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The core of DSE is the event dispatch system. This system is
5
responsible for calling Ren'Py code that implements each of the
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events. The event dispatcher chooses a list of events that should be
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run during a given period, and then is responsible for calling each of
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those events in turn until either all events are exhausted, or one of
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the events indicates that the period should come to an end.
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An event consists of a block of Ren'Py code. The name of the event
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is the name of the label that is called to execute that event. There
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are three ways of returning from an event. Simply executing a 'return'
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statement will end the event, and activate any later event in the same
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period. Jumping to events_end_period will end the current period,
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ignoring any future-scheduled event. Jumping to events_skip_period
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will both end the current period, and cause the next period to be
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Events are declared by calling the event(name, ...) function from
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inside an init block. This function takes a variable number of
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arguments. The first argument is always the name of the event, which
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is also the label that is called to start the event. The second and
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later arguments are conditions that must be true for the event to
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occur. These conditions may either be python expressions in strings,
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or the result of one of condition functions given below. The event
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function takes one keyword argument, which gives the priority of the
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event. Events with a smaller priority number are considered before
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those with a larget priority number, with the default priority being
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Consideration of events occurs in two phases. First, the conditions
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are evaluated on each event. If any condition is false, the event is
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discarded, otherwise it is added to the event list. Then, the list is
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filtered and random elements chosen such that only one event is in
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each choice group, for the events that are in choice groups. The
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events are always kept in priority order, with lower numbers being
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higher priority. The first event in the list is recorded as being
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executed, and then executed. Execution continues until all events are
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exhausted, or the period is forced to end.
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The following condition functions ship as part of the DSE.
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Returns True until the event has been executed once, and then
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returns False. It can be used to ensure that the user will only see
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Returns True if there are no higher-priority events scheduled. Use
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this on a very-low-priority event that should only occur if no
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high-priority events occur.
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Returns True if no higher-priority events have been . If it returns
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True, it prevents all other events from being considered.
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event.happened(*events)
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Supply this function with one or more events names (strings). It
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returns true if those events have happened already, at any time in
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event.depends(*events)
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Supply this function with one or more events names (strings). It
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returns true if those events have executed, yesterday or before.
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event.random(probability)
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Probability is a float between 0.0 and 1.0. Returns True with the
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supplied probability, each time it is evaluated. (Each period.)
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event.choose_one(group, count=1)
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This defines a group from which only one event can be chosen. DSE
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randomly picks one of the elements from the group such that all of
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the other conditions are True. An event can only be in one group at a
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time. (Objects returned from here should not have operators applied
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to them.) The count is used to determine the relative likelyhood of
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an event in a group being chosen, with a count of 10 being 10 times
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more likely then a count of 1.
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The objects returned from condition functions can be combined using
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the and, or, and not operators. For example:
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event('bachelor_party', event.depends('engaged_a') or event.depends('engaged_b'))
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There are a few entry points that are used in main to call the event
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dispatcher. First of all, there is the function check_skip_period(),
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that should be called to determine if a period should be run at
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all. The Ren'Py label events_run_period should be called to run a
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single period. Finally, the Ren'Py label events_end_day should be
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called to end a day. Ending a day stops skipping periods, and also
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changes the events that are considered executed by event.depends.
added
removed
dse/game/EVENTS.txt
