SL-18190 WIP -- Take 2 on linear space windlight (more methodical approach -- make desired interface but brute force color conversions). Placeholder PBR water and move to deprecate forward rendering shaders.

7 files changed, 34 insertions, 609 deletions

diff --git a/indra/newview/app_settings/shaders/class1/deferred/alphaF.glsl b/indra/newview/app_settings/shaders/class1/deferred/alphaF.glsl
index b72c9651c1..f4ec1ec532 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/alphaF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/alphaF.glsl
@@ -25,281 +25,11 @@
 
 //class1/deferred/alphaF.glsl
 
-#extension GL_ARB_texture_rectangle : enable
 
-/*[EXTRA_CODE_HERE]*/
-
-#define INDEXED 1
-#define NON_INDEXED 2
-#define NON_INDEXED_NO_COLOR 3
-
-#ifdef DEFINE_GL_FRAGCOLOR
 out vec4 frag_color;
-#else
-#define frag_color gl_FragColor
-#endif
-
-uniform mat3 env_mat;
-uniform vec3 sun_dir;
-uniform vec3 moon_dir;
-
-#ifdef USE_DIFFUSE_TEX
-uniform sampler2D diffuseMap;
-#endif
-
-VARYING vec3 vary_fragcoord;
-VARYING vec3 vary_position;
-VARYING vec2 vary_texcoord0;
-VARYING vec3 vary_norm;
-
-#ifdef USE_VERTEX_COLOR
-VARYING vec4 vertex_color; //vertex color should be treated as sRGB
-#endif
-
-#ifdef HAS_ALPHA_MASK
-uniform float minimum_alpha;
-#endif
-
-uniform mat4 proj_mat;
-uniform mat4 inv_proj;
-uniform vec2 screen_res;
-uniform int sun_up_factor;
-uniform vec4 light_position[8];
-uniform vec3 light_direction[8];
-uniform vec4 light_attenuation[8]; 
-uniform vec3 light_diffuse[8];
-
-#ifdef WATER_FOG
-vec4 applyWaterFogView(vec3 pos, vec4 color);
-#endif
 
-vec3 srgb_to_linear(vec3 c);
-vec3 linear_to_srgb(vec3 c);
-
-vec2 encode_normal (vec3 n);
-vec3 scaleSoftClipFrag(vec3 l);
-vec3 atmosFragLighting(vec3 light, vec3 additive, vec3 atten);
-
-void calcAtmosphericVars(vec3 inPositionEye, vec3 light_dir, float ambFactor, out vec3 sunlit, out vec3 amblit, out vec3 atten, out vec3 additive, bool use_ao);
-
-#ifdef HAS_SHADOW
-float sampleDirectionalShadow(vec3 pos, vec3 norm, vec2 pos_screen);
-#endif
-
-float getAmbientClamp();
-
-void sampleReflectionProbesLegacy(inout vec3 ambenv, inout vec3 glossenv, inout vec3 legacyenv, 
-        vec3 pos, vec3 norm, float glossiness, float envIntensity);
-
-vec3 calcPointLightOrSpotLight(vec3 light_col, vec3 diffuse, vec3 v, vec3 n, vec4 lp, vec3 ln, float la, float fa, float is_pointlight, float ambiance)
+void main()
 {
-    // SL-14895 inverted attenuation work-around
-    // This routine is tweaked to match deferred lighting, but previously used an inverted la value. To reconstruct
-    // that previous value now that the inversion is corrected, we reverse the calculations in LLPipeline::setupHWLights()
-    // to recover the `adjusted_radius` value previously being sent as la.
-    float falloff_factor = (12.0 * fa) - 9.0;
-    float inverted_la = falloff_factor / la;
-    // Yes, it makes me want to cry as well. DJH
-    
-    vec3 col = vec3(0);
-
-	//get light vector
-	vec3 lv = lp.xyz-v;
-
-	//get distance
-	float dist = length(lv);
-	float da = 1.0;
-
-    /*if (dist > inverted_la)
-    {
-        return col;
-    }
-
-    clip to projector bounds
-     vec4 proj_tc = proj_mat * lp;
-
-    if (proj_tc.z < 0
-     || proj_tc.z > 1
-     || proj_tc.x < 0
-     || proj_tc.x > 1 
-     || proj_tc.y < 0
-     || proj_tc.y > 1)
-    {
-        return col;
-    }*/
-
-	if (dist > 0.0 && inverted_la > 0.0)
-	{
-        dist /= inverted_la;
-
-		//normalize light vector
-		lv = normalize(lv);
-	
-		//distance attenuation
-		float dist_atten = clamp(1.0-(dist-1.0*(1.0-fa))/fa, 0.0, 1.0);
-		dist_atten *= dist_atten;
-        dist_atten *= 2.0f;
-
-        if (dist_atten <= 0.0)
-        {
-           return col;
-        }
-
-		// spotlight coefficient.
-		float spot = max(dot(-ln, lv), is_pointlight);
-		da *= spot*spot; // GL_SPOT_EXPONENT=2
-
-		//angular attenuation
-		da *= dot(n, lv);
-        da = max(0.0, da);
-
-		float lit = 0.0f;
-
-        float amb_da = 0.0;//ambiance;
-        if (da > 0)
-        {
-		    lit = max(da * dist_atten,0.0);
-            col = lit * light_col * diffuse;
-            amb_da += (da*0.5+0.5) * ambiance;
-        }
-        amb_da += (da*da*0.5 + 0.5) * ambiance;
-        amb_da *= dist_atten;
-        amb_da = min(amb_da, 1.0f - lit);
-
-        // SL-10969 ... need to work out why this blows out in many setups...
-        //col.rgb += amb_da * light_col * diffuse;
-
-        // no spec for alpha shader...
-    }
-    col = max(col, vec3(0));
-    return col;
-}
-
-void main() 
-{
-    vec2 frag = vary_fragcoord.xy/vary_fragcoord.z*0.5+0.5;
-    frag *= screen_res;
-    
-    vec4 pos = vec4(vary_position, 1.0);
-    vec3 norm = vary_norm;
-
-    float shadow = 1.0f;
-
-#ifdef HAS_SHADOW
-    shadow = sampleDirectionalShadow(pos.xyz, norm.xyz, frag);
-#endif
-
-#ifdef USE_DIFFUSE_TEX
-    vec4 diffuse_tap = texture2D(diffuseMap,vary_texcoord0.xy);
-#endif
-
-#ifdef USE_INDEXED_TEX
-    vec4 diffuse_tap = diffuseLookup(vary_texcoord0.xy);
-#endif
-
-    vec4 diffuse_srgb = diffuse_tap;
-
-#ifdef FOR_IMPOSTOR
-    vec4 color;
-    color.rgb = diffuse_srgb.rgb;
-    color.a = 1.0;
-
-    float final_alpha = diffuse_srgb.a * vertex_color.a;
-    diffuse_srgb.rgb *= vertex_color.rgb;
-    
-    // Insure we don't pollute depth with invis pixels in impostor rendering
-    //
-    if (final_alpha < minimum_alpha)
-    {
-        discard;
-    }
-
-    color.rgb = diffuse_srgb.rgb;
-    color.a = final_alpha;
-
-#else // FOR_IMPOSTOR
-
-    vec4 diffuse_linear = vec4(srgb_to_linear(diffuse_srgb.rgb), diffuse_srgb.a);
-
-    vec3 light_dir = (sun_up_factor == 1) ? sun_dir: moon_dir;
-
-    float final_alpha = diffuse_linear.a;
-
-#ifdef USE_VERTEX_COLOR
-    final_alpha *= vertex_color.a;
-
-    if (final_alpha < minimum_alpha)
-    { // TODO: figure out how to get invisible faces out of 
-        // render batches without breaking glow
-        discard;
-    }
-
-    diffuse_srgb.rgb *= vertex_color.rgb;
-    diffuse_linear.rgb = srgb_to_linear(diffuse_srgb.rgb);
-#endif // USE_VERTEX_COLOR
-
-    vec3 sunlit;
-    vec3 amblit;
-    vec3 additive;
-    vec3 atten;
-
-    calcAtmosphericVars(pos.xyz, light_dir, 1.0, sunlit, amblit, additive, atten, false);
-
-    vec3 ambenv;
-    vec3 glossenv;
-    vec3 legacyenv;
-    sampleReflectionProbesLegacy(ambenv, glossenv, legacyenv, pos.xyz, norm.xyz, 0.0, 0.0);
-    
-
-    float da = dot(norm.xyz, light_dir.xyz);
-          da = clamp(da, -1.0, 1.0);
- 
-    float final_da = da;
-          final_da = clamp(final_da, 0.0f, 1.0f);
-
-    vec4 color = vec4(0.0);
-
-    color.a   = final_alpha;
-
-    float ambient = min(abs(dot(norm.xyz, sun_dir.xyz)), 1.0);
-    ambient *= 0.5;
-    ambient *= ambient;
-    ambient = (1.0 - ambient);
-
-    vec3 sun_contrib = min(final_da, shadow) * sunlit;
-
-    color.rgb = max(amblit, ambenv);
-    color.rgb *= ambient;
-
-    color.rgb += sun_contrib;
-
-    color.rgb *= diffuse_linear.rgb;
-
-    color.rgb = atmosFragLighting(color.rgb, additive, atten);
-
-    vec4 light = vec4(0,0,0,0);
-    
-   #define LIGHT_LOOP(i) light.rgb += calcPointLightOrSpotLight(light_diffuse[i].rgb, diffuse_linear.rgb, pos.xyz, norm, light_position[i], light_direction[i].xyz, light_attenuation[i].x, light_attenuation[i].y, light_attenuation[i].z, light_attenuation[i].w);
-
-    LIGHT_LOOP(1)
-    LIGHT_LOOP(2)
-    LIGHT_LOOP(3)
-    LIGHT_LOOP(4)
-    LIGHT_LOOP(5)
-    LIGHT_LOOP(6)
-    LIGHT_LOOP(7)
-
-    // sum local light contrib in linear colorspace
-#if !defined(LOCAL_LIGHT_KILL)
-    color.rgb += light.rgb;
-#endif // !defined(LOCAL_LIGHT_KILL)
-
-#ifdef WATER_FOG
-    color = applyWaterFogView(pos.xyz, color);
-#endif // WATER_FOG
-
-#endif // #else // FOR_IMPOSTOR
-
-    frag_color = color;
+    frag_color = vec4(1,0,1,0.5);
 }
 
diff --git a/indra/newview/app_settings/shaders/class1/deferred/cloudShadowF.glsl b/indra/newview/app_settings/shaders/class1/deferred/cloudShadowF.glsl
index 0157d166e0..afcb309e33 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/cloudShadowF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/cloudShadowF.glsl
@@ -45,7 +45,6 @@ uniform float blend_factor;
 uniform vec4 cloud_pos_density1;
 uniform vec4 cloud_pos_density2;
 uniform vec4 sunlight_color;
-uniform vec4 cloud_color;
 uniform float cloud_shadow;
 uniform float cloud_scale;
 uniform float cloud_variance;
diff --git a/indra/newview/app_settings/shaders/class1/deferred/pbralphaF.glsl b/indra/newview/app_settings/shaders/class1/deferred/pbralphaF.glsl
index 3afa9fb435..cb91dfdcce 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/pbralphaF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/pbralphaF.glsl
@@ -25,229 +25,9 @@
 
 /*[EXTRA_CODE_HERE]*/
 
-#define DIFFUSE_ALPHA_MODE_NONE     0
-#define DIFFUSE_ALPHA_MODE_BLEND    1
-#define DIFFUSE_ALPHA_MODE_MASK     2
-#define DIFFUSE_ALPHA_MODE_EMISSIVE 3
-
-uniform sampler2D diffuseMap;  //always in sRGB space
-uniform sampler2D bumpMap;
-uniform sampler2D emissiveMap;
-uniform sampler2D specularMap; // PBR: Packed: Occlusion, Metal, Roughness
-
-uniform float metallicFactor;
-uniform float roughnessFactor;
-uniform vec3 emissiveColor;
-
-#if defined(HAS_SUN_SHADOW) || defined(HAS_SSAO)
-uniform sampler2DRect lightMap;
-#endif
-
-uniform int sun_up_factor;
-uniform vec3 sun_dir;
-uniform vec3 moon_dir;
-
-#if (DIFFUSE_ALPHA_MODE == DIFFUSE_ALPHA_MODE_BLEND)
-  #ifdef DEFINE_GL_FRAGCOLOR
-    out vec4 frag_color;
-  #else
-    #define frag_color gl_FragColor
-  #endif
-#else
-  #ifdef DEFINE_GL_FRAGCOLOR
-    out vec4 frag_data[4];
-  #else
-    #define frag_data gl_FragData
-  #endif
-#endif
-
-#ifdef HAS_SHADOW
-  VARYING vec3 vary_fragcoord;
-  uniform vec2 screen_res;
-#endif
-
-VARYING vec3 vary_position;
-VARYING vec4 vertex_color;
-VARYING vec2 vary_texcoord0;
-VARYING vec2 vary_texcoord1;
-VARYING vec2 vary_texcoord2;
-VARYING vec3 vary_normal;
-VARYING vec3 vary_tangent;
-flat in float vary_sign;
-
-
-#ifdef HAS_ALPHA_MASK
-uniform float minimum_alpha; // PBR alphaMode: MASK, See: mAlphaCutoff, setAlphaCutoff()
-#endif
-
-// Lights
-// See: LLRender::syncLightState()
-uniform vec4 light_position[8];
-uniform vec3 light_direction[8]; // spot direction
-uniform vec4 light_attenuation[8]; // linear, quadratic, is omni, unused, See: LLPipeline::setupHWLights() and syncLightState()
-uniform vec3 light_diffuse[8];
-uniform vec2 light_deferred_attenuation[8]; // light size and falloff
-
-vec3 srgb_to_linear(vec3 c);
-vec3 linear_to_srgb(vec3 c);
-
-// These are in deferredUtil.glsl but we can't set: mFeatures.isDeferred to include it
-void calcAtmosphericVars(vec3 inPositionEye, vec3 light_dir, float ambFactor, out vec3 sunlit, out vec3 amblit, out vec3 additive, out vec3 atten, bool use_ao);
-vec3 atmosFragLighting(vec3 l, vec3 additive, vec3 atten);
-vec3 scaleSoftClipFrag(vec3 l);
-
-void calcHalfVectors(vec3 lv, vec3 n, vec3 v, out vec3 h, out vec3 l, out float nh, out float nl, out float nv, out float vh, out float lightDist);
-float calcLegacyDistanceAttenuation(float distance, float falloff);
-float sampleDirectionalShadow(vec3 pos, vec3 norm, vec2 pos_screen);
-void sampleReflectionProbes(inout vec3 ambenv, inout vec3 glossenv, 
-        vec3 pos, vec3 norm, float glossiness);
-
-// PBR interface
-vec3 pbrIbl(vec3 diffuseColor,
-            vec3 specularColor,
-            vec3 radiance, // radiance map sample
-            vec3 irradiance, // irradiance map sample
-            float ao,       // ambient occlusion factor
-            float nv,       // normal dot view vector
-            float perceptualRoughness);
-
-vec3 pbrPunctual(vec3 diffuseColor, vec3 specularColor, 
-                    float perceptualRoughness, 
-                    float metallic,
-                    vec3 n, // normal
-                    vec3 v, // surface point to camera
-                    vec3 l); //surface point to light
-
-vec3 calcPointLightOrSpotLight(vec3 diffuseColor, vec3 specularColor, 
-                    float perceptualRoughness, 
-                    float metallic,
-                    vec3 n, // normal
-                    vec3 p, // pixel position
-                    vec3 v, // view vector (negative normalized pixel position)
-                    vec3 lp, // light position
-                    vec3 ld, // light direction (for spotlights)
-                    vec3 lightColor,
-                    float lightSize, float falloff, float is_pointlight, float ambiance)
-{
-    vec3 color = vec3(0,0,0);
-
-    vec3 lv = lp.xyz - p;
-
-    float lightDist = length(lv);
-
-    float dist = lightDist / lightSize;
-    if (dist <= 1.0)
-    {
-        lv /= lightDist;
-
-        float dist_atten = calcLegacyDistanceAttenuation(dist, falloff);
-
-        vec3 intensity = dist_atten * lightColor * 3.0;
-
-        color = intensity*pbrPunctual(diffuseColor, specularColor, perceptualRoughness, metallic, n.xyz, v, lv);
-    }
-
-    return color;
-}
+out vec4 frag_color;
 
 void main()
 {
-    vec3 color = vec3(0,0,0);
-
-    vec3  light_dir   = (sun_up_factor == 1) ? sun_dir : moon_dir;
-    vec3  pos         = vary_position;
-
-    float scol = 1.0;
-    float ambocc = 1.0;
-
-    vec3 sunlit;
-    vec3 amblit;
-    vec3 additive;
-    vec3 atten;
-    calcAtmosphericVars(pos.xyz, light_dir, ambocc, sunlit, amblit, additive, atten, true);
-
-
-// IF .mFeatures.mIndexedTextureChannels = LLGLSLShader::sIndexedTextureChannels;
-//    vec3 col = vertex_color.rgb * diffuseLookup(vary_texcoord0.xy).rgb;
-// else
-    vec4 albedo = texture(diffuseMap, vary_texcoord0.xy).rgba;
-    albedo.rgb = srgb_to_linear(albedo.rgb);
-#ifdef HAS_ALPHA_MASK
-    if (albedo.a < minimum_alpha)
-    {
-        discard;
-    }
-#endif
-
-    vec3 baseColor = vertex_color.rgb * albedo.rgb;
-
-    vec3 vNt = texture(bumpMap, vary_texcoord1.xy).xyz*2.0-1.0;
-    float sign = vary_sign;
-    vec3 vN = vary_normal;
-    vec3 vT = vary_tangent.xyz;
-    
-    vec3 vB = sign * cross(vN, vT);
-    vec3 norm = normalize( vNt.x * vT + vNt.y * vB + vNt.z * vN );
-
-    norm *= gl_FrontFacing ? 1.0 : -1.0;
-
-#ifdef HAS_SHADOW
-    vec2 frag = vary_fragcoord.xy/vary_fragcoord.z*0.5+0.5;
-    frag *= screen_res;
-    scol = sampleDirectionalShadow(pos.xyz, norm.xyz, frag);
-#endif
-
-    vec3 orm = texture(specularMap, vary_texcoord2.xy).rgb; //orm is packed into "emissiveRect" to keep the data in linear color space
-
-    float perceptualRoughness = orm.g * roughnessFactor;
-    float metallic = orm.b * metallicFactor;
-    float ao = orm.r;
-
-    // emissiveColor is the emissive color factor from GLTF and is already in linear space
-    vec3 colorEmissive = emissiveColor;
-    // emissiveMap here is a vanilla RGB texture encoded as sRGB, manually convert to linear
-    colorEmissive *= srgb_to_linear(texture2D(emissiveMap, vary_texcoord0.xy).rgb);
-
-    // PBR IBL
-    float gloss      = 1.0 - perceptualRoughness;
-    vec3  irradiance = vec3(0);
-    vec3  radiance  = vec3(0);
-    sampleReflectionProbes(irradiance, radiance, pos.xyz, norm.xyz, gloss);
-    irradiance       = max(srgb_to_linear(amblit),irradiance) * ambocc*4.0;
-
-    vec3 f0 = vec3(0.04);
-    
-    vec3 diffuseColor = baseColor.rgb*(vec3(1.0)-f0);
-    diffuseColor *= 1.0 - metallic;
-
-    vec3 specularColor = mix(f0, baseColor.rgb, metallic);
-
-    vec3 v = -normalize(pos.xyz);
-    float NdotV = clamp(abs(dot(norm.xyz, v)), 0.001, 1.0);
-
-    color += pbrIbl(diffuseColor, specularColor, radiance, irradiance, ao, NdotV, perceptualRoughness);
-    color += pbrPunctual(diffuseColor, specularColor, perceptualRoughness, metallic, norm.xyz, v, light_dir) * sunlit*8.0 * scol;
-    color += colorEmissive;
-    
-    vec3 light = vec3(0);
-
-    // Punctual lights
-#define LIGHT_LOOP(i) light += calcPointLightOrSpotLight(diffuseColor, specularColor, perceptualRoughness, metallic, norm.xyz, pos.xyz, v, light_position[i].xyz, light_direction[i].xyz, light_diffuse[i].rgb, light_deferred_attenuation[i].x, light_deferred_attenuation[i].y, light_attenuation[i].z, light_attenuation[i].w);
-
-    LIGHT_LOOP(1)
-    LIGHT_LOOP(2)
-    LIGHT_LOOP(3)
-    LIGHT_LOOP(4)
-    LIGHT_LOOP(5)
-    LIGHT_LOOP(6)
-    LIGHT_LOOP(7)
-
-    color.rgb += light.rgb;
-
-    color.rgb = linear_to_srgb(color.rgb);
-    color *= atten.r;
-    color += 2.0*additive;
-    color  = scaleSoftClipFrag(color);
-
-    frag_color = vec4(srgb_to_linear(color.rgb),albedo.a * vertex_color.a);
-}
+    frag_color = vec4(0,1,0,0.5);
+}
\ No newline at end of file
diff --git a/indra/newview/app_settings/shaders/class1/deferred/skyV.glsl b/indra/newview/app_settings/shaders/class1/deferred/skyV.glsl
index 28a1faf24f..223143bc1b 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/skyV.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/skyV.glsl
@@ -55,8 +55,6 @@ uniform float max_y;
 uniform vec4  glow;
 uniform float sun_moon_glow_factor;
 
-uniform vec4 cloud_color;
-
 // NOTE: Keep these in sync!
 //       indra\newview\app_settings\shaders\class1\deferred\skyV.glsl
 //       indra\newview\app_settings\shaders\class1\deferred\cloudsV.glsl
diff --git a/indra/newview/app_settings/shaders/class1/deferred/waterF.glsl b/indra/newview/app_settings/shaders/class1/deferred/waterF.glsl
index 03896f4c51..c9e7552312 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/waterF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/waterF.glsl
@@ -28,7 +28,7 @@
 /*[EXTRA_CODE_HERE]*/
 
 #ifdef DEFINE_GL_FRAGCOLOR
-out vec4 frag_data[3];
+out vec4 frag_data[4];
 #else
 #define frag_data gl_FragData
 #endif
@@ -162,11 +162,13 @@ void main()
 	
 	vec4 pos = vary_position;
 	
-	color.rgb += spec * specular;
+	//color.rgb += spec * specular;
 
-	color.rgb = atmosTransport(color.rgb);
-	color.rgb = scaleSoftClip(color.rgb);
+	//color.rgb = atmosTransport(color.rgb);
+	//color.rgb = scaleSoftClip(color.rgb);
     
+    //color.rgb = refcol.rgb;
+    color.rgb = vec3(0.0);
 	color.a   = spec * sunAngle2;
     
 	vec3 screenspacewavef = normalize((norm_mat*vec4(wavef, 1.0)).xyz);
@@ -176,9 +178,14 @@ void main()
     // TODO: The non-obvious assignment below is copied from the pre-EEP WL shader code
     //       Unfortunately, fixing it causes a mismatch for EEP, and so it remains...  for now
     //       SL-12975 (unfix pre-EEP broken alpha)
-    frag_data[0] = vec4(color.rgb, color);  // Effectively, color.rgbr
-
+    frag_data[0] = vec4(srgb_to_linear(color.rgb), 0.0);  // Effectively, color.rgbr
+    
+    frag_data[1] = vec4(1.0, 0.2, 0.0, 0.0);		// speccolor, spec
+	frag_data[2] = vec4(encode_normal(screenspacewavef.xyz), 0.0, GBUFFER_FLAG_HAS_PBR);// normalxy, env intens, flags (atmo kill)
+    frag_data[3] = vec4(srgb_to_linear(refcol.rgb),0);
 
-    frag_data[1] = vec4(0);		// speccolor, spec
-	frag_data[2] = vec4(encode_normal(screenspacewavef.xyz), 0.05, GBUFFER_FLAG_HAS_ATMOS);// normalxy, env intens, flags (atmo kill)
+    
+    //frag_data[0] = vec4(0.0,0,0,0);
+    //frag_data[1] = vec4(0, 1.0, 0.0, 0.0);
+    //frag_data[3] = vec4(0);
 }
diff --git a/indra/newview/app_settings/shaders/class1/windlight/atmosphericsFuncs.glsl b/indra/newview/app_settings/shaders/class1/windlight/atmosphericsFuncs.glsl
index 3831eeaa01..28d1ae2027 100644
--- a/indra/newview/app_settings/shaders/class1/windlight/atmosphericsFuncs.glsl
+++ b/indra/newview/app_settings/shaders/class1/windlight/atmosphericsFuncs.glsl
@@ -22,24 +22,8 @@
  * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
  * $/LicenseInfo$
  */
-uniform vec4  lightnorm;
-uniform vec4  sunlight_color;
-uniform vec4  moonlight_color;
-uniform int   sun_up_factor;
-uniform vec4  ambient_color;
-uniform vec4  blue_horizon;
-uniform vec4  blue_density;
-uniform float haze_horizon;
-uniform float haze_density;
-uniform float cloud_shadow;
-uniform float density_multiplier;
-uniform float distance_multiplier;
-uniform float max_y;
-uniform vec4  glow;
-uniform float scene_light_strength;
-uniform mat3  ssao_effect_mat;
-uniform int   no_atmo;
-uniform float sun_moon_glow_factor;
+
+// debug stub
 
 float getAmbientClamp() { return 1.0f; }
 
@@ -47,89 +31,17 @@ float getAmbientClamp() { return 1.0f; }
 void calcAtmosphericVars(vec3 inPositionEye, vec3 light_dir, float ambFactor, out vec3 sunlit, out vec3 amblit, out vec3 additive,
                          out vec3 atten, bool use_ao)
 {
-    vec3 rel_pos = inPositionEye;
-
-    //(TERRAIN) limit altitude
-    if (abs(rel_pos.y) > max_y) rel_pos *= (max_y / rel_pos.y);
-
-    vec3  rel_pos_norm = normalize(rel_pos);
-    float rel_pos_len  = length(rel_pos);
-    vec4  sunlight     = (sun_up_factor == 1) ? sunlight_color : moonlight_color;
-
-    // sunlight attenuation effect (hue and brightness) due to atmosphere
-    // this is used later for sunlight modulation at various altitudes
-    vec4 light_atten = (blue_density + vec4(haze_density * 0.25)) * (density_multiplier * max_y);
-    // I had thought blue_density and haze_density should have equal weighting,
-    // but attenuation due to haze_density tends to seem too strong
-
-    vec4 combined_haze = blue_density + vec4(haze_density);
-    vec4 blue_weight   = blue_density / combined_haze;
-    vec4 haze_weight   = vec4(haze_density) / combined_haze;
-
-    //(TERRAIN) compute sunlight from lightnorm y component. Factor is roughly cosecant(sun elevation) (for short rays like terrain)
-    float above_horizon_factor = 1.0 / max(1e-6, lightnorm.y);
-    sunlight *= exp(-light_atten * above_horizon_factor);  // for sun [horizon..overhead] this maps to an exp curve [0..1]
-
-    // main atmospheric scattering line integral
-    float density_dist = rel_pos_len * density_multiplier;
-
-    // Transparency (-> combined_haze)
-    // ATI Bugfix -- can't store combined_haze*density_dist*distance_multiplier in a variable because the ati
-    // compiler gets confused.
-    combined_haze = exp(-combined_haze * density_dist * distance_multiplier);
-
-    // final atmosphere attenuation factor
-    atten = combined_haze.rgb;
-
-    // compute haze glow
-    float haze_glow = dot(rel_pos_norm, lightnorm.xyz);
-
-    // dampen sun additive contrib when not facing it...
-    // SL-13539: This "if" clause causes an "additive" white artifact at roughly 77 degreees.
-    //    if (length(light_dir) > 0.01)
-    haze_glow *= max(0.0f, dot(light_dir, rel_pos_norm));
-
-    haze_glow = 1. - haze_glow;
-    // haze_glow is 0 at the sun and increases away from sun
-    haze_glow = max(haze_glow, .001);  // set a minimum "angle" (smaller glow.y allows tighter, brighter hotspot)
-    haze_glow *= glow.x;
-    // higher glow.x gives dimmer glow (because next step is 1 / "angle")
-    haze_glow = pow(haze_glow, glow.z);
-    // glow.z should be negative, so we're doing a sort of (1 / "angle") function
-
-    // add "minimum anti-solar illumination"
-    haze_glow += .25;
-
-    haze_glow *= sun_moon_glow_factor;
-
-    vec4 amb_color = ambient_color;
-
-    // increase ambient when there are more clouds
-    vec4 tmpAmbient = amb_color + (vec4(1.) - amb_color) * cloud_shadow * 0.5;
-
-    /*  decrease value and saturation (that in HSV, not HSL) for occluded areas
-     * // for HSV color/geometry used here, see http://gimp-savvy.com/BOOK/index.html?node52.html
-     * // The following line of code performs the equivalent of:
-     * float ambAlpha = tmpAmbient.a;
-     * float ambValue = dot(vec3(tmpAmbient), vec3(0.577)); // projection onto <1/rt(3), 1/rt(3), 1/rt(3)>, the neutral white-black axis
-     * vec3 ambHueSat = vec3(tmpAmbient) - vec3(ambValue);
-     * tmpAmbient = vec4(RenderSSAOEffect.valueFactor * vec3(ambValue) + RenderSSAOEffect.saturationFactor *(1.0 - ambFactor) * ambHueSat,
-     * ambAlpha);
-     */
-    if (use_ao)
-    {
-        tmpAmbient = vec4(mix(ssao_effect_mat * tmpAmbient.rgb, tmpAmbient.rgb, ambFactor), tmpAmbient.a);
-    }
-
-    // Similar/Shared Algorithms:
-    //     indra\llinventory\llsettingssky.cpp                                        -- LLSettingsSky::calculateLightSettings()
-    //     indra\newview\app_settings\shaders\class1\windlight\atmosphericsFuncs.glsl -- calcAtmosphericVars()
-    // haze color
-    vec3 cs = sunlight.rgb * (1. - cloud_shadow);
-    additive = (blue_horizon.rgb * blue_weight.rgb) * (cs + tmpAmbient.rgb) + (haze_horizon * haze_weight.rgb) * (cs * haze_glow + tmpAmbient.rgb);
+    amblit = vec3(0.2, 0, 0.2);
+    sunlit = vec3(1,0,1);
+    additive = vec3(0.5,0.5,0.5);
+    atten = vec3(1,0,1);
+}
 
-    // brightness of surface both sunlight and ambient
-    sunlit = sunlight.rgb * 0.5;
-    amblit = tmpAmbient.rgb * .25;
-    additive *= vec3(1.0 - combined_haze);
+void calcAtmosphericVarsLinear(vec3 inPositionEye, vec3 light_dir, float ambFactor, out vec3 sunlit, out vec3 amblit, out vec3 additive,
+                         out vec3 atten, bool use_ao)
+{
+    amblit = vec3(0.2, 0, 0.2);
+    sunlit = vec3(1,0,1);
+    additive = vec3(0.5,0.5,0.5);
+    atten = vec3(1,0,1);
 }
diff --git a/indra/newview/app_settings/shaders/class1/windlight/cloudShadowF.glsl b/indra/newview/app_settings/shaders/class1/windlight/cloudShadowF.glsl
index 82fad4db5a..332fb9d809 100644
--- a/indra/newview/app_settings/shaders/class1/windlight/cloudShadowF.glsl
+++ b/indra/newview/app_settings/shaders/class1/windlight/cloudShadowF.glsl
@@ -45,7 +45,6 @@ uniform float blend_factor;
 uniform vec4 cloud_pos_density1;
 uniform vec4 cloud_pos_density2;
 uniform vec4 sunlight_color;
-uniform vec4 cloud_color;
 uniform float cloud_shadow;
 uniform float cloud_scale;
 uniform float cloud_variance;