EEVEE: Shadow: Simplify the shadow module

Now the shadows are linked to a `Light` object. The `Light` object is
linked to an `ObjectKey` to ensure persistence and deletion tracking.

The Uniform data are packed so that there is 1 `ShadowPunctualData`
per light in a `LightBatch`. This means there is only a shadowmap
limit to the number of `Shadow` in a scene.

1 files changed, 39 insertions, 1 deletions

diff --git a/source/blender/draw/engines/eevee/shaders/eevee_shadow_lib.glsl b/source/blender/draw/engines/eevee/shaders/eevee_shadow_lib.glsl
index 743f4f16173..55733bf5b14 100644
--- a/source/blender/draw/engines/eevee/shaders/eevee_shadow_lib.glsl
+++ b/source/blender/draw/engines/eevee/shaders/eevee_shadow_lib.glsl
@@ -1,11 +1,12 @@
 
+#pragma BLENDER_REQUIRE(eevee_shader_shared.hh)
 
 /* ---------------------------------------------------------------------- */
 /** \name Shadow Sampling Functions
  * \{ */
 
 /* Turns local light coordinate into shadow region index. Matches eShadowCubeFace order. */
-int shadow_punctual_region_get(vec3 lL)
+int shadow_punctual_face_index_get(vec3 lL)
 {
   vec3 aP = abs(lL);
   if (all(greaterThan(aP.xx, aP.yz))) {
@@ -19,4 +20,41 @@ int shadow_punctual_region_get(vec3 lL)
   }
 }
 
+/* Transform vector to face local coordinate. */
+vec3 shadow_punctual_local_position_to_face_local(int face_id, vec3 lL)
+{
+  switch (face_id) {
+    case 1:
+      return vec3(-lL.y, lL.z, -lL.x);
+      break;
+    case 2:
+      return vec3(lL.y, lL.z, lL.x);
+      break;
+    case 3:
+      return vec3(lL.x, lL.z, -lL.y);
+      break;
+    case 4:
+      return vec3(-lL.x, lL.z, lL.y);
+      break;
+    case 5:
+      return vec3(lL.x, -lL.y, -lL.z);
+    default:
+      return lL;
+  }
+}
+
+vec3 shadow_punctual_coordinates_get(ShadowPunctualData data, vec3 lL)
+{
+  int face_id = shadow_punctual_face_index_get(lL);
+  lL = shadow_punctual_local_position_to_face_local(face_id, lL);
+  lL *= min(0.0, lL.z + data.shadow_bias) / lL.z;
+
+  vec3 shadow_co = project_point(data.shadow_mat, lL);
+  /* Add one more offset if not omni because region_offset is half a face (in this case) and
+   * only the first face is full sized. */
+  float offset_fac = float(face_id > 0 && !data.is_omni) + float(face_id);
+  shadow_co.y += offset_fac * data.region_offset;
+  return shadow_co;
+}
+
 /** \} */