Callback: Advanced effect creation

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Advanced effect creation (160)

Supported by OpenTTD 1.5 (r26747)1.5 Not supported by TTDPatch

This callback is used when advanced visual effects are enabled via the Visual Effect properties resp. Callback 10.

The callback is called whenever the effect spawning model issues the vehicle to generate a visual effect. This callback then decides the position, amount and looks of the visual effect.

Variable 10 specifies what type of visual effect to generate:

Bits Meaning
0-7 Effect
  • 00: Normal visual effect when driving.
  • 01-FF: Reserved, must be masked.
8-31 Reserved, must be masked.

Variable 18 contains 32 random bits.

If the callback fails, no visual effect is created. Otherwise the result consists of:

Bits Meaning
0-1 Amount of effects to spawn (0 to 3), details are specified via register 100+x
2-12 Reserved, must be set to zero.
13 Train and RV only: If set, position effect relative to vehicle center instead of relative to vehicle sprite. (behaves the same for vehicles with length 8/8)
14 If set, disable auto-rotation of effect position wrt. vehicle orientation.

Registers 100+x define the appearance of the x-th effect (amount specified via callback result):

Bits Meaning
0-7 Effect type
  • 00-EF: Reserved
  • F0: Reserved
  • F1: Default 'steam' effect.
  • F2: Default 'diesel' effect.
  • F3: Default 'electric' effect.
  • F4-F5: Reserved
  • F6: Default 'breakdown smoke' effect.
  • F7-F9: Reserved
  • FA: Default 'broken aircraft' effect.
  • FB-FE: Reserved
  • FF: No effect.
8-15
  • If result bit 14 is cleared: Longitudinal position (signed)
  • If result bit 14 is set: X position (signed)
16-23
  • If result bit 14 is cleared: Transversal position (signed)
  • If result bit 14 is set: Y position (signed)
24-31 Z position (signed)