Fix bug #750: allow cards or drivers not supporting dynamic indexing in fragment shaders to have simple shadows

Effects/sunlight.eff

@@ -4,14 +4,26 @@
 	<parameters>
 		<filtering><use>/sim/rendering/shadows/filtering</use></filtering>
 	</parameters>
-	<technique n="9">
+	<technique n="8">
 		<predicate>
 			<and>
 				<property>/sim/rendering/shadows/enabled</property>
-				<less>
-					<value type="float">1.0</value>
-					<float-property>/sim/rendering/shadows/filtering</float-property>
-				</less>
+				<or> <!-- filtering >= 3 || ( filtering >= 2 && num-cascades >= 2 ) -->
+					<less>
+						<value type="float">2.0</value>
+						<float-property>/sim/rendering/shadows/filtering</float-property>
+					</less>
+					<and>
+						<less>
+							<value type="float">1.0</value>
+							<float-property>/sim/rendering/shadows/filtering</float-property>
+						</less>
+						<less>
+							<value type="float">1.0</value>
+							<float-property>/sim/rendering/shadows/num-cascades</float-property>
+						</less>
+					</and>
+				</or>
 			</and>
 		</predicate>
 		<pass>
@@ -96,9 +108,16 @@
 			-->
 		</pass>
 	</technique>
-	<technique n="10">
+	<technique n="9">
 		<predicate>
-			<property>/sim/rendering/shadows/enabled</property>
+			<and>
+				<property>/sim/rendering/shadows/enabled</property>
+				<!-- num-cascades >= 2 -->
+				<less>
+					<value type="float">1.0</value>
+					<float-property>/sim/rendering/shadows/num-cascades</float-property>
+				</less>
+			</and>
 		</predicate>
 		<pass>
 			<lighting>false</lighting>
@@ -177,6 +196,92 @@
 			-->
 		</pass>
 	</technique>
+	<technique n="10">
+		<predicate>
+			<property>/sim/rendering/shadows/enabled</property>
+		</predicate>
+		<pass>
+			<lighting>false</lighting>
+			<depth>
+				<enabled>false</enabled>
+			</depth>
+			<blend>
+				<source>one</source>
+				<destination>one</destination>
+			</blend>
+			<render-bin>
+				<bin-number>1</bin-number>
+				<bin-name>RenderBin</bin-name>
+			</render-bin>
+			<texture-unit>
+				<unit>0</unit>
+				<type>depth-buffer</type>
+			</texture-unit>
+			<texture-unit>
+				<unit>1</unit>
+				<type>normal-buffer</type>
+			</texture-unit>
+			<texture-unit>
+				<unit>2</unit>
+				<type>diffuse-buffer</type>
+			</texture-unit>
+			<texture-unit>
+				<unit>3</unit>
+				<type>spec-emis-buffer</type>
+			</texture-unit>
+			<texture-unit>
+				<unit>4</unit>
+				<type>shadow-buffer</type>
+			</texture-unit>
+			<program>
+				<vertex-shader>Shaders/sunlight-simple.vert</vertex-shader>
+				<fragment-shader>Shaders/sunlight-simple.frag</fragment-shader>
+				<fragment-shader>Shaders/gbuffer-functions.frag</fragment-shader>
+			</program>
+			<uniform>
+				<name>depth_tex</name>
+				<type>sampler-2d</type>
+				<value type="int">0</value>
+			</uniform>
+			<uniform>
+				<name>normal_tex</name>
+				<type>sampler-2d</type>
+				<value type="int">1</value>
+			</uniform>
+			<uniform>
+				<name>color_tex</name>
+				<type>sampler-2d</type>
+				<value type="int">2</value>
+			</uniform>
+			<uniform>
+				<name>spec_emis_tex</name>
+				<type>sampler-2d</type>
+				<value type="int">3</value>
+			</uniform>
+			<uniform>
+				<name>shadow_tex</name>
+				<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
+				- fg_SunSpecularColor
+				- fg_SunDirection
+				- fg_ProjectionMatrixInverse
+				- fg_ViewMatrixInverse
+				- fg_ViewMatrix
+				- fg_Planes
+				- fg_ShadowNumber
+				- fg_ShadowDistances
+			-->
+		</pass>
+	</technique>
 	<technique n="11">
 		<pass>
 			<lighting>false</lighting>
@@ -210,6 +315,7 @@
 			<program>
 				<vertex-shader>Shaders/sunlight.vert</vertex-shader>
 				<fragment-shader>Shaders/sunlight-noshadow.frag</fragment-shader>
+				<fragment-shader>Shaders/gbuffer-functions.frag</fragment-shader>
 			</program>
 			<uniform>
 				<name>depth_tex</name>

Shaders/sunlight-noshadow.frag

@@ -8,23 +8,19 @@ uniform vec4 fg_SunSpecularColor;
 uniform vec3 fg_SunDirection;
 uniform vec3 fg_Planes;
 varying vec3 ray;
+
+vec3 normal_decode(vec2 enc);
+
 void main() {
     vec2 coords = gl_TexCoord[0].xy;
     vec4 spec_emis = texture2D( spec_emis_tex, coords );
     if ( spec_emis.a < 0.1 )
         discard;
-    vec3 normal;
-    normal.xy = texture2D( normal_tex, coords ).rg * 2.0 - vec2(1.0,1.0);
-    normal.z = sqrt( 1.0 - dot( normal.xy, normal.xy ) );
+    vec3 normal = normal_decode(texture2D( normal_tex, coords ).rg);
     float len = length(normal);
     normal /= len;
     vec3 viewDir = normalize(ray);
-    float depth = texture2D( depth_tex, coords ).r;
-    vec3 pos;
-    pos.z = - fg_Planes.y / (fg_Planes.x + depth * fg_Planes.z);
-    pos.xy = viewDir.xy / viewDir.z * pos.z;
 
-    vec4 tint;
     vec3 lightDir = (fg_ViewMatrix * vec4( fg_SunDirection, 0.0 )).xyz;
     lightDir = normalize( lightDir );
     vec3 color = texture2D( color_tex, coords ).rgb;

Shaders/sunlight-simple.frag

@@ -0,0 +1,74 @@
+uniform mat4 fg_ViewMatrix;
+uniform sampler2D depth_tex;
+uniform sampler2D normal_tex;
+uniform sampler2D color_tex;
+uniform sampler2D spec_emis_tex;
+uniform sampler2DShadow shadow_tex;
+uniform vec4 fg_SunDiffuseColor;
+uniform vec4 fg_SunSpecularColor;
+uniform vec3 fg_SunDirection;
+uniform vec3 fg_Planes;
+uniform vec4 fg_ShadowDistances;
+uniform int filtering;
+
+varying vec3 ray;
+varying vec4 eyePlaneS;
+varying vec4 eyePlaneT;
+varying vec4 eyePlaneR;
+varying vec4 eyePlaneQ;
+
+vec3 position( vec3 viewdir, float depth );
+vec3 normal_decode(vec2 enc);
+
+vec4 DynamicShadow( in vec4 ecPosition, out vec4 tint )
+{
+    vec4 coords;
+    if (ecPosition.z > -fg_ShadowDistances.x) {
+        tint = vec4(0.0,1.0,0.0,1.0);
+        coords.s = dot( ecPosition, eyePlaneS );
+        coords.t = dot( ecPosition, eyePlaneT );
+        coords.p = dot( ecPosition, eyePlaneR );
+        coords.q = dot( ecPosition, eyePlaneQ );
+    } else {
+        return vec4(1.1,1.1,0.0,1.0); // outside, clamp to border
+    }
+    return coords;
+}
+void main() {
+    vec2 coords = gl_TexCoord[0].xy;
+    vec4 spec_emis = texture2D( spec_emis_tex, coords );
+    if ( spec_emis.a < 0.1 )
+        discard;
+    vec3 normal = normal_decode(texture2D( normal_tex, coords ).rg);
+    float len = length(normal);
+    normal /= len;
+    vec3 viewDir = normalize(ray);
+    vec3 pos = position( viewDir, texture2D( depth_tex, coords ).r );
+
+    vec4 tint;
+    float shadow;
+    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 {
+        shadow = shadow2DProj( shadow_tex, DynamicShadow( vec4( pos, 1.0 ), tint ) ).r;
+    }
+
+    vec3 lightDir = (fg_ViewMatrix * vec4( fg_SunDirection, 0.0 )).xyz;
+    lightDir = normalize( lightDir );
+    vec3 color = texture2D( color_tex, coords ).rgb;
+    vec3 Idiff = clamp( dot( lightDir, normal ), 0.0, 1.0 ) * color * fg_SunDiffuseColor.rgb;
+    vec3 halfDir = lightDir - viewDir;
+    len = length( halfDir );
+    vec3 Ispec = vec3(0.0);
+    vec3 Iemis = spec_emis.z * color;
+    if (len > 0.0001) {
+        halfDir /= len;
+        Ispec = pow( clamp( dot( halfDir, normal ), 0.0, 1.0 ), spec_emis.y * 128.0 ) * spec_emis.x * fg_SunSpecularColor.rgb;
+    }
+    gl_FragColor = vec4(mix(vec3(0.0), Idiff + Ispec, shadow) + Iemis, 1.0);
+//    gl_FragColor = mix(tint, vec4(mix(vec3(0.0), Idiff + Ispec, shadow) + Iemis, 1.0), 0.92);
+}

Shaders/sunlight-simple.vert

@@ -0,0 +1,19 @@
+//uniform mat4 fg_ViewMatrixInverse;
+uniform mat4 fg_ProjectionMatrixInverse;
+varying vec3 ray;
+varying vec4 eyePlaneS;
+varying vec4 eyePlaneT;
+varying vec4 eyePlaneR;
+varying vec4 eyePlaneQ;
+
+void main() {
+    gl_Position = gl_Vertex;
+    gl_TexCoord[0] = gl_MultiTexCoord0;
+//    ray = (fg_ViewMatrixInverse * vec4((fg_ProjectionMatrixInverse * gl_Vertex).xyz, 0.0)).xyz;
+    ray = (fg_ProjectionMatrixInverse * gl_Vertex).xyz;
+    
+    eyePlaneS = gl_EyePlaneS[1];
+    eyePlaneT = gl_EyePlaneT[1];
+    eyePlaneR = gl_EyePlaneR[1];
+    eyePlaneQ = gl_EyePlaneQ[1];
+}