Fix not being able to change to cpu method

Author: lucascompython

src/app.rs

@@ -1,5 +1,5 @@
 use crate::camera::Camera;
-use crate::custom_renderer::UnsafeParticleCallback;
+use crate::custom_renderer::ClonedParticleCallback;
 use crate::renderer::ParticleRenderer;
 
 use crate::simulation::compute::ComputeParticleSimulation;
@@ -542,10 +542,11 @@ impl eframe::App for ParticleApp {
                 }
             }
 
-            let callback_obj = UnsafeParticleCallback {
-                render_pipeline_ptr: &self.renderer.render_pipeline as *const _,
-                camera_bind_group_ptr: &self.camera.bind_group as *const _,
-                particle_buffer_ptr: self.simulation.get_particle_buffer() as *const _,
+            let callback_obj = ClonedParticleCallback {
+                render_pipeline: self.renderer.render_pipeline.clone(),
+                camera_bind_group: self.camera.bind_group.clone(),
+                particle_buffer: self.simulation.get_particle_buffer().clone(),
+                num_particles: self.simulation.get_particle_count(),
             };
 
             let callback = egui_wgpu::Callback::new_paint_callback(rect, callback_obj);

src/custom_renderer.rs

@@ -1,60 +1,6 @@
 use egui::PaintCallbackInfo;
 use egui_wgpu::{CallbackResources, CallbackTrait};
 
-use crate::simulation::Particle;
-
-pub struct UnsafeParticleCallback {
-    pub render_pipeline_ptr: *const wgpu::RenderPipeline,
-    pub camera_bind_group_ptr: *const wgpu::BindGroup,
-    pub particle_buffer_ptr: *const wgpu::Buffer,
-}
-
-// Safe because we ensure the pointers remain valid during the callback's lifetime
-// and we're only reading from them
-unsafe impl Send for UnsafeParticleCallback {}
-unsafe impl Sync for UnsafeParticleCallback {}
-
-impl CallbackTrait for UnsafeParticleCallback {
-    fn prepare(
-        &self,
-        _device: &wgpu::Device,
-        _queue: &wgpu::Queue,
-        _screen_descriptor: &egui_wgpu::ScreenDescriptor,
-        _encoder: &mut wgpu::CommandEncoder,
-        _callback_resources: &mut CallbackResources,
-    ) -> Vec<wgpu::CommandBuffer> {
-        Vec::new()
-    }
-
-    fn paint(
-        &self,
-        _info: PaintCallbackInfo,
-        render_pass: &mut wgpu::RenderPass<'static>,
-        _callback_resources: &CallbackResources,
-    ) {
-        unsafe {
-            // Dereference the pointers - safe because we ensure they remain valid
-            let render_pipeline = &*self.render_pipeline_ptr;
-            let camera_bind_group = &*self.camera_bind_group_ptr;
-            let particle_buffer = &*self.particle_buffer_ptr;
-
-            let particle_struct_size = std::mem::size_of::<Particle>() as u64;
-            // Ensure particle_struct_size is not zero to avoid division by zero
-            let actual_drawable_particles = if particle_struct_size > 0 {
-                particle_buffer.size() / particle_struct_size
-            } else {
-                0 // Or handle error appropriately
-            };
-
-            render_pass.set_pipeline(render_pipeline);
-            render_pass.set_bind_group(0, camera_bind_group, &[]);
-            render_pass.set_vertex_buffer(0, particle_buffer.slice(..));
-            render_pass.draw(0..1, 0..actual_drawable_particles as u32);
-        }
-    }
-}
-
-// A callback for particle rendering using cloned resources
 pub struct ClonedParticleCallback {
     pub render_pipeline: wgpu::RenderPipeline,
     pub camera_bind_group: wgpu::BindGroup,