Allow to adjust ambient occlusion strength

Effects/ambient.eff

@@ -3,6 +3,7 @@
 	<name>Effects/ambient</name>
 	<parameters>
 		<ambient-occlusion type="bool"><use>/sim/rendering/rembrandt/ambient-occlusion</use></ambient-occlusion>
+		<ambient-occlusion-strength type="float"><use>/sim/rendering/rembrandt/ambient-occlusion-strength</use></ambient-occlusion-strength>
 	</parameters>
 	<technique n="11">
 		<pass>
@@ -71,7 +72,12 @@
 			<uniform>
 				<name>ambientOcclusion</name>
 				<type>bool</type>
-				<value type="bool"><use>ambient-occlusion</use></value>
+				<value><use>ambient-occlusion</use></value>
+			</uniform>
+			<uniform>
+				<name>ambientOcclusionStrength</name>
+				<type>float</type>
+				<value><use>ambient-occlusion-strength</use></value>
 			</uniform>
 			<!-- The following uniforms are automatically defined and initialized :
 				- fg_SunAmbientColor

Shaders/ambient.frag

@@ -4,6 +4,8 @@ uniform sampler2D normal_tex;
 uniform sampler2D spec_emis_tex;
 uniform vec4 fg_SunAmbientColor;
 uniform bool ambientOcclusion;
+uniform float ambientOcclusionStrength;
+
 void main() {
     vec2 coords = gl_TexCoord[0].xy;
     float initialized = texture2D( spec_emis_tex, coords ).a;
@@ -12,7 +14,7 @@ void main() {
     vec3 tcolor = texture2D( color_tex, coords ).rgb;
     float ao = 1.0;
     if (ambientOcclusion) {
-        ao = texture2D( ao_tex, coords ).r;
+        ao = 1.0 - ambientOcclusionStrength * (1.0 - texture2D( ao_tex, coords ).r);
     }
-    gl_FragColor = vec4(tcolor*fg_SunAmbientColor.rgb*ao, 1.0);
+    gl_FragColor = vec4(tcolor * fg_SunAmbientColor.rgb * ao, 1.0);
 }

gui/dialogs/rendering.xml

@@ -222,7 +222,7 @@
 					<command>dialog-apply</command>
 					<object-name>random-objects</object-name>
 				</binding>
-      </checkbox>
+			</checkbox>
 
 			<checkbox>
 				<halign>left</halign>
@@ -306,13 +306,13 @@
 				</text>
 			</group>
 
-      <button>
+			<button>
-        <legend>Reload Scenery</legend>
+				<legend>Reload Scenery</legend>
 				<binding>
 					<command>reinit</command>
 					<subsystem>tile-manager</subsystem>
 				</binding>
-      </button>
+			</button>
 
 			<group>
 				<layout>vbox</layout>
@@ -568,7 +568,10 @@
 					<object-name>bloom</object-name>
 				</binding>
 				<visible>
-					<property>/sim/rendering/rembrandt/enabled</property>
+					<and>
+						<property>/sim/rendering/rembrandt/enabled</property>
+						<property>/sim/rendering/rembrandt/bloom-buffers</property>
+					</and>
 				</visible>
 			</checkbox>
 			
@@ -582,10 +585,53 @@
 					<object-name>occlusion</object-name>
 				</binding>
 				<visible>
-					<property>/sim/rendering/rembrandt/enabled</property>
+					<and>
+						<property>/sim/rendering/rembrandt/enabled</property>
+						<property>/sim/rendering/rembrandt/ambient-occlusion-buffers</property>
+					</and>
 				</visible>
 			</checkbox>
-			
+
+			<group>
+				<layout>hbox</layout>
+				<halign>right</halign>
+				<visible>
+					<and>
+						<property>/sim/rendering/rembrandt/enabled</property>
+						<property>/sim/rendering/rembrandt/ambient-occlusion-buffers</property>
+					</and>
+				</visible>
+				<text>
+					<label>Ambient occlusion strength</label>
+					<enable>
+						<property>/sim/rendering/rembrandt/ambient-occlusion</property>
+					</enable>
+				</text>
+				<slider>
+					<name>ambient-occlusion-strength</name>
+					<enable>
+						<property>/sim/rendering/rembrandt/ambient-occlusion</property>
+					</enable>
+					<min>0.0</min>
+					<max>1.0</max>
+					<step>0.05</step>
+					<property>/sim/rendering/rembrandt/ambient-occlusion-strength</property>
+					<binding>
+						<command>dialog-apply</command>
+						<object-name>ambient-occlusion-strength</object-name>
+					</binding>
+				</slider>
+				<text>
+					<enable>
+						<property>/sim/rendering/rembrandt/ambient-occlusion</property>
+					</enable>
+					<label>12345678</label>
+					<format>%.1f</format>
+					<live>true</live>
+					<property>/sim/rendering/rembrandt/ambient-occlusion-strength</property>
+				</text>
+			</group>
+
 			<checkbox>
 				<halign>left</halign>
 				<label>Shadows</label>

gui/menubar.xml

@@ -658,15 +658,6 @@
 			</binding>
 		</item>
 
-		<item>
-			<name>ambient-occlusion</name>
-			<binding>
-				<command>property-toggle</command>
-				<property>/sim/rendering/rembrandt/ambient-occlusion</property>
-			</binding>
-			<enabled>false</enabled>
-		</item>
-
 		<item>
 			<name>rendering-buffers</name>
 			<binding>

preferences.xml

@@ -69,6 +69,7 @@ Started September 2000 by David Megginson, david@megginson.com
 				<renderer>default-pipeline</renderer>
 				<show-buffers type="bool" userarchive="y">false</show-buffers>
 				<ambient-occlusion type="bool" userarchive="y">false</ambient-occlusion>
+				<ambient-occlusion-strength type="float" userarchive="y">1.0</ambient-occlusion-strength>
 				<ambient-occlusion-buffers type="bool">true</ambient-occlusion-buffers>
 				<bloom type="bool" userarchive="y">true</bloom>
 				<bloom-buffers type="bool">true</bloom-buffers>