feat: SynthSound moved to utils

utils.c

@@ -0,0 +1,30 @@
+#include "utils.h"
+#include "stdlib.h"
+#include "string.h"
+
+// frees the original sounds
+SynthSound concat_sounds(SynthSound* sounds, size_t count) {
+    size_t total_count = 0;
+    for (size_t i = 0; i < count; i++) {
+        total_count += sounds[i].sample_count;
+    }
+    // array to hold the result
+    float* total = malloc(total_count * sizeof(float));
+
+    size_t current_count = 0;
+    for (size_t i = 0; i < count; i++) {
+        memcpy(total + current_count,
+            sounds[i].samples,
+            sounds[i].sample_count * sizeof(float));
+        current_count += sounds[i].sample_count;
+
+        free(sounds[i].samples);
+    }
+
+    SynthSound result = {
+        .samples = total,
+        .sample_count = total_count
+    };
+
+    return result;
+}