From bd4fe57524936dc227e97e06bf8774fd120fe67c Mon Sep 17 00:00:00 2001
From: Vincent Lejeune <vljn@ovi.com>
Date: Tue, 11 Nov 2014 21:52:54 +0100
Subject: [PATCH] Use fog start value to determine density

---
 data/shaders/fog.frag            | 8 ++------
 src/graphics/post_processing.cpp | 2 +-
 src/graphics/shaders.cpp         | 2 +-
 src/graphics/shaders.hpp         | 2 +-
 4 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/data/shaders/fog.frag b/data/shaders/fog.frag
index 3b97ab40f..3560b0a69 100644
--- a/data/shaders/fog.frag
+++ b/data/shaders/fog.frag
@@ -1,10 +1,6 @@
 uniform sampler2D tex;
 
-uniform float fogmax;
-uniform float startH;
-uniform float endH;
-uniform float start;
-uniform float end;
+uniform float density;
 uniform vec3 col;
 
 out vec4 FragColor;
@@ -19,7 +15,7 @@ void main()
     vec4 xpos = getPosFromUVDepth(vec3(uv, z), InverseProjectionMatrix);
 
     float dist = length(xpos.xyz);
-    vec3 fog = col * (1. - exp(- fogmax * .01 * dist));
+    vec3 fog = col * (1. - exp(- density * dist));
 
     FragColor = vec4(fog, 1.);
 }
diff --git a/src/graphics/post_processing.cpp b/src/graphics/post_processing.cpp
index 8322ae814..60938906a 100644
--- a/src/graphics/post_processing.cpp
+++ b/src/graphics/post_processing.cpp
@@ -477,7 +477,7 @@ void PostProcessing::renderFog()
 
 
     FullScreenShader::FogShader::getInstance()->SetTextureUnits(irr_driver->getDepthStencilTexture());
-    DrawFullScreenEffect<FullScreenShader::FogShader>(fogmax, startH, endH, start, end, col);
+    DrawFullScreenEffect<FullScreenShader::FogShader>(1. / (20. * start), col);
 
     glEnable(GL_DEPTH_TEST);
     glDisable(GL_BLEND);
diff --git a/src/graphics/shaders.cpp b/src/graphics/shaders.cpp
index 72b2b3576..14f2cf4cf 100644
--- a/src/graphics/shaders.cpp
+++ b/src/graphics/shaders.cpp
@@ -1842,7 +1842,7 @@ namespace FullScreenShader
             GL_FRAGMENT_SHADER, file_manager->getAsset("shaders/utils/getPosFromUVDepth.frag").c_str(),
             GL_FRAGMENT_SHADER, file_manager->getAsset("shaders/fog.frag").c_str());
 
-        AssignUniforms("fogmax", "startH", "endH", "start", "end", "col");
+        AssignUniforms("density", "col");
         AssignSamplerNames(Program, 0, "tex");
     }
 
diff --git a/src/graphics/shaders.hpp b/src/graphics/shaders.hpp
index f4fbd06f7..e6bb2e07f 100644
--- a/src/graphics/shaders.hpp
+++ b/src/graphics/shaders.hpp
@@ -537,7 +537,7 @@ public:
     SSAOShader();
 };
 
-class FogShader : public ShaderHelperSingleton<FogShader, float, float, float, float, float, core::vector3df>, public TextureRead<Nearest_Filtered>
+class FogShader : public ShaderHelperSingleton<FogShader, float, core::vector3df>, public TextureRead<Nearest_Filtered>
 {
 public:
     FogShader();