From 76f320e95662de53d420669301db56010f2f4f00 Mon Sep 17 00:00:00 2001
From: Hugo Willaume <hugo.willaume@epitech.eu>
Date: Mon, 8 Apr 2019 14:09:22 +0900
Subject: [PATCH] Dynamic ReflectFactor through Shilick's approximation of
 Fresnel's equation

---
 BaseGLProject/MyGLWindow.cpp |  3 +--
 BaseGLProject/skybox.frag    | 16 +++++++++-------
 BaseGLProject/skybox.vert    |  6 ++++++
 3 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/BaseGLProject/MyGLWindow.cpp b/BaseGLProject/MyGLWindow.cpp
index 78dd178..a890747 100644
--- a/BaseGLProject/MyGLWindow.cpp
+++ b/BaseGLProject/MyGLWindow.cpp
@@ -110,8 +110,7 @@ void MyGlWindow::shaderSetup()
 	shaders["Toon"]->uniformFlags &= ~ShaderFlags::SHINE_FLAG;
 
 	shaders["Skybox"] = new Shader("skybox.vert", "skybox.frag");
-	shaders["Skybox"]->uniformFlags = MVP_FLAG | MODEL_MATRIX_FLAG | SKYBOX_TEX_FLAG;
-	shaders["Skybox"]->addUniform("ReflectFactor", (float)0.1);
+	shaders["Skybox"]->uniformFlags = MVP_FLAG | MODEL_MATRIX_FLAG | SKYBOX_TEX_FLAG;	
 	shaders["Skybox"]->addUniform("RefractionIndex", glm::vec3(0.65, 0.67, 0.69));
 
 }
diff --git a/BaseGLProject/skybox.frag b/BaseGLProject/skybox.frag
index e571766..f11dbc1 100644
--- a/BaseGLProject/skybox.frag
+++ b/BaseGLProject/skybox.frag
@@ -8,19 +8,21 @@ in vec3 refractDir_R;
 in vec3 refractDir_G;
 in vec3 refractDir_B;
 
-uniform float ReflectFactor;
+in float reflectFactor;
 uniform bool DrawSkyBox;
 uniform samplerCube CubeMapTex;
 
 void main()
 { 	
-	vec4 reflectColor = texture(CubeMapTex, reflectDir);
-	float refractColor_R = texture(CubeMapTex, refractDir_R).r;
-	float refractColor_G = texture(CubeMapTex, refractDir_G).g;
-	float refractColor_B = texture(CubeMapTex, refractDir_B).b;
-	vec4 refractColor = vec4(refractColor_R, refractColor_G, refractColor_B, 1); 
+	vec4 reflectColor = texture(CubeMapTex, reflectDir);	
 	if (DrawSkyBox == true)
 		FragColors = reflectColor;
 	else	
-		FragColors = vec4(mix(refractColor, reflectColor, ReflectFactor));	
+	{		
+		float refractColor_R = texture(CubeMapTex, refractDir_R).r;
+		float refractColor_G = texture(CubeMapTex, refractDir_G).g;
+		float refractColor_B = texture(CubeMapTex, refractDir_B).b;		
+		vec4 refractColor = vec4(refractColor_R, refractColor_G, refractColor_B, 1); 
+		FragColors = vec4(mix(refractColor, reflectColor, reflectFactor));	
+	}
 }
diff --git a/BaseGLProject/skybox.vert b/BaseGLProject/skybox.vert
index 705aa0e..459ad0d 100644
--- a/BaseGLProject/skybox.vert
+++ b/BaseGLProject/skybox.vert
@@ -6,6 +6,8 @@ layout(location=2) in vec3 v_color;
 layout(location=3) in vec2 v_texmap;
 
 out vec3 reflectDir;
+out float reflectFactor;
+
 out vec3 refractDir_R;
 out vec3 refractDir_G;
 out vec3 refractDir_B;
@@ -28,6 +30,10 @@ void main(void)
 		vec3 P = (ModelMatrix * vec4(coord3d, 1)).xyz;
 		vec3 N = normalize(ModelMatrix * vec4(v_normal, 1)).xyz;
 		vec3 V = normalize(WorldCamPos - coord3d);
+
+		float R0 = pow(1 - 1.5,2) / pow(1 + 1.5, 2);
+		reflectFactor = R0 + (1 - R0) * pow(1 - dot(V, N), 5);
+
 		reflectDir = reflect(-V, N);
 		refractDir_R = refract(-V, N, RefractionIndex.r);
 		refractDir_G = refract(-V, N, RefractionIndex.g);