feat: backporting existing raylib-cs examples and new official raylib examples to WASM, adopting raylib's original code style

Examples/Audio/MixedProcessor.cs

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+/*******************************************************************************************
+*
+*   raylib [audio] example - mixed processor
+*
+*   Example complexity rating: [★★★★] 4/4
+*
+*   Example originally created with raylib 4.2, last time updated with raylib 4.2
+*
+*   Example contributed by hkc (@hatkidchan) and reviewed by Ramon Santamaria (@raysan5)
+*
+*   Example licensed under an unmodified zlib/libpng license, which is an OSI-certified,
+*   BSD-like license that allows static linking with closed source software
+*
+*   Copyright (c) 2023-2025 hkc (@hatkidchan)
+*
+********************************************************************************************/
+
+using System;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using static Raylib_cs.Raylib;
+
+namespace Examples.Audio;
+
+[ExcludeFromBrowser("AttachAudioMixedProcessor callback is unreliable on the wasm audio backend")]
+public unsafe partial class MixedProcessor : IExample
+{
+    private const int screenWidth = 800;
+    private const int screenHeight = 450;
+
+    public string Name => "Audio / Mixed Processor";
+
+    public string Title => "raylib [audio] example - mixed processor";
+
+    private static float exponent = 1.0f;                       // Audio exponentiation value
+    private static readonly float[] averageVolume = new float[400];   // Average volume history
+
+    private Music music;
+    private Sound sound;
+
+    //------------------------------------------------------------------------------------
+    // Audio processing function
+    //------------------------------------------------------------------------------------
+    [UnmanagedCallersOnly(CallConvs = new[] { typeof(CallConvCdecl) })]
+    private static void ProcessAudio(void* buffer, uint frames)
+    {
+        float* samples = (float*)buffer;    // Samples internally stored as <float>s
+        float average = 0.0f;               // Temporary average volume
+
+        for (uint frame = 0; frame < frames; frame++)
+        {
+            float* left = &samples[frame * 2 + 0];
+            float* right = &samples[frame * 2 + 1];
+
+            *left = MathF.Pow(MathF.Abs(*left), exponent) * ((*left < 0.0f) ? -1.0f : 1.0f);
+            *right = MathF.Pow(MathF.Abs(*right), exponent) * ((*right < 0.0f) ? -1.0f : 1.0f);
+
+            average += MathF.Abs(*left) / frames;   // accumulating average volume
+            average += MathF.Abs(*right) / frames;
+        }
+
+        // Moving history to the left
+        for (int i = 0; i < 399; i++) averageVolume[i] = averageVolume[i + 1];
+
+        averageVolume[399] = average;       // Adding last average value
+    }
+
+    public void Init()
+    {
+        InitAudioDevice();              // Initialize audio device
+
+        exponent = 1.0f;
+        Array.Clear(averageVolume, 0, averageVolume.Length);
+
+        AttachAudioMixedProcessor(&ProcessAudio);
+
+        music = LoadMusicStream("resources/audio/country.mp3");
+        sound = LoadSound("resources/audio/coin.wav");
+
+        PlayMusicStream(music);
+    }
+
+    public void Update()
+    {
+        // Update
+        //----------------------------------------------------------------------------------
+        UpdateMusicStream(music);   // Update music buffer with new stream data
+
+        // Modify processing variables
+        //----------------------------------------------------------------------------------
+        if (IsKeyPressed(KeyboardKey.Left)) exponent -= 0.05f;
+        if (IsKeyPressed(KeyboardKey.Right)) exponent += 0.05f;
+
+        if (exponent <= 0.5f) exponent = 0.5f;
+        if (exponent >= 3.0f) exponent = 3.0f;
+
+        if (IsKeyPressed(KeyboardKey.Space)) PlaySound(sound);
+
+        // Draw
+        //----------------------------------------------------------------------------------
+        BeginDrawing();
+
+        ClearBackground(Color.RayWhite);
+
+        DrawText("MUSIC SHOULD BE PLAYING!", 255, 150, 20, Color.LightGray);
+
+        DrawText($"EXPONENT = {exponent:F2}", 215, 180, 20, Color.LightGray);
+
+        DrawRectangle(199, 199, 402, 34, Color.LightGray);
+        for (int i = 0; i < 400; i++)
+        {
+            DrawLine(201 + i, 232 - (int)(averageVolume[i] * 32), 201 + i, 232, Color.Maroon);
+        }
+        DrawRectangleLines(199, 199, 402, 34, Color.Gray);
+
+        DrawText("PRESS SPACE TO PLAY OTHER SOUND", 200, 250, 20, Color.LightGray);
+        DrawText("USE LEFT AND RIGHT ARROWS TO ALTER DISTORTION", 140, 280, 20, Color.LightGray);
+
+        EndDrawing();
+        //----------------------------------------------------------------------------------
+    }
+
+    public void Unload()
+    {
+        UnloadMusicStream(music);   // Unload music stream buffers from RAM
+
+        DetachAudioMixedProcessor(&ProcessAudio);  // Disconnect audio processor
+
+        CloseAudioDevice();         // Close audio device (music streaming is automatically stopped)
+    }
+
+    public static int Main()
+    {
+        // Initialization
+        //--------------------------------------------------------------------------------------
+        InitWindow(screenWidth, screenHeight, "raylib [audio] example - mixed processor");
+
+        SetTargetFPS(60);               // Set our game to run at 60 frames-per-second
+        //--------------------------------------------------------------------------------------
+
+        var game = new MixedProcessor();
+        game.Init();
+
+        // Main game loop
+        while (!WindowShouldClose())    // Detect window close button or ESC key
+        {
+            game.Update();
+        }
+
+        game.Unload();
+
+        // De-Initialization
+        //--------------------------------------------------------------------------------------
+        CloseWindow();              // Close window and OpenGL context
+        //--------------------------------------------------------------------------------------
+
+        return 0;
+    }
+}