Sound: Implement pitch effect

Author: adazem009

include/scratchcpp/sound.h

@@ -16,6 +16,11 @@ class SoundPrivate;
 class LIBSCRATCHCPP_EXPORT Sound : public Asset
 {
     public:
+        enum class Effect
+        {
+            Pitch
+        };
+
         Sound(const std::string &name, const std::string &id, const std::string &format);
         Sound(const Sound &) = delete;
         virtual ~Sound() { }
@@ -27,6 +32,7 @@ class LIBSCRATCHCPP_EXPORT Sound : public Asset
         void setSampleCount(int newSampleCount);
 
         virtual void setVolume(double volume);
+        virtual void setEffect(Effect effect, double value);
 
         virtual void start();
         virtual void stop();

src/scratch/sound.cpp

@@ -3,11 +3,18 @@
 #include <scratchcpp/sound.h>
 #include <scratchcpp/sprite.h>
 #include <iostream>
+#include <unordered_map>
+#include <algorithm>
+#include <cmath>
 
 #include "sound_p.h"
 
 using namespace libscratchcpp;
 
+static std::unordered_map<Sound::Effect, std::pair<double, double>> EFFECT_RANGE = {
+    { Sound::Effect::Pitch, { -360, 360 } } // -3 to 3 octaves
+};
+
 /*! Constructs Sound. */
 Sound::Sound(const std::string &name, const std::string &id, const std::string &format) :
     Asset(name, id, format),
@@ -45,6 +52,25 @@ void Sound::setVolume(double volume)
     impl->player->setVolume(volume / 100);
 }
 
+/*! Sets the value of the given sound effect. */
+void Sound::setEffect(Effect effect, double value)
+{
+    auto it = EFFECT_RANGE.find(effect);
+
+    if (it == EFFECT_RANGE.cend())
+        return;
+
+    value = std::clamp(value, it->second.first, it->second.second);
+
+    switch (effect) {
+        case Effect::Pitch:
+            // Convert from linear
+            const double root = std::pow(2, 1 / 12.0);
+            impl->player->setPitch(std::pow(root, value / 10));
+            break;
+    }
+}
+
 /*! Starts the playback of the sound. */
 void Sound::start()
 {
@@ -88,6 +114,7 @@ std::shared_ptr<Sound> Sound::clone() const
     sound->setSampleCount(sampleCount());
     sound->impl->cloneRoot = root;
     sound->impl->player->setVolume(impl->player->volume());
+    sound->impl->player->setPitch(impl->player->pitch());
 
     if (root->impl->player->isLoaded()) {
         sound->impl->player->loadCopy(root->impl->player.get());

test/assets/sound_test.cpp

@@ -79,6 +79,33 @@ TEST_F(SoundTest, SetVolume)
     sound.setVolume(56.04);
 }
 
+TEST_F(SoundTest, SetEffect)
+{
+    Sound sound("sound1", "a", "wav");
+
+    // Pitch
+    EXPECT_CALL(*m_player, setPitch(0.125));
+    sound.setEffect(Sound::Effect::Pitch, -400);
+
+    EXPECT_CALL(*m_player, setPitch(0.125));
+    sound.setEffect(Sound::Effect::Pitch, -360);
+
+    EXPECT_CALL(*m_player, setPitch(0.5));
+    sound.setEffect(Sound::Effect::Pitch, -120);
+
+    EXPECT_CALL(*m_player, setPitch(1));
+    sound.setEffect(Sound::Effect::Pitch, 0);
+
+    EXPECT_CALL(*m_player, setPitch(2));
+    sound.setEffect(Sound::Effect::Pitch, 120);
+
+    EXPECT_CALL(*m_player, setPitch(8));
+    sound.setEffect(Sound::Effect::Pitch, 360);
+
+    EXPECT_CALL(*m_player, setPitch(8));
+    sound.setEffect(Sound::Effect::Pitch, 400);
+}
+
 TEST_F(SoundTest, Start)
 {
     Sound sound("sound1", "a", "wav");
@@ -137,6 +164,8 @@ TEST_F(SoundTest, Clone)
     EXPECT_CALL(*clonePlayer, loadCopy(m_player.get())).WillOnce(Return(true));
     EXPECT_CALL(*m_player, volume()).WillOnce(Return(0.45));
     EXPECT_CALL(*clonePlayer, setVolume(0.45));
+    EXPECT_CALL(*m_player, pitch()).WillOnce(Return(1.25));
+    EXPECT_CALL(*clonePlayer, setPitch(1.25));
     EXPECT_CALL(*clonePlayer, isLoaded()).WillOnce(Return(true));
     auto clone = sound->clone();
     ASSERT_TRUE(clone);
@@ -152,6 +181,8 @@ TEST_F(SoundTest, Clone)
     EXPECT_CALL(*cloneClonePlayer, loadCopy(m_player.get())).WillOnce(Return(true));
     EXPECT_CALL(*clonePlayer, volume()).WillOnce(Return(0.62));
     EXPECT_CALL(*cloneClonePlayer, setVolume(0.62));
+    EXPECT_CALL(*clonePlayer, pitch()).WillOnce(Return(0.5));
+    EXPECT_CALL(*cloneClonePlayer, setPitch(0.5));
     EXPECT_CALL(*cloneClonePlayer, isLoaded()).WillOnce(Return(true));
     auto cloneClone = clone->clone();
     ASSERT_TRUE(cloneClone);
@@ -162,6 +193,8 @@ TEST_F(SoundTest, Clone)
     EXPECT_CALL(*anotherClonePlayer, loadCopy).Times(0);
     EXPECT_CALL(*clonePlayer, volume()).WillOnce(Return(0.62));
     EXPECT_CALL(*anotherClonePlayer, setVolume(0.62));
+    EXPECT_CALL(*clonePlayer, pitch()).WillOnce(Return(2));
+    EXPECT_CALL(*anotherClonePlayer, setPitch(2));
     EXPECT_CALL(*anotherClonePlayer, isLoaded()).Times(0);
     auto anotherClone = clone->clone();
     ASSERT_TRUE(anotherClone);