#include <acknex.h>
#include <default.c>

STRING* key_forward = "w";
STRING* key_backward = "s";
STRING* key_left = "a";
STRING* key_right = "d";
STRING* key_jump = "space";
STRING* key_run = "shiftl"; // left shift key

var t_player_speed = 25; // player's movement speed
var t_fwdbk_accel = 7; // player's forward / backward acceleration
var t_side_accel = 3; // player's sideway (strafe) acceleration
var t_friction = 1.5; // player's friction - this value should always be greater than 1
var t_fallspeed = 1; // player's fall down speed
var t_jump = 20; // player's jumping force
var t_resilience = 4; // pushes the player upwards a bit if it sinks too much in the floor
var t_disttoground = 64; // distance between the origin of player's model and the ground (used by the camera as well)
var t_camera_h = 12; // horizontal camera acceleration
var t_camera_h_frict = 0.95; // always use a value below 1 here
var t_camera_v = 8; // vertical camera acceleration
var t_camera_v_frict = 0.8; // always use a value below 1 here
var t_players_health = 100; // the player starts with 100 health points


var camera_h_speed = 0;
var camera_v_speed = 0;

VECTOR dist;
VECTOR absdist;

function first_person_camera()
{
	vec_set(camera.x, my.x);
	// accelerate camera's pan and tilt angles depending on mouse_force.x and mouse_force.y in order to create a smooth camera
	camera.pan -= accelerate (camera_h_speed, t_camera_h * (mouse_force.x), t_camera_h_frict);
	camera.tilt += accelerate (camera_v_speed, t_camera_v * (mouse_force.y), t_camera_v_frict);
	my.pan = camera.pan;
}

function handle_camera()
{
	camera.genius = my;
	camera.arc = 80;
	vec_set(camera.x,vector(my.x,my.y,my.z+30));
	my.pan = camera.pan;
	camera.pan -= 10 * mouse_force.x * time_step;
	camera.tilt += 10 * mouse_force.y * time_step;
	camera.tilt = clamp(camera.tilt,-90,90);
}

function handle_movement()
{
	if(key_shift)
	{
		dist.x = 15 * (key_w - key_s) * time_step;
		dist.y = 15 * (key_a - key_d) * time_step;
	}
	else

	{
		
		dist.x = 10 * (key_w - key_s) * time_step;
		dist.y = 10 * (key_a - key_d) * time_step;
		
		
	}
}

function handle_gravity()
{
	result = c_trace(my.x,vector(my.x,my.y,my.z-1000),IGNORE_PASSABLE|IGNORE_MODELS|USE_BOX);
	if(result > 5)
	{
		absdist.z -= 2 * time_step;
	}
	else
	{
		absdist.z = 0;
	}
}

#define health skill1
#define state skill2

action player_code()
{
	

	set (my, INVISIBLE); // using a 1st person player
	set (my, FLAG2); // will be used by enemies' c_scan instructions to detect the player
	var forward_on, backward_on, right_on, left_on, jump_on, run_on;
	var current_height = 0, jump_handle;
	VECTOR horizontal_speed, vertical_speed, temp;
	vec_set(horizontal_speed.x, nullvector); // initialize this vector
	vec_set(vertical_speed.x, nullvector); // initialize this vector
	player = me;
	my.eflags |= FAT | NARROW;
	wait(1);
	my.health = 400;
	
	while(my.health > 0) // while I'm alive
	
	{
		
		
		handle_gravity();
		handle_movement();
		c_move(my,dist,absdist,IGNORE_PASSABLE|GLIDE);
		
		handle_camera();
		wait(1);
	}
	{
		
		// key input start
		forward_on = 0; // reset all the key values at the beginning of each frame
		backward_on = 0;
		right_on = 0;
		left_on = 0;
		jump_on = 0;
		run_on = 0;
		// set the proper variables if their corresponding keys are pressed
		if(key_pressed(key_for_str(key_forward)))
		
		forward_on = 1;
		
		if(key_pressed(key_for_str(key_backward)))
		backward_on = 1;  
		if(key_pressed(key_for_str(key_left)))
		left_on = 1;
		if(key_pressed(key_for_str(key_right)))
		right_on = 1;  
		if(key_pressed(key_for_str(key_jump)))
		jump_on = 1;     
		if(key_pressed(key_for_str(key_run)))
		run_on = 1;     
		
		// key input end

		first_person_camera(); // calls the shooter camera function

		// player movement start
		// player's horizontal speed (forward / backward / sideways) movement uses acceleration and friction as well
		
		horizontal_speed.x = (horizontal_speed.x > 0) * maxv(horizontal_speed.x - time_step * t_friction, 0) + (horizontal_speed.x < 0) * minv(horizontal_speed.x + time_step * t_friction, 0);
		if(forward_on)
		
		{
			
			horizontal_speed.x += time_step * t_fwdbk_accel;
			
			horizontal_speed.x = minv(horizontal_speed.x, time_step * t_player_speed  * (1 + run_on));
			
		}    
		if(backward_on)
		{
			horizontal_speed.x -= time_step * t_fwdbk_accel;
			horizontal_speed.x = maxv(horizontal_speed.x, -(time_step * t_player_speed * (1 + run_on)));
		}    
		horizontal_speed.y = (horizontal_speed.y > 0) * maxv(horizontal_speed.y - time_step * t_friction, 0) + (horizontal_speed.y < 0) * minv(horizontal_speed.y + time_step * t_friction, 0);
		if(left_on)
		{
			horizontal_speed.y += time_step * t_side_accel;
			horizontal_speed.y = minv(horizontal_speed.y, time_step * t_player_speed * (1 + run_on));
		}
		if(right_on)
		{
			horizontal_speed.y -= time_step * t_side_accel;
			horizontal_speed.y = maxv(horizontal_speed.y, -(time_step * t_player_speed * (1 + run_on)));
		}    	
		// disable the friction, allow smooth gliding along the surfaces
		move_friction = 0;
		
		vec_set(temp.x, my.x);
		temp.z -= 10000;
		current_height = c_trace(my.x, temp.x, IGNORE_ME | IGNORE_PASSABLE | USE_BOX | GLIDE); // compute the distance between player's origin and the floor below its feet 
		if(current_height < (t_disttoground * 0.97)) // if it is smaller than the default value (64 quants) push the player upwards a bit (resilience) - 0.97 gives the hysteresis
		{
			vertical_speed.z = t_resilience * time_step;
			
		}
		else
		{
			if(current_height > t_disttoground) // if it is bigger than the default value (64 quants), move the player downwards
			{
				vertical_speed.z -= t_fallspeed * time_step;
			}
			else // sitting properly on the floor?
			{
				vertical_speed.z = 0; // then don't do anything on the z axis
			}
		}    
		if((jump_on) && (current_height < t_disttoground)) // jumping while player's feet are placed on the floor?
		{
			vertical_speed.z = t_jump * 0.25; // push the player upwards
		}
		// this c_move instruction does all the job, moving the player in the direction given by horizontal_speed (forward, backward, sideways) and vertical_speed (on the z axis)
		c_move (my, horizontal_speed.x , vertical_speed.x, IGNORE_PASSABLE | USE_BOX | GLIDE); 
		
		// player movement end

		wait(1);
		
	}
}

function main()
{
	video_set(sys_metrics(0),sys_metrics(1),0,1);
	fps_max = 70;
	level_load("small.hmp");
	wait(2);
	ent_create("player.mdl", vector(0,0,100),player_code);
}