From e413392694be4aa1f91aa0fad00e43b276a4f9f0 Mon Sep 17 00:00:00 2001
From: Joshua Barretto <joshua.s.barretto@gmail.com>
Date: Wed, 25 Nov 2020 15:17:37 +0000
Subject: [PATCH] Better mist access

---
 assets/voxygen/shaders/include/cloud/regular.glsl | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/assets/voxygen/shaders/include/cloud/regular.glsl b/assets/voxygen/shaders/include/cloud/regular.glsl
index f6ede5a697..5a57faebf1 100644
--- a/assets/voxygen/shaders/include/cloud/regular.glsl
+++ b/assets/voxygen/shaders/include/cloud/regular.glsl
@@ -44,6 +44,8 @@ vec4 cloud_at(vec3 pos, float dist, out vec3 emission) {
     float turb_noise = 0.0;
     float sun_access = 0.0;
     float moon_access = 0.0;
+    float cloud_sun_access = 0.0;
+    float cloud_moon_access = 0.0;
     // This is a silly optimisation but it actually nets us a fair few fps by skipping quite a few expensive calcs
     if (cloud_tendency > 0 || mist > 0.0) {
         // Turbulence (small variations in clouds/mist)
@@ -66,9 +68,9 @@ vec4 cloud_at(vec3 pos, float dist, out vec3 emission) {
         cloud = cloud_flat * pow(cloud_factor, 2) * 20;
 
         // What proportion of sunlight is *not* being blocked by nearby cloud? (approximation)
-        sun_access = clamp((pos.z - cloud_attr.x + turb_noise * 250.0) * 0.002 + 0.35 + max(mist * 20000, 0), 0, 1);
+        cloud_sun_access = clamp((pos.z - cloud_attr.x + turb_noise * 250.0) * 0.002 + 0.35, 0, 1);
         // Since we're assuming the sun/moon is always above (not always correct) it's the same for the moon
-        moon_access = sun_access;
+        cloud_moon_access = sun_access;
 
         #if (CLOUD_MODE >= CLOUD_MODE_HIGH)
             // Try to calculate a reasonable approximation of the cloud normal
@@ -79,11 +81,16 @@ vec4 cloud_at(vec3 pos, float dist, out vec3 emission) {
                 (cloud_tendency - cloud_tendency_y) * 4,
                 (pos.z - cloud_attr.x) / 250 + turb_noise + 0.25
             );
-            sun_access = mix(max(dot(-sun_dir.xyz, cloud_norm) + 0.0, 0.025), sun_access, 0.25);
-            moon_access = mix(max(dot(-moon_dir.xyz, cloud_norm) + 0.35, 0.025), moon_access, 0.25);
+            cloud_sun_access = mix(max(dot(-sun_dir.xyz, cloud_norm) + 0.0, 0.025), cloud_sun_access, 0.25);
+            cloud_moon_access = mix(max(dot(-moon_dir.xyz, cloud_norm) + 0.35, 0.025), cloud_moon_access, 0.25);
         #endif
     }
 
+    float mist_sun_access = 0.5 + turb_noise;
+    float mist_moon_access = mist_sun_access;
+    sun_access = mix(cloud_sun_access, mist_sun_access, clamp(mist * 20000, 0, 1));
+    moon_access = mix(cloud_moon_access, mist_moon_access, clamp(mist * 20000, 0, 1));
+
     // Prevent mist (i.e: vapour beneath clouds) being accessible to the sun to avoid visual problems
     //float suppress_mist = clamp((pos.z - cloud_attr.x + cloud_attr.y) / 300, 0, 1);
     //sun_access *= suppress_mist;