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

Examples/Textures/ScreenBuffer.cs

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+/*******************************************************************************************
+*
+*   raylib [textures] example - screen buffer
+*
+*   Example complexity rating: [★★☆☆] 2/4
+*
+*   Example originally created with raylib 5.5, last time updated with raylib 5.5
+*
+*   Example contributed by Agnis Aldiņš (@nezvers) 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) 2025 Agnis Aldiņš (@nezvers)
+*
+********************************************************************************************/
+
+using System.Numerics;
+using static Raylib_cs.Raylib;
+
+namespace Examples.Textures;
+
+public partial class ScreenBuffer : IExample
+{
+    private const int screenWidth = 800;
+    private const int screenHeight = 450;
+
+    private const int MaxColors = 256;
+    private const int ScaleFactor = 2;
+
+    private const int imageWidth = screenWidth / ScaleFactor;
+    private const int imageHeight = screenHeight / ScaleFactor;
+    private const int flameWidth = screenWidth / ScaleFactor;
+
+    public string Name => "Textures / Screen Buffer";
+
+    public string Title => "raylib [textures] example - screen buffer";
+
+    private Color[] palette;
+    private byte[] indexBuffer;
+    private byte[] flameRootBuffer;
+    private Image screenImage;
+    private Texture2D screenTexture;
+
+    public void Init()
+    {
+        palette = new Color[MaxColors];
+        indexBuffer = new byte[imageWidth * imageWidth];
+        flameRootBuffer = new byte[flameWidth];
+
+        screenImage = GenImageColor(imageWidth, imageHeight, Color.Black);
+        screenTexture = LoadTextureFromImage(screenImage);
+
+        // Generate flame color palette
+        for (var i = 0; i < MaxColors; i++)
+        {
+            var t = (float)i / (float)(MaxColors - 1);
+            var hue = t * t;
+            var saturation = t;
+            var value = t;
+
+            palette[i] = ColorFromHSV(250.0f + 150.0f * hue, saturation, value);
+        }
+    }
+
+    public unsafe void Update()
+    {
+        // Update
+        //----------------------------------------------------------------------------------
+        // Grow flameRoot
+        for (var x = 2; x < flameWidth; x++)
+        {
+            var flame = (int)flameRootBuffer[x];
+            flame += GetRandomValue(0, 2);
+            flameRootBuffer[x] = (flame > 255) ? (byte)255 : (byte)flame;
+        }
+
+        // Transfer flameRoot to indexBuffer
+        for (var x = 0; x < flameWidth; x++)
+        {
+            var i = x + (imageHeight - 1) * imageWidth;
+            indexBuffer[i] = flameRootBuffer[x];
+        }
+
+        // Clear top row, because it can't move any higher
+        for (var x = 0; x < imageWidth; x++)
+        {
+            if (indexBuffer[x] != 0)
+            {
+                indexBuffer[x] = 0;
+            }
+        }
+
+        // Skip top row, it is already cleared
+        for (var y = 1; y < imageHeight; y++)
+        {
+            for (var x = 0; x < imageWidth; x++)
+            {
+                var i = x + y * imageWidth;
+                int colorIndex = indexBuffer[i];
+
+                if (colorIndex != 0)
+                {
+                    // Move pixel a row above
+                    indexBuffer[i] = 0;
+                    var moveX = GetRandomValue(0, 2) - 1;
+                    var newX = x + moveX;
+
+                    if ((newX > 0) && (newX < imageWidth))
+                    {
+                        var iabove = i - imageWidth + moveX;
+                        var decay = GetRandomValue(0, 3);
+                        colorIndex -= (decay < colorIndex) ? decay : colorIndex;
+                        indexBuffer[iabove] = (byte)colorIndex;
+                    }
+                }
+            }
+        }
+
+        // Update screenImage with palette colors
+        for (var y = 1; y < imageHeight; y++)
+        {
+            for (var x = 0; x < imageWidth; x++)
+            {
+                var i = x + y * imageWidth;
+                int colorIndex = indexBuffer[i];
+                var col = palette[colorIndex];
+
+                ImageDrawPixel(ref screenImage, x, y, col);
+            }
+        }
+
+        UpdateTexture(screenTexture, screenImage.Data);
+        //----------------------------------------------------------------------------------
+
+        // Draw
+        //----------------------------------------------------------------------------------
+        BeginDrawing();
+
+        ClearBackground(Color.RayWhite);
+
+        DrawTextureEx(screenTexture, new Vector2(0, 0), 0.0f, 2.0f, Color.White);
+
+        EndDrawing();
+        //----------------------------------------------------------------------------------
+    }
+
+    public void Unload()
+    {
+        UnloadTexture(screenTexture);
+        UnloadImage(screenImage);
+    }
+
+    public static int Main()
+    {
+        // Initialization
+        //--------------------------------------------------------------------------------------
+        InitWindow(screenWidth, screenHeight, "raylib [textures] example - screen buffer");
+
+        SetTargetFPS(60);
+        //--------------------------------------------------------------------------------------
+
+        var game = new ScreenBuffer();
+        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;
+    }
+}