SL-18190 Fix alpha not playing nice with water surface by split LLDrawPoolAlpha into two passes, one above water, one below water, and clip against water plane. Currently brute forces two complete alpha passes, still need to cull against water plane and add support for fullbright shaders.

4 files changed, 37 insertions, 1 deletions

diff --git a/indra/newview/app_settings/shaders/class1/deferred/deferredUtil.glsl b/indra/newview/app_settings/shaders/class1/deferred/deferredUtil.glsl
index 2ec859fdae..9405a125fd 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/deferredUtil.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/deferredUtil.glsl
@@ -505,3 +505,28 @@ vec3 pbrPunctual(vec3 diffuseColor, vec3 specularColor,
 
     return color;
 }
+
+uniform vec4 waterPlane;
+uniform float waterSign;
+
+// discard if given position in eye space is on the wrong side of the waterPlane according to waterSign
+void waterClip(vec3 pos)
+{
+    // TODO: make this less branchy
+    if (waterSign > 0)
+    {
+        if ((dot(pos.xyz, waterPlane.xyz) + waterPlane.w) < -0.1)
+        {
+            discard;
+        }
+    }
+    else
+    {
+        if ((dot(pos.xyz, waterPlane.xyz) + waterPlane.w) > -0.1)
+        {
+            discard;
+        }
+    }
+
+}
+
diff --git a/indra/newview/app_settings/shaders/class2/deferred/alphaF.glsl b/indra/newview/app_settings/shaders/class2/deferred/alphaF.glsl
index b4406aabc0..b3f15f81f1 100644
--- a/indra/newview/app_settings/shaders/class2/deferred/alphaF.glsl
+++ b/indra/newview/app_settings/shaders/class2/deferred/alphaF.glsl
@@ -69,6 +69,8 @@ uniform vec3 light_direction[8];
 uniform vec4 light_attenuation[8]; 
 uniform vec3 light_diffuse[8];
 
+void waterClip(vec3 pos);
+
 #ifdef WATER_FOG
 vec4 applyWaterFogView(vec3 pos, vec4 color);
 #endif
@@ -181,6 +183,7 @@ void main()
     frag *= screen_res;
     
     vec4 pos = vec4(vary_position, 1.0);
+    waterClip(pos.xyz);
     vec3 norm = vary_norm;
 
     float shadow = 1.0f;
@@ -295,6 +298,7 @@ void main()
 
 #endif // #else // FOR_IMPOSTOR
 
+    //color.rgb = waterPlane.xyz * 0.5 + 0.5;
     frag_color = color;
 }
 
diff --git a/indra/newview/app_settings/shaders/class2/deferred/pbralphaF.glsl b/indra/newview/app_settings/shaders/class2/deferred/pbralphaF.glsl
index 9bbc4f87bf..922da0c441 100644
--- a/indra/newview/app_settings/shaders/class2/deferred/pbralphaF.glsl
+++ b/indra/newview/app_settings/shaders/class2/deferred/pbralphaF.glsl
@@ -84,6 +84,8 @@ float sampleDirectionalShadow(vec3 pos, vec3 norm, vec2 pos_screen);
 void sampleReflectionProbes(inout vec3 ambenv, inout vec3 glossenv, 
         vec3 pos, vec3 norm, float glossiness);
 
+void waterClip(vec3 pos);
+
 // PBR interface
 vec3 pbrIbl(vec3 diffuseColor,
             vec3 specularColor,
@@ -139,6 +141,7 @@ void main()
     vec3  light_dir   = (sun_up_factor == 1) ? sun_dir : moon_dir;
     vec3  pos         = vary_position;
 
+    waterClip(pos);
 
 // IF .mFeatures.mIndexedTextureChannels = LLGLSLShader::sIndexedTextureChannels;
 //    vec3 col = vertex_color.rgb * diffuseLookup(vary_texcoord0.xy).rgb;
diff --git a/indra/newview/app_settings/shaders/class3/deferred/materialF.glsl b/indra/newview/app_settings/shaders/class3/deferred/materialF.glsl
index 1150d40007..8016022d78 100644
--- a/indra/newview/app_settings/shaders/class3/deferred/materialF.glsl
+++ b/indra/newview/app_settings/shaders/class3/deferred/materialF.glsl
@@ -90,6 +90,7 @@ uniform vec4 light_attenuation[8];
 uniform vec3 light_diffuse[8];
 
 float getAmbientClamp();
+void waterClip(vec3 pos);
 
 vec3 calcPointLightOrSpotLight(vec3 light_col, vec3 npos, vec3 diffuse, vec4 spec, vec3 v, vec3 n, vec4 lp, vec3 ln, float la, float fa, float is_pointlight, float ambiance)
 {
@@ -219,6 +220,10 @@ vec2 encode_normal(vec3 n);
 
 void main()
 {
+#if (DIFFUSE_ALPHA_MODE == DIFFUSE_ALPHA_MODE_BLEND)
+    waterClip(vary_position.xyz);
+#endif
+
     vec2 pos_screen = vary_texcoord0.xy;
 
     vec4 diffcol = texture2D(diffuseMap, vary_texcoord0.xy);
@@ -277,7 +282,6 @@ void main()
 #endif
 
 #if (DIFFUSE_ALPHA_MODE == DIFFUSE_ALPHA_MODE_BLEND)
-
     //forward rendering, output lit linear color
     diffcol.rgb = srgb_to_linear(diffcol.rgb);
     final_specular.rgb = srgb_to_linear(final_specular.rgb);