Migrate types for multiply modifier

@@ -0,0 +112,4 @@
+  const int masked_handle = instances->add_reference(bke::InstanceReference{masked_geo});
+  const int unselected_handle = instances->add_reference(bke::InstanceReference{unselected_geo});
+
+  for (int i = 0; i < count; i++) {

@@ -0,0 +171,4 @@
+
+  threading::parallel_for(duplicated_strokes.points_range().take_front(points_num_pending),
+                          1024,
+                          [&](const IndexRange parallel_range) {

@@ -0,0 +189,4 @@
+    Span<float3> use_pos_r = pos_r.as_span().slice(this_stroke);
+    const float offset_fac = (mmd.duplications == 1) ? 0.5f :
+                                                       (float(i) / float(mmd.duplications - 1));
+    const float thickness_factor = use_fading ? interpf(1.0f - fading_thickness,

@@ -0,0 +227,4 @@
+  GreasePencil &grease_pencil = *geometry_set->get_grease_pencil_for_write();
+  const int frame = grease_pencil.runtime->eval_frame;
+
+  IndexMaskMemory mask_memory;

@@ -0,0 +94,4 @@
+                                             const IndexMask curves_mask,
+                                             const IndexMask unselected_mask,
+                                             const int count,
+                                             int &original_point_count)

@@ -0,0 +149,4 @@
+  const float offset = math::length(math::to_scale(float4x4(ctx.object->object_to_world))) *
+                       mmd.offset;
+  const float distance = mmd.distance;
+  bool use_fading = (mmd.flag & MOD_GREASE_PENCIL_MULTIPLY_ENABLE_FADING) != 0;

@@ -0,0 +173,4 @@
+                          1024,
+                          [&](const IndexRange range) {
+                            for (const int point : range) {
+                              const float3 minter = math::cross(normals[point], tangents[point]) *

@@ -2767,0 +2774,4 @@
+  int flag;
+
+  /* ? */
+  int flags;

@@ -8424,0 +8447,4 @@
+  RNA_define_lib_overridable(true);
+
+  prop = RNA_def_property(srna, "use_fade", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, nullptr, "flags", MOD_GREASE_PENCIL_MULTIPLY_ENABLE_FADING);

@@ -0,0 +142,4 @@
+
+  const IndexMask unselected_mask = curves_mask.complement(curves.curves_range(), mask_memory);
+
+  int original_point_count;

@@ -0,0 +164,4 @@
+  bke::SpanAttributeWriter<float> radii = attributes.lookup_or_add_for_write_span<float>(
+      "radii", bke::AttrDomain::Point);
+
+  const int points_num_pending = (mmd.duplications + 1) * original_point_count;

@@ -0,0 +182,4 @@
+
+  for (const int i : IndexRange(mmd.duplications)) {
+    using bke::attribute_math::mix2;
+    const IndexRange this_stroke = IndexRange(original_point_count * i, original_point_count);

@@ -0,0 +186,4 @@
+    MutableSpan<float3> instance_positions = positions.slice(this_stroke);
+    MutableSpan<float> instance_opacity = opacities.span.slice(this_stroke);
+    MutableSpan<float> instance_radii = radii.span.slice(this_stroke);
+    Span<float3> use_pos_l = pos_l.as_span().slice(this_stroke);

@@ -0,0 +194,4 @@
+                                                     1.0f - fading_thickness,
+                                                     1.0f) :
+                                                1.0f;
+    const float opacity_factor = use_fading ? interpf(1.0f - fading_opacity,

@@ -0,0 +162,4 @@
+  bke::SpanAttributeWriter<float> opacities = attributes.lookup_or_add_for_write_span<float>(
+      "opacity", bke::AttrDomain::Point);
+  bke::SpanAttributeWriter<float> radii = attributes.lookup_or_add_for_write_span<float>(
+      "radii", bke::AttrDomain::Point);

@@ -223,1 +223,4 @@
      "Duplicate strokes like a mirror"},
+    {eModifierType_GreasePencilMultiply,
+     "GREASE_PENCIL_MULTIPLY",
+     ICON_MOD_CURVE,

@@ -0,0 +155,4 @@
+  const float fading_center = mmd.fading_center;
+
+  MutableSpan<float3> positions = duplicated_strokes.positions_for_write();
+  const Span<float3> normals = duplicated_strokes.evaluated_normals();

@@ -0,0 +154,4 @@
+  const float fading_center = mmd.fading_center;
+
+  MutableSpan<float3> positions = duplicated_strokes.positions_for_write();
+  const Span<float3> normals = duplicated_strokes.evaluated_normals();