Updates to sample-accurte event processing

free-audio · Jun 24, 2022 · 9bb6a09 · 9bb6a09
1 parent d1b34a6
commit 9bb6a09
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Showing 3 changed files with 33 additions and 30 deletions.
diff --git a/README.md b/README.md
@@ -119,10 +119,10 @@ are available
 * `CLAP_MISBHEAVIOUR_HANDLER_LEVEL` can be set to `Terminate` or `Ignore` (default
   is `Ignore`) to choose your behaviour for a misbehaving host.
 * `CLAP_CHECKING_LEVEL` can be set to `None`, `Minimal`, or `Maximal` (default is
-  `Minimal`) to choose the error checking level for the plugin.
-* `CLAP_SMALLEST_ALLOWED_BLOCK_SIZE` can be set to any integer value to choose the
-  smallest allowed block size for doing sample-accurate event processing. Setting the
-  value to `0` (the default value) will turn off sample-accurate event processing.
+  `Minimal`) to choose the level of sanity checks enabled for the plugin.
+* `CLAP_EVENT_RESOLUTION_SAMPLES` can be set to any integer value to choose the
+  resolution (in samples) used by the wrapper for doing sample-accurate event processing.
+  Setting the value to `0` (the default value) will turn off sample-accurate event processing.
 
 ## Risks of using this library
 

diff --git a/cmake/ClapTargetHelpers.cmake b/cmake/ClapTargetHelpers.cmake
@@ -1,5 +1,5 @@
 function(clap_juce_extensions_plugin_internal)
-    set(oneValueArgs TARGET TARGET_PATH PLUGIN_NAME IS_JUCER DO_COPY CLAP_MANUAL_URL CLAP_SUPPORT_URL CLAP_MISBEHAVIOUR_HANDLER_LEVEL CLAP_CHECKING_LEVEL CLAP_SMALLEST_ALLOWED_BLOCK_SIZE)
+    set(oneValueArgs TARGET TARGET_PATH PLUGIN_NAME IS_JUCER DO_COPY CLAP_MANUAL_URL CLAP_SUPPORT_URL CLAP_MISBEHAVIOUR_HANDLER_LEVEL CLAP_CHECKING_LEVEL CLAP_EVENT_RESOLUTION_SAMPLES)
     set(multiValueArgs CLAP_ID CLAP_FEATURES)
 
     cmake_parse_arguments(CJA "" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
@@ -31,11 +31,11 @@ function(clap_juce_extensions_plugin_internal)
         message( STATUS "Setting Checking handler level to '${CJA_CLAP_CHECKING_LEVEL}'")
     endif()
 
-    if ("${CJA_CLAP_SMALLEST_ALLOWED_BLOCK_SIZE}" STREQUAL "")
-        message( STATUS "Setting smallest allowed block size to 0 (no sample-accurate automation)")
-        set(CJA_CLAP_SMALLEST_ALLOWED_BLOCK_SIZE 0)
+    if ("${CJA_CLAP_EVENT_RESOLUTION_SAMPLES}" STREQUAL "")
+        message( STATUS "Setting event resolution to 0 samples (no sample-accurate automation)")
+        set(CJA_CLAP_EVENT_RESOLUTION_SAMPLES 0)
     else()
-        message( STATUS "Setting smallest allowed block size to ${CJA_CLAP_SMALLEST_ALLOWED_BLOCK_SIZE}")
+        message( STATUS "Setting event resolution to ${CJA_CLAP_EVENT_RESOLUTION_SAMPLES} samples")
     endif()
 
     # we need the list of features as comma separated quoted strings
@@ -92,6 +92,7 @@ function(clap_juce_extensions_plugin_internal)
             CLAP_SUPPORT_URL="${CJA_CLAP_SUPPORT_URL}"
             CLAP_MISBEHAVIOUR_HANDLER_LEVEL=${CJA_CLAP_MISBEHAVIOUR_HANDLER_LEVEL}
             CLAP_CHECKING_LEVEL=${CJA_CLAP_CHECKING_LEVEL}
+            CLAP_EVENT_RESOLUTION_SAMPLES=${CJA_CLAP_EVENT_RESOLUTION_SAMPLES}
             )
 
     if(${CJA_IS_JUCER})

diff --git a/src/wrapper/clap-juce-wrapper.cpp b/src/wrapper/clap-juce-wrapper.cpp
@@ -113,8 +113,8 @@ JUCE_BEGIN_IGNORE_WARNINGS_MSVC(4996) // allow strncpy
 #define CLAP_CHECKING_LEVEL "Minimal"
 #endif
 
-#if !defined(CLAP_SMALLEST_ALLOWED_BLOCK_SIZE)
-#define CLAP_SMALLEST_ALLOWED_BLOCK_SIZE 0 // sample-accurate events are off by default
+#if !defined(CLAP_EVENT_RESOLUTION_SAMPLES)
+#define CLAP_EVENT_RESOLUTION_SAMPLES 0 // sample-accurate events are off by default
 #endif
 
 // This is useful for debugging overrides
@@ -830,12 +830,25 @@ class ClapJuceWrapper : public clap::helpers::Plugin<
         int currentEvent = 0;
         int nextEventTime = numSamples;
 
-        if (numEvents > 0)
+        if (numEvents > 0) // load first event
         {
             auto event = events->get(events, 0);
             nextEventTime = (int)event->time;
         }
 
+        auto processEvent = [&](int sampleOffset) {
+            auto event = events->get(events, (uint32_t)currentEvent);
+            process_clap_event(event, sampleOffset);
+
+            currentEvent++;
+            nextEventTime = (currentEvent < numEvents)
+                                ? (int)events->get(events, (uint32_t)currentEvent)->time
+                                : numSamples;
+        };
+
+        while (nextEventTime == 0) // process events with timestamp 0
+            processEvent(0);
+
         /*
          * OK so here is what JUCE expects in its audio buffer. It *always* uses input as output
          * buffer so we need to create a buffer where each channel is the channel of the associated
@@ -848,7 +861,7 @@ class ClapJuceWrapper : public clap::helpers::Plugin<
         for (int n = 0; n < numSamples;)
         {
             auto getSamplesToProcess = [&]() {
-                if (CLAP_SMALLEST_ALLOWED_BLOCK_SIZE <= 0)
+                if (CLAP_EVENT_RESOLUTION_SAMPLES <= 0)
                 {
                     // Sample-accurate events are turned off, so just process the whole block!
                     return numSamples;
@@ -858,25 +871,17 @@ class ClapJuceWrapper : public clap::helpers::Plugin<
                     // How many samples should we process at a time?
                     // In the spirit of sample-accurate events, we want to process a batch of
                     // samples until we hit the next event, but we don't want to have a batch
-                    // smaller than the `CLAP_SMALLEST_ALLOWED_BLOCK_SIZE`. If there's no more
+                    // smaller than the `CLAP_EVENT_RESOLUTION_SAMPLES`. If there's no more
                     // events, just process the rest of the block!
-                    return (numSamples - n >= CLAP_SMALLEST_ALLOWED_BLOCK_SIZE)
-                               ? juce::jmax(nextEventTime - n, CLAP_SMALLEST_ALLOWED_BLOCK_SIZE)
+                    return (numSamples - n >= CLAP_EVENT_RESOLUTION_SAMPLES)
+                               ? juce::jmax(nextEventTime - n, CLAP_EVENT_RESOLUTION_SAMPLES)
                                : (numSamples - n);
                 }
             };
 
             const auto numSamplesToProcess = getSamplesToProcess();
             while (nextEventTime < n + numSamplesToProcess && currentEvent < numEvents)
-            {
-                auto event = events->get(events, (uint32_t)currentEvent);
-                process_clap_event(event, n);
-
-                currentEvent++;
-                nextEventTime = (currentEvent < numEvents)
-                                    ? (int)events->get(events, (uint32_t)currentEvent)->time
-                                    : numSamples;
-            }
+                processEvent(n);
 
             uint32_t outputChannels = 0;
             for (uint32_t idx = 0; idx < process->audio_outputs_count && outputChannels < maxBuses;
@@ -949,11 +954,8 @@ class ClapJuceWrapper : public clap::helpers::Plugin<
         }
 
         // process any leftover events
-        for (; currentEvent < numEvents; ++currentEvent)
-        {
-            auto event = events->get(events, (uint32_t)currentEvent);
-            process_clap_event(event, 0);
-        }
+        while (currentEvent < numEvents)
+            processEvent(numSamples);
 
         return CLAP_PROCESS_CONTINUE;
     }