WML Utilities
From The Battle for Wesnoth Wiki
Contents
Filter by Terrain
# Check whethers or not the terrain in the given coordinates is of the given
# type or types. Filtering by terrain isn't possible directly.
#
# You can use it for example like this:
#
# [event]
# name=moveto
# first_time_only=no
#
# {IF_TERRAIN $x1 $y1 Gg,Gs^Fp,Mm (
# [then]
# {DEBUG_MSG "Stepped on grassland, forest or mountains!"}
# [/then]
# )}
# [/event]
#define IF_TERRAIN X Y TERRAIN CONTENTS
[store_locations]
x={X}
y={Y}
terrain={TERRAIN}
variable=IF_TERRAIN_temp
[/store_locations]
[if]
[variable]
name=IF_TERRAIN_temp.length
not_equals=0
[/variable]
{CONTENTS}
[/if]
{CLEAR_VARIABLE IF_TERRAIN_temp}
#enddef
Iterate
# You can iterate through a range of numbers with this macro. The CONTENTS
# are repeated with every iteration, and you can use the VAR variable to
# insert the number of the current step into each iteration. Note that
# when using this, you must iterate from a smaller number to the bigger
# number, because the increment is always 1.
#
# Example that spawns a row of skeletons into the coordinates (4,5),
# (5,5), (6,5), (7,5), (8,5) and (9,5):
#
# {ITERATE 4 9 i (
# [unit]
# type=Skeleton
# x=$i
# y=5
# [/unit]
# )}
#define ITERATE FROM TO VAR CONTENTS
{VARIABLE {VAR} {FROM}}
[while]
[variable]
name={VAR}
less_than_equal_to={TO}
[/variable]
[do]
{CONTENTS}
{VARIABLE_OP {VAR} add 1}
[/do]
[/while]
#enddef
Adding unit overlays with a filter instead of (x,y)
# UNIT_OVERLAY adds an overlay to a unit, taking in a standard filter
#
# Example that gives all spearmen a book:
# {UNIT_OVERLAY type=Spearman items/book1.png}
#define UNIT_OVERLAY FILTER IMG
[store_unit]
[filter]
{FILTER}
[/filter]
variable=UNIT_OVERLAY_store
kill=no
[/store_unit]
{FOREACH UNIT_OVERLAY_store UNIT_OVERLAY_i}
{VARIABLE_OP UNIT_OVERLAY_tempx format $UNIT_OVERLAY_store[$UNIT_OVERLAY_i].x}
{VARIABLE_OP UNIT_OVERLAY_tempy format $UNIT_OVERLAY_store[$UNIT_OVERLAY_i].y}
[unit_overlay]
x=$UNIT_OVERLAY_tempx
y=$UNIT_OVERLAY_tempy
image={IMG}
[/unit_overlay]
{NEXT UNIT_OVERLAY_i}
{CLEAR_VARIABLE UNIT_OVERLAY_store}
#enddef
Determining opposite coordinates
# Using this, you can determine the coordinates on the "opposite side" of a
# central hex, relative to another hex adjacent to it. What this really means
# is illustrated below:
# __ __ __
# __/ \__ __/2 \__ __/ \__
# / \__/1 \ / \__/ \ /2 \__/ \ C: central point
# \__/C \__/ \__/C \__/ \__/C \__/ 1: the hex to "mirror"
# /2 \__/ \ / \__/ \ / \__/1 \ 2: the result
# \__/ \__/ \__/1 \__/ \__/ \__/
# \__/ \__/ \__/
#
# The coordinates of the central point are given in {CENTER_X} and {CENTER_Y},
# and the coordinates of hex 1 in {X} and {Y}. The coordinates of hex 2 are
# then stored in {VAR}, which will have member variables x and y.
#
# Note that this uses the IF macro given earlier on this page.
#define OPPOSITE_SIDE CENTER_X CENTER_Y X Y VAR
{VARIABLE x_odd {X}}
{VARIABLE_OP x_odd modulo 2}
{VARIABLE c_x {CENTER_X}}
{VARIABLE c_y {CENTER_Y}}
{VARIABLE s_x {X}}
{VARIABLE s_y {Y}}
{VARIABLE result_x {CENTER_X}}
{VARIABLE result_y {CENTER_Y}}
{IF_VAR s_x greater_than $c_x (
[then]
{VARIABLE_OP result_x add -1}
[/then]
)}
{IF_VAR s_x less_than $c_x (
[then]
{VARIABLE_OP result_x add 1}
[/then]
)}
{IF_VAR s_x equals $c_x (
[then]
{IF_VAR s_y less_than $c_y (
[then]
{VARIABLE_OP result_y add 1}
[/then]
)}
{IF_VAR s_y greater_than $c_y (
[then]
{VARIABLE_OP result_y add -1}
[/then]
)}
[/then]
)}
{IF_VAR x_odd equals 1 (
[then]
{IF_VAR s_y equals $c_y (
[then]
{VARIABLE_OP result_y add 1}
[/then]
)}
[/then]
[else]
{IF_VAR s_y equals $c_y (
[then]
{VARIABLE_OP result_y add -1}
[/then]
)}
[/else]
)}
{VARIABLE {VAR}.x $result_x}
{VARIABLE {VAR}.y $result_y}
{CLEAR_VARIABLE c_x}
{CLEAR_VARIABLE c_y}
{CLEAR_VARIABLE s_x}
{CLEAR_VARIABLE s_y}
{CLEAR_VARIABLE result_x}
{CLEAR_VARIABLE result_y}
{CLEAR_VARIABLE x_odd}
#enddef
Find nearest hex(es)
#define FIND_NEARBY FILTER X Y LIMIT
# Does a search for a nearby location that matches the given filter.
# Basically just looks for such a location with increasing radius until it
# finds at least one. This is sadly inefficient, but implementing BFS in
# WML is... difficult. Once LIMIT is reached, the entire map is searched.
# This macro creates the 'nearby_locations' and 'nearby_distance'
# variables, which can be used to access a list of locations found and the
# distance to those locations, respectively. They should eventually be
# cleared, which can be accomplished using the CLEANUP_SEARCH macro.
[clear_variable]
name=nearby_locations
[/clear_variable]
[set_variable]
name=nearby_distance
value=0
[/set_variable]
[while]
[not]
[variable]
name=nearby_locations.length
greater_than=0
[/variable]
[/not]
[and]
[variable]
name=nearby_distance
less_than={LIMIT}
[/variable]
[/and]
[do]
{DEBUG "Searching depth $nearby_distance around ({X}, {Y})..."}
[store_locations]
variable=nearby_locations
{FILTER}
[and]
x,y={X},{Y}
radius=$nearby_distance
[/and]
[/store_locations]
{DEBUG "...found $nearby_locations.length locations."}
[set_variable]
name=nearby_distance
add=1
[/set_variable]
[/do]
[/while]
[if]
[variable]
name=nearby_locations.length
equals=0
[/variable]
[then]
[store_locations]
variable=nearby_locations
{FILTER}
[/store_locations]
[/then]
[/if]
#enddef
#define CLEANUP_SEARCH
# Clears variables involved in searching (the FIND_NEARBY macro). Put this
# in your name=victory,defeat tag to clean up if you use FIND_NEARBY within
# a scenario.
[clear_variable]
name=nearby_locations, nearby_distance
[/clear_variable]
#enddef