Put encode_gbuffer in a separate shader to please ATI and/or Mac OSX that doesn't like to have gl_FragData and gl_FragColor in the same program, even if one is never called

Effects/building.eff

@@ -79,12 +79,14 @@
   </technique>
 
   <!-- Rembrandt -->
+  <!-- FredB: What is the purpose of that ? -->
   <technique n="10">
   	<pass n="0">
 		  <program n="0">
 	  		<vertex-shader n="0">Shaders/deferred-gbuffer.vert</vertex-shader>
 		  	<fragment-shader n="0">Shaders/deferred-gbuffer.frag</fragment-shader>
 		  	<fragment-shader n="1">Shaders/gbuffer-functions.frag</fragment-shader>
+			<fragment-shader n="2">Shaders/gbuffer-encode.frag</fragment-shader>
 		  </program>
     </pass>
   </technique>

Effects/model-combined-deferred.eff

@@ -53,8 +53,7 @@ the objects that use it, and replaces it with the default shader.
 		<vertex-shader>Shaders/ubershader.vert</vertex-shader>
 		<fragment-shader>Shaders/ubershader-gbuffer.frag</fragment-shader>
 		<fragment-shader>Shaders/gbuffer-functions.frag</fragment-shader>
-<!--		<vertex-shader n="1">Shaders/deferred-gbuffer.vert</vertex-shader>
-		<fragment-shader n="1">Shaders/deferred-gbuffer.frag</fragment-shader>-->
+		<fragment-shader>Shaders/gbuffer-encode.frag</fragment-shader>
 	  </program>
 	</pass>
   </technique>

Effects/model-default.eff

@@ -195,6 +195,7 @@
 			<vertex-shader>Shaders/deferred-gbuffer.vert</vertex-shader>
 			<fragment-shader>Shaders/deferred-gbuffer.frag</fragment-shader>
 			<fragment-shader>Shaders/gbuffer-functions.frag</fragment-shader>
+			<fragment-shader>Shaders/gbuffer-encode.frag</fragment-shader>
 		</program>
 		<uniform>
 			<name>texture</name>

Effects/terrain-default.eff

@@ -465,6 +465,7 @@
 			<vertex-shader>Shaders/deferred-gbuffer.vert</vertex-shader>
 			<fragment-shader>Shaders/deferred-gbuffer.frag</fragment-shader>
 			<fragment-shader>Shaders/gbuffer-functions.frag</fragment-shader>
+			<fragment-shader>Shaders/gbuffer-encode.frag</fragment-shader>
 		</program>
 		<uniform>
 			<name>texture</name>

Effects/tree.eff

@@ -68,6 +68,7 @@
 				<vertex-shader>Shaders/deferred-tree.vert</vertex-shader>
 				<fragment-shader>Shaders/deferred-tree.frag</fragment-shader>
 				<fragment-shader>Shaders/gbuffer-functions.frag</fragment-shader>
+				<fragment-shader>Shaders/gbuffer-encode.frag</fragment-shader>
 			</program>
 			<uniform>
 				<name>texture</name>

Effects/urban.eff

@@ -159,6 +159,7 @@
 				<vertex-shader>Shaders/urban-gbuffer.vert</vertex-shader>
 				<fragment-shader>Shaders/urban-gbuffer.frag</fragment-shader>
 				<fragment-shader>Shaders/gbuffer-functions.frag</fragment-shader>
+				<fragment-shader>Shaders/gbuffer-encode.frag</fragment-shader>
 				<attribute>
 					<name>tangent</name>
 					<index>6</index>
@@ -323,6 +324,7 @@
 				<vertex-shader>Shaders/urban-gbuffer.vert</vertex-shader>
 				<fragment-shader>Shaders/urban-gbuffer.frag</fragment-shader>
 				<fragment-shader>Shaders/gbuffer-functions.frag</fragment-shader>
+				<fragment-shader>Shaders/gbuffer-encode.frag</fragment-shader>
 				<attribute>
 					<name>tangent</name>
 					<index>6</index>

Shaders/gbuffer-encode.frag

@@ -0,0 +1,22 @@
+// -*- mode: C; -*-
+// Licence: GPL v2
+// Author: Frederic Bouvier.
+
+uniform bool fg_DepthInColor;
+
+vec2 normal_encode(vec3 n);
+vec3 float_to_color(in float f);
+
+// attachment 0:  normal.x  |  normal.y  |    0.0     |    1.0
+// attachment 1: diffuse.r  | diffuse.g  | diffuse.b  | material Id
+// attachment 2: specular.l | shininess  | emission.l |  unused
+// attachment 3:     ---------- depth ------------    |  unused        (optional)
+//
+void encode_gbuffer(vec3 normal, vec3 color, int mId, float specular, float shininess, float emission, float depth)
+{
+    gl_FragData[0] = vec4( normal_encode(normal), 0.0, 1.0 );
+    gl_FragData[1] = vec4( color, float( mId ) / 255.0 );
+    gl_FragData[2] = vec4( specular, shininess / 128.0, emission, 1.0 );
+    if (fg_DepthInColor)
+        gl_FragData[3] = vec4(float_to_color(depth), 1.0);
+}

Shaders/gbuffer-functions.frag

@@ -67,17 +67,3 @@ vec3 position( vec3 viewDir, vec2 coords, sampler2D depth_tex )
         depth = texture2D( depth_tex, coords ).r;
     return position( viewDir, depth );
 }
-
-// attachment 0:  normal.x  |  normal.y  |    0.0     |    1.0
-// attachment 1: diffuse.r  | diffuse.g  | diffuse.b  | material Id
-// attachment 2: specular.l | shininess  | emission.l |  unused
-// attachment 3:     ---------- depth ------------    |  unused        (optional)
-//
-void encode_gbuffer(vec3 normal, vec3 color, int mId, float specular, float shininess, float emission, float depth)
-{
-    gl_FragData[0] = vec4( normal_encode(normal), 0.0, 1.0 );
-    gl_FragData[1] = vec4( color, float( mId ) / 255.0 );
-    gl_FragData[2] = vec4( specular, shininess / 128.0, emission, 1.0 );
-    if (fg_DepthInColor)
-        gl_FragData[3] = vec4(float_to_color(depth), 1.0);
-}