raylib-zig/examples/models/models_loading.zig

//
// models_loading
// Zig version: 
// Author: Nikolas Wipper
// Date: 2020-02-15
//

usingnamespace @import("raylib");

pub fn main() anyerror!void
{
    // Initialization
    //--------------------------------------------------------------------------------------
    const screenWidth = 800;
    const screenHeight = 450;

    InitWindow(screenWidth, screenHeight, "raylib [models] example - models loading");

    // Define the camera to look into our 3d world
    var camera = Camera {
        .position = Vector3 { .x = 50.0, .y = 50.0, .z = 50.0 }, // Camera position
        .target = Vector3 { .x = 0.0, .y = 10.0, .z = 0.0 },     // Camera looking at point
        .up = Vector3 { .x = 0.0, .y = 1.0, .z = 0.0 },          // Camera up vector (rotation towards target)
        .fovy = 45.0,                             // Camera field-of-view Y
        .type = CameraType.CAMERA_PERSPECTIVE     // Camera mode type
    };

    var model = LoadModel("resources/models/castle.obj");                  // Load model
    var texture = LoadTexture("resources/models/castle_diffuse.png");      // Load model texture
    model.materials[0].maps[@enumToInt(MAP_DIFFUSE)].texture = texture;                 // Set map diffuse texture

    //var position = Vector3 { .x = 0.0, .y = 0.0, .z = 0.0 };                // Set model position

    var bounds = MeshBoundingBox(model.meshes[0]);  // Set model bounds

    // NOTE: bounds are calculated from the original size of the model,
    // if model is scaled on drawing, bounds must be also scaled

    camera.SetMode(CameraMode.CAMERA_FREE);     // Set a free camera mode

    var selected = false;          // Selected object flag

    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
        //----------------------------------------------------------------------------------
        camera.Update();

        // Load new models/textures on drag&drop
        if (IsFileDropped())
        {
            var count: c_int = 0;
            var droppedFiles = GetDroppedFiles(&count);

            if (count == 1) // Only support one file dropped
            {
                if (IsFileExtension(droppedFiles[0], ".obj") or
                    IsFileExtension(droppedFiles[0], ".gltf") or
                    IsFileExtension(droppedFiles[0], ".iqm"))       // Model file formats supported
                {
                    UnloadModel(model);                     // Unload previous model
                    model = LoadModel(droppedFiles[0]);     // Load new model
                    model.materials[0].maps[@enumToInt(MAP_DIFFUSE)].texture = texture; // Set current map diffuse texture

                    bounds = MeshBoundingBox(model.meshes[0]);

                    // TODO: Move camera position from target enough distance to visualize model properly
                }
                else if (IsFileExtension(droppedFiles[0], ".png"))  // Texture file formats supported
                {
                    // Unload current model texture and load new one
                    UnloadTexture(texture);
                    texture = LoadTexture(droppedFiles[0]);
                    model.materials[0].maps[@enumToInt(MAP_DIFFUSE)].texture = texture;
                }
            }

            ClearDroppedFiles();    // Clear internal buffers
        }

        // Select model on mouse click
        if (IsMouseButtonPressed(MouseButton.MOUSE_LEFT_BUTTON))
        {
            // Check collision between ray and box
            //if (CheckCollisionRayBox(GetMouseRay(GetMousePosition(), camera), bounds))
            //{
            //    selected = !selected;
            //}
            //else
            //{
            //    selected = false;
            //}
        }
        //----------------------------------------------------------------------------------

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

            ClearBackground(RAYWHITE);

            camera.Begin();

                //DrawModel(model, position, 1.0, WHITE);        // Draw 3d model with texture

                DrawGrid(20, 10.0);         // Draw a grid

                if (selected) DrawBoundingBox(bounds, GREEN);   // Draw selection box

            camera.End();

            DrawText("Drag & drop model to load mesh/texture.", 10, GetScreenHeight() - 20, 10, DARKGRAY);
            if (selected) DrawText("MODEL SELECTED", GetScreenWidth() - 110, 10, 10, GREEN);

            DrawText("(c) Castle 3D model by Alberto Cano", screenWidth - 200, screenHeight - 20, 10, GRAY);

            DrawFPS(10, 10);

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

    // De-Initialization
    //--------------------------------------------------------------------------------------
    UnloadTexture(texture);     // Unload texture
    UnloadModel(model);         // Unload model

    CloseWindow();              // Close window and OpenGL context
    //--------------------------------------------------------------------------------------
}