refactor shaders

res/shaders/lib/lighting.glsl

@@ -0,0 +1,27 @@
+#ifndef LIGHTING_GLSL_
+#define LIGHTING_GLSL_
+
+uniform float u_fogFactor;
+uniform float u_fogCurve;
+uniform float u_weatherFogOpacity;
+uniform float u_weatherFogDencity;
+uniform float u_weatherFogCurve;
+
+float calc_torch_light(vec3 modelpos) {
+    return max(0.0, 1.0 - distance(u_cameraPos, modelpos.xyz) / u_torchlightDistance);
+}
+
+vec3 calc_screen_normal(vec3 normal) {
+    return transpose(inverse(mat3(u_view * u_model))) * normal;
+}
+
+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 // LIGHTING_GLSL_