Add (broken) models loading example

examples/models/models_loading.zig

@@ -0,0 +1,134 @@
+//
+// ModelsLoading
+// 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, c"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(c"resources/models/castle.obj");                  // Load model
+    var texture = LoadTexture(c"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
+
+    SetCameraMode(camera, 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
+        //----------------------------------------------------------------------------------
+        UpdateCamera(&camera);
+
+        // 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], c".obj") or
+                    IsFileExtension(droppedFiles[0], c".gltf") or
+                    IsFileExtension(droppedFiles[0], c".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], c".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);
+
+            BeginMode3D(camera);
+
+                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
+
+            EndMode3D();
+
+            DrawText(c"Drag & drop model to load mesh/texture.", 10, GetScreenHeight() - 20, 10, DARKGRAY);
+            if (selected) DrawText(c"MODEL SELECTED", GetScreenWidth() - 110, 10, 10, GREEN);
+
+            DrawText(c"(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
+    //--------------------------------------------------------------------------------------
+}