Merge pull request #309 from ahall99/dash-improvements

Make dash frequency invariant and smoother

Source/PluginProcessor.cpp

@@ -14,6 +14,7 @@
 #include "audio/DistortEffect.h"
 #include "audio/MultiplexEffect.h"
 #include "audio/SmoothEffect.h"
+#include "audio/DashedLineEffect.h"
 #include "audio/VectorCancellingEffect.h"
 #include "parser/FileParser.h"
 #include "parser/FrameProducer.h"
@@ -137,11 +138,16 @@ OscirenderAudioProcessor::OscirenderAudioProcessor() : CommonAudioProcessor(Buse
         std::vector<osci::EffectParameter*>{
             new osci::EffectParameter("Delay Decay", "Adds repetitions, delays, or echos to the audio. This slider controls the volume of the echo.", "delayDecay", VERSION_HINT, 0.4, 0.0, 1.0),
             new osci::EffectParameter("Delay Length", "Controls the time in seconds between echos.", "delayLength", VERSION_HINT, 0.5, 0.0, 1.0)}));
-    toggleableEffects.push_back(std::make_shared<osci::Effect>(
-        dashedLineEffect,
+    auto dashedLineEffect = std::make_shared<osci::Effect>(
+        std::make_shared<DashedLineEffect>(*this),
         std::vector<osci::EffectParameter*>{
-            new osci::EffectParameter("Dash Length", "Controls the length of the dashed line.", "dashLength", VERSION_HINT, 0.2, 0.0, 1.0),
-        }));
+            new osci::EffectParameter("Dash Count", "Controls the number of dashed lines in the drawing.", "dashCount", VERSION_HINT, 16.0, 1.0, 32.0),
+            new osci::EffectParameter("Dash Coverage", "Controls the fraction of each dash unit that is drawn.", "dashCoverage", VERSION_HINT, 0.5, 0.0, 1.0),
+            new osci::EffectParameter("Dash Offset", "Offsets the location of the dashed lines.", "dashOffset", VERSION_HINT, 0.0, 0.0, 1.0),
+    });
+    dashedLineEffect->getParameter("dashOffset")->lfo->setUnnormalisedValueNotifyingHost((int)osci::LfoType::Sawtooth);
+    dashedLineEffect->getParameter("dashOffset")->lfoRate->setUnnormalisedValueNotifyingHost(1.0);
+    toggleableEffects.push_back(dashedLineEffect);
     toggleableEffects.push_back(custom);
     toggleableEffects.push_back(trace);
     trace->getParameter("traceLength")->lfo->setUnnormalisedValueNotifyingHost((int)osci::LfoType::Sawtooth);

Source/PluginProcessor.h

@@ -18,7 +18,6 @@
 #include "UGen/Env.h"
 #include "UGen/ugen_JuceEnvelopeComponent.h"
 #include "audio/CustomEffect.h"
-#include "audio/DashedLineEffect.h"
 #include "audio/DelayEffect.h"
 #include "audio/PerspectiveEffect.h"
 #include "audio/PublicSynthesiser.h"
@@ -90,8 +89,6 @@ public:
 
     std::shared_ptr<DelayEffect> delayEffect = std::make_shared<DelayEffect>();
 
-    std::shared_ptr<DashedLineEffect> dashedLineEffect = std::make_shared<DashedLineEffect>();
-
     std::function<void(int, juce::String, juce::String)> errorCallback = [this](int lineNum, juce::String fileName, juce::String error) { notifyErrorListeners(lineNum, fileName, error); };
     std::shared_ptr<CustomEffect> customEffect = std::make_shared<CustomEffect>(errorCallback, luaValues);
     std::shared_ptr<osci::Effect> custom = std::make_shared<osci::Effect>(

Source/audio/DashedLineEffect.h

@@ -1,34 +1,42 @@
 #pragma once
 #include <JuceHeader.h>
+#include "../PluginProcessor.h"
 
 class DashedLineEffect : public osci::EffectApplication {
 public:
-	osci::Point apply(int index, osci::Point vector, const std::vector<std::atomic<double>>& values, double sampleRate) override {
-		// dash length in seconds
-		double dashLength = values[0] / 400;
-		int dashLengthSamples = (int)(dashLength * sampleRate);
-		dashLengthSamples = juce::jmin(dashLengthSamples, MAX_BUFFER);
-		
-		if (dashIndex >= dashLengthSamples) {
-			dashIndex = 0;
+	DashedLineEffect(OscirenderAudioProcessor& p) : audioProcessor(p) {}
+
+	osci::Point apply(int index, osci::Point input, const std::vector<std::atomic<double>>& values, double sampleRate) override {
+		double dashCount = juce::jmax(1.0, values[0].load()); // Dashes per cycle
+		double dashCoverage = juce::jlimit(0.0, 1.0, values[1].load());
+		double dashOffset = values[2];
+		double dashLengthSamples = (sampleRate / audioProcessor.frequency) / dashCount;
+		double dashPhase = framePhase * dashCount - dashOffset;
+		dashPhase = dashPhase - std::floor(dashPhase); // Wrap
+		buffer[bufferIndex] = input;
+
+		// Linear interpolation works much better than nearest for this
+		double samplePos = bufferIndex - dashLengthSamples * dashPhase * (1 - dashCoverage);
+		samplePos = samplePos - buffer.size() * std::floor(samplePos / buffer.size()); // Wrap to [0, size]
+		int lowIndex = (int)std::floor(samplePos) % buffer.size();
+		int highIndex = (lowIndex + 1) % buffer.size();
+		double mixFactor = samplePos - std::floor(samplePos); // Fractional part
+		osci::Point output = (1 - mixFactor) * buffer[lowIndex] + mixFactor * buffer[highIndex];
+
+		bufferIndex++;
+		if (bufferIndex >= buffer.size()) {
 			bufferIndex = 0;
 		}
+		framePhase += audioProcessor.frequency / sampleRate;
+		framePhase = framePhase - std::floor(framePhase);
 
-		buffer[bufferIndex] = vector;
-		bufferIndex++;
-		
-		vector = buffer[dashIndex];
-		
-		if (index % 2 == 0) {
-			dashIndex++;
-		}
-		
-		return vector;
+		return output;
 	}
 
 private:
+	OscirenderAudioProcessor &audioProcessor;
 	const static int MAX_BUFFER = 192000;
 	std::vector<osci::Point> buffer = std::vector<osci::Point>(MAX_BUFFER);
-	int dashIndex = 0;
 	int bufferIndex = 0;
-};
+	double framePhase = 0.0; // [0, 1]
+};