fixes vertice and index creation in geometry shader mode

src/app_data.rs

@@ -53,4 +53,6 @@ pub struct AppData {
     pub color_image_memory: vk::DeviceMemory,
     pub color_image_view: vk::ImageView,
     pub use_geometry_shader: bool,
+
+    pub topology: vk::PrimitiveTopology,
 }

src/main.rs

@@ -162,7 +162,7 @@ impl App {
         let loader = LibloadingLoader::new(LIBRARY)?;
         let entry = Entry::new(loader).map_err(|b| anyhow!("{}", b))?;
         let mut data = app_data::AppData::default();
-        data.use_geometry_shader = false;
+        data.use_geometry_shader = true;
         let mut scene_handler = scene::Scene::default();
         
         //load_model::load_model(&mut data)?;
@@ -676,6 +676,7 @@ unsafe fn create_pipeline(device: &Device, data: &mut app_data::AppData) -> Resu
     if data.use_geometry_shader {
         topology = vk::PrimitiveTopology::POINT_LIST;
     } 
+    data.topology = topology;
 
     let input_assembly_state = vk::PipelineInputAssemblyStateCreateInfo::builder()
         .topology(topology)

src/scene.rs

@@ -37,7 +37,7 @@ impl Scene {
                     tex_coord: vec2(0.0, 0.0)
                 };
 
-                cube.draw(&vk::PrimitiveTopology::TRIANGLE_LIST, index, self);
+                cube.draw(&data.topology, index, self);
             }
         }