[ViewVC] Contents of: cvs/deliantra/server/doc/Developers/regions

Included herein is a description of the Region system, as implemented in March 2005.

If by the time you read this, this date is old, then this file may not have been kept
up to date, either that or no relevant changes have occurred, the Changelog should help
you determine which is the case.

*****Contents*****

How to read this file
Overview
Struct values and meaning
Sample region file entry and meaning.
Functions exposed and purpose thereof
player visible changes
Known/suspected bugs.
Future plans

*****How to read this file*****

If you are a mapper and want to create a new region for your maps
read: 
Overview 
Sample region file entry and meaning.

If you want to add new features to regions, read 
Struct values and meaning.
Known/suspected bugs.
Future plans
maybe the rest if you can be bothered.

If you are developing something else and want to interact with region information read:
Functions exposed and purpose thereof
Known/suspected bugs.

If you are merely a curious player who stumbled upon this by accident, read:
player visible changes
and, if you care enough...
Future plans

*****Overview*****
Regions are connected to maps, they allow a set of common properties to be associated with
the maps in the game.
The map struct has had a pointer to a region struct added. This pointer points to the region
that the map is in. 

The map files are altered to have a new field in the header

The line should read
region name

where 'name' is the name of a region defined in the regions file.

The maps are linked to their regions at load time.

Each region is guaranteed only to have 3 values, a name, next and a parent
 exception to this, there is a base region with a NULL parent pointer, this should have *all*
 other fields defined, if a region doesn't have a field defined, then it traverses up the
 inheritance tree, until it finds a definition of the field.
 
Look to the next section to see what the values stored in the region are.
 
Example of this.
region world, this is the base region, with no parent.
region scorn, this has parent world, and longname "Kingdom of scorn"
        it has msg "you are in scorn"
region scornoldcity, this has parent scorn, and no longname, it has msg
        "you are under scorn"

if we call get_region_msg(region) with scornoldcity as the region, it will return
"you are under scorn"
if we call get_region_longname(region) with scornoldcity as the region, it will return
"Kingdom of scorn"

This means that any combination of values can be used scoped appropriately.

Next the values themselves....

*****Struct Values and Meaning*****
This contains a list of the information about the regions and what the fields mean.
*next; 
 we construct a singly-linked list of regions, to check all, you go through one by one
 calling region->next until such time as next is NULL. This is the same as the way most
 other structures in the game work.

*name
 This field is compulsory, it is the name of the region, which is used to connect the maps to the
 regions.

*parent_name
 This is the name of the parent, only used during initialisation
 
*parent
 pointer to the parent region.
 
*longname
 The title of the region, this should be the full, verbose title, with lots of pompousness
 
*counter
 This doesn't really have a fixed meaning, it is just somewhere to count things 
 (at the moment the number of players)
 
*msg
 The description of the region, think guidebook entry.
 Displayed to provide some background flavour.
 
*fallback
 If a map has a misspelling, say scron instead of scorn, then we can't match the name.
 One region should have this set, so that the map can still be assigned a region
 until such time the map creator learns to spell.

*****Sample Regions file entry*****

region scorn
longname The Kingdom of Scorn
msg
Nestled snugly in a sheltered bay at the west of the Imperial Highway, etc
endmsg
parent world
end

Here we see a relatively high level region, it has a longname, that is the title of the kingdom
It has a description, and a parent.
the region is called scorn, and all maps containing the line 'region scorn' will be in this region

The msg field (description) is contained within the lines msg and endmsg
NB see Known Bugs section about this...

The other line that it could have contained was 
fallback 1
this would've made it the default region for maps with no region set.
However Scorn isn't a sensible choice for this.

Each entry in the regions file is finished with a line saying
end

The regions file stops being parsed when a line saying 
nomore

is encountered.

*****Functions exposed and purpose thereof*****

The following functions are currently accessible, this list is still fluid, expect it to change.

Note, I am describing the functions' specification, what they should be doing, look at the 
source code to see what they /are/ doing....

extern char *get_region_longname(region *r);
        returns the longname that the region should use

extern char *get_region_msg(region *r);
        returns the description of the region.

extern region *get_region_by_name(char *region_name);
        given a name returns the region with that name, or the fallback if there isn't one.
        Used by the map loader and stuff using get_name_of_region_for_map at the moment.
        
extern int region_is_child_of_region(region *child, region *r);
        1 if the child is a subregion of r
        0 otherwise

extern region *get_region_from_string(char *name);
        tries to guess which region 'name' corresponds to

extern region *get_region_by_map(mapstruct *m);
        takes a map returns the region it is in.

extern char *get_name_of_region_for_map(mapstruct *m);
        takes a map and returns the name of the region it is in.
        
extern void parse_regions();
        used to load the values for the regions at startup
        called by init regions, may end up being called during runtime if region updating is added.
        
extern void init_regions();
        calls parse regions, performs some checks beforehand.
        called by the startup code.
        
extern region *get_region_struct();
        calloc's a new region struct and blanks it for use
        shouldn't really be used externally yet (maybe later though)
        
extern void assign_region_parents();
        called after parse regions, makes the child regions find their parents.
        shouldn't be called externally yet (maybe later though)
        
*****Player visible changes*****

The command mapinfo now returns the region name (not longname, but what is included in the map file)

There is a command whereami that prints the regions name and description.

There is a command whereabouts that shows region names and the number of players there.

who can be given regions as arguments, and only show the players in that region.

*****Known/suspected bugs*****

Random maps probably don't get their regions set properly (though I am not quite sure what
 'properly' should be here).

The region parser is not particularly robust, it dies if the 'endmsg' line is missing, 
or if 'nomore' is missing, or if the 'end' line is missing. These stop the server from
starting, if it starts, it should be fine afterwards.

*****Future plans*****

medium term:

Have the regions file 'compiled' in the same way the archetypes are.

Limit word of recall's range based upon region, add a default savebed to each region, 
and store in the player the savebeds for each region. 

add a 'capabilities' field to the region, defining what the region can do. eg, 
limits_word_of_recall, if set then casting Word of recall takes to the savebed for 
that region, otherwise for the parent region.

Long term:

All sorts of other things, regional leaders, governments, economies, justice systems, 
wars, import restrictions, citizenship, etc, etc

Look on CFMB for some of the things that have been suggested.
Revision:	1.1
Committed:	Fri Feb 3 07:12:35 2006 UTC (18 years, 5 months ago) by root
Branch:	MAIN
Branch point for:	UPSTREAM
Log Message:	Initial revision
#	Content
1	Included herein is a description of the Region system, as implemented in March 2005.
2
3	If by the time you read this, this date is old, then this file may not have been kept
4	up to date, either that or no relevant changes have occurred, the Changelog should help
5	you determine which is the case.
6
7	***Contents***
8
9	How to read this file
10	Overview
11	Struct values and meaning
12	Sample region file entry and meaning.
13	Functions exposed and purpose thereof
14	player visible changes
15	Known/suspected bugs.
16	Future plans
17
18	***How to read this file***
19
20	If you are a mapper and want to create a new region for your maps
21	read:
22	Overview
23	Sample region file entry and meaning.
24
25	If you want to add new features to regions, read
26	Struct values and meaning.
27	Known/suspected bugs.
28	Future plans
29	maybe the rest if you can be bothered.
30
31	If you are developing something else and want to interact with region information read:
32	Functions exposed and purpose thereof
33	Known/suspected bugs.
34
35	If you are merely a curious player who stumbled upon this by accident, read:
36	player visible changes
37	and, if you care enough...
38	Future plans
39
40	***Overview***
41	Regions are connected to maps, they allow a set of common properties to be associated with
42	the maps in the game.
43	The map struct has had a pointer to a region struct added. This pointer points to the region
44	that the map is in.
45
46	The map files are altered to have a new field in the header
47
48	The line should read
49	region name
50
51	where 'name' is the name of a region defined in the regions file.
52
53	The maps are linked to their regions at load time.
54
55	Each region is guaranteed only to have 3 values, a name, next and a parent
56	exception to this, there is a base region with a NULL parent pointer, this should have all
57	other fields defined, if a region doesn't have a field defined, then it traverses up the
58	inheritance tree, until it finds a definition of the field.
59
60	Look to the next section to see what the values stored in the region are.
61
62	Example of this.
63	region world, this is the base region, with no parent.
64	region scorn, this has parent world, and longname "Kingdom of scorn"
65	it has msg "you are in scorn"
66	region scornoldcity, this has parent scorn, and no longname, it has msg
67	"you are under scorn"
68
69	if we call get_region_msg(region) with scornoldcity as the region, it will return
70	"you are under scorn"
71	if we call get_region_longname(region) with scornoldcity as the region, it will return
72	"Kingdom of scorn"
73
74	This means that any combination of values can be used scoped appropriately.
75
76	Next the values themselves....
77
78	***Struct Values and Meaning***
79	This contains a list of the information about the regions and what the fields mean.
80	*next;
81	we construct a singly-linked list of regions, to check all, you go through one by one
82	calling region->next until such time as next is NULL. This is the same as the way most
83	other structures in the game work.
84
85	*name
86	This field is compulsory, it is the name of the region, which is used to connect the maps to the
87	regions.
88
89	*parent_name
90	This is the name of the parent, only used during initialisation
91
92	*parent
93	pointer to the parent region.
94
95	*longname
96	The title of the region, this should be the full, verbose title, with lots of pompousness
97
98	*counter
99	This doesn't really have a fixed meaning, it is just somewhere to count things
100	(at the moment the number of players)
101
102	*msg
103	The description of the region, think guidebook entry.
104	Displayed to provide some background flavour.
105
106	*fallback
107	If a map has a misspelling, say scron instead of scorn, then we can't match the name.
108	One region should have this set, so that the map can still be assigned a region
109	until such time the map creator learns to spell.
110
111	***Sample Regions file entry***
112
113	region scorn
114	longname The Kingdom of Scorn
115	msg
116	Nestled snugly in a sheltered bay at the west of the Imperial Highway, etc
117	endmsg
118	parent world
119	end
120
121	Here we see a relatively high level region, it has a longname, that is the title of the kingdom
122	It has a description, and a parent.
123	the region is called scorn, and all maps containing the line 'region scorn' will be in this region
124
125	The msg field (description) is contained within the lines msg and endmsg
126	NB see Known Bugs section about this...
127
128	The other line that it could have contained was
129	fallback 1
130	this would've made it the default region for maps with no region set.
131	However Scorn isn't a sensible choice for this.
132
133	Each entry in the regions file is finished with a line saying
134	end
135
136	The regions file stops being parsed when a line saying
137	nomore
138
139	is encountered.
140
141	***Functions exposed and purpose thereof***
142
143	The following functions are currently accessible, this list is still fluid, expect it to change.
144
145	Note, I am describing the functions' specification, what they should be doing, look at the
146	source code to see what they /are/ doing....
147
148	extern char get_region_longname(region r);
149	returns the longname that the region should use
150
151	extern char get_region_msg(region r);
152	returns the description of the region.
153
154	extern region get_region_by_name(char region_name);
155	given a name returns the region with that name, or the fallback if there isn't one.
156	Used by the map loader and stuff using get_name_of_region_for_map at the moment.
157
158	extern int region_is_child_of_region(region child, region r);
159	1 if the child is a subregion of r
160	0 otherwise
161
162	extern region get_region_from_string(char name);
163	tries to guess which region 'name' corresponds to
164
165	extern region get_region_by_map(mapstruct m);
166	takes a map returns the region it is in.
167
168	extern char get_name_of_region_for_map(mapstruct m);
169	takes a map and returns the name of the region it is in.
170
171	extern void parse_regions();
172	used to load the values for the regions at startup
173	called by init regions, may end up being called during runtime if region updating is added.
174
175	extern void init_regions();
176	calls parse regions, performs some checks beforehand.
177	called by the startup code.
178
179	extern region *get_region_struct();
180	calloc's a new region struct and blanks it for use
181	shouldn't really be used externally yet (maybe later though)
182
183	extern void assign_region_parents();
184	called after parse regions, makes the child regions find their parents.
185	shouldn't be called externally yet (maybe later though)
186
187	***Player visible changes***
188
189	The command mapinfo now returns the region name (not longname, but what is included in the map file)
190
191	There is a command whereami that prints the regions name and description.
192
193	There is a command whereabouts that shows region names and the number of players there.
194
195	who can be given regions as arguments, and only show the players in that region.
196
197	***Known/suspected bugs***
198
199	Random maps probably don't get their regions set properly (though I am not quite sure what
200	'properly' should be here).
201
202	The region parser is not particularly robust, it dies if the 'endmsg' line is missing,
203	or if 'nomore' is missing, or if the 'end' line is missing. These stop the server from
204	starting, if it starts, it should be fine afterwards.
205
206	***Future plans***
207
208	medium term:
209
210	Have the regions file 'compiled' in the same way the archetypes are.
211
212	Limit word of recall's range based upon region, add a default savebed to each region,
213	and store in the player the savebeds for each region.
214
215	add a 'capabilities' field to the region, defining what the region can do. eg,
216	limits_word_of_recall, if set then casting Word of recall takes to the savebed for
217	that region, otherwise for the parent region.
218
219	Long term:
220
221	All sorts of other things, regional leaders, governments, economies, justice systems,
222	wars, import restrictions, citizenship, etc, etc
223
224	Look on CFMB for some of the things that have been suggested.