1 /***************************************************************************
2  *                                                                         *
3  *   LinuxSampler - modular, streaming capable sampler                     *
4  *                                                                         *
5  *   Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck   *
6  *   Copyright (C) 2005 - 2021 Christian Schoenebeck                       *
7  *                                                                         *
8  *   This program is free software; you can redistribute it and/or modify  *
9  *   it under the terms of the GNU General Public License as published by  *
10  *   the Free Software Foundation; either version 2 of the License, or     *
11  *   (at your option) any later version.                                   *
12  *                                                                         *
13  *   This program is distributed in the hope that it will be useful,       *
14  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
15  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
16  *   GNU General Public License for more details.                          *
17  *                                                                         *
18  *   You should have received a copy of the GNU General Public License     *
19  *   along with this program; if not, write to the Free Software           *
20  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston,                 *
21  *   MA  02111-1307  USA                                                   *
22  ***************************************************************************/
23 
24 #include "Event.h"
25 
26 namespace LinuxSampler {
27 
28     /**
29      * Create an EventGenerator.
30      *
31      * @param SampleRate - sample rate of the sampler engine's audio output
32      *                     signal (in Hz)
33      */
EventGenerator(uint SampleRate)34     EventGenerator::EventGenerator(uint SampleRate) {
35         uiSampleRate       = SampleRate;
36         uiSamplesProcessed = 0;
37         FragmentTime.end   = RTMath::CreateTimeStamp();
38         uiTotalSamplesProcessed = 0;
39     }
40 
SetSampleRate(uint SampleRate)41     void EventGenerator::SetSampleRate(uint SampleRate) {
42         uiSampleRate = SampleRate;
43     }
44 
45     /**
46      * Updates the time stamps for the beginning and end of the current audio
47      * fragment. This is needed to be able to calculate the respective sample
48      * point later to which an event belongs to.
49      *
50      * @param SamplesToProcess - number of sample points to process in this
51      *                           audio fragment cycle
52      */
UpdateFragmentTime(uint SamplesToProcess)53     void EventGenerator::UpdateFragmentTime(uint SamplesToProcess) {
54         // update total amount of sample points being processed since this object was created
55         uiTotalSamplesProcessed += uiSamplesProcessed;
56         // update time stamp for this audio fragment cycle
57         FragmentTime.begin = FragmentTime.end;
58         FragmentTime.end   = RTMath::CreateTimeStamp();
59         // recalculate sample ratio for this audio fragment
60         time_stamp_t fragmentDuration = FragmentTime.end - FragmentTime.begin;
61         FragmentTime.sample_ratio = (float) uiSamplesProcessed / (float) fragmentDuration;
62         // store amount of samples to process for the next cycle
63         uiSamplesProcessed = SamplesToProcess;
64     }
65 
66     /**
67      * Get the next scheduled MIDI event (the one with the lowest time value)
68      * for the current audio fragment cycle and remove it from the queue. This
69      * method will not return any event scheduled past the current audio
70      * fragment boundary.
71      *
72      * @param queue - where the MIDI events are scheduled on
73      * @param pool - used to allocate and deallocate ScheduledEvent objects
74      * @param end - you @b MUST always pass EventGenerator::schedTimeAtCurrentFragmentEnd()
75      *              here reflecting the current audio fragment's scheduler end time
76      */
popNextScheduledEvent(RTAVLTree<ScheduledEvent> & queue,Pool<ScheduledEvent> & pool,sched_time_t end)77     RTList<ScheduledEvent>::Iterator EventGenerator::popNextScheduledEvent(RTAVLTree<ScheduledEvent>& queue, Pool<ScheduledEvent>& pool, sched_time_t end) {
78         if (queue.isEmpty())
79             return RTList<ScheduledEvent>::Iterator(); // return invalid iterator
80         ScheduledEvent& e = queue.lowest();
81         if (e.scheduleTime >= end)
82             return RTList<ScheduledEvent>::Iterator(); // no event scheduled before 'end'
83         RTList<ScheduledEvent>::Iterator itEvent = pool.fromPtr(&e);
84         queue.erase(e);
85         if (!itEvent || !itEvent->itEvent) {
86             dmsg(1,("EventGenerator::popNextScheduledEvent(): !itEvent\n"));
87             return itEvent; // should never happen at this point, but just to be sure
88         }
89         if (!itEvent->itEvent) {
90             dmsg(1,("EventGenerator::popNextScheduledEvent(): !itEvent->itEvent\n"));
91             return itEvent; // should never happen at this point, but just to be sure
92         }
93 
94         // update position of this event in the current audio fragment
95         // (since calling scheduleAheadMicroSec() will relate to this)
96         itEvent->itEvent->iFragmentPos = int32_t( uiSamplesProcessed - (end - itEvent->scheduleTime) );
97         // safety first: fragment boundary sanity checks
98         if (itEvent->itEvent->iFragmentPos < 0)
99             itEvent->itEvent->iFragmentPos = 0;
100         if (itEvent->itEvent->iFragmentPos >= uiSamplesProcessed)
101             itEvent->itEvent->iFragmentPos = uiSamplesProcessed - 1;
102 
103         return itEvent;
104     }
105 
106     /**
107      * Get the next instrument script event (the one with the lowest time value)
108      * for the current audio fragment cycle and remove it from the queue. This
109      * method will not return any event scheduled past the current audio
110      * fragment boundary.
111      *
112      * @param queue - where the instrument script events are scheduled on
113      * @param pool - used to allocate and deallocate ScriptEvent objects
114      * @param end - you @b MUST always pass EventGenerator::schedTimeAtCurrentFragmentEnd()
115      *              here reflecting the current audio fragment's scheduler end time
116      */
popNextScheduledScriptEvent(RTAVLTree<ScriptEvent> & queue,Pool<ScriptEvent> & pool,sched_time_t end)117     RTList<ScriptEvent>::Iterator EventGenerator::popNextScheduledScriptEvent(RTAVLTree<ScriptEvent>& queue, Pool<ScriptEvent>& pool, sched_time_t end) {
118         if (queue.isEmpty())
119             return RTList<ScriptEvent>::Iterator(); // return invalid iterator
120         ScriptEvent& e = queue.lowest();
121         if (e.scheduleTime >= end)
122             return RTList<ScriptEvent>::Iterator(); // no event scheduled before 'end'
123         RTList<ScriptEvent>::Iterator itEvent = pool.fromPtr(&e);
124         queue.erase(e);
125         if (!itEvent) { // should never happen at this point, but just to be sure
126             dmsg(1,("EventGenerator::popNextScheduledScriptEvent(): !itEvent\n"));
127             return itEvent;
128         }
129 
130         // update position of this event in the current audio fragment
131         // (since calling scheduleAheadMicroSec() will relate to this)
132         itEvent->cause.iFragmentPos = int32_t( uiSamplesProcessed - (end - itEvent->scheduleTime) );
133         // safety first: fragment boundary sanity checks
134         if (itEvent->cause.iFragmentPos < 0)
135             itEvent->cause.iFragmentPos = 0;
136         if (itEvent->cause.iFragmentPos >= uiSamplesProcessed)
137             itEvent->cause.iFragmentPos = uiSamplesProcessed - 1;
138 
139         return itEvent;
140     }
141 
142     /**
143      * Create a new event with the current time as time stamp.
144      */
CreateEvent()145     Event EventGenerator::CreateEvent() {
146         return Event(this, RTMath::CreateTimeStamp());
147     }
148 
149     /**
150      * Create a new event for the given sample point position in the current
151      * audio fragment.
152      *
153      * @param FragmentPos - actual sample point position in the current
154      *                      audio fragment to which the new event belongs to
155      */
CreateEvent(int32_t FragmentPos)156     Event EventGenerator::CreateEvent(int32_t FragmentPos) {
157         return Event(this, FragmentPos);
158     }
159 
160     /**
161      * Will be called by an EventGenerator to create a new Event.
162      * This Constructor expects a time stamp. The actual sample point
163      * position to which this event belongs to will be calculated later
164      * when FragmentPos() was called the first time.
165      *
166      * @param pGenerator - creator of this event
167      * @param Time       - time stamp on which this event occured
168      */
Event(EventGenerator * pGenerator,time_stamp_t Time)169     Event::Event(EventGenerator* pGenerator, time_stamp_t Time) {
170         Init();
171         pEventGenerator = pGenerator;
172         TimeStamp       = Time;
173         iFragmentPos    = -1;
174     }
175 
176     /**
177      * Will be called by an EventGenerator to create a new Event.
178      * This constructor expects the final sample point position to which
179      * this event belongs to.
180      *
181      * @param pGenerator  - creator of this event
182      * @param FragmentPos - actual sample point position in the current
183      *                      audio fragment to which this event belongs to
184      */
Event(EventGenerator * pGenerator,int32_t FragmentPos)185     Event::Event(EventGenerator* pGenerator, int32_t FragmentPos) {
186         Init();
187         pEventGenerator = pGenerator;
188         iFragmentPos    = FragmentPos;
189     }
190 
191     /**
192      * Implements fork() behavior, that is it copies the current state of this
193      * script event handler to the new event handler @a e with entire execution
194      * state and polyphonic data.
195      *
196      * After calling this method, addChildHandler() should be called as well.
197      */
forkTo(ScriptEvent * e,bool bAutoAbort) const198     void ScriptEvent::forkTo(ScriptEvent* e, bool bAutoAbort) const {
199         e->scheduleTime = scheduleTime;
200         e->cause = cause;
201         e->id = id;
202         // forked script shall only run the current event handler of parent,
203         // no other potentially chained handlers
204         e->handlers[0] = handlers[currentHandler];
205         e->handlers[1] = NULL; // NULL termination of list
206         e->currentHandler = 0;
207         e->executionSlices = 0;
208         e->ignoreAllWaitCalls = ignoreAllWaitCalls;
209         e->releaseMatched = true; // this is not the original: never match a release handler with a forked note handler instance
210         e->handlerType = handlerType;
211         e->parentHandlerID = 0; // just an arbitrary init value, must still be set later!
212         e->childHandlerID[0] = 0;
213         e->autoAbortByParent = bAutoAbort;
214         e->forkIndex = 1; // just an arbitrary init value, must still be set later!
215 
216         execCtx->forkTo(e->execCtx);
217     }
218 
219     /**
220      * Returns amount of child event handlers that have been created so far
221      * during the entire life time of this event handler instance by calls of
222      * this event handler instace to the built-in script function fork().
223      *
224      * To make this clear: this number does never decrease during the entire
225      * life time of an event handler instance! It may only increase, i.e. by
226      * additional calls to fork(). Consequently even if child event handler
227      * instances already terminated, this will not decrease this count.
228      */
countChildHandlers() const229     int ScriptEvent::countChildHandlers() const {
230         int n = 0;
231         for (int i = 0; i < MAX_FORK_PER_SCRIPT_HANDLER && childHandlerID[i]; ++i)
232             ++n;
233         return n;
234     }
235 
236     /**
237      * This must be called after calling forkTo() to stick the script callback
238      * ID of the newly forked child execution instance to the parent execution
239      * instance.
240      *
241      * @param childID - script callback ID of the newly forked child handler
242      */
addChildHandlerID(script_callback_id_t childID)243     void ScriptEvent::addChildHandlerID(script_callback_id_t childID) {
244         const int n = countChildHandlers();
245         if (n >= MAX_FORK_PER_SCRIPT_HANDLER) {
246             dmsg(1,("ScriptEvent::addChildHandlerID(): MAX_FORK_PER_SCRIPT_HANDLER exceeded, this is a bug!\n"));
247             return;
248         }
249         childHandlerID[n]   = childID;
250         childHandlerID[n+1] = 0; // zero termination of list
251     }
252 
253 } // namespace LinuxSampler
254