Initial commit: Minecraft 光追着色器包（从零实现的 path tracing）

shaders/Lib/BasicFunctions/LightingConstants.glsl

@@ -0,0 +1,91 @@
+#include "/Lib/Settings.glsl"
+#include "/Lib/Utilities.glsl"
+// MinecraftPT — Lighting Constants
+// Per-frame lighting values computed inline (no SSBO dependency).
+// These are cheap functions of the sun angle and camera position; computed
+// per-pass instead of via a shared buffer for maximum loader compatibility.
+
+#ifndef LIGHTING_CONSTANTS_GLSL
+#define LIGHTING_CONSTANTS_GLSL
+
+#include "/Lib/BasicFunctions/PrecomputedAtmosphere.glsl"
+
+// Sun direction in world space (matches the shadow camera direction)
+vec3 GetSunDirWorld(){
+	#ifndef DIMENSION_NETHER
+		#ifndef DIMENSION_END
+			return normalize(shadowModelViewInverse2);
+		#else
+			return normalize(shadowModelViewInverse2) * fsign(0.5 - sunAngle);
+		#endif
+	#else
+		return normalize(shadowModelViewInverse2) * fsign(0.5 - sunAngle);
+	#endif
+}
+
+// Atmosphere camera position (scaled Earth radius + camera altitude)
+vec3 GetAtmoCamera(){
+	return vec3(0.0, max(cameraPosition.y, 63.0) * 0.001 + atmosphereModel_bottom_radius, 0.0);
+}
+
+// Sun irradiance (direct light color/intensity)
+vec3 GetSunIrradiance(){
+	vec3 sunDir = GetSunDirWorld();
+	vec3 moon, sunSky, moonSky;
+	return GetSunAndSkyIrradiance(GetAtmoCamera(), sunDir, -sunDir, moon, sunSky, moonSky);
+}
+
+vec3 GetMoonIrradiance(){
+	vec3 sunDir = GetSunDirWorld();
+	vec3 moon, sunSky, moonSky;
+	GetSunAndSkyIrradiance(GetAtmoCamera(), sunDir, -sunDir, moon, sunSky, moonSky);
+	return moon;
+}
+
+vec3 GetCelestialIrradiance(){
+	return GetSunIrradiance() + GetMoonIrradiance();
+}
+
+vec3 GetAtmoIrradiance(){
+	vec3 sunDir = GetSunDirWorld();
+	vec3 moon, sunSky, moonSky;
+	GetSunAndSkyIrradiance(GetAtmoCamera(), sunDir, -sunDir, moon, sunSky, moonSky);
+	return sunSky + moonSky;
+}
+
+// Cloud-altitude irradiances
+vec3 GetCloudSunIrradiance(){
+	vec3 sunDir = GetSunDirWorld();
+	vec3 atmoCamera = vec3(0.0, mix(CLOUD_CLEAR_ALTITUDE, CLOUD_RAIN_ALTITUDE, wetness) * 0.001 + atmosphereModel_bottom_radius, 0.0);
+	vec3 moon, sunSky, moonSky;
+	return GetSunAndSkyIrradiance(atmoCamera, sunDir, -sunDir, moon, sunSky, moonSky);
+}
+
+vec3 GetCloudAtmoIrradiance(){
+	vec3 sunDir = GetSunDirWorld();
+	vec3 atmoCamera = vec3(0.0, mix(CLOUD_CLEAR_ALTITUDE, CLOUD_RAIN_ALTITUDE, wetness) * 0.001 + atmosphereModel_bottom_radius, 0.0);
+	vec3 moon, sunSky, moonSky;
+	GetSunAndSkyIrradiance(atmoCamera, sunDir, -sunDir, moon, sunSky, moonSky);
+	return sunSky + moonSky;
+}
+
+// Moon/sun phase for fog time factor
+vec2 GetFogTimeFactor(){
+	vec3 sunDir = GetSunDirWorld();
+	float timeNoon = pow(1.0 - (clamp(sunDir.y, 0.2, 0.99) - 0.2) / 0.8, 6.0);
+	float moonlightStrength = curve(saturate(sunDir.y * -5.0));
+	return vec2(timeNoon, moonlightStrength);
+}
+
+// Dimension-aware irradiance override
+vec3 GetDimensionAmbient(){
+	#ifdef DIMENSION_NETHER
+		return vec3(0.08, 0.02, 0.01) * NETHER_BRIGHTNESS;
+	#elif defined DIMENSION_END
+		return vec3(0.02, 0.02, 0.04);
+	#else
+		return GetAtmoIrradiance();
+	#endif
+}
+
+#endif