Action0/Bridges

Defining properties of bridges

Action 0 - Properties for bridges

Defining properties of bridges

-=ID Allocation=-

Since TTDPatch 2.6 alpha 0 rUnknown it's possible to use more than the default TTD bridges. All ids starting with 0x0D are id allocated and property 0x00 has to be set, otherwise the bridge will be ignored. As these bridges have no old type, all properties have to be set. Not yet available; it is currently not possible to use ids 0x0D and up.

-=Properties=-

||Number|Version|Size|Description

00|(d)|B|Failback Type, a default TTD Bridge ID

01|(d)|-|-reserved-

08*|(a)|B|Year of availability, counted from 1920 (set to 1920 for first bridge if newstartyear<1930)

09|(a)|B|Minimum length, not counting ramps

0A|(a)|B|Maximum length, not counting ramps

0B|(a)|B|Cost factor

0C|(a)|W|Max. speed

0D|(a)|V|Sprite layout, see below

0E|(a)|B|Various flags, bitcoded

0F|(b)|D|Long format year of availability, counted from year 0

10|(c)|W|Purchase text

11|(c)|W|Description of a rail bridge

12|(c)|W|Description of a road bridge|

13|(d)|W|cost factor word access||

<nowiki>*</nowiki> The meaning of prop. 08 has changed in alpha 34, it used to be what is now prop. 0D.

(a) Available since TTDPatch 2.0.1 alpha 34

(b) 2.5 r1702, OpenTTD r7191

(c) 2.5 r1824, OpenTTD r10269

(d) rUnknown, OpenTTD rUnknown, planned feature for id allocation

-=Comments=-

Sprite layout (0D)

Property 0D sets the sprite layout for bridges.  Each part of a bridge has eight sprites for each of the four types (rail, road, monorail, maglev), making 32 sprites in total.  Each bridge has 7 parts, though not all of them have different graphics.

The data for property 0D is variable sized, with the format being

||Size|Field|Description

B|tableid|First table to define sprites for

B|numtables|Number of tables to define sprites for

V|spritedata|spritedata, numtables*32 DWORDs with sprite numbers||

The tableid is the number of the first table to change.  There are seven tables for each bridge, with the first six (0-5) being various middle parts and the last one (6) being the end pieces.

In each of the six middle part tables, there are four entries each for the following:

• Rail X, Rail Y, Road X, Road Y, Monorail X, Monorail Y, Maglev X, Maglev Y

Where X is a bridge in /-direction and Y a bridge in \-direction.

The four entries are

• Back&Floor;, Front, Pillars, 0

Front and Pillars can be 0, meaning no sprite to draw.  The fourth entry is always ignored.

In the end part table, there are again four entries each, but now for ?* Rail flat, Rail ramp, Road flat, Road ramp, Monorail flat, Monorail ramp and Maglev flat, Maglev ramp.

The four entries in this case are

• northern end X, northern end Y, southern end X, southern end Y

The sprite numbers can be any of TTD's sprite numbers.

To summarize, there are 7 tables for each of the 11 bridges.  Each table contains 4*8 entries, making it 128 (80h) bytes large.  The first six tables, number 0 to 5, are middle pieces, the last table, number 6, is the end pieces.

Colour Translations

In order to recolour a bridge, you can add one of the values from the table below to the sprite number of the sprite you wish to recolour. The colour translations from the table will use the default colour translation tables from trg1(r).grf. These translation tables will translate the 'brownish red' as used in the default bridges (see trg1(r).grf) to the colour you specify.

||Added value|Little Endian|Colour

031B8000h|00 80 1B 03|Blue

031C8000h|00 80 1C 03|Brown

031D8000h|00 80 1D 03|Pure white

031E8000h|00 80 1E 03|Red

031F8000h|00 80 1F 03|Green

03208000h|00 80 20 03|Blueish white (concrete)

03218000h|00 80 21 03|Yellow (golden steel)

03238000h|00 80 23 03|Grey||

Example: Translate sprite 4366 to grey:

4366 translates to 0E 11 in little endian value and as such to 0E 11 00 00 in a dword. In order to convert to grey you'll have to add 00 80 23 03 to the dword value. This yields 0E 91 23 03. Use the latter in your bridge table to colour one of the monorail bridgeheads grey.

Advanced Technique You can also use the company colour blue to draw your bridges and use the default colour translation tables to recolour your bridge in any of the player colours. See the Action2HousesIndustryTiles page for information on the location of the colour translation tables.

Bridge Layouts

There are five possible bridge layouts in TTD. The numbers in the table below reflect the bridge table numbers in the NFO code.

||Layout|Description

--|Bridge without middle part

-0-|Bridge of length 3

-0(23)1-|Bridge of even length

-0(23)4(23)1-|Bridge of (uneven) lengths 5, 9, 13, 17 etc.

-0(23)253(23)1-|Bridge of (uneven) lengths 7, 11, 15, 19 etc.||

- is used as a symbol to indicate bridgeheads (as defined in table 6).

Part 0 is always at the farthest end from the viewer.

Parts (23) are repeated n times as necessary, where n is any number equal or greater than 0.

Flags (0E)

The following flags can be set here:

||Bit|Value|Meaning

0|1|Do not draw the far pillars for higher bridges||

Long format year of availability (0F)

Set the year of availability of the bridge in years since 0. The date range is from 0 to 5000000. This property must be set after property 08 to take effect. In TTDPatch, bridge introduction dates outside the range 1920..2175 will be limited to this range.

Purchase text (10)

Set the text appearing in the purchase window, describing what this bridge is made of, or what kind of bridge it is.

Description of a rail(11) or road(12) bridge

Set the text used as a description by the query tool.  When the bridge is used for carrying a rail, it will use property 11, and will use property 12 when it will be for road.

• Note that, as for property 10, the textID can be either a TTD ID or a TextID in the DCxx range.

Bridge IDs

||ID (dec)|ID (hex)|Description

0|00|Wooden Bridge

1|01|Concrete Bridge

2|02|Girder, Steel Bridge

3|03|Suspension, Concrete Bridge

4|04|Suspension, Steel (Bronze) Bridge

5|05|Suspension, Steel (Golden) Bridge

6|06|Cantilever, Steel (Bronze) Bridge

7|07|Cantilever, Steel (Brown) Bridge

8|08|Cantilever, Steel (Red) Bridg

9|09|Girder, Steel Bridge

10|0A|Tubular, Steel (Bronze) Bridge

11|0B|(OpenTTD Only) Tubular, Steel (Golden) Bridge

12|0C|(OpenTTD Only) Tubular, Silicon Bridge||

-=Example=-

Below is an example code which rebuilds the bronze steel suspension bridge (ID 04). The code fragment by itself has no use (no visual difference in game), but might be useful in order to understand the bridge code. Sprite numbers refer to the numbers in trg1(r).grf. The code might also be useful to re-enstate the default bridge if you only want to replace only one certain tracktype.

The complete recode of all default bridges including colour translations is available at TT-Forums: http://www.tt-forums.net/viewtopic.php?p=715362#p715362

//SUSPENSION, STEEL (BRONZE) bridge (04)

-1 * 0 00 06 01 01 04 0D 00 07 //action 00 bridges, 01 property, 01 ID, ID, prop 0D, tableID 00, 07 tables

//table 00

A9 09 00 00  9F 09 00 00  B1 09 00 00  00 00 00 00 //rail X: Back&Floor;, Front, Pillars, 0

A5 09 00 00  97 09 00 00  AD 09 00 00  00 00 00 00 //rail Y: Back&Floor;, Front, Pillars, 0

9D 09 00 00  9F 09 00 00  B1 09 00 00  00 00 00 00 //Road X: Back&Floor;, Front, Pillars, 0

95 09 00 00  97 09 00 00  AD 09 00 00  00 00 00 00 //Road Y: Back&Floor;, Front, Pillars, 0

F2 10 00 00  9F 09 00 00  B1 09 00 00  00 00 00 00 //Mono X: Back&Floor;, Front, Pillars, 0

EE 10 00 00  97 09 00 00  AD 09 00 00  00 00 00 00 //Mono Y: Back&Floor;, Front, Pillars, 0

1A 11 00 00  9F 09 00 00  B1 09 00 00  00 00 00 00 //Mlev X: Back&Floor;, Front, Pillars, 0

16 11 00 00  97 09 00 00  AD 09 00 00  00 00 00 00 //Mlev Y: Back&Floor;, Front, Pillars, 0

//table 01

AA 09 00 00  A0 09 00 00  B2 09 00 00  00 00 00 00 //rail X: Back&Floor;, Front, Pillars, 0

A6 09 00 00  98 09 00 00  AE 09 00 00  00 00 00 00 //rail Y: Back&Floor;, Front, Pillars, 0

9E 09 00 00  A0 09 00 00  B2 09 00 00  00 00 00 00 //Road X: Back&Floor;, Front, Pillars, 0

96 09 00 00  98 09 00 00  AE 09 00 00  00 00 00 00 //Road Y: Back&Floor;, Front, Pillars, 0

F3 10 00 00  A0 09 00 00  B2 09 00 00  00 00 00 00 //Mono X: Back&Floor;, Front, Pillars, 0

EF 10 00 00  98 09 00 00  AE 09 00 00  00 00 00 00 //Mono Y: Back&Floor;, Front, Pillars, 0

1B 11 00 00  A0 09 00 00  B2 09 00 00  00 00 00 00 //Mlev X: Back&Floor;, Front, Pillars, 0

17 11 00 00  98 09 00 00  AE 09 00 00  00 00 00 00 //Mlev Y: Back&Floor;, Front, Pillars, 0

//table 02

AC 09 00 00  A4 09 00 00  B4 09 00 00  00 00 00 00 //rail X: Back&Floor;, Front, Pillars, 0

A8 09 00 00  9C 09 00 00  B0 09 00 00  00 00 00 00 //rail Y: Back&Floor;, Front, Pillars, 0

A2 09 00 00  A4 09 00 00  B4 09 00 00  00 00 00 00 //Road X: Back&Floor;, Front, Pillars, 0

9A 09 00 00  9C 09 00 00  B0 09 00 00  00 00 00 00 //Road Y: Back&Floor;, Front, Pillars, 0

F5 10 00 00  A4 09 00 00  B4 09 00 00  00 00 00 00 //Mono X: Back&Floor;, Front, Pillars, 0

F1 10 00 00  9C 09 00 00  B0 09 00 00  00 00 00 00 //Mono Y: Back&Floor;, Front, Pillars, 0

1D 11 00 00  A4 09 00 00  B4 09 00 00  00 00 00 00 //Mlev X: Back&Floor;, Front, Pillars, 0

19 11 00 00  9C 09 00 00  B0 09 00 00  00 00 00 00 //Mlev Y: Back&Floor;, Front, Pillars, 0

//table 03

AB 09 00 00  A3 09 00 00  B3 09 00 00  00 00 00 00 //rail X: Back&Floor;, Front, Pillars, 0

A7 09 00 00  9B 09 00 00  AF 09 00 00  00 00 00 00 //rail Y: Back&Floor;, Front, Pillars, 0

A1 09 00 00  A3 09 00 00  B3 09 00 00  00 00 00 00 //Road X: Back&Floor;, Front, Pillars, 0

99 09 00 00  9B 09 00 00  AF 09 00 00  00 00 00 00 //Road Y: Back&Floor;, Front, Pillars, 0

F4 10 00 00  A3 09 00 00  B3 09 00 00  00 00 00 00 //Mono X: Back&Floor;, Front, Pillars, 0

F0 10 00 00  9B 09 00 00  AF 09 00 00  00 00 00 00 //Mono Y: Back&Floor;, Front, Pillars, 0

1C 11 00 00  A3 09 00 00  B3 09 00 00  00 00 00 00 //Mlev X: Back&Floor;, Front, Pillars, 0

18 11 00 00  9B 09 00 00  AF 09 00 00  00 00 00 00 //Mlev Y: Back&Floor;, Front, Pillars, 0

//table 04

B6 09 00 00  BA 09 00 00  BC 09 00 00  00 00 00 00 //rail X: Back&Floor;, Front, Pillars, 0

B5 09 00 00  B9 09 00 00  BB 09 00 00  00 00 00 00 //rail Y: Back&Floor;, Front, Pillars, 0

B8 09 00 00  BA 09 00 00  BC 09 00 00  00 00 00 00 //Road X: Back&Floor;, Front, Pillars, 0

B7 09 00 00  B9 09 00 00  BB 09 00 00  00 00 00 00 //Road Y: Back&Floor;, Front, Pillars, 0

F7 10 00 00  BA 09 00 00  BC 09 00 00  00 00 00 00 //Mono X: Back&Floor;, Front, Pillars, 0

F6 10 00 00  B9 09 00 00  BB 09 00 00  00 00 00 00 //Mono Y: Back&Floor;, Front, Pillars, 0

1F 11 00 00  BA 09 00 00  BC 09 00 00  00 00 00 00 //Mlev X: Back&Floor;, Front, Pillars, 0

1E 11 00 00  B9 09 00 00  BB 09 00 00  00 00 00 00 //Mlev Y: Back&Floor;, Front, Pillars, 0

//table 05

BD 09 00 00  C1 09 00 00  00 00 00 00  00 00 00 00 //rail X: Back&Floor;, Front, Pillars, 0

BE 09 00 00  C2 09 00 00  00 00 00 00  00 00 00 00 //rail Y: Back&Floor;, Front, Pillars, 0

BF 09 00 00  C1 09 00 00  00 00 00 00  00 00 00 00 //Road X: Back&Floor;, Front, Pillars, 0

C0 09 00 00  C2 09 00 00  00 00 00 00  00 00 00 00 //Road Y: Back&Floor;, Front, Pillars, 0

F8 10 00 00  C1 09 00 00  00 00 00 00  00 00 00 00 //Mono X: Back&Floor;, Front, Pillars, 0

F9 10 00 00  C2 09 00 00  00 00 00 00  00 00 00 00 //Mono Y: Back&Floor;, Front, Pillars, 0

20 11 00 00  C1 09 00 00  00 00 00 00  00 00 00 00 //Mlev X: Back&Floor;, Front, Pillars, 0

21 11 00 00  C2 09 00 00  00 00 00 00  00 00 00 00 //Mlev Y: Back&Floor;, Front, Pillars, 0

//table 06

86 09 00 00  88 09 00 00  85 09 00 00  87 09 00 00 //rail flat: northern end X, northern end Y, southern end X, southern end Y

8A 09 00 00  8C 09 00 00  89 09 00 00  8B 09 00 00 //rail ramp: northern end X, northern end Y, southern end X, southern end Y

8E 09 00 00  90 09 00 00  8D 09 00 00  8F 09 00 00 //road flat: northern end X, northern end Y, southern end X, southern end Y

92 09 00 00  94 09 00 00  91 09 00 00  93 09 00 00 //road ramp: northern end X, northern end Y, southern end X, southern end Y

E7 10 00 00  E9 10 00 00  E6 10 00 00  E8 10 00 00 //mono flat: northern end X, northern end Y, southern end X, southern end Y

EB 10 00 00  ED 10 00 00  EA 10 00 00  EC 10 00 00 //mono ramp: northern end X, northern end Y, southern end X, southern end Y

0F 11 00 00  11 11 00 00  0E 11 00 00  10 11 00 00 //mlev flat: northern end X, northern end Y, southern end X, southern end Y

13 11 00 00  15 11 00 00  12 11 00 00  14 11 00 00 //mlev ramp: northern end X, northern end Y, southern end X, southern end Y