Fixes to the UI

Examples/WavetableSynthTutorial/Source/WavetableSynthTutorial_02.h

@@ -0,0 +1,196 @@
+/*
+  ==============================================================================
+
+   This file is part of the JUCE tutorials.
+   Copyright (c) 2020 - Raw Material Software Limited
+
+   The code included in this file is provided under the terms of the ISC license
+   http://www.isc.org/downloads/software-support-policy/isc-license. Permission
+   To use, copy, modify, and/or distribute this software for any purpose with or
+   without fee is hereby granted provided that the above copyright notice and
+   this permission notice appear in all copies.
+
+   THE SOFTWARE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES,
+   WHETHER EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR
+   PURPOSE, ARE DISCLAIMED.
+
+  ==============================================================================
+*/
+
+/*******************************************************************************
+ The block below describes the properties of this PIP. A PIP is a short snippet
+ of code that can be read by the Projucer and used to generate a JUCE project.
+
+ BEGIN_JUCE_PIP_METADATA
+
+ name:             WavetableSynthTutorial
+ version:          2.0.0
+ vendor:           JUCE
+ website:          http://juce.com
+ description:      Wavetable synthesiser.
+
+ dependencies:     juce_audio_basics, juce_audio_devices, juce_audio_formats,
+                   juce_audio_processors, juce_audio_utils, juce_core,
+                   juce_data_structures, juce_events, juce_graphics,
+                   juce_gui_basics, juce_gui_extra
+ exporters:        xcode_mac, vs2019, linux_make
+
+ type:             Component
+ mainClass:        MainContentComponent
+
+ useLocalCopy:     1
+
+ END_JUCE_PIP_METADATA
+
+*******************************************************************************/
+
+
+#pragma once
+
+//==============================================================================
+class WavetableOscillator
+{
+public:
+    WavetableOscillator (const juce::AudioSampleBuffer& wavetableToUse)
+        : wavetable (wavetableToUse)
+    {
+        jassert (wavetable.getNumChannels() == 1);
+    }
+
+    void setFrequency (float frequency, float sampleRate)
+    {
+        auto tableSizeOverSampleRate = (float) wavetable.getNumSamples() / sampleRate;
+        tableDelta = frequency * tableSizeOverSampleRate;
+    }
+
+    forcedinline float getNextSample() noexcept
+    {
+        auto tableSize = (unsigned int) wavetable.getNumSamples();
+
+        auto index0 = (unsigned int) currentIndex;              // [6]
+        auto index1 = index0 == (tableSize - 1) ? (unsigned int) 0 : index0 + 1;
+
+        auto frac = currentIndex - (float) index0;              // [7]
+
+        auto* table = wavetable.getReadPointer (0);             // [8]
+        auto value0 = table[index0];
+        auto value1 = table[index1];
+
+        auto currentSample = value0 + frac * (value1 - value0); // [9]
+
+        if ((currentIndex += tableDelta) > (float) tableSize)   // [10]
+            currentIndex -= (float) tableSize;
+
+        return currentSample;
+    }
+
+private:
+    const juce::AudioSampleBuffer& wavetable;
+    float currentIndex = 0.0f, tableDelta = 0.0f;
+};
+
+//==============================================================================
+class MainContentComponent   : public juce::AudioAppComponent,
+                               public juce::Timer
+{
+public:
+    MainContentComponent()
+    {
+        cpuUsageLabel.setText ("CPU Usage", juce::dontSendNotification);
+        cpuUsageText.setJustificationType (juce::Justification::right);
+        addAndMakeVisible (cpuUsageLabel);
+        addAndMakeVisible (cpuUsageText);
+
+        createWavetable();
+
+        setSize (400, 200);
+        setAudioChannels (0, 2); // no inputs, two outputs
+        startTimer (50);
+    }
+
+    ~MainContentComponent() override
+    {
+        shutdownAudio();
+    }
+
+    void resized() override
+    {
+        cpuUsageLabel.setBounds (10, 10, getWidth() - 20, 20);
+        cpuUsageText .setBounds (10, 10, getWidth() - 20, 20);
+    }
+
+    void timerCallback() override
+    {
+        auto cpu = deviceManager.getCpuUsage() * 100;
+        cpuUsageText.setText (juce::String (cpu, 6) + " %", juce::dontSendNotification);
+    }
+
+    void createWavetable()
+    {
+        sineTable.setSize (1, (int) tableSize);
+        auto* samples = sineTable.getWritePointer (0);                                   // [3]
+
+        auto angleDelta = juce::MathConstants<double>::twoPi / (double) (tableSize - 1); // [4]
+        auto currentAngle = 0.0;
+
+        for (unsigned int i = 0; i < tableSize; ++i)
+        {
+            auto sample = std::sin (currentAngle);                                       // [5]
+            samples[i] = (float) sample;
+            currentAngle += angleDelta;
+        }
+    }
+
+    void prepareToPlay (int, double sampleRate) override
+    {
+        auto numberOfOscillators = 200;
+
+        for (auto i = 0; i < numberOfOscillators; ++i)
+        {
+            auto* oscillator = new WavetableOscillator (sineTable);
+
+            auto midiNote = juce::Random::getSystemRandom().nextDouble() * 36.0 + 48.0;
+            auto frequency = 440.0 * pow (2.0, (midiNote - 69.0) / 12.0);
+
+            oscillator->setFrequency ((float) frequency, (float) sampleRate);
+            oscillators.add (oscillator);
+        }
+
+        level = 0.25f / (float) numberOfOscillators;
+    }
+
+    void releaseResources() override {}
+
+    void getNextAudioBlock (const juce::AudioSourceChannelInfo& bufferToFill) override
+    {
+        auto* leftBuffer  = bufferToFill.buffer->getWritePointer (0, bufferToFill.startSample);
+        auto* rightBuffer = bufferToFill.buffer->getWritePointer (1, bufferToFill.startSample);
+
+        bufferToFill.clearActiveBufferRegion();
+
+        for (auto oscillatorIndex = 0; oscillatorIndex < oscillators.size(); ++oscillatorIndex)
+        {
+            auto* oscillator = oscillators.getUnchecked (oscillatorIndex);
+
+            for (auto sample = 0; sample < bufferToFill.numSamples; ++sample)
+            {
+                auto levelSample = oscillator->getNextSample() * level;
+
+                leftBuffer[sample]  += levelSample;
+                rightBuffer[sample] += levelSample;
+            }
+        }
+    }
+
+private:
+    juce::Label cpuUsageLabel;
+    juce::Label cpuUsageText;
+
+    const unsigned int tableSize = 1 << 7;      // [2]
+    float level = 0.0f;
+
+    juce::AudioSampleBuffer sineTable;          // [1]
+    juce::OwnedArray<WavetableOscillator> oscillators;
+
+    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (MainContentComponent)
+};