Difference between revisions of "Callback: Ambient sound effects"

From GRFSpecs
Jump to navigationJump to search
m (Create a separate page for each callback)
 
(grf version 8)
Line 5: Line 5:
 
The 15-bit return value is the sound effect number. Values from 0 to 72 (dec) are TTD's built-in sound effects, values beyond that refer to the sounds from [[Action11|Action 11]].
 
The 15-bit return value is the sound effect number. Values from 0 to 72 (dec) are TTD's built-in sound effects, values beyond that refer to the sounds from [[Action11|Action 11]].
   
To decide whether to play a sound, and what sound to play, Var.Action 2 variable 10 holds the following information: THRRxxxt
+
To decide whether to play a sound, and what sound to play, Var.Action 2 variable 10 holds the following information:
  +
* {{grf|7}} For GRF version 7 and below: THRRxxxt
  +
* {{grf|8}} For GRF version 8 and above: xTHHRRtt
   
 
{| |-
 
{| |-
Line 12: Line 14:
 
|T||Tile class, 0=bare land, 4=trees, 6=water
 
|T||Tile class, 0=bare land, 4=trees, 6=water
 
|-
 
|-
  +
|HH||
|H||Height of north corner of tile
+
{{grf|7}} Height of north corner of tile (multiple of 8)<br/>
  +
{{grf|8}} Height of lowest corner of tile (multiple of 1)
 
|-
 
|-
 
|RR||8 random bits
 
|RR||8 random bits
Line 18: Line 22:
 
|xxx||Reserved
 
|xxx||Reserved
 
|-
 
|-
  +
|tt||
|t||Terrain type; &nbsp;0 normal (grass), 1 desert, 2 rainforest, 4 on or above snowline
+
* Bits 0..2: Terrain type: 0 normal (grass), 1 desert, 2 rainforest, 4 on or above snowline.
  +
* Bits 3..5: {{grf|8}} Water class: 0 - undefined / land; 1 - sea; 2 - canal; 3 - river.
 
|}
 
|}
   

Revision as of 20:35, 8 November 2011

Ambient sound effects (144)

This callback is a generic callback for feature 0C (new sounds) used for playing ambient sound effects.

The 15-bit return value is the sound effect number. Values from 0 to 72 (dec) are TTD's built-in sound effects, values beyond that refer to the sounds from Action 11.

To decide whether to play a sound, and what sound to play, Var.Action 2 variable 10 holds the following information:

  • GRFv7 For GRF version 7 and below: THRRxxxt
  • GRFv8 For GRF version 8 and above: xTHHRRtt
Field Meaning
T Tile class, 0=bare land, 4=trees, 6=water
HH

GRFv7 Height of north corner of tile (multiple of 8)
GRFv8 Height of lowest corner of tile (multiple of 1)

RR 8 random bits
xxx Reserved
tt
  • Bits 0..2: Terrain type: 0 normal (grass), 1 desert, 2 rainforest, 4 on or above snowline.
  • Bits 3..5: GRFv8 Water class: 0 - undefined / land; 1 - sea; 2 - canal; 3 - river.

This callback must be enabled by bit 4 in action D var 9E.