feat: deferred shading (day 2)

res/shaders/lib/fog.glsl

@@ -0,0 +1,19 @@
+#ifndef FOG_GLSL_
+#define FOG_GLSL_
+
+uniform float u_fogFactor;
+uniform float u_fogCurve;
+uniform float u_weatherFogOpacity;
+uniform float u_weatherFogDencity;
+uniform float u_weatherFogCurve;
+
+float calc_fog(float depth) {
+    return min(
+        1.0,
+        max(pow(depth * u_fogFactor, u_fogCurve),
+            min(pow(depth * u_weatherFogDencity, u_weatherFogCurve),
+                u_weatherFogOpacity))
+    );
+}
+
+#endif // FOG_GLSL_