Improve physical geometry, fluid solvers, audio, and profiling

tests/fluid_validation.cpp

@@ -794,6 +794,38 @@ int main(int argc,char** argv) {
              "thermal relaxation differs from exact exponential");
     });
 
+    test("pipe solver scratch follows runtime solver changes", [] {
+        Pipe1D pipe(.001f,.2f,16);
+        pipe.left_ghost=pipe.state(0);
+        pipe.right_ghost=pipe.state(15);
+        pipe.solver=PipeSolver::Rusanov;
+        pipe.prepare_step();
+        const auto rusanov_bytes=pipe.scratch_bytes();
+        pipe.solver=PipeSolver::Hlle;
+        pipe.prepare_step();
+        const auto hlle_bytes=pipe.scratch_bytes();
+        pipe.solver=PipeSolver::Muscl;
+        pipe.prepare_step();
+        const auto muscl_bytes=pipe.scratch_bytes();
+        check(rusanov_bytes<hlle_bytes && hlle_bytes<muscl_bytes,
+              "solver-specific work buffers were not allocated on demand");
+        for(auto solver : {PipeSolver::Rusanov,PipeSolver::Hlle,PipeSolver::Hllc,
+                           PipeSolver::Muscl,PipeSolver::Rusanov}) {
+            pipe.solver=solver;
+            for(int step=0;step<8;++step) {
+                pipe.left_ghost=pipe.state(0);
+                pipe.right_ghost=pipe.state(15);
+                const float dt=.5f*pipe.prepare_step();
+                pipe.advance(dt);
+            }
+        }
+        for(int i=0;i<16;++i) {
+            const auto state=pipe.state(i);
+            check(std::isfinite(state.rho)&&std::isfinite(state.pressure)&&
+                  state.rho>0&&state.pressure>0,"solver switch produced a nonphysical pipe state");
+        }
+    });
+
     test("sealed crankcase compression conserves mass above five bar", [] {
         Crankshaft crank;
         crank.angle = 0;