From 321a0cd118368be266664f91d13c9a475484d672 Mon Sep 17 00:00:00 2001
From: Borin Ouch <borin.ouch@gmail.com>
Date: Thu, 25 Apr 2024 09:17:03 -0700
Subject: [PATCH] Plot generated samples

---
 src/sound.cpp | 14 ++++++++------
 src/sound.h   |  1 +
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/src/sound.cpp b/src/sound.cpp
index c353552..3576de2 100644
--- a/src/sound.cpp
+++ b/src/sound.cpp
@@ -1,6 +1,7 @@
 #include "sound.h"
 
 #include <cmath>
+#include <cstring>
 #include <spdlog/spdlog.h>
 #include <raylib.h>
 #include <imgui.h>
@@ -47,11 +48,6 @@ void WaveGeneratorSource::render() {
     }
     ImGui::EndCombo();
   }
-
-  std::array<float, 100> samples;
-  for (int n = 0; n < 100; n += 1) {
-    samples[n] = sinf(n * 0.2f + ImGui::GetTime() * 5.f);
-  }
   ImGui::PlotLines("Sound", samples.data(), samples.size(), 0, nullptr, -1.5f, 1.5f, ImVec2(0, 80.0f));
   ImGui::SliderFloat("Volume", &volume, 0.0f, 100.0f);
   ImGui::SliderFloat("Frequency", &frequency, 10.0f, 2048.0f);
@@ -88,6 +84,7 @@ static inline float sawtooth_wave(float idx) {
 void WaveGeneratorSource::gen_sound_data(bool play_sound, short buffer[], size_t buffer_size) {
   if (!play_sound && !force_play) {
     memset(buffer, 0, sizeof(short) * buffer_size);
+    memset(&samples, 0, sizeof(float) * samples.size());
     return;
   }
 
@@ -104,7 +101,12 @@ void WaveGeneratorSource::gen_sound_data(bool play_sound, short buffer[], size_t
   })();
 
   for (int i = 0; i < buffer_size; i++) {
-    buffer[i] = static_cast<short>(((1 << 15) - 1) * wave_func(wave_idx) * (volume / 100.0f));
+    float sample = wave_func(wave_idx) * (volume / 100.0f);
+    buffer[i] = static_cast<short>(((1 << 15) - 1) * sample);
+
+    if (i < samples.size()) {
+      samples[i] = sample;
+    }
 
     wave_idx += incr;
     if (wave_idx > 1.0f)
diff --git a/src/sound.h b/src/sound.h
index 7803387..4c86039 100644
--- a/src/sound.h
+++ b/src/sound.h
@@ -28,6 +28,7 @@ class WaveGeneratorSource : public SoundSource {
   virtual void gen_sound_data(bool play_sound, short buffer[], size_t buffer_size) override;
 
 private:
+  std::array<float, 1000> samples;
   bool force_play = false;
   float frequency = 440.0f;
   float volume = 100.0f;