SL-18190 WIP - Add refraction to water without splitting scene between above and below water

2 files changed, 43 insertions, 0 deletions

diff --git a/indra/newview/app_settings/shaders/class1/environment/waterFogF.glsl b/indra/newview/app_settings/shaders/class1/environment/waterFogF.glsl
index df640cba05..7dbba12502 100644
--- a/indra/newview/app_settings/shaders/class1/environment/waterFogF.glsl
+++ b/indra/newview/app_settings/shaders/class1/environment/waterFogF.glsl
@@ -32,6 +32,8 @@ uniform float waterFogKS;
 
 vec3 getPositionEye();
 
+vec3 srgb_to_linear(vec3 col);
+
 vec4 applyWaterFogView(vec3 pos, vec4 color)
 {
     vec3 view = normalize(pos);
@@ -71,6 +73,46 @@ vec4 applyWaterFogView(vec3 pos, vec4 color)
     return color;
 }
 
+vec4 applyWaterFogViewLinear(vec3 pos, vec4 color)
+{
+    vec3 view = normalize(pos);
+    //normalize view vector
+    float es = -(dot(view, waterPlane.xyz));
+
+    //find intersection point with water plane and eye vector
+
+    //get eye depth
+    float e0 = max(-waterPlane.w, 0.0);
+
+    vec3 int_v = waterPlane.w > 0.0 ? view * waterPlane.w / es : vec3(0.0, 0.0, 0.0);
+
+    //get object depth
+    float depth = length(pos - int_v);
+
+    //get "thickness" of water
+    float l = max(depth, 0.1);
+
+    float kd = waterFogDensity;
+    float ks = waterFogKS;
+    vec4 kc = waterFogColor;
+    kc.rgb = srgb_to_linear(kc.rgb); // TODO -- pass in waterFogColor linear
+
+    float F = 0.98;
+
+    float t1 = -kd * pow(F, ks * e0);
+    float t2 = kd + ks * es;
+    float t3 = pow(F, t2 * l) - 1.0;
+
+    float L = min(t1 / t2 * t3, 1.0);
+
+    float D = pow(0.98, l * kd);
+
+    color.rgb = color.rgb * D + kc.rgb * L;
+    color.a = kc.a + color.a;
+
+    return color;
+}
+
 vec4 applyWaterFog(vec4 color)
 {
     //normalize view vector
diff --git a/indra/newview/app_settings/shaders/class1/environment/waterV.glsl b/indra/newview/app_settings/shaders/class1/environment/waterV.glsl
index e95f268681..a0a0e7dfca 100644
--- a/indra/newview/app_settings/shaders/class1/environment/waterV.glsl
+++ b/indra/newview/app_settings/shaders/class1/environment/waterV.glsl
@@ -46,6 +46,7 @@ out vec3 vary_position;
 out vec3 vary_light_dir;
 out vec3 vary_tangent;
 out vec3 vary_normal;
+out vec2 vary_fragcoord;
 
 float wave(vec2 v, float t, float f, vec2 d, float s) 
 {