added fog (need to set the fog params)

[demo] / gl_shaders / default.f.glsl

diff --git a/gl_shaders/default.f.glsl b/gl_shaders/default.f.glsl
index 490efab..17d4353 100644 (file)
--- a/gl_shaders/default.f.glsl
+++ b/gl_shaders/default.f.glsl
@@ -11,11 +11,14 @@ varying vec3 normal;
 varying vec3 ldir;
 varying vec2 tex_coord;
 
+const float fog_density = 0.005;
+const vec4 sky_color = vec4(0.35, 0.5, 0.65, 1.0);
+
 out vec4 color;
 
 void main()
 {
-       vec3 p = normalize(pos);
+       vec3 p = normalize(pos); // view space dir
        vec3 n = normalize(normal);
        vec3 l = normalize(ldir);
 
@@ -25,7 +28,14 @@ void main()
        float cdiff = max(dot(l, n), 0.0);
        float cspec = pow(max(dot(r, vdir), 0.0), shininess);
 
+       float dist = -pos.z;
+       float fog = clamp(exp(-fog_density * dist), 0.0, 1.0);
+
        vec4 texel = texture2D(tex, tex_coord);
-       color.xyz = diffuse.xyz * cdiff * texel.xyz + specular.xyz * cspec;
-       color.w = 1.0;
+
+       vec4 object_color;
+       object_color.xyz = diffuse.xyz * cdiff * texel.xyz + specular.xyz * cspec;
+       object_color.w = 1.0;
+
+       color = mix(sky_color, object_color, fog);
 }