raylib-cs/Examples/core/core_3d_picking.cs

using Raylib;
using static Raylib.Raylib;
using static Raylib.CameraType;
using static Raylib.CameraMode;

public partial class core_3d_picking
{
    /*******************************************************************************************
    *
    *   raylib [core] example - Picking in 3d mode
    *
    *   This example has been created using raylib 1.3 (www.raylib.com)
    *   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
    *
    *   Copyright (c) 2015 Ramon Santamaria (@raysan5)
    *
    ********************************************************************************************/


    public static int Main()
    {
        // Initialization
        //--------------------------------------------------------------------------------------
        int screenWidth = 800;
        int screenHeight = 450;

        InitWindow(screenWidth, screenHeight, "raylib [core] example - 3d picking");

        // Define the camera to look into our 3d world
        Camera3D camera;
        camera.position = new Vector3( 10.0f, 10.0f, 10.0f ); // Camera3D position
        camera.target = new Vector3( 0.0f, 0.0f, 0.0f );      // Camera3D looking at point
        camera.up = new Vector3( 0.0f, 1.0f, 0.0f );          // Camera3D up vector (rotation towards target)
        camera.fovy = 45.0f;                                // Camera3D field-of-view Y
        camera.type = (int)CAMERA_PERSPECTIVE;                   // Camera3D mode type

        Vector3 cubePosition = new Vector3( 0.0f, 1.0f, 0.0f );
        Vector3 cubeSize = new Vector3( 2.0f, 2.0f, 2.0f );

        Ray ray = new Ray(new Vector3(0.0f, 0.0f, 0.0f), Vector3.Zero);        // Picking line ray

        bool collision = false;

        SetCameraMode(camera, (int)CAMERA_FREE); // Set a free camera mode

        SetTargetFPS(60);                   // Set our game to run at 60 frames-per-second
        //--------------------------------------------------------------------------------------

        // Main game loop
        while (!WindowShouldClose())        // Detect window close button or ESC key
        {
            // Update
            //----------------------------------------------------------------------------------
            UpdateCamera(ref camera);          // Update camera

            if (IsMouseButtonPressed(MOUSE_LEFT_BUTTON))
            {
                ray = GetMouseRay(GetMousePosition(), camera);

                // Check collision between ray and box
                collision = CheckCollisionRayBox(ray,
                            new BoundingBox(new Vector3( cubePosition.x - cubeSize.x/2, cubePosition.y - cubeSize.y/2, cubePosition.z - cubeSize.z/2 ),
                                          new Vector3( cubePosition.x + cubeSize.x/2, cubePosition.y + cubeSize.y/2, cubePosition.z + cubeSize.z/2 )));
            }
            //----------------------------------------------------------------------------------

            // Draw
            //----------------------------------------------------------------------------------
            BeginDrawing();

                ClearBackground(RAYWHITE);

                BeginMode3D(camera);

                    if (collision)
                    {
                        DrawCube(cubePosition, cubeSize.x, cubeSize.y, cubeSize.z, RED);
                        DrawCubeWires(cubePosition, cubeSize.x, cubeSize.y, cubeSize.z, MAROON);

                        DrawCubeWires(cubePosition, cubeSize.x + 0.2f, cubeSize.y + 0.2f, cubeSize.z + 0.2f, GREEN);
                    }
                    else
                    {
                        DrawCube(cubePosition, cubeSize.x, cubeSize.y, cubeSize.z, GRAY);
                        DrawCubeWires(cubePosition, cubeSize.x, cubeSize.y, cubeSize.z, DARKGRAY);
                    }

                    DrawRay(ray, MAROON);
                    DrawGrid(10, 1.0f);

                EndMode3D();

                DrawText("Try selecting the box with mouse!", 240, 10, 20, DARKGRAY);

                if(collision) DrawText("BOX SELECTED", (screenWidth - MeasureText("BOX SELECTED", 30)) / 2, (int)(screenHeight * 0.1f), 30, GREEN);

                DrawFPS(10, 10);

            EndDrawing();
            //----------------------------------------------------------------------------------
        }

        // De-Initialization
        //--------------------------------------------------------------------------------------
        CloseWindow();        // Close window and OpenGL context
        //--------------------------------------------------------------------------------------

        return 0;
    }
}