dust_2.tga", pos_place, autofog); }
	}
}