Deterministic CSG

src/main.rs

@@ -270,7 +270,7 @@ impl App {
                 enabled_extensions: InstanceExtensions {
                     ..required_extensions
                 },
-                engine_name: Some("ImplEng".to_owned()),
+                engine_name: Some("Tape Drive".to_owned()),
                 engine_version: Version::major_minor(0, 1),
                 application_name: Some(env!("CARGO_PKG_NAME").to_owned()),
                 application_version: app_version(),
@@ -949,6 +949,7 @@ impl ApplicationHandler for App {
                                 self.descriptor_set_allocator.clone(),
                                 rcx.swapchain.image_count(),
                                 DEFAULT_SUBDIVISION,
+                                rand::random(),
                                 0,
                             ))
                             .unwrap();
@@ -1407,6 +1408,7 @@ impl App {
                         self.descriptor_set_allocator.clone(),
                         rcx.swapchain.image_count(),
                         DEFAULT_SUBDIVISION,
+                        rand::random(),
                         -1,
                     ))
                     .unwrap();

src/objects.rs

@@ -39,6 +39,7 @@ pub(crate) struct Mesh {
 #[derive(Debug)]
 pub(crate) struct CSG {
     pub(crate) name: String,
+    pub(crate) seed: u64,
     pub(crate) parts: SSATape,
     pub(crate) pos: Vec3,
     pub(crate) rot: Vec3,

src/ssa.rs

@@ -457,7 +457,7 @@ impl SSATape {
         } else {
             let mut b = rspirv::dr::Builder::new();
             b.set_version(1, 6);
-            b.module_processed(format!("ImplEng JIT {JIT_VERSION}"));
+            b.module_processed(format!("Tape Drive JIT {JIT_VERSION}"));
             b.memory_model(spirv::AddressingModel::Logical, spirv::MemoryModel::GLSL450);
             b
         };
@@ -493,8 +493,8 @@ impl SSATape {
                     if with_module { Some(1000) } else { None },
                     //spirv::FunctionControl::DONT_INLINE
                     spirv::FunctionControl::INLINE
-                       | spirv::FunctionControl::PURE
-                       | spirv::FunctionControl::CONST,
+                        | spirv::FunctionControl::PURE
+                        | spirv::FunctionControl::CONST,
                     point_fn_type,
                 )
                 .unwrap();

src/threads.rs

@@ -9,6 +9,7 @@ use std::{
 use foldhash::HashSet;
 use glam::{EulerRot, Mat4, Vec3};
 use log::info;
+use rand::{Rng, SeedableRng, rngs::SmallRng};
 use rspirv::{binary::Assemble, dr::Module};
 use vulkano::{
     buffer::{Subbuffer, allocator::SubbufferAllocator},
@@ -63,6 +64,7 @@ pub enum WorkItem {
         Arc<StandardDescriptorSetAllocator>,
         u32,
         u32,
+        u64,
         isize,
     ),
     GetPushConstants(
@@ -106,10 +108,11 @@ pub fn thread_loop(recv: mpmc::Receiver<WorkItem>, send: mpsc::SyncSender<WorkCo
                 descriptor_set_allocator,
                 frames,
                 subdivision,
+                seed,
                 index,
             ) => {
                 let csg_start = Instant::now();
-                let parts = create_csg();
+                let parts = create_csg(seed);
 
                 let trace_shader_module =
                     sdf_specialize_module(device.clone(), &parts, trace_module, &format!("trace"));
@@ -187,6 +190,7 @@ pub fn thread_loop(recv: mpmc::Receiver<WorkItem>, send: mpsc::SyncSender<WorkCo
 
                 let csg = Arc::new(RwLock::new(CSG {
                     name: "example".to_string(),
+                    seed,
                     parts,
                     pos: Vec3::ZERO,
                     rot: Vec3::ZERO,
@@ -418,7 +422,8 @@ fn deferred_pipelines_recompile(
     (trace_pipeline, normals_pipeline)
 }
 
-fn create_csg() -> SSATape {
+fn create_csg(seed: u64) -> SSATape {
+    let mut rng = SmallRng::seed_from_u64(seed);
     let mut tape = SSATape::default();
     let pos = tape.push_instruction(
         SSAOpcodeSized {
@@ -436,9 +441,9 @@ fn create_csg() -> SSATape {
             pos[0],
             pos[1],
             pos[2],
-            SSAInput::Constant(rand::random_range(0.0..1.0)),
-            SSAInput::Constant(rand::random_range(0.0..1.0)),
-            SSAInput::Constant(rand::random_range(0.0..1.0)),
+            SSAInput::Constant(rng.random_range(0.0..1.0)),
+            SSAInput::Constant(rng.random_range(0.0..1.0)),
+            SSAInput::Constant(rng.random_range(0.0..1.0)),
         ],
     );
     let sphere = tape.push_instruction(
@@ -450,7 +455,7 @@ fn create_csg() -> SSATape {
             offset[0],
             offset[1],
             offset[2],
-            SSAInput::Constant(rand::random_range(0.0..1.0)),
+            SSAInput::Constant(rng.random_range(0.0..1.0)),
         ],
     );
     let torus = tape.push_instruction(
@@ -462,8 +467,8 @@ fn create_csg() -> SSATape {
             pos[0],
             pos[1],
             pos[2],
-            SSAInput::Constant(rand::random_range(0.0..1.0)),
-            SSAInput::Constant(rand::random_range(0.0..1.0)),
+            SSAInput::Constant(rng.random_range(0.0..1.0)),
+            SSAInput::Constant(rng.random_range(0.0..1.0)),
         ],
     );
     let min = tape.push_instruction(