From a831fdb02757b8a882f1fb22321de35e9e8ed01f Mon Sep 17 00:00:00 2001
From: Magnus Norddahl <dpjudas@users.noreply.github.com>
Date: Mon, 26 Feb 2024 16:21:04 +0100
Subject: [PATCH] Move monte carlo math functions to its own file

---
 .../static/shaders/lightmap/montecarlo.glsl   | 30 +++++++++++++++++++
 .../lightmap/trace_ambient_occlusion.glsl     | 18 +----------
 .../static/shaders/lightmap/trace_light.glsl  | 18 ++---------
 .../shaders/lightmap/trace_sunlight.glsl      |  3 +-
 4 files changed, 35 insertions(+), 34 deletions(-)
 create mode 100644 wadsrc/static/shaders/lightmap/montecarlo.glsl

diff --git a/wadsrc/static/shaders/lightmap/montecarlo.glsl b/wadsrc/static/shaders/lightmap/montecarlo.glsl
new file mode 100644
index 000000000..9a84d0af9
--- /dev/null
+++ b/wadsrc/static/shaders/lightmap/montecarlo.glsl
@@ -0,0 +1,30 @@
+
+float RadicalInverse_VdC(uint bits)
+{
+	bits = (bits << 16u) | (bits >> 16u);
+	bits = ((bits & 0x55555555u) << 1u) | ((bits & 0xAAAAAAAAu) >> 1u);
+	bits = ((bits & 0x33333333u) << 2u) | ((bits & 0xCCCCCCCCu) >> 2u);
+	bits = ((bits & 0x0F0F0F0Fu) << 4u) | ((bits & 0xF0F0F0F0u) >> 4u);
+	bits = ((bits & 0x00FF00FFu) << 8u) | ((bits & 0xFF00FF00u) >> 8u);
+	return float(bits) * 2.3283064365386963e-10f; // / 0x100000000
+}
+
+vec2 Hammersley(uint i, uint N)
+{
+	return vec2(float(i) / float(N), RadicalInverse_VdC(i));
+}
+
+vec2 getVogelDiskSample(int sampleIndex, int sampleCount, float phi) 
+{
+    const float goldenAngle = radians(180.0) * (3.0 - sqrt(5.0));
+    float sampleIndexF = float(sampleIndex);
+    float sampleCountF = float(sampleCount);
+    
+    float r = sqrt((sampleIndexF + 0.5) / sampleCountF);  // Assuming index and count are positive
+    float theta = sampleIndexF * goldenAngle + phi;
+    
+    float sine = sin(theta);
+    float cosine = cos(theta);
+    
+    return vec2(cosine, sine) * r;
+}
diff --git a/wadsrc/static/shaders/lightmap/trace_ambient_occlusion.glsl b/wadsrc/static/shaders/lightmap/trace_ambient_occlusion.glsl
index 154b4036a..76e64aab2 100644
--- a/wadsrc/static/shaders/lightmap/trace_ambient_occlusion.glsl
+++ b/wadsrc/static/shaders/lightmap/trace_ambient_occlusion.glsl
@@ -1,6 +1,5 @@
 
-vec2 Hammersley(uint i, uint N);
-float RadicalInverse_VdC(uint bits);
+#include <shaders/lightmap/montecarlo.glsl>
 
 float TraceAORay(vec3 origin, float tmin, vec3 dir, float tmax);
 
@@ -58,18 +57,3 @@ float TraceAORay(vec3 origin, float tmin, vec3 dir, float tmax)
 	}
 	return tmax;
 }
-
-vec2 Hammersley(uint i, uint N)
-{
-	return vec2(float(i) / float(N), RadicalInverse_VdC(i));
-}
-
-float RadicalInverse_VdC(uint bits)
-{
-	bits = (bits << 16u) | (bits >> 16u);
-	bits = ((bits & 0x55555555u) << 1u) | ((bits & 0xAAAAAAAAu) >> 1u);
-	bits = ((bits & 0x33333333u) << 2u) | ((bits & 0xCCCCCCCCu) >> 2u);
-	bits = ((bits & 0x0F0F0F0Fu) << 4u) | ((bits & 0xF0F0F0F0u) >> 4u);
-	bits = ((bits & 0x00FF00FFu) << 8u) | ((bits & 0xFF00FF00u) >> 8u);
-	return float(bits) * 2.3283064365386963e-10f; // / 0x100000000
-}
diff --git a/wadsrc/static/shaders/lightmap/trace_light.glsl b/wadsrc/static/shaders/lightmap/trace_light.glsl
index e4323970b..6ab51fc01 100644
--- a/wadsrc/static/shaders/lightmap/trace_light.glsl
+++ b/wadsrc/static/shaders/lightmap/trace_light.glsl
@@ -1,6 +1,7 @@
 
+#include <shaders/lightmap/montecarlo.glsl>
+
 vec4 TracePointLightRay(vec3 origin, vec3 lightpos, float tmin, vec4 rayColor);
-vec2 getVogelDiskSample(int sampleIndex, int sampleCount, float phi);
 
 vec3 TraceLight(vec3 origin, vec3 normal, LightInfo light, int surfaceIndex)
 {
@@ -86,18 +87,3 @@ vec4 TracePointLightRay(vec3 origin, vec3 lightpos, float tmin, vec4 rayColor)
 	}
 	return vec4(0.0);
 }
-
-vec2 getVogelDiskSample(int sampleIndex, int sampleCount, float phi) 
-{
-    const float goldenAngle = radians(180.0) * (3.0 - sqrt(5.0));
-    float sampleIndexF = float(sampleIndex);
-    float sampleCountF = float(sampleCount);
-    
-    float r = sqrt((sampleIndexF + 0.5) / sampleCountF);  // Assuming index and count are positive
-    float theta = sampleIndexF * goldenAngle + phi;
-    
-    float sine = sin(theta);
-    float cosine = cos(theta);
-    
-    return vec2(cosine, sine) * r;
-}
diff --git a/wadsrc/static/shaders/lightmap/trace_sunlight.glsl b/wadsrc/static/shaders/lightmap/trace_sunlight.glsl
index 44bfaf636..01fed131c 100644
--- a/wadsrc/static/shaders/lightmap/trace_sunlight.glsl
+++ b/wadsrc/static/shaders/lightmap/trace_sunlight.glsl
@@ -1,5 +1,6 @@
 
-vec2 getVogelDiskSample(int sampleIndex, int sampleCount, float phi);
+#include <shaders/lightmap/montecarlo.glsl>
+
 vec4 TraceSunRay(vec3 origin, float tmin, vec3 dir, float tmax, vec4 rayColor);
 
 vec3 TraceSunLight(vec3 origin, vec3 normal, int surfaceIndex)