makes geometry shader an option

src/main.rs

@@ -45,6 +45,7 @@ pub mod command_buffer;
 pub mod depth_buffer;
 pub mod load_model;
 pub mod scene;
+pub mod primitives;
 
 const PORTABILITY_MACOS_VERSION: Version = Version::new(1, 3, 216);
 const VALIDATION_ENABLED: bool =
@@ -70,6 +71,7 @@ fn main() -> Result<()> {
         .build(&event_loop)?;
     //window.set_cursor_visible(false);
 
+    // event_loop.set_control_flow(winit::event_loop::ControlFlow::Poll);
     // App
 
     let mut app = unsafe { App::create(&window)? };
@@ -160,6 +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;
         let mut scene_handler = scene::Scene::default();
         
         //load_model::load_model(&mut data)?;
@@ -201,7 +204,7 @@ impl App {
             last_pos: LogicalPosition::new(-1 as f32, -1 as f32), 
             view_direction: vertex::Vec3::new(0.0, 0.0, 0.0),
             cur_pos: cgmath::point3(0.0, 0.0, 0.0),
-            scene_handler,
+            scene_handler
         })
     }
 
@@ -393,7 +396,8 @@ impl App {
                 10000.0,
             );
 
-        let ubo = buffer::UniformBufferObject { model, geom_rot: rot_mat4, view, proj };
+        let ubo = buffer::UniformBufferObject { model, geom_rot: rot_mat4, view, proj, 
+            use_geom_shader: [self.data.use_geometry_shader, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false]};
 
         let memory = self.device.map_memory(
             self.data.uniform_buffers_memory[image_index],
@@ -668,8 +672,13 @@ unsafe fn create_pipeline(device: &Device, data: &mut app_data::AppData) -> Resu
         .vertex_binding_descriptions(binding_descriptions)
         .vertex_attribute_descriptions(&attribute_descriptions);
 
+    let mut topology = vk::PrimitiveTopology::TRIANGLE_LIST;
+    if data.use_geometry_shader {
+        topology = vk::PrimitiveTopology::POINT_LIST;
+    } 
+
     let input_assembly_state = vk::PipelineInputAssemblyStateCreateInfo::builder()
-        .topology(vk::PrimitiveTopology::TRIANGLE_LIST)
+        .topology(topology)
         .primitive_restart_enable(false);
 
     let viewport = vk::Viewport::builder()
@@ -736,8 +745,9 @@ unsafe fn create_pipeline(device: &Device, data: &mut app_data::AppData) -> Resu
     data.pipeline_layout = device.create_pipeline_layout(&layout_info, None)?;
 
     let stages = &[vert_stage, frag_stage];
-    let info = vk::GraphicsPipelineCreateInfo::builder()
-        .stages(stages)
+    let stages_geom = &[vert_stage, geo_stage,frag_stage];
+
+    let mut info = vk::GraphicsPipelineCreateInfo::builder()
         .vertex_input_state(&vertex_input_state)
         .input_assembly_state(&input_assembly_state)
         .viewport_state(&viewport_state)
@@ -749,6 +759,13 @@ unsafe fn create_pipeline(device: &Device, data: &mut app_data::AppData) -> Resu
         .render_pass(data.render_pass)
         .subpass(0);
 
+    if data.use_geometry_shader {
+        info = info.stages(stages_geom);
+    }
+    else {
+        info = info.stages(stages);
+    }
+
     data.pipeline = device.create_graphics_pipelines(
         vk::PipelineCache::null(), &[info], None)?.0[0];