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

Examples/Core/Camera2dMouseZoom.cs

@@ -0,0 +1,184 @@
+/*******************************************************************************************
+*
+*   raylib [core] example - 2d camera mouse zoom
+*
+*   Example complexity rating: [★★☆☆] 2/4
+*
+*   Example originally created with raylib 4.2, last time updated with raylib 4.2
+*
+*   Example contributed by Jeffery Myers (@JeffM2501) 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) 2022-2025 Jeffery Myers (@JeffM2501)
+*
+********************************************************************************************/
+
+using System;
+using System.Numerics;
+using static Raylib_cs.Raylib;
+using static Raylib_cs.Raymath;
+
+namespace Examples.Core;
+
+public partial class Camera2dMouseZoom : IExample
+{
+    private const int screenWidth = 800;
+    private const int screenHeight = 450;
+
+    public string Name => "Core / Camera 2D Mouse Zoom";
+
+    public string Title => "raylib [core] example - 2d camera mouse zoom";
+
+    private Camera2D camera;
+    private int zoomMode;       // 0-Mouse Wheel, 1-Mouse Move
+
+    public void Init()
+    {
+        camera = new Camera2D();
+        camera.Zoom = 1.0f;
+
+        zoomMode = 0;
+    }
+
+    public void Update()
+    {
+        // Update
+        //----------------------------------------------------------------------------------
+        if (IsKeyPressed(KeyboardKey.One))
+        {
+            zoomMode = 0;
+        }
+        else if (IsKeyPressed(KeyboardKey.Two))
+        {
+            zoomMode = 1;
+        }
+
+        // Translate based on mouse right click
+        if (IsMouseButtonDown(MouseButton.Left))
+        {
+            Vector2 delta = GetMouseDelta();
+            delta = Vector2Scale(delta, -1.0f / camera.Zoom);
+            camera.Target = Vector2Add(camera.Target, delta);
+        }
+
+        if (zoomMode == 0)
+        {
+            // Zoom based on mouse wheel
+            float wheel = GetMouseWheelMove();
+            if (wheel != 0)
+            {
+                // Get the world point that is under the mouse
+                Vector2 mouseWorldPos = GetScreenToWorld2D(GetMousePosition(), camera);
+
+                // Set the offset to where the mouse is
+                camera.Offset = GetMousePosition();
+
+                // Set the target to match, so that the camera maps the world space point
+                // under the cursor to the screen space point under the cursor at any zoom
+                camera.Target = mouseWorldPos;
+
+                // Zoom increment
+                // Uses log scaling to provide consistent zoom speed
+                float scale = 0.2f * wheel;
+                camera.Zoom = Clamp(MathF.Exp(MathF.Log(camera.Zoom) + scale), 0.125f, 64.0f);
+            }
+        }
+        else
+        {
+            // Zoom based on mouse right click
+            if (IsMouseButtonPressed(MouseButton.Right))
+            {
+                // Get the world point that is under the mouse
+                Vector2 mouseWorldPos = GetScreenToWorld2D(GetMousePosition(), camera);
+
+                // Set the offset to where the mouse is
+                camera.Offset = GetMousePosition();
+
+                // Set the target to match, so that the camera maps the world space point
+                // under the cursor to the screen space point under the cursor at any zoom
+                camera.Target = mouseWorldPos;
+            }
+
+            if (IsMouseButtonDown(MouseButton.Right))
+            {
+                // Zoom increment
+                // Uses log scaling to provide consistent zoom speed
+                float deltaX = GetMouseDelta().X;
+                float scale = 0.005f * deltaX;
+                camera.Zoom = Clamp(MathF.Exp(MathF.Log(camera.Zoom) + scale), 0.125f, 64.0f);
+            }
+        }
+        //----------------------------------------------------------------------------------
+
+        // Draw
+        //----------------------------------------------------------------------------------
+        BeginDrawing();
+        ClearBackground(Color.RayWhite);
+
+        BeginMode2D(camera);
+        // Draw the 3d grid, rotated 90 degrees and centered around 0,0
+        // just so we have something in the XY plane
+        Rlgl.PushMatrix();
+        Rlgl.Translatef(0, 25 * 50, 0);
+        Rlgl.Rotatef(90, 1, 0, 0);
+        DrawGrid(100, 50);
+        Rlgl.PopMatrix();
+
+        // Draw a reference circle
+        DrawCircle(GetScreenWidth() / 2, GetScreenHeight() / 2, 50, Color.Maroon);
+        EndMode2D();
+
+        // Draw mouse reference
+        //Vector2 mousePos = GetWorldToScreen2D(GetMousePosition(), camera)
+        DrawCircleV(GetMousePosition(), 4, Color.DarkGray);
+        DrawTextEx(GetFontDefault(), $"[{GetMouseX()}, {GetMouseY()}]",
+            Vector2Add(GetMousePosition(), new Vector2(-44, -24)), 20, 2, Color.Black);
+
+        DrawText("[1][2] Select mouse zoom mode (Wheel or Move)", 20, 20, 20, Color.DarkGray);
+        if (zoomMode == 0)
+        {
+            DrawText("Mouse left button drag to move, mouse wheel to zoom", 20, 50, 20, Color.DarkGray);
+        }
+        else
+        {
+            DrawText("Mouse left button drag to move, mouse press and move to zoom", 20, 50, 20, Color.DarkGray);
+        }
+
+        EndDrawing();
+        //----------------------------------------------------------------------------------
+    }
+
+    public void Unload()
+    {
+    }
+
+    public static int Main()
+    {
+        // Initialization
+        //--------------------------------------------------------------------------------------
+        InitWindow(screenWidth, screenHeight, "raylib [core] example - 2d camera mouse zoom");
+
+        SetTargetFPS(60);       // Set our game to run at 60 frames-per-second
+        //--------------------------------------------------------------------------------------
+
+        var game = new Camera2dMouseZoom();
+        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;
+    }
+}