Industries - cargo sub-type display callback

[andythenorth]

I want to set the cargo sub-type display for an industry, so I have set prop 21 to 40.

Code: Select all

    2 * 19	 04 0A 9F 01 00 DC "Catfood Mine" 00
    3 * 28	 00 0A 09 01 00 // action 0 for industry
      08 00 
      09 00 
      10 01 09 // cargo types accepted
      17 02
      18 02
      19 D0
      1A 00 00 00 00
      1F 00 DC // text string to use for name
      21 40 // callback flags

I assume I now need:
- another action 4 to set the ID and contents of text string for the cargo-sub type
- an action 3 and variational action 2 chain referencing the ID of the text string

However I am being very dense and can't figure out the logic of the variational action 2 (or how to terminate it). I am modifying the default coal mine as a learning exercise, I haven't defined any layouts or real sprites for this industry.

Apologies if I am being extra-dim about this, can't seem to shake off jet lag

[michael blunck]

Well, it´s straoghtforward:

Code: Select all

//------------------------------------------------------------------
// D001  cargo sub-texts
//------------------------------------------------------------------

  -1 * 19       04 00 83 01 01 D0 " (furniture)" 00
  -1 * 15       04 00 84 01 01 D0 " (Möbel)" 00
  -1 * 17       04 00 88 01 01 D0 " (meubles) 00
  -1 * 17       04 00 90 01 01 D0 " (muebles)" 00

[...]

// extra callback info2:
// return subtext for first produced cargo type
   -1 * 14       02 0A 0C 81 18 00 FF 01
                        01 80 03 03	// D001
                        FF 80

// CBs
   -1 * 14       02 0A 0D 81 0C 00 FF 01
                        0C 00 37 37	// cargo sub-text 
                        0B 00		   // industry

// attach industry callbacks to industry
   -1 * 7        03 0A 01 07 00 0D 00  

HTH
regards
Michael

[andythenorth]

Well, it´s straoghtforward:

Brilliant, thankyou.

catfood (canned).png (39.23 KiB) Viewed 1341 times

One question - I don't have an action 2 to apply graphics, so I have terminated on FF 80, which appears to work. Is that a very stupid thing to do? (It's something I think remember reading somewhere - I am now avidly reading action 2 documentation to see if I've misremembered it).

EDIT, can't find any documentation on this FF 80 business, I think I've imagined it; as far I can see my code should cause a crash?

What's the correct way to terminate this chain? I don't have any graphics to apply, and I don't need to setup the production callback for this industry.

Code: Select all

// extra callback info2:
// return subtext for first produced cargo type
    5 * 14	 02 0A 0C
      81 18 00 FF 01
        01 FF 03 03   // D001
        FF FF
// CBs
    6 * 14	 02 0A 0D
      81 0C 00 FF 01
        0C 00 37 37   // cargo sub-text
        FF 80         // terminate chain
// attach industry callbacks to industry
    7 * 7	 03 0A 01 00
      00 0D 00 

[frosch]

Industries do not have graphics. Images are assigned to industry tiles.

Industries' action2 is the production callback. Just define one, it won't be used until it is activated by action0.

For other features, which have graphics, you can define a action1 with zero sprites.

Since 2.0.1 alpha 63, it is possible to have <num-ent>=0. This is useful for defining an action 1/2 combination that only serves as invalid callback result. If the .grf file defines no graphics otherwise, this way callbacks can return an explicit failure code without needing any actual sprites to be allocated.

[andythenorth]

Industries do not have graphics. Images are assigned to industry tiles.

Industries' action2 is the production callback. Just define one, it won't be used until it is activated by action0.

Thanks Frosch. As the production callback is unused, I've zeroed everything, is this a sensible approach?

6 * 15 02 0A 0A // action 2 setup production callback
00
00 00
00 00
00 00
00 00
00 00
00

[michael blunck]

[...]
Industries' action2 is the production callback. Just define one, it won't be used until it is activated by action0.

Thanks Frosch. As the production callback is unused, I've zeroed everything, is this a sensible approach?

Yes, looks good. In my example above, the 0B branch has been indeed linked with a production CB. Sorry, I missed to post it.

regards
Michael

[andythenorth]

Thanks Michael and Frosch, very helpful.

I am now adding a callback 3A to provide extra text in the industry window. This is sprite 8 / Action 2 ID 0B in the code below, and should return the text string at D002. There are no conditions that I want to check, so I am unsure of how to set this up. Needless to say, the code below doesn't produce the desired result (although it doesn't crash either).

Code: Select all

   4 * 16	 04 00 9F 01 01 D0 " (canned)" 00
    5 * 19	 04 00 9F 01 02 D0 "\90 Mmmm, cats love it" 00
    6 * 15	 02 0A 0A // action 2 setup production callback
      00 
      00 00
      00 00
      00 00
      00 00
      00 00
      00
// extra callback info2:
// return subtext for first produced cargo type
    7 * 14	 02 0A 0C
      81 18 00 FF 01 
          01 FF 03 03   // D001
        FF FF
// 
    8 * 14	 02 0A 0B
      81 0C 00 FF 01  // why am I checking 0C?  Because I don't want to check anything here and can't figure out how.
          02 FF 3A 3A   // D002 
        FF FF
// CBs
    9 * 18	 02 0A 0D
      81 0C 00 FF 02
          0C 00 37 37   // cargo sub-text
          0B 00 3A 3A   // industry window text
        0A 00         // default
// attach industry callbacks to industry
   10 * 7	 03 0A 01 00
      00 0D 00 

[frosch]

If I understand you correctly, remove sprite 8 and replace

Code: Select all

 0B 00 3A 3A

by

Code: Select all

 02 80 3A 3A

Edit: however I cannot see, why your code should not work. Did you enable the callback? Or what it the effect in game?

[andythenorth]

Did you enable the callback?

No I did not, and there you have found the source of my problem. Now corrected:

catfood_success.png (41.34 KiB) Viewed 1272 times

Thanks!