feat: deferred shading (day 2)

res/shaders/effects/deferred_lighting.glsl

@@ -1,15 +1,24 @@
+#include <shadows>
+#include <fog>
+
 vec4 effect() {
     float ssao = 0.0;
-    float z = texture(u_position, v_uv).z;
+    vec4 pos = texture(u_position, v_uv);
+    float z = pos.z;
     for (int y = -2; y <= 2; y++) {
         for (int x = -2; x <= 2; x++) {
             vec2 offset = vec2(x, y) / u_screenSize;
-            if (abs(z - texture(u_position, v_uv + offset * 2.0).z) > 0.05)
-                ssao += 1.0;
-            else
-                ssao += texture(u_ssao, v_uv + offset * 2.0).r;
+            ssao += texture(u_ssao, v_uv + offset * 2.0).r;
         }
     }
     ssao /= 24.0;
-    return vec4(texture(u_screen, v_uv).rgb * mix(1.0, ssao, 1.0), 1.0);
+    vec4 modelpos = u_inverseView * pos;
+    vec3 normal = transpose(mat3(u_view)) * texture(u_normal, v_uv).xyz;
+    vec3 dir = modelpos.xyz - u_cameraPos;
+#ifdef ENABLE_SHADOWS
+    ssao *= calc_shadow(modelpos, normal, length(pos));
+#endif
+    vec3 fogColor = texture(u_skybox, dir).rgb;
+    float fog = calc_fog(length(u_view * vec4((modelpos.xyz - u_cameraPos) * FOG_POS_SCALE, 0.0)) / 256.0);
+    return vec4(mix(texture(u_screen, v_uv).rgb * mix(1.0, ssao, 1.0), fogColor, fog), 1.0);
 }