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

shaders/Lib/Programs/Final_FS.glsl

@@ -0,0 +1,108 @@
+// MinecraftPT — Final_FS
+// HDR tonemapping, color grading, dithering, and output to screen.
+
+#include "/Lib/Settings.glsl"
+#include "/Lib/Utilities.glsl"
+#include "/Lib/BasicFunctions/TemporalNoise.glsl"
+
+uniform sampler2D exposureTex;
+
+#if defined PROGRAM_FINAL_0
+layout(location = 0) out vec4 colorOut;
+#elif defined PROGRAM_FINAL_1
+layout(location = 0) out vec4 colorOut;
+#endif
+
+// Tonemapping operators
+vec3 TonemapACES(vec3 color){
+	// ACES filmic
+	float a = 2.51;
+	float b = 0.03;
+	float c = 2.43;
+	float d = 0.59;
+	float e = 0.14;
+	return saturate((color * (a * color + b)) / (color * (c * color + d) + e));
+}
+
+vec3 TonemapAGX(vec3 color){
+	// AGX-inspired: log-shaping curve
+	vec3 logColor = log2(max(color, 1e-6));
+	vec3 mid = vec3(AGX_HDR_MIDGREY);
+	vec3 shaped = logColor - mid;
+	shaped = tanh(shaped * 0.5) * 0.5 + 0.5;
+	vec3 result = exp2(shaped + mid);
+	return result;
+}
+
+vec3 TonemapFilmic(vec3 color){
+	// Uncharted 2 filmic
+	vec3 x = max(color, 0.0);
+	return (x * (6.2 * x + 0.5)) / (x * (6.2 * x + 1.7) + 0.06);
+}
+
+// Color grading
+vec3 ApplyColorGrading(vec3 color){
+	// White/black point
+	color = (color - BLACK_POINT) / (WHITE_POINT - BLACK_POINT + 1e-6);
+
+	// Saturation
+	float lum = luminance(color);
+	color = mix(vec3(lum), color, SATURATION);
+
+	// Gamma
+	color = pow(color, vec3(GAMMA));
+
+	// Hue shifts (simplified)
+	#ifdef ADVANCED_COLOR
+		vec3 midtone = color * MIDTONE_HUE * MIDTONE_STRENGTH;
+		vec3 highlight = color * HIGHLIGHT_HUE * HIGHLIGHT_STRENGTH;
+		vec3 shadow = color * SHADOW_HUE * SHADOW_STRENGTH;
+		color += midtone + highlight + shadow;
+	#endif
+
+	return color;
+}
+
+void main(){
+	vec3 color = texelFetch(colortex12, ivec2(gl_FragCoord.xy), 0).rgb;
+
+	// Exposure
+	#ifdef MANUAL_EXPOSURE
+		float exposure = MANUAL_EXPOSURE * pow(2.0, EV_VALUE);
+	#else
+		float exposure = textureLod(exposureTex, vec2(0.5), 0.0).r;
+	#endif
+	color *= exposure;
+
+	// Bloom composite
+	#ifdef BLOOM
+		vec3 bloom = vec3(0.0);
+		// Simple bloom: sample from bloom buffer
+		bloom = textureLod(colortex15, gl_FragCoord.xy / screenSize, 0.0).rgb;
+		color += bloom * BLOOM_AMOUNT;
+	#endif
+
+	// Tonemapping
+	#if TONEMAP_OPERATOR == 0
+		color = TonemapACES(color);
+	#elif TONEMAP_OPERATOR == 1
+		color = TonemapAGX(color);
+	#elif TONEMAP_OPERATOR == 2
+		color = TonemapFilmic(color);
+	#else
+		// Vanilla-like: Reinhard
+		color = color / (color + 1.0);
+	#endif
+
+	// Color grading
+	color = ApplyColorGrading(color);
+
+	// Dithering
+	vec2 noise = BlueNoiseTemporal2();
+	color += (noise - 0.5) / 255.0;
+
+	// Gamma correction
+	color = LinearToGamma(color);
+
+	colorOut = vec4(color, 1.0);
+}