SL-20611 Followup -- fix for artifacts on water surface from GPUs that don't like to read from a depth buffer that is bound for writing

3 files changed, 19 insertions, 4 deletions

diff --git a/indra/newview/app_settings/shaders/class3/deferred/waterHazeF.glsl b/indra/newview/app_settings/shaders/class3/deferred/waterHazeF.glsl
index 025bcdaf3e..13619a82d3 100644
--- a/indra/newview/app_settings/shaders/class3/deferred/waterHazeF.glsl
+++ b/indra/newview/app_settings/shaders/class3/deferred/waterHazeF.glsl
@@ -35,10 +35,26 @@ float getDepth(vec2 pos_screen);
 
 vec4 getWaterFogView(vec3 pos);
 
+uniform int above_water;
+
 void main()
 {
     vec2  tc           = vary_fragcoord.xy/vary_fragcoord.w*0.5+0.5;
     float depth        = getDepth(tc.xy);
+
+    if (above_water > 0)
+    { 
+        // we want to depth test when the camera is above water, but some GPUs have a hard time
+        // with depth testing against render targets that are bound for sampling in the same shader
+        // so we do it manually here
+
+        float cur_depth = vary_fragcoord.z/vary_fragcoord.w*0.5+0.5;
+        if (cur_depth > depth)
+        {
+            discard;
+        }
+    }
+
     vec4  pos          = getPositionWithDepth(tc, depth);
     vec4  norm         = texture(normalMap, tc);
 
diff --git a/indra/newview/app_settings/shaders/class3/environment/underWaterF.glsl b/indra/newview/app_settings/shaders/class3/environment/underWaterF.glsl
index ddb1b79681..223e55eb69 100644
--- a/indra/newview/app_settings/shaders/class3/environment/underWaterF.glsl
+++ b/indra/newview/app_settings/shaders/class3/environment/underWaterF.glsl
@@ -30,7 +30,6 @@ uniform sampler2D bumpMap;
 
 #ifdef TRANSPARENT_WATER
 uniform sampler2D screenTex;
-uniform sampler2D screenDepth;
 #endif
 
 uniform vec4 fogCol;
diff --git a/indra/newview/app_settings/shaders/class3/environment/waterF.glsl b/indra/newview/app_settings/shaders/class3/environment/waterF.glsl
index f53bc2e13e..b364e454e8 100644
--- a/indra/newview/app_settings/shaders/class3/environment/waterF.glsl
+++ b/indra/newview/app_settings/shaders/class3/environment/waterF.glsl
@@ -76,7 +76,7 @@ uniform sampler2D bumpMap2;
 uniform float     blend_factor;
 #ifdef TRANSPARENT_WATER
 uniform sampler2D screenTex;
-uniform sampler2D screenDepth;
+uniform sampler2D depthMap;
 #endif
 
 uniform sampler2D refTex;
@@ -210,7 +210,7 @@ void main()
 
 #ifdef TRANSPARENT_WATER
     vec4 fb = texture(screenTex, distort2);
-    float depth = texture(screenDepth, distort2).r;
+    float depth = texture(depthMap, distort2).r;
     vec3 refPos = getPositionWithNDC(vec3(distort2*2.0-vec2(1.0), depth*2.0-1.0));
 
     if (refPos.z > pos.z-0.05)
@@ -218,7 +218,7 @@ void main()
         //we sampled an above water sample, don't distort
         distort2 = distort;
         fb = texture(screenTex, distort2);
-        depth = texture(screenDepth, distort2).r;
+        depth = texture(depthMap, distort2).r;
         refPos = getPositionWithNDC(vec3(distort2 * 2.0 - vec2(1.0), depth * 2.0 - 1.0));
     }