raylib-src/examples/core/core_3d_picking.c

/*******************************************************************************************
*
*   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)
*
********************************************************************************************/

#include "raylib.h"

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
    Camera camera;
    camera.position = (Vector3){ 10.0f, 10.0f, 10.0f }; // Camera position
    camera.target = (Vector3){ 0.0f, 0.0f, 0.0f };      // Camera looking at point
    camera.up = (Vector3){ 0.0f, 1.0f, 0.0f };          // Camera up vector (rotation towards target)
    camera.fovy = 45.0f;                                // Camera field-of-view Y

    Vector3 cubePosition = { 0.0f, 1.0f, 0.0f };
    Vector3 cubeSize = { 2.0f, 2.0f, 2.0f };
    
    Ray ray;        // Picking line ray
    
    bool collision = false;
    
    SetCameraMode(camera, 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(&camera);          // Update camera
        
        if (IsMouseButtonPressed(MOUSE_LEFT_BUTTON))
        {
            // NOTE: This function is NOT WORKING properly!
            ray = GetMouseRay(GetMousePosition(), camera);
            
            // Check collision between ray and box
            collision = CheckCollisionRayBox(ray,
                        (BoundingBox){(Vector3){ cubePosition.x - cubeSize.x/2, cubePosition.y - cubeSize.y/2, cubePosition.z - cubeSize.z/2 },
                                      (Vector3){ cubePosition.x + cubeSize.x/2, cubePosition.y + cubeSize.y/2, cubePosition.z + cubeSize.z/2 }});
        }
        //----------------------------------------------------------------------------------

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

            ClearBackground(RAYWHITE);

            Begin3dMode(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);

            End3dMode();
            
            DrawText("Try selecting the box with mouse!", 240, 10, 20, DARKGRAY);
            
            if(collision) DrawText("BOX SELECTED", (screenWidth - MeasureText("BOX SELECTED", 30)) / 2, screenHeight * 0.1f, 30, GREEN);

            DrawFPS(10, 10);

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

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

    return 0;
}