#include <global.h>
#include <math.h>

Data Structures
struct	blstr
Defines
#define	SPACE_BLOCK 0.5
#define	MAX_MASK_SIZE 81
#define	NR_LIGHT_MASK 10
#define	MAX_LIGHT_SOURCE 13
#define	BLOCKED_LOS_EXPAND 0x20
Typedefs
typedef struct blstr	blocks
Functions
static void	expand_sight (object *op)
void	init_block ()
void	set_block (int x, int y, int bx, int by)
static void	set_wall (object *op, int x, int y)
static void	check_wall (object *op, int x, int y)
static void	blinded_sight (object *op)
void	update_los (object *op)
void	clear_los (object *op)
static int	get_real_light_source_value (int l)
static void	remove_light_mask (mapstruct *map, int x, int y, int mid)
static int	add_light_mask (mapstruct *map, int x, int y, int mid)
void	adjust_light_source (mapstruct *map, int x, int y, int light)
static void	restore_light_mask (mapstruct restore_map, mapstruct map, int x, int y, int mid)
void	check_light_source_list (mapstruct *map)
static void	remove_light_mask_other (mapstruct *map, int x, int y, int mid)
void	remove_light_source_list (mapstruct *map)
int	obj_in_line_of_sight (object obj, rv_vector rv)
Variables
static blocks	block [MAP_CLIENT_X][MAP_CLIENT_Y]
static int	lmask_x [MAX_MASK_SIZE]
static int	lmask_y [MAX_MASK_SIZE]
static int	light_mask [MAX_LIGHT_SOURCE+1]
static int	light_mask_width [NR_LIGHT_MASK]
static int	light_mask_size [NR_LIGHT_MASK]
static int	light_masks [NR_LIGHT_MASK][MAX_MASK_SIZE]

Detailed Description

Line of sight related functions.

Definition in file los.c.

Define Documentation

#define SPACE_BLOCK 0.5

Distance must be less than this for the object to be blocked. An object is 1.0 wide, so if set to 0.5, it means the object that blocks half the view (0.0 is complete block) will block view in our tables. .4 or less lets you see through walls. .5 is about right.

Definition at line 39 of file los.c.

Function Documentation

void adjust_light_source	(	mapstruct *	map,
		int	x,
		int	y,
		int	light
	)

Add or remove a light source to a map space. Adjust the light source map counter and apply the area of light it invokes around it.

Parameters:

map	The map of this light
x	X position of light
y	Y position of light
light	Glow radius of the light

Definition at line 754 of file los.c.

static void blinded_sight ( object * op ) [static]

Sets all viewable squares to blocked except for the central one that the player occupies. A little odd that you can see yourself (and what you're standing on), but really need for any reasonable game play.

Parameters:

op	Player's object for which to reset los.

Definition at line 475 of file los.c.

void check_light_source_list ( mapstruct * map )

Check light source list of specified map. This will also check all tiled maps attached to the map.

Parameters:

map	The map to check.

Definition at line 890 of file los.c.

static void check_wall	(	object *	op,
		int	x,
		int	y
	)		`[static]`

Used to initialize the array used by the LOS routines. Instead of light values, blocked_los[][] now tells the client update function what kind of tile we have: visible, sight blocked, blocksview trigger or out of map.

Parameters:

op	The player object
x	X position based on MAP_CLIENT_X
y	Y position based on MAP_CLIENT_Y

Definition at line 389 of file los.c.

void clear_los ( object * op )

Clears/initializes the LOS array associated to the player controlling the object.

Parameters:

op	The player object.

Definition at line 556 of file los.c.

static void expand_sight ( object * op ) [static]

This goes through the array of what the given player is able to see, and expands the visible area a bit, so the player will, to a certain degree, be able to see into corners. This is somewhat suboptimal, would be better to improve the formula.

Parameters:

op	The player object.

Todo:: Improve the formula.

Definition at line 571 of file los.c.

void init_block ( )

Initializes the array used by the LOS routines. This is NOT called for every LOS - only at server start to init the base block structure.

Since we are only doing the upper left quadrant, only these spaces could possibly get blocked, since these are the only ones further out that are still possibly in the sightline.

Definition at line 226 of file los.c.

int obj_in_line_of_sight	(	object *	obj,
		rv_vector *	rv
	)

Check if object is in line of sight, based on rv_vector. This will check also check for blocksview 1 objects.

Uses the Bresenham line algorithm.

Parameters:

obj	The object to check
rv	rv_vector to get distances, map, etc from

Returns:: 1 if in line of sight, 0 otherwise

Definition at line 1193 of file los.c.

void remove_light_source_list ( mapstruct * map )

Remove light sources list from a map.

Parameters:

map	The map to remove from

Definition at line 1166 of file los.c.

static void restore_light_mask	(	mapstruct *	restore_map,
		mapstruct *	map,
		int	x,
		int	y,
		int	mid
	)		`[static]`

After loading a map, we check here all possible connected maps for overlapping light sources. When we find one, we add the overlapping area to our new loaded map.

Parameters:

restore_map	Map to restore from
map	Map
x	X position
y	Y position
mid	Light value

Definition at line 834 of file los.c.

void set_block	(	int	x,
		int	y,
		int	bx,
		int	by
	)

Used to initialize the array used by the LOS routines. What this sets if that x, y blocks the view of bx, by This then sets up a relation - for example, something at 5, 4 blocks view at 5, 3 which blocks view at 5, 2 etc. So when we check 5, 4 and find it block, we have the data to know that 5, 3 and 5, 2 and 5, 1 should also be blocked.

Parameters:

x	X position
y	Y position
bx	Blocked X position
by	Blocked Y position

Definition at line 312 of file los.c.

static void set_wall	(	object *	op,
		int	x,
		int	y
	)		`[static]`

Used to initialize the array used by the LOS routines. x, y are indexes into the blocked[][] array. This recursively sets the blocked line of sight view. From the blocked[][] array, we know for example that if some particular space is blocked, it blocks the view of the spaces 'behind' it, and those blocked spaces behind it may block other spaces, etc. In this way, the chain of visibility is set.

Parameters:

op	Player object
x	X position
y	Y position

Definition at line 346 of file los.c.

void update_los ( object * op )

Recalculates the array which specifies what is visible for the given player object.

Parameters:

op	The player object

Definition at line 494 of file los.c.

Variable Documentation

int light_mask[MAX_LIGHT_SOURCE+1] [static]

Initial value:

{
    0,
    1,
    2, 3,
    4, 5, 6, 6,
    7, 7, 8, 8,
    8, 9
}

Definition at line 68 of file los.c.

int light_mask_size[NR_LIGHT_MASK] [static]

Initial value:

{
    0, 9, 25, 25, 49,
    49, 49, 81, 81, 81
}

Definition at line 84 of file los.c.

int light_mask_width[NR_LIGHT_MASK] [static]

Initial value:

{
    0, 1, 2, 2, 3,
    3, 3, 4, 4, 4
}

Definition at line 78 of file los.c.

int lmask_x[MAX_MASK_SIZE] [static]

Initial value:

{
    0, 0, 1, 1, 1, 0, -1, -1, -1, 0, 1, 2, 2, 2, 2, 2, 1, 0, -1, -2, -2, -2, -2, -2, -1,
    0, 1, 2, 3, 3, 3, 3, 3, 3, 3, 2, 1, 0, -1, -2, -3, -3, -3, -3, -3, -3, -3, -2, -1,
    0, 1, 2, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 3, 2, 1, 0, -1, -2, -3, -4, -4, -4, -4, -4, -4, -4, -4, -4, -3, -2, -1
}

Definition at line 54 of file los.c.

int lmask_y[MAX_MASK_SIZE] [static]

Initial value:

{
    0, -1, -1, 0, 1, 1, 1, 0, -1, -2, -2, -2, -1, 0, 1, 2, 2, 2, 2, 2, 1, 0, -1, -2, -2,
    -3, -3, -3, -3, -2, -1, 0, 1, 2, 3, 3, 3, 3, 3, 3, 3, 2, 1, 0, -1, -2, -3, -3, -3,
    4, 4, 4, 4, 4, 3, 2, 1, 0, -1, -2, -3, -4, -4, -4, -4, -4, -4, -4, -4, -4, -3, -2, -1, 0, 1, 2, 3, 4, 4, 4, 4
}

Definition at line 61 of file los.c.

Data Structures

Defines

Typedefs

Functions

Variables

Detailed Description

Define Documentation

Function Documentation

Variable Documentation