Add WIP water shader. Not yet used because not satisfying

git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/trunk@10740 178a84e3-b1eb-0310-8ba1-8eac791a3b58

data/shaders/water.frag

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+// Shader based on work by Fabien Sanglard
+// Released under the terms of CC-BY 3.0
+
+uniform sampler2D BumpTex1; // Normal map 1
+uniform sampler2D BumpTex2; // Normal map 2
+uniform sampler2D DecalTex; //The texture
+
+uniform vec2 delta1;
+uniform vec2 delta2;
+
+varying vec3 lightVec;
+varying vec3 halfVec;
+varying vec3 eyeVec;
+
+void main()
+{
+	// lookup normal from normal map, move from [0,1] to  [-1, 1] range, normalize
+	vec3 normal  = 2.0 * texture2D (BumpTex1, gl_TexCoord[0].st + delta1).rgb - 1.0;
+    vec3 normal2 = 2.0 * texture2D (BumpTex2, gl_TexCoord[0].st + delta2).rgb - 1.0;
+    
+    // scale normals
+    //normal.y = 4.0*normal.y;
+    //normal2.y = 4.0*normal2.y;
+    
+	normal = (normalize(normal) + normalize(normal2))/2.0;
+	    
+	// compute diffuse lighting
+	float lamberFactor = max (dot (lightVec, normal), 0.0);
+	vec4 diffuseMaterial;
+	vec4 diffuseLight;
+
+    diffuseMaterial = texture2D (DecalTex, gl_TexCoord[0].st + vec2(delta1.x, 0.0));
+    diffuseLight  = vec4(1.0, 1.0, 1.0, 1.0);
+
+    //if (lamberFactor < 0.7)
+    //{
+    //    lamberFactor = 0.0;
+    //}
+
+    gl_FragColor =	diffuseMaterial * (lamberFactor);
+    
+    // specular (phong)
+    vec3 R = normalize(reflect(lightVec, normal));
+    float specular = max(dot(R,eyeVec),0.0);
+    
+    if (specular > 0.0)
+    {
+        // weak specular
+        specular = specular*specular;
+        float specular03 = specular*0.2;
+        gl_FragColor += vec4(specular03, specular03, specular03, 0.0);
+        
+        // strong specular
+        specular = specular*specular*specular;
+        float specular06 = specular*0.5;
+        gl_FragColor += vec4(specular06, specular06, specular06, 0.0);
+    }
+}

data/shaders/water.vert

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+// Shader based on work by Fabien Sanglard
+// Released under the terms of CC-BY 3.0
+
+varying vec3 lightVec;
+varying vec3 halfVec;
+varying vec3 eyeVec;
+
+uniform vec3 lightdir;
+
+void main()
+{
+
+	gl_TexCoord[0] =  gl_MultiTexCoord0;
+	
+	// Building the matrix Eye Space -> Tangent Space
+	vec3 n = normalize (gl_NormalMatrix * gl_Normal);
+    // gl_MultiTexCoord1.xyz
+	vec3 t = normalize (gl_NormalMatrix * vec3(1.0, 0.0, 0.0)); // tangent
+	vec3 b = cross (n, t);
+	
+	vec3 vertexPosition = vec3(gl_ModelViewMatrix *  gl_Vertex);
+    
+	// transform light and half angle vectors by tangent basis
+	vec3 v;
+	v.x = dot (lightdir, t);
+	v.y = dot (lightdir, b);
+	v.z = dot (lightdir, n);
+	lightVec = normalize (v);
+
+	vertexPosition = normalize(vertexPosition);
+	
+    eyeVec = normalize(-vertexPosition); // we are in Eye Coordinates, so EyePos is (0,0,0)  
+
+	// Normalize the halfVector to pass it to the fragment shader
+
+	// No need to divide by two, the result is normalized anyway.
+	// vec3 halfVector = normalize((vertexPosition + lightDir) / 2.0); 
+	vec3 halfVector = normalize(vertexPosition + lightdir);
+	v.x = dot (halfVector, t);
+	v.y = dot (halfVector, b);
+	v.z = dot (halfVector, n);
+
+	// No need to normalize, t,b,n and halfVector are normal vectors.
+	//normalize (v);
+	halfVec = v ; 
+    
+	gl_Position = ftransform();
+}