WML Utilities
From The Battle for Wesnoth Wiki
Contents
General shortcuts
# MODIFY_UNIT alters a unit variable (such as unit.x, unit.type,
# unit.side), handling all the storing and unstoring.
#
# Example that flips all spearmen to side 2:
# {MODIFY_UNIT type=Spearman side 2}
#define MODIFY_UNIT FILTER VAR VALUE
[store_unit]
[filter]
{FILTER}
[/filter]
variable=MODIFY_UNIT_store
kill=yes
[/store_unit]
{FOREACH MODIFY_UNIT_store MODIFY_UNIT_i}
[set_variable]
name=MODIFY_UNIT_store[$MODIFY_UNIT_i].{VAR}
value={VALUE}
[/set_variable]
[unstore_unit]
variable=MODIFY_UNIT_store[$MODIFY_UNIT_i]
find_vacant=no
[/unstore_unit]
{NEXT MODIFY_UNIT_i}
{CLEAR_VARIABLE MODIFY_UNIT_store}
#enddef
# Shortcut for IF statements testing the value of a variable. You still need to
# write [then] and [else] tags manually, though.
#
# You can use it like this:
#
# {IF some_variable equals yes (
# [then]
# # something
# [/then]
#
# [else]
# # something else
# [/else]
# )}
#define IF VAR OP VAL CONTENTS
[if]
[variable]
name={VAR}
{OP}={VAL}
[/variable]
{CONTENTS}
[/if]
#enddef
# Just a variation of the above, testing [have_unit] instead of [variable].
#define IF_HAVE_UNIT FILTER CONTENTS [if] [have_unit] {FILTER} [/have_unit]
{CONTENTS} [/if] #enddef
# Stores an attribute of a unit to the given variable.
#
# Example that flips all orcs to whatever side James is on:
#
# {STORE_UNIT_VAR description=James side side_of_James}
# {MODIFY_UNIT race=orc side $side_of_James}
#define STORE_UNIT_VAR FILTER VAR TO_VAR
[store_unit]
[filter]
{FILTER}
[/filter]
kill=no
variable=STORE_UNIT_VAR_store
[/store_unit]
{VARIABLE_OP {TO_VAR} format $STORE_UNIT_VAR_store.{VAR}}
{CLEAR_VARIABLE STORE_UNIT_VAR_store}
#enddef
# Moves a unit from its current location to the given location along a
# relatively straight line displaying the movement just like [move_unit_fake]
# does.
#
# Note that setting the destination on an existing unit does not kill either
# one, but causes the unit to move to the nearest vacant hex instead.
#define MOVE_UNIT FILTER TO_X TO_Y
[store_unit]
[filter]
{FILTER}
[/filter]
variable=MOVE_UNIT_temp
kill=no
[/store_unit]
[scroll_to]
x=$MOVE_UNIT_temp.x
y=$MOVE_UNIT_temp.y
[/scroll_to]
[hide_unit]
x=$MOVE_UNIT_temp.x
y=$MOVE_UNIT_temp.y
[/hide_unit]
{VARIABLE_OP x_coords format ("$MOVE_UNIT_temp.x|,{TO_X}")}
{VARIABLE_OP y_coords format ("$MOVE_UNIT_temp.y|,{TO_Y}")}
[move_unit_fake]
type=$MOVE_UNIT_temp.type
x=$x_coords
y=$y_coords
[/move_unit_fake]
[teleport]
[filter]
{FILTER}
[/filter]
x,y={TO_X},{TO_Y}
[/teleport]
[unhide_unit][/unhide_unit]
[redraw][/redraw]
#enddef
# This is a way to check whether or not the terrain in the given coordinates
# is of the given type or types. Might be useful, since 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 $y1 gfm (
# [then]
# {DEBUG_MSG "Stepped on grassland, forest or mountains!"}
# [/then]
# )}
# [/event]
#define IF_TERRAIN X Y TYPES CONTENTS
[store_locations]
x={X}
y={Y}
terrain={TYPES}
variable=IF_TERRAIN_temp
[/store_locations]
[if]
[variable]
name=IF_TERRAIN_temp.length
not_equals=0
[/variable]
{CONTENTS}
[/if]
{CLEAR_VARIABLE IF_TERRAIN_temp}
#enddef
# You can iterate through a range of numbers with this macro. The CONTENTS
# are repeated with every iteration, and you can use the VAR variable to
# insert the number of the current step into each iteration. Note that
# when using this, you must iterate from a smaller number to the bigger
# number, because the increment is always 1.
#
# Example that spawns a row of skeletons into the coordinates (4,5),
# (5,5), (6,5), (7,5), (8,5) and (9,5):
#
# {ITERATE 4 9 i (
# [unit]
# type=Skeleton
# x=$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
More uncommon tasks
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
Returning a unit to the recall list
# This places a given unit back to the recall list of the side it is on.
# Note however, that the unit is not healed to full health, so when
# recalled (even if not until the next scenario) the unit may have less
# than his maximum hp left.
#
# An example, that returns all units stepping on (20,38) back to the recall
# list:
#
# [event]
# name=moveto
#
# [filter]
# x,y=20,38
# [/filter]
#
# {PUT_TO_RECALL_LIST x,y=20,38}
# [/event]
#define PUT_TO_RECALL_LIST FILTER
[store_unit]
[filter]
{FILTER}
[/filter]
variable=temp
kill=yes
[/store_unit]
{FOREACH temp i}
{VARIABLE temp[$i].x "recall"}
{VARIABLE temp[$i].y "recall"}
[unstore_unit]
variable=temp[$i]
find_vacant=no
[/unstore_unit]
{NEXT i}
#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 multiply 0.5}
{VARIABLE_OP x_odd multiply 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 s_x greater_than $c_x (
[then]
{VARIABLE_OP result_x add -1}
[/then]
)}
{IF s_x less_than $c_x (
[then]
{VARIABLE_OP result_x add 1}
[/then]
)}
{IF s_x equals $c_x (
[then]
{IF s_y less_than $c_y (
[then]
{VARIABLE_OP result_y add 1}
[/then]
)}
{IF s_y greater_than $c_y (
[then]
{VARIABLE_OP result_y add -1}
[/then]
)}
[/then]
)}
{IF x_odd not_equals $s_x (
[then]
{IF s_y equals $c_y (
[then]
{VARIABLE_OP result_y add 1}
[/then]
)}
[/then]
[else]
{IF 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