From 537964f8d8c89bc5434fe2400699963018b12803 Mon Sep 17 00:00:00 2001
From: Alexei Kotov <alexdobrohotov@yandex.ru>
Date: Thu, 18 Apr 2024 11:23:21 +0300
Subject: [PATCH] Reconstruct normal Z *properly*

---
 files/shaders/compatibility/bs/default.frag  | 5 +++--
 files/shaders/compatibility/groundcover.frag | 5 +++--
 files/shaders/compatibility/objects.frag     | 5 +++--
 files/shaders/compatibility/terrain.frag     | 5 +++--
 4 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/files/shaders/compatibility/bs/default.frag b/files/shaders/compatibility/bs/default.frag
index d2c8de0b22..3c665752d1 100644
--- a/files/shaders/compatibility/bs/default.frag
+++ b/files/shaders/compatibility/bs/default.frag
@@ -77,10 +77,11 @@ void main()
     vec3 specularColor = getSpecularColor().xyz;
 #if @normalMap
     vec4 normalTex = texture2D(normalMap, normalMapUV);
+    vec3 normal = normalTex.xyz * 2.0 - 1.0;
 #if @reconstructNormalZ
-    normalTex.z = sqrt(1.0 - dot(normalTex.xy, normalTex.xy));
+    normal.z = sqrt(1.0 - dot(normal.xy, normal.xy));
 #endif
-    vec3 viewNormal = normalToView(normalTex.xyz * 2.0 - 1.0);
+    vec3 viewNormal = normalToView(normal);
     specularColor *= normalTex.a;
 #else
     vec3 viewNormal = normalize(gl_NormalMatrix * passNormal);
diff --git a/files/shaders/compatibility/groundcover.frag b/files/shaders/compatibility/groundcover.frag
index aab37d465d..96a79c8793 100644
--- a/files/shaders/compatibility/groundcover.frag
+++ b/files/shaders/compatibility/groundcover.frag
@@ -60,10 +60,11 @@ void main()
 
 #if @normalMap
     vec4 normalTex = texture2D(normalMap, normalMapUV);
+    vec3 normal = normalTex.xyz * 2.0 - 1.0;
 #if @reconstructNormalZ
-    normalTex.z = sqrt(1.0 - dot(normalTex.xy, normalTex.xy));
+    normal.z = sqrt(1.0 - dot(normal.xy, normal.xy));
 #endif
-    vec3 viewNormal = normalToView(normalTex.xyz * 2.0 - 1.0);
+    vec3 viewNormal = normalToView(normal);
 #else
     vec3 viewNormal = normalToView(normalize(passNormal));
 #endif
diff --git a/files/shaders/compatibility/objects.frag b/files/shaders/compatibility/objects.frag
index eb5b79a0c2..7f163580cc 100644
--- a/files/shaders/compatibility/objects.frag
+++ b/files/shaders/compatibility/objects.frag
@@ -168,10 +168,11 @@ vec2 screenCoords = gl_FragCoord.xy / screenRes;
 
 #if @normalMap
     vec4 normalTex = texture2D(normalMap, normalMapUV + offset);
+    vec3 normal = normalTex.xyz * 2.0 - 1.0;
 #if @reconstructNormalZ
-    normalTex.z = sqrt(1.0 - dot(normalTex.xy, normalTex.xy));
+    normal.z = sqrt(1.0 - dot(normal.xy, normal.xy));
 #endif
-    vec3 viewNormal = normalToView(normalTex.xyz * 2.0 - 1.0);
+    vec3 viewNormal = normalToView(normal);
 #else
     vec3 viewNormal = normalize(gl_NormalMatrix * passNormal);
 #endif
diff --git a/files/shaders/compatibility/terrain.frag b/files/shaders/compatibility/terrain.frag
index f45f1f024e..9d89217f35 100644
--- a/files/shaders/compatibility/terrain.frag
+++ b/files/shaders/compatibility/terrain.frag
@@ -64,10 +64,11 @@ void main()
 
 #if @normalMap
     vec4 normalTex = texture2D(normalMap, adjustedUV);
+    vec3 normal = normalTex.xyz * 2.0 - 1.0;
 #if @reconstructNormalZ
-    normalTex.z = sqrt(1.0 - dot(normalTex.xy, normalTex.xy));
+    normal.z = sqrt(1.0 - dot(normal.xy, normal.xy));
 #endif
-    vec3 viewNormal = normalToView(normalTex.xyz * 2.0 - 1.0);
+    vec3 viewNormal = normalToView(normal);
 #else
     vec3 viewNormal = normalize(gl_NormalMatrix * passNormal);
 #endif