1 files changed, 188 insertions, 0 deletions
diff --git a/source/blender/draw/engines/eevee_next/shaders/eevee_light_culling_tile_comp.glsl b/source/blender/draw/engines/eevee_next/shaders/eevee_light_culling_tile_comp.glsl
new file mode 100644
index 00000000000..37705e22b22
--- /dev/null
+++ b/source/blender/draw/engines/eevee_next/shaders/eevee_light_culling_tile_comp.glsl
@@ -0,0 +1,188 @@
+
+/**
+ * 2D Culling pass for lights.
+ * We iterate over all items and check if they intersect with the tile frustum.
+ * Dispatch one thread per word.
+ */
+
+#pragma BLENDER_REQUIRE(common_view_lib.glsl)
+#pragma BLENDER_REQUIRE(common_intersect_lib.glsl)
+#pragma BLENDER_REQUIRE(eevee_light_iter_lib.glsl)
+
+/* ---------------------------------------------------------------------- */
+/** \name Culling shapes extraction
+ * \{ */
+
+struct CullingTile {
+  IsectFrustum frustum;
+  vec4 bounds;
+};
+
+/* Corners are expected to be in viewspace so that the cone is starting from the origin.
+ * Corner order does not matter. */
+vec4 tile_bound_cone(vec3 v00, vec3 v01, vec3 v10, vec3 v11)
+{
+  v00 = normalize(v00);
+  v01 = normalize(v01);
+  v10 = normalize(v10);
+  v11 = normalize(v11);
+  vec3 center = normalize(v00 + v01 + v10 + v11);
+  float angle_cosine = dot(center, v00);
+  angle_cosine = max(angle_cosine, dot(center, v01));
+  angle_cosine = max(angle_cosine, dot(center, v10));
+  angle_cosine = max(angle_cosine, dot(center, v11));
+  return vec4(center, angle_cosine);
+}
+
+/* Corners are expected to be in viewspace. Returns Z-aligned bounding cylinder.
+ * Corner order does not matter. */
+vec4 tile_bound_cylinder(vec3 v00, vec3 v01, vec3 v10, vec3 v11)
+{
+  vec3 center = (v00 + v01 + v10 + v11) * 0.25;
+  vec4 corners_dist;
+  float dist_sqr = distance_squared(center, v00);
+  dist_sqr = max(dist_sqr, distance_squared(center, v01));
+  dist_sqr = max(dist_sqr, distance_squared(center, v10));
+  dist_sqr = max(dist_sqr, distance_squared(center, v11));
+  /* Return a cone. Later converted to cylinder. */
+  return vec4(center, sqrt(dist_sqr));
+}
+
+vec2 tile_to_ndc(vec2 tile_co, vec2 offset)
+{
+  /* Add a margin to prevent culling too much if the frustum becomes too much unstable. */
+  const float margin = 0.02;
+  tile_co += margin * (offset * 2.0 - 1.0);
+
+  tile_co += offset;
+  return tile_co * light_cull_buf.tile_to_uv_fac * 2.0 - 1.0;
+}
+
+CullingTile tile_culling_get(uvec2 tile_co)
+{
+  vec2 ftile = vec2(tile_co);
+  /* Culling frustum corners for this tile. */
+  vec3 corners[8];
+  /* Follow same corners order as view frustum. */
+  corners[1].xy = corners[0].xy = tile_to_ndc(ftile, vec2(0, 0));
+  corners[5].xy = corners[4].xy = tile_to_ndc(ftile, vec2(1, 0));
+  corners[6].xy = corners[7].xy = tile_to_ndc(ftile, vec2(1, 1));
+  corners[2].xy = corners[3].xy = tile_to_ndc(ftile, vec2(0, 1));
+  corners[1].z = corners[5].z = corners[6].z = corners[2].z = -1.0;
+  corners[0].z = corners[4].z = corners[7].z = corners[3].z = 1.0;
+
+  for (int i = 0; i < 8; i++) {
+    /* Culling in view space for precision. */
+    corners[i] = project_point(ProjectionMatrixInverse, corners[i]);
+  }
+
+  bool is_persp = ProjectionMatrix[3][3] == 0.0;
+  CullingTile tile;
+  tile.bounds = (is_persp) ? tile_bound_cone(corners[0], corners[4], corners[7], corners[3]) :
+                             tile_bound_cylinder(corners[0], corners[4], corners[7], corners[3]);
+
+  tile.frustum = isect_data_setup(shape_frustum(corners));
+  return tile;
+}
+
+/** \} */
+
+/* ---------------------------------------------------------------------- */
+/** \name Intersection Tests
+ * \{ */
+
+bool intersect(CullingTile tile, Sphere sphere)
+{
+  bool isect = true;
+  /* Test tile intersection using bounding cone or bounding cylinder.
+   * This has less false positive cases when the sphere is large. */
+  if (ProjectionMatrix[3][3] == 0.0) {
+    isect = intersect(shape_cone(tile.bounds.xyz, tile.bounds.w), sphere);
+  }
+  else {
+    /* Simplify to a 2D circle test on the view Z axis plane. */
+    isect = intersect(shape_circle(tile.bounds.xy, tile.bounds.w),
+                      shape_circle(sphere.center.xy, sphere.radius));
+  }
+  /* Refine using frustum test. If the sphere is small it avoids intersection
+   * with a neighbor tile. */
+  if (isect) {
+    isect = intersect(tile.frustum, sphere);
+  }
+  return isect;
+}
+
+bool intersect(CullingTile tile, Box bbox)
+{
+  return intersect(tile.frustum, bbox);
+}
+
+bool intersect(CullingTile tile, Pyramid pyramid)
+{
+  return intersect(tile.frustum, pyramid);
+}
+
+/** \} */
+
+void main()
+{
+  uint word_idx = gl_GlobalInvocationID.x % light_cull_buf.tile_word_len;
+  uint tile_idx = gl_GlobalInvocationID.x / light_cull_buf.tile_word_len;
+  uvec2 tile_co = uvec2(tile_idx % light_cull_buf.tile_x_len,
+                        tile_idx / light_cull_buf.tile_x_len);
+
+  if (tile_co.y >= light_cull_buf.tile_y_len) {
+    return;
+  }
+
+  /* TODO(fclem): We could stop the tile at the HiZ depth. */
+  CullingTile tile = tile_culling_get(tile_co);
+
+  uint l_idx = word_idx * 32u;
+  uint l_end = min(l_idx + 32u, light_cull_buf.visible_count);
+  uint word = 0u;
+  for (; l_idx < l_end; l_idx++) {
+    LightData light = light_buf[l_idx];
+
+    /* Culling in view space for precision and simplicity. */
+    vec3 vP = transform_point(ViewMatrix, light._position);
+    vec3 v_right = transform_direction(ViewMatrix, light._right);
+    vec3 v_up = transform_direction(ViewMatrix, light._up);
+    vec3 v_back = transform_direction(ViewMatrix, light._back);
+    float radius = light.influence_radius_max;
+
+    Sphere sphere = shape_sphere(vP, radius);
+    bool intersect_tile = intersect(tile, sphere);
+
+    switch (light.type) {
+      case LIGHT_SPOT:
+        /* Only for < ~170° Cone due to plane extraction precision. */
+        if (light.spot_tan < 10.0) {
+          Pyramid pyramid = shape_pyramid_non_oblique(
+              vP,
+              vP - v_back * radius,
+              v_right * radius * light.spot_tan / light.spot_size_inv.x,
+              v_up * radius * light.spot_tan / light.spot_size_inv.y);
+          intersect_tile = intersect_tile && intersect(tile, pyramid);
+          break;
+        }
+        /* Fallthrough to the hemispheric case. */
+      case LIGHT_RECT:
+      case LIGHT_ELLIPSE:
+        vec3 v000 = vP - v_right * radius - v_up * radius;
+        vec3 v100 = v000 + v_right * (radius * 2.0);
+        vec3 v010 = v000 + v_up * (radius * 2.0);
+        vec3 v001 = v000 - v_back * radius;
+        Box bbox = shape_box(v000, v100, v010, v001);
+        intersect_tile = intersect_tile && intersect(tile, bbox);
+      default:
+        break;
+    }
+
+    if (intersect_tile) {
+      word |= 1u << (l_idx % 32u);
+    }
+  }
+
+  out_light_tile_buf[gl_GlobalInvocationID.x] = word;
+}