Visualize attribute floats on verts

- Handle integer attribute types
- Use "convert to static type" utility to handle all formats
- Fix handling of float colors (implicit conversion to float4 will give asserts)
- Handle byte colors
- Combine extraction to a single loop with `if constexpr` switches
- Standardize variable naming
- Avoid looking up theme color for every element
- Move code to C++ namespace
- Avoid a few unnecessary local variables
- Pass matrix by const reference

@@ -220,0 +240,4 @@
+
+  UI_GetThemeColor4ubv(TH_DRAWEXTRA_FACEANG, col);
+
+  Mesh *me = static_cast<Mesh *>(object.data);

@@ -220,0 +243,4 @@
+  Mesh *me = static_cast<Mesh *>(object.data);
+
+  const AttributeAccessor attributes = me->attributes();
+  const VArray viewer_attributes = *attributes.lookup<float3>(".viewer");

@@ -220,0 +244,4 @@
+
+  const AttributeAccessor attributes = me->attributes();
+  const VArray viewer_attributes = *attributes.lookup<float3>(".viewer");
+  const VArray position_attributes = *attributes.lookup<float3>("position");

@@ -220,0 +248,4 @@
+
+  float4x4 object_to_world = float4x4(object.object_to_world);
+
+  for (int i = 0; i < me->totvert; i++) {

@@ -575,3 +574,1 @@
-  V3D_OVERLAY_SCULPT_SHOW_FACE_SETS = (1 << 15),
-  V3D_OVERLAY_SCULPT_CURVES_CAGE = (1 << 16),
-  V3D_OVERLAY_SHOW_LIGHT_COLORS = (1 << 17),
+  V3D_OVERLAY_VIEWER_ATTRIBUTE_TEXT = (1 << 14),

@@ -4562,0 +4563,4 @@
+  RNA_def_property_boolean_sdna(prop, nullptr, "overlay.flag", V3D_OVERLAY_VIEWER_ATTRIBUTE_TEXT);
+  RNA_def_property_clear_flag(prop, PROP_ANIMATABLE);
+  RNA_def_property_ui_text(
+      prop, "View attribute text", "Show attribute values as text on vertices");

@@ -220,0 +279,4 @@
+      }
+    }
+  }
+  return std::make_tuple(viewer_attributes, positions);

@@ -220,0 +242,4 @@
+  VArray<float> viewer_attributes;
+  Span<float3> positions;
+
+  switch (type) {

@@ -404,6 +406,12 @@ static void OVERLAY_cache_populate(void *vedata, Object *ob)
     }
   }
 
+  if (pd->overlay.flag & V3D_OVERLAY_VIEWER_ATTRIBUTE_TEXT) {

@@ -9,0 +9,4 @@
+#include "DNA_curve_types.h"
+#include "DNA_pointcloud_types.h"
+
+#define DEBUG_TIME

@@ -8,6 +8,9 @@
 
 #pragma once
 
+#include "BLI_math_vector_types.hh"

@@ -7029,0 +7040,4 @@
+        row.prop(overlay, "show_viewer_attribute", text="")
+        subrow = row.row(align=True)
+        subrow.active = overlay.show_viewer_attribute
+        subrow.prop(overlay, "viewer_attribute_opacity", text="Overlay Color")

@@ -0,0 +1,141 @@
+#include "BKE_attribute.hh"

@@ -0,0 +17,4 @@
+#include <optional>
+
+using namespace blender;
+using namespace blender::bke;

@@ -0,0 +18,4 @@
+
+using namespace blender;
+using namespace blender::bke;
+

@@ -0,0 +19,4 @@
+using namespace blender;
+using namespace blender::bke;
+
+static void add_data_based_on_type(GVArray attributes,

@@ -0,0 +40,4 @@
+    DRW_text_viewer_attribute(attributes.get<float3>(index), pos);
+  }
+  if (CD_PROP_COLOR == type || CD_PROP_QUATERNION == type) {
+    DRW_text_viewer_attribute(attributes.get<float4>(index), pos);

@@ -0,0 +44,4 @@
+  }
+}
+
+// function for passing mesh, pointcloud, and curve data to text cache

@@ -0,0 +48,4 @@
+static void add_attributes_to_text_cache(AttributeAccessor attribute_accessor,
+                                         float4x4 modelMatrix)
+{
+  if (attribute_accessor.contains(".viewer")) {

@@ -0,0 +79,4 @@
+  float3 pos = blender::math::transform_point(modelMatrix, loc);
+  eCustomDataType type = attribute_accessor.lookup_meta_data(".viewer")->data_type;
+
+  // and add that data to the text cache based on it's type

@@ -0,0 +131,4 @@
+      break;
+    }
+    case OB_CURVES: {
+      Curves *curves_id = static_cast<Curves *>(object.data);

@@ -220,0 +228,4 @@
+  DRW_text_cache_add(dt, position, numstr, numstr_len, 0, 0, txt_flag, col);
+}
+
+void DRW_text_viewer_attribute(float attribute_value, blender::float3 position)

@@ -53,2 +57,4 @@
 }
 #endif
+
+#ifdef __cplusplus

@@ -4565,0 +4566,4 @@
+  RNA_def_property_boolean_sdna(prop, nullptr, "overlay.flag", V3D_OVERLAY_VIEWER_ATTRIBUTE_TEXT);
+  RNA_def_property_clear_flag(prop, PROP_ANIMATABLE);
+  RNA_def_property_ui_text(
+      prop, "View Attribute Text", "Show attribute values as text on vertices");