Update/merge examples back into main repo (#192)

Examples/Models/MeshPicking.cs

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+/*******************************************************************************************
+*
+*   raylib [models] example - Mesh picking in 3d mode, ground plane, triangle, mesh
+*
+*   This example has been created using raylib 1.7 (www.raylib.com)
+*   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
+*
+*   Copyright (c) 2015 Ramon Santamaria (@raysan5)
+*   Example contributed by Joel Davis (@joeld42)
+*
+********************************************************************************************/
+
+using System.Numerics;
+using static Raylib_cs.Raylib;
+using static Raylib_cs.Raymath;
+
+namespace Examples.Models;
+
+public class MeshPicking
+{
+    public unsafe static int Main()
+    {
+        // Initialization
+        //--------------------------------------------------------------------------------------
+        const int screenWidth = 800;
+        const int screenHeight = 450;
+
+        InitWindow(screenWidth, screenHeight, "raylib [models] example - mesh picking");
+
+        // Define the camera to look into our 3d world
+        Camera3D camera;
+        camera.Position = new Vector3(20.0f, 20.0f, 20.0f);
+        camera.Target = new Vector3(0.0f, 8.0f, 0.0f);
+        camera.Up = new Vector3(0.0f, 1.6f, 0.0f);
+        camera.FovY = 45.0f;
+        camera.Projection = CameraProjection.CAMERA_PERSPECTIVE;
+
+        // Picking ray
+        Ray ray = new();
+
+        Model tower = LoadModel("resources/models/obj/turret.obj");
+        Texture2D texture = LoadTexture("resources/models/obj/turret_diffuse.png");
+        Raylib.SetMaterialTexture(ref tower, 0, MaterialMapIndex.MATERIAL_MAP_ALBEDO, ref texture);
+
+        Vector3 towerPos = new(0.0f, 0.0f, 0.0f);
+        BoundingBox towerBBox = GetMeshBoundingBox(tower.Meshes[0]);
+
+        // Ground quad
+        Vector3 g0 = new(-50.0f, 0.0f, -50.0f);
+        Vector3 g1 = new(-50.0f, 0.0f, 50.0f);
+        Vector3 g2 = new(50.0f, 0.0f, 50.0f);
+        Vector3 g3 = new(50.0f, 0.0f, -50.0f);
+
+        // Test triangle
+        Vector3 ta = new(-25.0f, 0.5f, 0.0f);
+        Vector3 tb = new(-4.0f, 2.5f, 1.0f);
+        Vector3 tc = new(-8.0f, 6.5f, 0.0f);
+
+        Vector3 bary = new(0.0f, 0.0f, 0.0f);
+
+        // Test sphere
+        Vector3 sp = new(-30.0f, 5.0f, 5.0f);
+        float sr = 4.0f;
+
+        SetTargetFPS(60);
+        //--------------------------------------------------------------------------------------
+
+        //----------------------------------------------------------------------------------
+        // Main game loop
+        //--------------------------------------------------------------------------------------
+        while (!WindowShouldClose())
+        {
+            //----------------------------------------------------------------------------------
+            // Update
+            //----------------------------------------------------------------------------------
+            if (IsCursorHidden())
+            {
+                UpdateCamera(ref camera, CameraMode.CAMERA_FIRST_PERSON);
+            }
+
+            // Toggle camera controls
+            if (IsMouseButtonPressed(MouseButton.MOUSE_BUTTON_RIGHT))
+            {
+                if (IsCursorHidden())
+                {
+                    EnableCursor();
+                }
+                else
+                {
+                    DisableCursor();
+                }
+            }
+
+            // Display information about closest hit
+            RayCollision collision = new();
+            string hitObjectName = "None";
+            collision.Distance = float.MaxValue;
+            collision.Hit = false;
+            Color cursorColor = Color.WHITE;
+
+            // Get ray and test against objects
+            ray = GetMouseRay(GetMousePosition(), camera);
+
+            // Check ray collision aginst ground quad
+            RayCollision groundHitInfo = GetRayCollisionQuad(ray, g0, g1, g2, g3);
+            if (groundHitInfo.Hit && (groundHitInfo.Distance < collision.Distance))
+            {
+                collision = groundHitInfo;
+                cursorColor = Color.GREEN;
+                hitObjectName = "Ground";
+            }
+
+            // Check ray collision against test triangle
+            RayCollision triHitInfo = GetRayCollisionTriangle(ray, ta, tb, tc);
+            if (triHitInfo.Hit && (triHitInfo.Distance < collision.Distance))
+            {
+                collision = triHitInfo;
+                cursorColor = Color.PURPLE;
+                hitObjectName = "Triangle";
+
+                bary = Vector3Barycenter(collision.Point, ta, tb, tc);
+            }
+
+            // Check ray collision against test sphere
+            RayCollision sphereHitInfo = GetRayCollisionSphere(ray, sp, sr);
+            if ((sphereHitInfo.Hit) && (sphereHitInfo.Distance < collision.Distance))
+            {
+                collision = sphereHitInfo;
+                cursorColor = Color.ORANGE;
+                hitObjectName = "Sphere";
+            }
+
+            // Check ray collision against bounding box first, before trying the full ray-mesh test
+            RayCollision boxHitInfo = GetRayCollisionBox(ray, towerBBox);
+            if (boxHitInfo.Hit && boxHitInfo.Distance < collision.Distance)
+            {
+                collision = boxHitInfo;
+                cursorColor = Color.ORANGE;
+                hitObjectName = "Box";
+
+                // Check ray collision against model meshes
+                RayCollision meshHitInfo = new();
+                for (int m = 0; m < tower.MeshCount; m++)
+                {
+                    // NOTE: We consider the model.Transform for the collision check but
+                    // it can be checked against any transform matrix, used when checking against same
+                    // model drawn multiple times with multiple transforms
+                    meshHitInfo = GetRayCollisionMesh(ray, tower.Meshes[m], tower.Transform);
+                    if (meshHitInfo.Hit)
+                    {
+                        // Save the closest hit mesh
+                        if ((!collision.Hit) || (collision.Distance > meshHitInfo.Distance))
+                        {
+                            collision = meshHitInfo;
+                        }
+                        break;
+                    }
+                }
+
+                if (meshHitInfo.Hit)
+                {
+                    collision = meshHitInfo;
+                    cursorColor = Color.ORANGE;
+                    hitObjectName = "Mesh";
+                }
+            }
+            //----------------------------------------------------------------------------------
+
+            // Draw
+            //----------------------------------------------------------------------------------
+            BeginDrawing();
+            ClearBackground(Color.RAYWHITE);
+
+            BeginMode3D(camera);
+
+            // Draw the tower
+            DrawModel(tower, towerPos, 1.0f, Color.WHITE);
+
+            // Draw the test triangle
+            DrawLine3D(ta, tb, Color.PURPLE);
+            DrawLine3D(tb, tc, Color.PURPLE);
+            DrawLine3D(tc, ta, Color.PURPLE);
+
+            // Draw the test sphere
+            DrawSphereWires(sp, sr, 8, 8, Color.PURPLE);
+
+            // Draw the mesh bbox if we hit it
+            if (boxHitInfo.Hit)
+            {
+                DrawBoundingBox(towerBBox, Color.LIME);
+            }
+
+            // If we hit something, draw the cursor at the hit point
+            if (collision.Hit)
+            {
+                DrawCube(collision.Point, 0.3f, 0.3f, 0.3f, cursorColor);
+                DrawCubeWires(collision.Point, 0.3f, 0.3f, 0.3f, Color.RED);
+
+                Vector3 normalEnd = collision.Point + collision.Normal;
+                DrawLine3D(collision.Point, normalEnd, Color.RED);
+            }
+
+            DrawRay(ray, Color.MAROON);
+
+            DrawGrid(10, 10.0f);
+
+            EndMode3D();
+
+            // Draw some debug GUI text
+            DrawText($"Hit Object: {hitObjectName}", 10, 50, 10, Color.BLACK);
+
+            if (collision.Hit)
+            {
+                int ypos = 70;
+
+                DrawText($"Distance: {collision.Distance}", 10, ypos, 10, Color.BLACK);
+
+                DrawText($"Hit Pos: {collision.Point}", 10, ypos + 15, 10, Color.BLACK);
+
+                DrawText($"Hit Norm: {collision.Normal}", 10, ypos + 30, 10, Color.BLACK);
+
+                if (triHitInfo.Hit)
+                {
+                    DrawText($"Barycenter: {bary}", 10, ypos + 45, 10, Color.BLACK);
+                }
+            }
+
+            DrawText("Right click mouse to toggle camera controls", 10, 430, 10, Color.GRAY);
+
+            DrawText("(c) Turret 3D model by Alberto Cano", screenWidth - 200, screenHeight - 20, 10, Color.GRAY);
+
+            DrawFPS(10, 10);
+
+            EndDrawing();
+            //----------------------------------------------------------------------------------
+        }
+
+        // De-Initialization
+        //--------------------------------------------------------------------------------------
+        UnloadModel(tower);
+        UnloadTexture(texture);
+
+        CloseWindow();
+        //--------------------------------------------------------------------------------------
+
+        return 0;
+    }
+}