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

Examples/Core/CustomFrameControl.cs

@@ -0,0 +1,188 @@
+/*******************************************************************************************
+*
+*   raylib [core] example - custom frame control
+*
+*   Example complexity rating: [★★★★] 4/4
+*
+*   NOTE: WARNING: This is an example for advanced users willing to have full control over
+*   the frame processes. By default, EndDrawing() calls the following processes:
+*       1. Draw remaining batch data: rlDrawRenderBatchActive()
+*       2. SwapScreenBuffer()
+*       3. Frame time control: WaitTime()
+*       4. PollInputEvents()
+*
+*   To avoid steps 2, 3 and 4, flag SUPPORT_CUSTOM_FRAME_CONTROL can be enabled in
+*   config.h (it requires recompiling raylib). This way those steps are up to the user
+*
+*   Note that enabling this flag invalidates some functions:
+*       - GetFrameTime()
+*       - SetTargetFPS()
+*       - GetFPS()
+*
+*   Example originally created with raylib 4.0, last time updated with raylib 4.0
+*
+*   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) 2021-2025 Ramon Santamaria (@raysan5)
+*
+********************************************************************************************/
+
+using static Raylib_cs.Raylib;
+
+namespace Examples.Core;
+
+// NOTE: This example is intended to run against a raylib built with SUPPORT_CUSTOM_FRAME_CONTROL,
+// where EndDrawing() does NOT swap buffers, wait or poll input, leaving those to the user code
+// below. The stock raylib-cs native library is built WITHOUT that flag, so EndDrawing() still
+// performs those steps and the manual SwapScreenBuffer()/WaitTime()/PollInputEvents() calls here
+// run in addition to them. The port is kept faithful to upstream regardless.
+[ExcludeFromBrowser("manual PollInputEvents/SwapScreenBuffer/WaitTime clashes with the emscripten main loop")]
+public partial class CustomFrameControl : IExample
+{
+    private const int screenWidth = 800;
+    private const int screenHeight = 450;
+
+    public string Name => "Core / Custom Frame Control";
+
+    public string Title => "raylib [core] example - custom frame control";
+
+    // Custom timming variables
+    private double previousTime;    // Previous time measure
+    private double currentTime;     // Current time measure
+    private double updateDrawTime;  // Update + Draw time
+    private double waitTime;        // Wait time (if target fps required)
+    private float deltaTime;        // Frame time (Update + Draw + Wait time)
+
+    private float timeCounter;      // Accumulative time counter (seconds)
+    private float position;         // Circle position
+    private bool pause;             // Pause control flag
+
+    private int targetFPS;          // Our initial target fps
+
+    public void Init()
+    {
+        previousTime = GetTime();
+        currentTime = 0.0;
+        updateDrawTime = 0.0;
+        waitTime = 0.0;
+        deltaTime = 0.0f;
+
+        timeCounter = 0.0f;
+        position = 0.0f;
+        pause = false;
+
+        targetFPS = 60;
+    }
+
+    public void Update()
+    {
+        // Update
+        //----------------------------------------------------------------------------------
+#if !BROWSER
+        // NOTE: On non web platforms the PollInputEvents just works before the inputs checks
+        PollInputEvents();          // Poll input events (SUPPORT_CUSTOM_FRAME_CONTROL)
+#endif
+
+        if (IsKeyPressed(KeyboardKey.Space)) pause = !pause;
+
+        if (IsKeyPressed(KeyboardKey.Up)) targetFPS += 20;
+        else if (IsKeyPressed(KeyboardKey.Down)) targetFPS -= 20;
+
+        if (targetFPS < 0) targetFPS = 0;
+
+        if (!pause)
+        {
+            position += 200 * deltaTime;  // We move at 200 pixels per second
+            if (position >= GetScreenWidth()) position = 0;
+            timeCounter += deltaTime;   // We count time (seconds)
+        }
+
+#if BROWSER
+        // NOTE: On web platform for some reason the PollInputEvents only works after the inputs
+        // check, so just call it after check all your inputs (on web)
+        PollInputEvents();          // Poll input events (SUPPORT_CUSTOM_FRAME_CONTROL)
+#endif
+        //----------------------------------------------------------------------------------
+
+        // Draw
+        //----------------------------------------------------------------------------------
+        BeginDrawing();
+
+        ClearBackground(Color.RayWhite);
+
+        for (int i = 0; i < GetScreenWidth() / 200; i++) DrawRectangle(200 * i, 0, 1, GetScreenHeight(), Color.SkyBlue);
+
+        DrawCircle((int)position, GetScreenHeight() / 2 - 25, 50, Color.Red);
+
+        DrawText($"{timeCounter * 1000.0f:000} ms", (int)position - 40, GetScreenHeight() / 2 - 100, 20, Color.Maroon);
+        DrawText($"PosX: {position:000}", (int)position - 50, GetScreenHeight() / 2 + 40, 20, Color.Black);
+
+        DrawText("Circle is moving at a constant 200 pixels/sec,\nindependently of the frame rate.", 10, 10, 20, Color.DarkGray);
+        DrawText("PRESS SPACE to PAUSE MOVEMENT", 10, GetScreenHeight() - 60, 20, Color.Gray);
+        DrawText("PRESS UP | DOWN to CHANGE TARGET FPS", 10, GetScreenHeight() - 30, 20, Color.Gray);
+        DrawText($"TARGET FPS: {targetFPS}", GetScreenWidth() - 220, 10, 20, Color.Lime);
+        if (deltaTime != 0)
+        {
+            DrawText($"CURRENT FPS: {(int)(1.0f / deltaTime)}", GetScreenWidth() - 220, 40, 20, Color.Green);
+        }
+
+        EndDrawing();
+
+        // NOTE: In case raylib is configured to SUPPORT_CUSTOM_FRAME_CONTROL,
+        // Events polling, screen buffer swap and frame time control must be managed by the user
+
+        SwapScreenBuffer();         // Flip the back buffer to screen (front buffer)
+
+        currentTime = GetTime();
+        updateDrawTime = currentTime - previousTime;
+
+        if (targetFPS > 0)          // We want a fixed frame rate
+        {
+            waitTime = (1.0f / (float)targetFPS) - updateDrawTime;
+            if (waitTime > 0.0)
+            {
+                WaitTime((float)waitTime);
+                currentTime = GetTime();
+                deltaTime = (float)(currentTime - previousTime);
+            }
+        }
+        else deltaTime = (float)updateDrawTime;    // Framerate could be variable
+
+        previousTime = currentTime;
+        //----------------------------------------------------------------------------------
+    }
+
+    public void Unload()
+    {
+    }
+
+    public static int Main()
+    {
+        // Initialization
+        //--------------------------------------------------------------------------------------
+        InitWindow(screenWidth, screenHeight, "raylib [core] example - custom frame control");
+
+        // NOTE: Not calling SetTargetFPS(): this example manages frame timing manually with
+        // WaitTime() (SetTargetFPS/GetFrameTime/GetFPS are invalidated by SUPPORT_CUSTOM_FRAME_CONTROL)
+        //--------------------------------------------------------------------------------------
+
+        var game = new CustomFrameControl();
+        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;
+    }
+}