From adf766aeffed56935a3ca654ac143c53490a035c Mon Sep 17 00:00:00 2001
From: Frederic Bouvier <fredfgfs01@free.fr>
Date: Wed, 18 Apr 2012 09:13:38 +0200
Subject: [PATCH] Add optional shadow filtering

---
 Effects/sunlight.eff  |  8 ++++++++
 Shaders/sunlight.frag | 36 +++++++++++++++++-------------------
 preferences.xml       | 11 ++++++-----
 3 files changed, 31 insertions(+), 24 deletions(-)

diff --git a/Effects/sunlight.eff b/Effects/sunlight.eff
index 638c83dfc..444b92985 100644
--- a/Effects/sunlight.eff
+++ b/Effects/sunlight.eff
@@ -1,6 +1,9 @@
 <?xml version="1.0" encoding="utf-8"?>
 <PropertyList>
 	<name>Effects/sunlight</name>
+	<parameters>
+		<filtering><use>/sim/rendering/shadows/filtering</use></filtering>
+	</parameters>
 	<technique n="10">
 		<predicate>
 			<property>/sim/rendering/shadows/enabled</property>
@@ -68,6 +71,11 @@
 				<type>sampler-2d</type>
 				<value type="int">4</value>
 			</uniform>
+			<uniform>
+				<name>filtering</name>
+				<type>int</type>
+				<value type="int"><use>filtering</use></value>
+			</uniform>
 			<!-- The following uniforms are automatically defined and initialized :
 				- fg_SunAmbientColor
 				- fg_SunDiffuseColor
diff --git a/Shaders/sunlight.frag b/Shaders/sunlight.frag
index f99f6637d..c1e812d18 100644
--- a/Shaders/sunlight.frag
+++ b/Shaders/sunlight.frag
@@ -10,6 +10,7 @@ uniform vec3 fg_SunDirection;
 uniform vec3 fg_Planes;
 uniform int fg_ShadowNumber;
 uniform vec4 fg_ShadowDistances;
+uniform int filtering;
 varying vec3 ray;
 
 vec3 position( vec3 viewdir, float depth );
@@ -60,26 +61,23 @@ void main() {
     vec3 pos = position( viewDir, texture2D( depth_tex, coords ).r );
 
     vec4 tint;
-#if 0
-    float shadow = 1.0;
-#elif 1
-    float shadow = shadow2DProj( shadow_tex, DynamicShadow( vec4( pos, 1.0 ), tint ) ).r;
-#elif 0
     float shadow = 0.0;
-    shadow += 0.333 * shadow2DProj( shadow_tex, DynamicShadow( vec4(pos, 1.0), tint ) ).r;
-    shadow += 0.166 * shadow2DProj( shadow_tex, DynamicShadow( vec4(pos + vec3(-0.003 * pos.z, -0.003 * pos.z, 0), 1.0), tint ) ).r;
-    shadow += 0.166 * shadow2DProj( shadow_tex, DynamicShadow( vec4(pos + vec3( 0.003 * pos.z,  0.003 * pos.z, 0), 1.0), tint ) ).r;
-    shadow += 0.166 * shadow2DProj( shadow_tex, DynamicShadow( vec4(pos + vec3(-0.003 * pos.z,  0.003 * pos.z, 0), 1.0), tint ) ).r;
-    shadow += 0.166 * shadow2DProj( shadow_tex, DynamicShadow( vec4(pos + vec3( 0.003 * pos.z, -0.003 * pos.z, 0), 1.0), tint ) ).r;
-#else
-    float kernel[9] = float[]( 36/256.0, 24/256.0, 6/256.0,
-                           24/256.0, 16/256.0, 4/256.0,
-                           6/256.0,  4/256.0, 1/256.0 );
-    float shadow = 0;
-    for( int x = -2; x <= 2; ++x )
-      for( int y = -2; y <= 2; ++y )
-        shadow += kernel[abs(x)*3 + abs(y)] * shadow2DProj( shadow_tex, DynamicShadow( vec4(pos + vec3(-0.005 * x * pos.z, -0.005 * y * pos.z, 0), 1.0), tint ) ).r;
-#endif
+    if (filtering == 1) {
+        shadow = shadow2DProj( shadow_tex, DynamicShadow( vec4( pos, 1.0 ), tint ) ).r;
+    } else if (filtering == 2) {
+        shadow += 0.333 * shadow2DProj( shadow_tex, DynamicShadow( vec4(pos, 1.0), tint ) ).r;
+        shadow += 0.166 * shadow2DProj( shadow_tex, DynamicShadow( vec4(pos + vec3(-0.003 * pos.z, -0.002 * pos.z, 0), 1.0), tint ) ).r;
+        shadow += 0.166 * shadow2DProj( shadow_tex, DynamicShadow( vec4(pos + vec3( 0.003 * pos.z,  0.002 * pos.z, 0), 1.0), tint ) ).r;
+        shadow += 0.166 * shadow2DProj( shadow_tex, DynamicShadow( vec4(pos + vec3(-0.003 * pos.z,  0.002 * pos.z, 0), 1.0), tint ) ).r;
+        shadow += 0.166 * shadow2DProj( shadow_tex, DynamicShadow( vec4(pos + vec3( 0.003 * pos.z, -0.002 * pos.z, 0), 1.0), tint ) ).r;
+    } else {
+        float kernel[9] = float[]( 36/256.0, 24/256.0, 6/256.0,
+                               24/256.0, 16/256.0, 4/256.0,
+                               6/256.0,  4/256.0, 1/256.0 );
+        for( int x = -2; x <= 2; ++x )
+          for( int y = -2; y <= 2; ++y )
+            shadow += kernel[abs(x)*3 + abs(y)] * shadow2DProj( shadow_tex, DynamicShadow( vec4(pos + vec3(-0.0025 * x * pos.z, -0.0025 * y * pos.z, 0), 1.0), tint ) ).r;
+    }
     vec3 lightDir = (fg_ViewMatrix * vec4( fg_SunDirection, 0.0 )).xyz;
     lightDir = normalize( lightDir );
     vec3 color = texture2D( color_tex, coords ).rgb;
diff --git a/preferences.xml b/preferences.xml
index 766f57388..2092fd7bb 100644
--- a/preferences.xml
+++ b/preferences.xml
@@ -182,11 +182,12 @@ Started September 2000 by David Megginson, david@megginson.com
 				<debug type="bool"
 							 userarchive="y">false</debug>
 				<map-size type="int">4096</map-size>
-				<num-cascades type="int">4</num-cascades>
-				<cascade-far-m index="0" type="float">5.0</cascade-far-m>
-				<cascade-far-m index="1" type="float">50.0</cascade-far-m>
-				<cascade-far-m index="2" type="float">500.0</cascade-far-m>
-				<cascade-far-m index="3" type="float">5000.0</cascade-far-m>
+				<num-cascades type="int" userarchive="y">4</num-cascades>
+				<cascade-far-m index="0" type="float" userarchive="y">5.0</cascade-far-m>
+				<cascade-far-m index="1" type="float" userarchive="y">50.0</cascade-far-m>
+				<cascade-far-m index="2" type="float" userarchive="y">500.0</cascade-far-m>
+				<cascade-far-m index="3" type="float" userarchive="y">5000.0</cascade-far-m>
+				<filtering type="int" userarchive="y">2</filtering>
 			</shadows>
 			<shader-experimental type="bool"
 													 userarchive="y">false</shader-experimental>