From f74abf1d2b00343524252abf3385ab38082c6bf9 Mon Sep 17 00:00:00 2001
From: engineer_apple <engineer_apple@dfc29bdd-3216-0410-991c-e03cc46cb475>
Date: Sun, 1 Mar 2020 16:19:03 +0000
Subject: [PATCH] burning: GL_FOG_COORDINATE_SOURCE ,GL_FRAGMENT_DEPTH ->
 abs(EyeSpace.vertex.z)

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@6104 dfc29bdd-3216-0410-991c-e03cc46cb475
---
 source/Irrlicht/CSoftwareDriver2.cpp | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/source/Irrlicht/CSoftwareDriver2.cpp b/source/Irrlicht/CSoftwareDriver2.cpp
index 0536491d..cb8f1a18 100644
--- a/source/Irrlicht/CSoftwareDriver2.cpp
+++ b/source/Irrlicht/CSoftwareDriver2.cpp
@@ -1592,16 +1592,21 @@ void CBurningVideoDriver::VertexCache_fill(const u32 sourceIndex, const u32 dest
 	{
 		f32 fog_factor = 1.f;
 
+		// GL_FRAGMENT_DEPTH -> abs(EyeSpace.vertex.z)
+		ieee754 fog_frag_coord;
+		fog_frag_coord.f = EyeSpace.vertex.z;
+		fog_frag_coord.fields.sign = 0;
+
 		switch (FogType)
 		{
 		case EFT_FOG_LINEAR:
-			fog_factor = (FogEnd - EyeSpace.vertex.z) * EyeSpace.fog_scale;
+			fog_factor = (FogEnd - fog_frag_coord.f) * EyeSpace.fog_scale;
 			break;
 		case EFT_FOG_EXP:
-			fog_factor = (f32)exp(-FogDensity * EyeSpace.vertex.z);
+			fog_factor = (f32)exp(-FogDensity * fog_frag_coord.f);
 			break;
 		case EFT_FOG_EXP2:
-			fog_factor = (f32)exp(-FogDensity * FogDensity * EyeSpace.vertex.z * EyeSpace.vertex.z);
+			fog_factor = (f32)exp(-FogDensity * FogDensity * fog_frag_coord.f * fog_frag_coord.f);
 			break;
 		}