Callback: Cargo sub-type display for industries
Cargo sub-type display for industries (37)
This callback allows you to display some text after the cargo name in the industry fund window and in industry windows.
GRFv≤7 For GRF version 7 and below the valid return values are:
| 00..FE | Display D0xx (D000..D0FE) text. |
| FF | Display no text. |
| 100..1FE | Display D0xx (D100..D1FE) text. |
| 200..2FE | Display D0xx (D200..D2FE) text. |
| 300..3FE | Display D0xx (D300..D3FE) text. |
GRFv≥8 For GRF version 8 and above the valid return values are:
| 00..3FF | Display D0xx (D000..D3FF) text. Display waiting amount if production CB is used. |
| 400 | Display no text. Display waiting amount if production CB is used. |
| 401 |  1.7  Display no waiting amount and no text.
|
| 800..BFF | 1.7 Display D0xx (D000..D3FF) text without waiting amount.
|
During the callback, variable 18 specifies which cargo sub-type is queried. The meaning of variable 18 changes with industry property 1A flag 18.
Bits 0..7 of var. 18 can have the following values:
- If property 1A flag 18 is clear.
| Number | Meaning |
|---|---|
| 00 | Return subtext for first accepted cargo type |
| 01 | Return subtext for second accepted cargo type |
| 02 | Return subtext for third accepted cargo type |
| 03 | Return subtext for first produced cargo type |
| 04 | Return subtext for second produced cargo type |
1.9 
If property 1A flag 18 is set.
| Number | Meaning |
|---|---|
| 00 | Return subtext for an accepted cargo type. Use bits 16..23 to distinguish them. |
| 01 | Return subtext for a produced cargo type. Use bits 16..23 to distinguish them. |
Bits 8..15 of var. 18 can have the following values:
| Number | Meaning |
|---|---|
| 00 | The text is to be displayed in the industry fund window. The industry isn't built yet, so you can't access the industry variables |
| 01 | The text is to be displayed in the window of the industry. You can use the industry variables here. |
| 02 | The text is to be displayed in the industry directory window. You can use the industry variables here. |
| other values | Reserved for future use |
Bit 16..23 of var. 18 contain the cargo type from the CTT (only if property 1A flag 18 is set).
Other bits of var. 18 are reserved for future use.
1.0 Since OpenTTD r17802, the contents of registers 100h..105h are copied onto the text reference stack.
