Improve physical geometry, fluid solvers, audio, and profiling

include/FluidSim/Desktop/PressurePalette.hpp

@@ -3,10 +3,29 @@
 #include <algorithm>
 #include <cmath>
 namespace fluidsim::port::desktop {
-// Fixed absolute scale: vacuum blue, atmosphere green, >=1 MPa red.
-inline Vec3 pressure_tint(float pressure) {
+// Keep the established absolute vacuum palette. Above atmosphere, use a
+// narrower positive range so modest pulses stand out from the green baseline.
+inline Vec3 pressure_tint(float pressure, bool exhaust=false, float temperature=300.f) {
     if(pressure<=101325) {float t=std::clamp(pressure/101325,0.f,1.f);return {.05f,.15f+.70f*t,1-.95f*t};}
-    float t=std::sqrt(std::clamp((pressure-101325)/(1000000-101325),0.f,1.f));
-    return {.05f+.95f*t,.85f-.80f*t,.05f-.03f*t};
+    const float temperature_boost=std::sqrt(std::clamp(temperature/300.f,.25f,9.f));
+    const float pulse=(pressure-101325.f)*temperature_boost;
+    // Exhaust reaches the warm colors sooner, while using the same continuous
+    // ramp so the atmosphere boundary and pulse edges stay smooth.
+    const float scale=exhaust?45000.f:150000.f;
+    const float t=pulse/(pulse+scale);
+    const auto mix=[](Vec3 a,Vec3 b,float u) {
+        u=u*u*(3.f-2.f*u);
+        return Vec3{a.x+(b.x-a.x)*u,a.y+(b.y-a.y)*u,a.z+(b.z-a.z)*u};
+    };
+    constexpr Vec3 green{.05f,.85f,.05f},yellow{1.f,1.f,.03f},orange{1.f,.52f,.02f},red{1.f,0.f,0.f};
+    if(t<.35f)return mix(green,yellow,t/.35f);
+    if(t<.68f)return mix(yellow,orange,(t-.35f)/.33f);
+    return mix(orange,red,(t-.68f)/.32f);
+}
+inline float pressure_expansion(float pressure,float temperature=300.f) {
+    if(pressure<=101325.f)return 0.f;
+    const float temperature_boost=std::sqrt(std::clamp(temperature/300.f,.25f,9.f));
+    const float pulse=(pressure-101325.f)*temperature_boost;
+    return .10f*pulse/(pulse+80000.f);
 }
 }