sine: added project

sine/Source/MainComponent.cpp

@@ -0,0 +1,86 @@
+#include "../JuceLibraryCode/JuceHeader.h"
+
+class MainContentComponent : public AudioAppComponent,
+                             public Slider::Listener {
+public:
+    MainContentComponent() : samplerate(0.0),
+                             angle(0.0),
+                             delta(0.0),
+                             current(500.0),
+                             target(current) {
+        addAndMakeVisible(freqslider);
+        freqslider.setRange(50.0, 5000.0);
+        freqslider.setSkewFactorFromMidPoint(500.0);
+        freqslider.setValue(current, dontSendNotification);
+        freqslider.addListener(this);
+        
+        setSize(800, 600);
+
+        setAudioChannels(0, 1);
+    }
+
+    ~MainContentComponent() {
+        shutdownAudio();
+    }
+
+    void prepareToPlay (int, double sampleRate) override {
+        samplerate = sampleRate;
+        updateDelta();
+    }
+    
+    void getNextAudioBlock(const AudioSourceChannelInfo& buf) override {
+        const float level = 0.125f;
+        float* const buffer = buf.buffer->getWritePointer(0, buf.startSample);
+        const double lt = target;
+        
+        if (lt != current) {
+            const double i = (lt - current) / buf.numSamples;
+            
+            for (int s = 0; s < buf.numSamples; ++s) {
+                const float c = (float) std::sin (angle);
+                current += i;
+                updateDelta();
+                angle += delta;
+                buffer[s] = c * level;
+            }
+            
+            current = lt;
+        } else {
+            for (int s = 0; s < buf.numSamples; ++s) {
+                const float c = (float) std::sin (angle);
+                angle += delta;
+                buffer[s] = c* level;
+            }
+        }
+    }
+    
+    void updateDelta() {
+        const double c = freqslider.getValue() / samplerate;
+        delta = c * 2.0 * double_Pi;
+    }
+                                 
+    void sliderValueChanged(Slider* s) override {
+        if (s == &freqslider) target = freqslider.getValue();
+    }
+
+    void releaseResources() override {}
+
+    void paint (Graphics& g) override {
+        g.fillAll (getLookAndFeel().findColour(ResizableWindow::backgroundColourId));
+    }
+
+    void resized() override{
+        freqslider.setBounds(10, 10, getWidth() - 10, 20);
+    }
+
+
+private:
+    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (MainContentComponent)
+    
+    double samplerate, angle, delta;
+    double current, target;
+    
+    Slider freqslider;
+};
+
+Component* createMainContentComponent() { return new MainContentComponent(); }