[Scummvm-tracker] [ScummVM] #10615: QFG4: Tentacle doesn't retract after crossing pit at start of game

[ScummVM]

#10615: QFG4: Tentacle doesn't retract after crossing pit at start of game
--------------------------------+-------------------------
  Reporter:  2Mourty            |      Owner:  (none)
      Type:  defect             |     Status:  new
  Priority:  normal             |  Component:  Engine: SCI
Resolution:                     |   Keywords:  Tentacle
      Game:  Quest for Glory 4  |
--------------------------------+-------------------------

Comment (by Vhati):

 The tentacle is given a RandCycle, which gets stuck.
 \\
 \\
 script 710 - sTentacleDeath::changeState(3)
 {{{
 (tentacle setCycle: RandCycle tentacle)
 }}}

 It's not that RandCycle itself is broken because the torch flickering
 works.
 \\
 \\
 script 710 - rm710::init()
 {{{
 (torchEff init: setScaler: global0 setCycle: RandCycle)
 }}}

 One obvious difference: the torch cycler has no arg.
 \\
 \\
 setCycle() constructs a new cycler and calls the cycler's init(),
 prepending self to the args.
 \\
 \\
 script 64998 - Prop::setCycle()
 {{{
 (method (setCycle param1)
         (if cycler (cycler dispose:))
         (if param1
                 (= cycler
                         (if (& (param1 -info-?) $8000)
                                 (param1 new:)
                         else
                                 param1
                         )
                 )
                 (cycler init: self &rest)
         else
                 (= cycler 0)
         )
 )
 }}}

 That means
 "(tentacle setCycle: RandCycle tentacle)"
 becomes
 "(RandCycle init: tentacle tentacle)"
 \\
 \\
 script 64941 - RandCycle::init()
 {{{
 (method (init param1 param2 param3 param4)
         (super init: param1)
         (if (>= argc 4) (= reset param4))
         (if reset (client cel: 0))
         (= cycleCnt (GetTime))
         (if (>= argc 2)
                 (if (!= param2 -1)
                         (= count (+ (GetTime) param2))
                 else
                         (= count -1)
                 )
                 (if (>= argc 3) (= caller param3))
         else
                 (= count -1)
         )
 )
 }}}

 This must be why someone added an
 [https://bugs.scummvm.org/ticket/10615#comment:6 arithmetic workaround].
 RandCycle::doit() does a greater-than op with count.
 The extra tentacle arg is being assigned to count!

 Strange that ScummVM doesn't panic when init() attempts addition on the
 object.

-- 
Ticket URL: <https://bugs.scummvm.org/ticket/10615#comment:14>
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