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

Examples/Core/TextFileLoading.cs

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+/*******************************************************************************************
+*
+*   raylib [core] example - text file loading
+*
+*   Example complexity rating: [★☆☆☆] 1/4
+*
+*   Example originally created with raylib 5.5, last time updated with raylib 5.6
+*
+*   Example contributed by Aanjishnu Bhattacharyya (@NimComPoo-04) 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) 0 Aanjishnu Bhattacharyya (@NimComPoo-04)
+*
+********************************************************************************************/
+
+using System.Numerics;
+using static Raylib_cs.Raylib;
+using static Raylib_cs.Raymath;
+
+namespace Examples.Core;
+
+// NOTE: The upstream C code mutates the raw char buffers returned by LoadTextLines() in place,
+// temporarily null-terminating to reuse MeasureText for word wrapping. This C# port keeps the
+// same algorithm but works on managed char arrays: LoadFileText + split on '\n' reproduces
+// raylib's LoadTextLines('\n') behaviour, and '\n' characters are inserted where lines wrap.
+public partial class TextFileLoading : IExample
+{
+    private const int screenWidth = 800;
+    private const int screenHeight = 450;
+
+    public string Name => "Core / Text File Loading";
+
+    public string Title => "raylib [core] example - text file loading";
+
+    private Camera2D cam;
+    private string fileName;
+    private string[] lines;
+    private int lineCount;
+    private int fontSize;
+    private int textTop;
+    private int wrapWidth;
+    private int textHeight;
+    private Rectangle scrollBar;
+
+    public void Init()
+    {
+        // Setting up the camera
+        cam = new Camera2D();
+        cam.Offset = new Vector2(0, 0);
+        cam.Target = new Vector2(0, 0);
+        cam.Rotation = 0;
+        cam.Zoom = 1;
+
+        // Loading text file from resources/text_file.txt
+        fileName = "resources/text_file.txt";
+        string text = LoadFileText(fileName);
+
+        // Loading all the text lines (raylib's LoadTextLines splits on '\n')
+        lines = text.Split('\n');
+        lineCount = lines.Length;
+
+        // Stylistic choises
+        fontSize = 20;
+        textTop = 25 + fontSize; // Top of the screen from where the text is rendered
+        wrapWidth = screenWidth - 20;
+
+        // Wrap the lines as needed
+        for (int i = 0; i < lineCount; i++)
+        {
+            char[] chars = lines[i].ToCharArray();
+            int len = chars.Length;
+            int j = 0;
+            int lastSpace = 0;          // Keeping track of last valid space to insert '\n'
+            int lastWrapStart = 0;      // Keeping track of the start of this wrapped line.
+
+            while (j <= len)
+            {
+                char cur = (j < len) ? chars[j] : '\0';
+                if (cur == ' ' || cur == '\0')
+                {
+                    // Making a C style string by "cutting" at the required location so that we can use MeasureText
+                    string sub = new string(chars, lastWrapStart, j - lastWrapStart);
+
+                    // Checking if the text has crossed the wrapWidth, then going back and inserting a newline
+                    if (MeasureText(sub, fontSize) > wrapWidth)
+                    {
+                        chars[lastSpace] = '\n';
+
+                        // Since we added a newline the place of wrap changed so we update our lastWrapStart
+                        lastWrapStart = lastSpace + 1;
+                    }
+
+                    lastSpace = j; // Since we encountered a new space we update our last encountered space location
+                }
+
+                j++;
+            }
+
+            lines[i] = new string(chars);
+        }
+
+        // Calculating the total height so that we can show a scrollbar
+        textHeight = 0;
+
+        for (int i = 0; i < lineCount; i++)
+        {
+            Vector2 size = MeasureTextEx(GetFontDefault(), lines[i], (float)fontSize, 2);
+            textHeight += (int)size.Y + 10;
+        }
+
+        // A simple scrollbar on the side to show how far we have read into the file
+        scrollBar = new Rectangle(
+            (float)screenWidth - 5,
+            0,
+            5,
+            screenHeight * 100.0f / (textHeight - screenHeight)); // Scrollbar height is just a percentage
+    }
+
+    public void Update()
+    {
+        // Update
+        //----------------------------------------------------------------------------------
+        float scroll = GetMouseWheelMove();
+        cam.Target.Y -= scroll * fontSize * 1.5f;   // Choosing an arbitrary speed for scroll
+
+        if (cam.Target.Y < 0) cam.Target.Y = 0;  // Snapping to 0 if we go too far back
+
+        // Ensuring that the camera does not scroll past all text
+        if (cam.Target.Y > textHeight - screenHeight + textTop)
+            cam.Target.Y = (float)textHeight - screenHeight + textTop;
+
+        // Computing the position of the scrollBar depending on the percentage of text covered
+        scrollBar.Y = Lerp((float)textTop, (float)screenHeight - scrollBar.Height, (float)(cam.Target.Y - textTop) / (textHeight - screenHeight));
+        //----------------------------------------------------------------------------------
+
+        // Draw
+        //----------------------------------------------------------------------------------
+        BeginDrawing();
+
+        ClearBackground(Color.RayWhite);
+
+        BeginMode2D(cam);
+        // Going through all the read lines
+        for (int i = 0, t = textTop; i < lineCount; i++)
+        {
+            // Each time we go through and calculate the height of the text to move the cursor appropriately
+            Vector2 size;
+            if (lines[i] != "")
+            {
+                size = MeasureTextEx(GetFontDefault(), lines[i], (float)fontSize, 2);
+            }
+            else
+            {
+                // Fix for empty line in the text file
+                size = MeasureTextEx(GetFontDefault(), " ", (float)fontSize, 2);
+            }
+
+            DrawText(lines[i], 10, t, fontSize, Color.Red);
+
+            // Inserting extra space for real newlines,
+            // wrapped lines are rendered closer together
+            t += (int)size.Y + 10;
+        }
+        EndMode2D();
+
+        // Header displaying which file is being read currently
+        DrawRectangle(0, 0, screenWidth, textTop - 10, Color.Beige);
+        DrawText($"File: {fileName}", 10, 10, fontSize, Color.Maroon);
+
+        DrawRectangleRec(scrollBar, Color.Maroon);
+
+        EndDrawing();
+        //----------------------------------------------------------------------------------
+    }
+
+    public void Unload()
+    {
+    }
+
+    public static int Main()
+    {
+        // Initialization
+        //--------------------------------------------------------------------------------------
+        InitWindow(screenWidth, screenHeight, "raylib [core] example - text file loading");
+
+        var game = new TextFileLoading();
+        game.Init();
+
+        SetTargetFPS(60);
+        //--------------------------------------------------------------------------------------
+
+        // 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;
+    }
+}