1 files changed, 67 insertions, 0 deletions
diff --git a/gl-asylum/world_fs.glsl b/gl-asylum/world_fs.glsl
new file mode 100644
index 0000000..8c27019
--- /dev/null
+++ b/gl-asylum/world_fs.glsl
@@ -0,0 +1,67 @@
+#version 330 core
+
+in vec3 v_p;
+in vec3 v_n;
+in vec2 v_t;
+
+in vec4 v_p_lightspace;
+
+out vec4 f_color;
+
+uniform vec3      u_cam;
+uniform float     u_fog_start;
+uniform float     u_fog_end;
+uniform vec3      u_fog_color;
+uniform vec3      u_sun;
+
+uniform sampler2D u_diffuse;
+uniform sampler2D u_shadow_depth;
+
+uniform vec4 u_diffusion;
+
+float calc_shadow(vec4 p_lightspace) {
+  // ref: https://learnopengl.com/Advanced-Lighting/Shadows/Shadow-Mapping
+  vec3 pcoord = (p_lightspace.xyz / p_lightspace.w) * 0.5f + 0.5f;
+  float closest_depth = texture(u_shadow_depth, pcoord.xy).r;
+  float current_depth = pcoord.z;
+  return current_depth - 0.0005f > closest_depth ? 1.0 : 0.0;
+}
+
+float calc_diffuse(vec4 a, vec2 uv)
+{
+  float top    = mix(a.x, a.y, uv.x);
+  float bottom = mix(a.w, a.z, uv.x);
+  return mix(bottom, top, uv.y);
+}
+
+void main()
+{
+  vec4 diffuse = texture(u_diffuse, v_t);
+
+  float shadow = 1.0 - calc_shadow(v_p_lightspace);
+  vec3 sun_dir = normalize(u_sun);
+  if (dot(sun_dir, v_n) < 0) {
+    shadow = 0.0f;
+  }
+
+  //shadow -= dot()
+  //float shadow = 1.0 - calc_shadow2(v_p_lightspace, v_n, normalize(v_p - u_cam));
+  shadow *= 0.25;
+  shadow += 0.75;
+  diffuse.r *= shadow;
+  diffuse.g *= shadow;
+  diffuse.b *= shadow;
+
+  float diff = calc_diffuse(u_diffusion, v_t);
+  if (v_p.y > 0) {
+    diff = clamp(1.0f - v_p.y, 0.0f, 1.0f);
+  }
+  diff = pow(diff, 2.0f) * 0.25f;
+  diffuse.rgb -= diff;
+
+  float d   = distance(v_p, u_cam);
+  float fog = clamp((d - u_fog_start) / max(u_fog_end - u_fog_start, 1e-6), 0.0f, 1.0f);
+
+  vec3 rgb = mix(diffuse.rgb, u_fog_color, fog);
+  f_color = vec4(rgb, 1.0f);
+}