ReadingPatchVariables

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Introduction

Since 2.0.1 alpha 48, it has been possible to use action D to read various special Patch variables. These are usually switch values, but there are also a few other useful values.

Syntax

<Sprite-number> * <Length> 0D <target> <operation> <variable> FE FF FF 00 00
Element Size Description
0D B Defines action 0D
<target> B Target parameter
<operation> B As for ActionD, but only assignment is valid.
<variable> B Patch variable number to read. See below.
FE B Defines a special variable access
FF FF 00 00 D Indicates that a patch variable is being read

variable

The following patch variables are defined:

variable Switch Value
00 miscmods/-Yo Bit switch
01 experimentalfeatures/-XF Bit switch
02 morevehicles/-x Vehicle array multiplier
03 mountains&curves;/-mc Two bytes with four sets of two bits
04 planecrashcontrol/-Xc Bit switch
05 autorenew/-Xa Signed value
06 multihead/-M Speed increase, in percent
07 disasters/-XD Bit switch
08 unifiedmaglev/-XM Unified maglev mode
09 bridgespeedlimits/-XX Speed fraction, in percent
0A --- TTD Language, see the "new scheme" for action 4
0B startyear/-XY Year-1920
0C morebuildoptions/-YB Bit switch
0D moresteam/-YM value=LF (two hex digits), L=length, F=frequency
0E freighttrains/-Yf weight factor
0F wagonspeedlimits/-YL Speed increase for empty wagons
10 planespeed/-YP speed factor
11 dual company colors 2CC colormap base sprite (since r1404)
12 miscmods2/-Zm Bit switch (since r1738)
13 map size information Format = -MABXYSS (since r11961 and r1817)
M : the type of map
bit 0 set : squared map. Clear : rectangular map
bit 1 set : Y is the bigger edge(bit 0 is clear).Clear : X is the bigger edge.
A : minimum edge(log2) of the map
B : maximum edge(log2) of the map
XY : edges(log2) of each side of the map.
SS : combination of both X and Y, thus giving the size(log2) of the map
All map sizes will be substracted by 6, as to keep the size 64 the smallest one, thus zero based

If experimentalfeatures, miscmods, or miscmods2 are off, the corresponding value will be zero. For all other switches, the value is unspecified if the switch is off, so action 7 variable 85 should be checked first.