opengl: Replaced temp lighting with sun transmission lighting

src/render/opengl/OpenGLSkybox.cpp

@@ -25,7 +25,7 @@ void OpenGLSkybox::initialize()
 {
     program = createShader("skybox");
     program->addVertexSource("skybox");
-    program->addFragmentSource("bruneton");
+    program->addFragmentSource("atmosphere");
     program->addFragmentSource("tonemapping");
     program->addFragmentSource("skybox");
 

src/render/opengl/OpenGLTerrain.cpp

@@ -52,7 +52,7 @@ void OpenGLTerrain::initialize()
     // Prepare shader programs
     program = createShader("terrain");
     program->addVertexSource("terrain");
-    program->addFragmentSource("bruneton");
+    program->addFragmentSource("atmosphere");
     program->addFragmentSource("tonemapping");
     program->addFragmentSource("fadeout");
     program->addFragmentSource("terrain");

src/render/opengl/OpenGLWater.cpp

@@ -24,7 +24,7 @@ void OpenGLWater::initialize()
 {
     program = createShader("water");
     program->addVertexSource("water");
-    program->addFragmentSource("bruneton");
+    program->addFragmentSource("atmosphere");
     program->addFragmentSource("tonemapping");
     program->addFragmentSource("fadeout");
     program->addFragmentSource("noise");

src/render/opengl/shaders/atmosphere.frag

@@ -224,3 +224,53 @@ vec4 getSkyColor(vec3 location, vec3 direction)
     result += sunTransmittance + vec4(inscattering, 0.0);
     return result;
 }
+
+vec4 applyLighting(vec3 location, vec3 normal, vec4 color, float shininess)
+{
+    float material_hardness = 0.3;
+    float material_reflection = 1.0;
+
+    float r0 = Rg + location.y * WORLD_SCALING;
+    vec3 sun_position = sunDirection * SUN_DISTANCE;
+    float muS = dot(vec3(0.0, 1.0, 0.0), normalize(sun_position - vec3(0.0, r0, 0.0)));
+
+    vec4 light_color = _transmittanceWithShadow(r0, muS);
+
+    vec4 result = vec4(0.0, 0.0, 0.0, 1.0);
+
+    /* diffused light */
+    float diffuse = dot(sunDirection, normal);
+    float sign = (diffuse < 0.0) ? -1.0 : 1.0;
+    if (material_hardness <= 0.5)
+    {
+        float hardness = material_hardness * 2.0;
+        diffuse = (1.0 - hardness) * (diffuse * diffuse) * sign + hardness * diffuse;
+    }
+    else if (diffuse != 0.0)
+    {
+        float hardness = (material_hardness - 0.5) * 2.0;
+        diffuse = (1.0 - hardness) * diffuse + hardness * sign * sqrt(abs(diffuse));
+    }
+    if (diffuse > 0.0)
+    {
+        result += diffuse * color * light_color;
+    }
+
+    /* specular reflection */
+    if (shininess > 0.0 && material_reflection > 0.0)
+    {
+        vec3 view = normalize(location - cameraLocation);
+        vec3 reflect = sunDirection - normal * 2.0 * dot(sunDirection, normal);
+        float specular = dot(reflect, view);
+        if (specular > 0.0)
+        {
+            specular = pow(specular, shininess) * material_reflection;
+            if (specular > 0.0)
+            {
+                result += specular * light_color;
+            }
+        }
+    }
+
+    return result;
+}

src/render/opengl/shaders/resources.qrc

@@ -4,7 +4,7 @@
         <file>skybox.vert</file>
         <file>water.frag</file>
         <file>water.vert</file>
-        <file>bruneton.frag</file>
+        <file>atmosphere.frag</file>
         <file>tonemapping.frag</file>
         <file>terrain.frag</file>
         <file>terrain.vert</file>

src/render/opengl/shaders/water.frag

@@ -1,32 +1,11 @@
 uniform vec4 waterColor;
 uniform float waterReflection;
 
-vec4 applyLighting(vec3 location, vec3 normal, vec4 color, float shininess)
-{
-    // TEMP phong lighting implementation for testing
-    vec3 N = normalize(normal);
-    vec3 L = sunDirection;
-    vec3 E = normalize(cameraLocation - location);
-    vec3 R = normalize(-reflect(L, N));
-
-    //calculate Ambient Term:
-    vec4 Iamb = vec4(0.1, 0.1, 0.1, 1.0);
-
-    //calculate Diffuse Term:
-    vec4 Idiff = vec4(3.0, 3.0, 3.0, 1.0) * color * max(dot(N, L), 0.0);
-
-    // calculate Specular Term:
-    vec4 Ispec = vec4(3.0, 3.0, 3.0, 1.0) * pow(max(dot(R,E),0.0),0.3*shininess);
-
-    // write Total Color:
-    return Iamb + Idiff + Ispec;
-}
-
 void main(void)
 {
     vec3 normal = noiseNormal2d(unprojected.xz, 0.001);
 
-    gl_FragColor = applyLighting(unprojected, normal, waterColor, 100.0);
+    gl_FragColor = applyLighting(unprojected, normal, waterColor, 16.0);
 
     vec3 reflected = reflect(unprojected - cameraLocation, normal);
     reflected.y = max(reflected.y, 0.0);