wyvern.kernel.maps
Class Frame

java.lang.Object
  wyvern.kernel.maps.Frame

All Implemented Interfaces:

DisplayPolicy, LightingConstants, Visitor

Direct Known Subclasses:

EyeFrame

public class Frame

extends java.lang.Object

implements DisplayPolicy, Visitor, LightingConstants

This is the DisplayPolicy implementation that handles sending map updates to the client map view. Each MapCamera in the game has one Frame object (at a time) for gathering the updates.

When it's time to gather the frame data, a DisplayPolicy is given a set of invalid map rectangles. It's the DisplayPolicy's responsibility to query the map for the information needed to generate a "snapshot" of the map for the client.

This DisplayPolicy implementation gets all the map objects in its invalid regions and sorts them into "buckets" based on their DrawingLayer properties. The Frame decides how many objects in each layer to send to the client. For some layers it may be only one; for other layers it may choose to send 2 or more objects per cell.

The Frame will provide a mechanism for "input filters" to filter the object stream coming from the map. This is the way, for example, that the visibility and lighting-model computations are merged into the data that goes to the client.

Version:

1.0, Aug 28, 1997, 1.1, Sept 7, 1998

Author:

Steve Yegge

Nested Class Summary

protected class

Frame.VisibilityConstants Basically we hardcode all the properties on the agent that affect what they can see.

Field Summary

protected Commandable	agent_
protected short[]	allTerrain_ A packed 2D array for sending over all the terrain.
protected wyvern.kernel.lighting.RayShadowCaster	caster_
protected boolean	completeUpdate_ Set to true when visiting map objects during a complete frame refresh, false when doing a partial refresh.
protected java.util.HashSet	frameCache_
protected boolean	handheld_ True if player is playing on a PDA.
protected int	height_
protected boolean	lightOff_
protected GameMap	map_
protected int	nightVision_ The amount to add to the light level based on racial night vision.
protected java.util.ArrayList	objects_ This set contains a "sparse array" of the objects to send to the client.
protected java.util.HashMap	terrain_ Information about the terrain & borders - used for smaller updates where the whole view isn't being sent over.
protected int[][]	terrainInfo_ A 2D array of terrain records used in drawing borders.
protected BitMatrix	updateMap_
protected int	viewx_
protected int	viewy_
protected Frame.VisibilityConstants	visCache_ This is an optimization, plain and simple.
protected int	width_

Fields inherited from interface wyvern.lib.properties.LightingConstants

DARKNESS, DAYLIGHT, DIM, DUSK, GLOOM, NUM_SHADES, SHADED, TWILIGHT

Constructor Summary

Frame(Commandable agent)
Constructs a new Frame object with a default 1x1 bounding rectangle, anchored at (0, 0) in the map.

Frame(Commandable agent, int x, int y, int width, int height)
Constructs a new Frame object with the specified bounds.

Method Summary

protected void	add(GameObject obj) Adds an object to the specified layer in the snapshot.
protected void	addDescriptor(int x, int y, int layer, int tile, GameObject obj, int alpha) Adds an object appearance descriptor to the sorted frame list.
void	addObject(GameObject obj) Adds an object to the frame.
void	addTerrain(int x, int y) Adds a terrain object.
void	addUpdateRegions(MapDirtyRegions updates) Adds in all the cells in the map that have become invalid since this method was last called.
protected void	cacheVisFlags() Looks up any properties on the agent we need in advance, and remembers them.
boolean	canSee(int x, int y) Returns true if the player has a clear line of sight to this square.
boolean	checkAdd(GameObject obj) Returns true if this object should be added to the snapshot.
protected int	computeDistance(int x, int y) Computes the distance from the passed point to the caster.
protected int	computeNightVision(int distance) Returns the lighting level contribution from night vision.
protected boolean	computeXRayVision(int distance) Returns true if the agent's x-ray vision allows them to see this point regardless of line-of-sight.
void	discardChanges() Discards any information the frame is currently caching.
void	doRayCast() Invokes a raycaster to see what's visible to the frame.
static java.lang.String	getProfilingInfo() Returns a profiling string.
java.lang.Object[]	getSparseTerrainInfo() Returns information about the terrain in, and immediately adjacent to, the update rectangles.
int[][]	getTerrainInfo() Returns the array of terrain records produced in the last call to grabAll().
void	grabAll() Grabs the entire view from the map.
boolean	grabLight(int x, int y) Grabs the lighting tile at (x, y).
boolean	grabLocation(int tcol, int trow) Grabs all the objects at the given map location and adds their appearances to the frame.
void	grabObjects() This is called by the CameraManager to tell the Frame which regions of the camera have become invalid, so it can refresh them.
boolean	isHandheld() Returns true if player is playing on a handheld device.
short[]	makeSparseArray() Returns an array of the objects to draw in the client view.
void	printSparseTree() Prints all the objects in the tree (debugging method).
void	setBounds(int x, int y, int w, int h, GameMap map) Sets the bounds of the frame.
void	setBounds(int x, int y, int w, int h, GameMap map, boolean raycast) Sets the bounds of the frame.
void	setHandheld(boolean handheld) Sets whether we're playing on a handheld.
static short	stuffPoint(short x, short y) Stuffs two short values ( which must each be < 256 ) into a single short value with x in the high byte and y in the low byte.
void	visit(GameObject obj) Visits an object in the map and puts its appearance in the frame.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

viewx_

protected int viewx_

viewy_

protected int viewy_

width_

protected int width_

height_

protected int height_

map_

protected GameMap map_

updateMap_

protected BitMatrix updateMap_

lightOff_

protected boolean lightOff_

terrain_

protected java.util.HashMap terrain_

Information about the terrain & borders - used for smaller updates where the whole view isn't being sent over. Each square that needs to be updated has a little 3x3 array of terrain "records" containing neighboring border information.

allTerrain_

protected short[] allTerrain_

A packed 2D array for sending over all the terrain.

terrainInfo_

protected int[][] terrainInfo_

A 2D array of terrain records used in drawing borders. Replaces allTerrain_ when borders are turned on in the client.

frameCache_

protected java.util.HashSet frameCache_

objects_

protected java.util.ArrayList objects_

This set contains a "sparse array" of the objects to send to the client. They're sorted in three dimensions: first on Z-depth (i.e. drawing layer), next horizontally, then vertically. Each element of the set is an ObjDescriptor containing the data to send to the client, including the bitmap tile number and the x/y view offsets at which to draw the bitmap.

completeUpdate_

protected boolean completeUpdate_

Set to true when visiting map objects during a complete frame refresh, false when doing a partial refresh.

caster_

protected wyvern.kernel.lighting.RayShadowCaster caster_

visCache_

protected Frame.VisibilityConstants visCache_

This is an optimization, plain and simple. I don't want to have to do property lookups on the player/monster for every single object we're visiting - it's expensive. So before I start iterating over the objects, I look up all the built-in visibility properties I've hardcoded into this crappy implementation, and store them as flags on this object for quick lookup.

agent_

protected Commandable agent_

nightVision_

protected int nightVision_

The amount to add to the light level based on racial night vision.

handheld_

protected boolean handheld_

True if player is playing on a PDA.

Constructor Detail

Frame

public Frame(Commandable agent)

Constructs a new Frame object with a default 1x1 bounding rectangle, anchored at (0, 0) in the map. The caller should use setBounds() to change the frame bounds before using it.

Frame

public Frame(Commandable agent,
             int x,
             int y,
             int width,
             int height)

Constructs a new Frame object with the specified bounds.

Parameters:

x - the left (x) coord of the snapshot (in world coords)

y - the top (y) coord of the snapshot (in world coords)

width - the width of the snapshot we're taking

height - the height of the snapshot we're taking

Method Detail

grabObjects

public void grabObjects()

This is called by the CameraManager to tell the Frame which regions of the camera have become invalid, so it can refresh them.

The Frame implementation gets a Visitor and visits the map at all the invalid spots. It also gathers the terrain. The data is sorted into drawing layers for the client.

Before calling this method, the MapCamera must add all the invalid rectangles to the Frame with calls to addUpdateRect(), so the frame knows what map squares to visit.

Specified by:

grabObjects in interface DisplayPolicy

grabLocation

public boolean grabLocation(int tcol,
                            int trow)

Grabs all the objects at the given map location and adds their appearances to the frame.

Parameters:

tcol - map x location (in map coordinate space)

trow - map y location (in map coordinate space)

Returns:

true if we could see this location

grabLight

public boolean grabLight(int x,
                         int y)

Grabs the lighting tile at (x, y).

Parameters:

x - map x location

y - map y location

Returns:

true if we're drawing a completely dark tile at this location (i.e. player can't see there)

computeNightVision

protected int computeNightVision(int distance)

Returns the lighting level contribution from night vision. Only takes into account the point's distance from the agent,

Parameters:

distance - the distance from the point to the agent

Returns:

how much to add to the lighting level at this point

computeXRayVision

protected boolean computeXRayVision(int distance)

Returns true if the agent's x-ray vision allows them to see this point regardless of line-of-sight.

Parameters:

distance - the distance from the agent to the point

Returns:

true if they can see it via x-ray vision

computeDistance

protected int computeDistance(int x,
                              int y)

Computes the distance from the passed point to the caster.

Parameters:

x - map x

y - map y

Returns:

distance

grabAll

public void grabAll()

Grabs the entire view from the map. Called when camera is completely invalid.

Specified by:

grabAll in interface DisplayPolicy

doRayCast

public void doRayCast()

Invokes a raycaster to see what's visible to the frame.

Specified by:

doRayCast in interface DisplayPolicy

visit

public void visit(GameObject obj)

Visits an object in the map and puts its appearance in the frame.

Specified by:

visit in interface Visitor

Parameters:

obj - the object (a GameObject) to examine

addObject

public void addObject(GameObject obj)

Adds an object to the frame. Calls checkAdd() to see if it wants the object; subclasses can override checkAdd() if they like. This is a callback for the Visitor that the Frame employs to get its objects.

Parameters:

obj - the object to consider for adding

setBounds

public void setBounds(int x,
                      int y,
                      int w,
                      int h,
                      GameMap map,
                      boolean raycast)

Sets the bounds of the frame. (Tells the frame where the camera is currently looking.)

Specified by:

setBounds in interface DisplayPolicy

Parameters:

x - map x

y - map y

w - view width

h - view height

map - the map

raycast - true to do a raycast

setBounds

public void setBounds(int x,
                      int y,
                      int w,
                      int h,
                      GameMap map)

Sets the bounds of the frame. (Tells the frame where the camera is currently looking.)

Specified by:

setBounds in interface DisplayPolicy

Parameters:

x - map x

y - map y

w - view width

h - view height

map - the map

discardChanges

public void discardChanges()

Discards any information the frame is currently caching. Used when the frame is invalidated.

canSee

public boolean canSee(int x,
                      int y)

Returns true if the player has a clear line of sight to this square.

Specified by:

canSee in interface DisplayPolicy

Parameters:

x - map x

y - map y

Returns:

true if their line of sight to (x, y) is unblocked

addUpdateRegions

public void addUpdateRegions(MapDirtyRegions updates)

Adds in all the cells in the map that have become invalid since this method was last called.

Specified by:

addUpdateRegions in interface DisplayPolicy

Parameters:

updates - a matrix, the size of the map, that has all areas that have become invalid in the map since the last camera refresh.

addTerrain

public void addTerrain(int x,
                       int y)

Adds a terrain object. Called by grabObjects() for each square that has become invalid since the last refresh.

We need to send over border information with the terrain, so for each square to be redrawn, we add a 3x3 int[][] of info (obtained from the map) so the client can draw the center square.

Parameters:

x - the x map location (not view location)

y - the y map location (not view location)

checkAdd

public boolean checkAdd(GameObject obj)

Returns true if this object should be added to the snapshot. Default implementation is for player client; it returns false if the object is invisible to the player.

Specified by:

checkAdd in interface DisplayPolicy

Parameters:

obj - the object to consider for adding

Returns:

true if the object is visible to the player, false if it's invisible. Note: use canSee() to see if the player has line-of-sight to the object. You really need to call both methods (this and canSee()) to determine whether a player can see a given object.

add

protected void add(GameObject obj)

Adds an object to the specified layer in the snapshot.

Parameters:

obj - the object (needed for hashcode comparison)

addDescriptor

protected void addDescriptor(int x,
                             int y,
                             int layer,
                             int tile,
                             GameObject obj,
                             int alpha)

Adds an object appearance descriptor to the sorted frame list.

Parameters:

x - map x

y - map y

layer - drawing layer

tile - tile number

obj - the object whose bitmap we're drawing. Can be null, if we're drawing some sort of effect (e.g. lighting level).

alpha - the transparency, 0-100

getTerrainInfo

public int[][] getTerrainInfo()

Returns the array of terrain records produced in the last call to grabAll().

getSparseTerrainInfo

public java.lang.Object[] getSparseTerrainInfo()

Returns information about the terrain in, and immediately adjacent to, the update rectangles.

Returns:

multiple return values stuffed into an Object array. The first entry in the array is a short[] of "stuffed" view coords at which to redraw the terrain. The second entry is an array (int[][][]) of 3x3 2D terrain descriptors, one per location in the short[].

stuffPoint

public static short stuffPoint(short x,
                               short y)

Stuffs two short values ( which must each be < 256 ) into a single short value with x in the high byte and y in the low byte.

Parameters:

x - a short value between -128 and 127

y - a short value between -128 and 127

Returns:

a short value with x in the high byte and y in the low byte

makeSparseArray

public short[] makeSparseArray()

Returns an array of the objects to draw in the client view. The array consists of pairs of short values, the first being the "stuffed" (x,y) view coordinates and the second being the tile number of the bitmap to draw. If the high bit is set, the following byte is the alpha level (0-100).

printSparseTree

public void printSparseTree()

Prints all the objects in the tree (debugging method).

cacheVisFlags

protected void cacheVisFlags()

Looks up any properties on the agent we need in advance, and remembers them.

isHandheld

public boolean isHandheld()

Returns true if player is playing on a handheld device.

Returns:

true if player is on a PDA

setHandheld

public void setHandheld(boolean handheld)

Sets whether we're playing on a handheld.

Parameters:

handheld - true if playing on a handheld

getProfilingInfo

public static java.lang.String getProfilingInfo()

Returns a profiling string.