Cleanup: move BKE_scene_unit_scale to BKE_unit_value_scale

This doesn't use any scene types, move to BKE_unit.hh

source/blender/blenkernel/BKE_scene.hh

@@ -241,12 +241,6 @@ int BKE_render_preview_pixel_size(const RenderData *r);
 
 /**********************************/
 
-/**
- * Apply the needed correction factor to value, based on unit_type
- * (only length-related are affected currently) and `unit->scale_length`.
- */
-double BKE_scene_unit_scale(const UnitSettings *unit, int unit_type, double value);
-
 /* Multi-view. */
 
 bool BKE_scene_multiview_is_stereo3d(const RenderData *rd);

source/blender/blenkernel/BKE_unit.hh

@@ -87,6 +87,12 @@ double BKE_unit_base_scalar(int system, int type);
  */
 bool BKE_unit_is_valid(int system, int type);
 
+/**
+ * Apply the needed correction factor to value, based on unit_type
+ * (only length-related are affected currently) and `unit->scale_length`.
+ */
+double BKE_unit_value_scale(const UnitSettings *unit, int unit_type, double value);
+
 /**
  * Loop over scales, could add names later.
  */

source/blender/blenkernel/intern/scene.cc

@@ -2885,32 +2885,6 @@ int BKE_render_preview_pixel_size(const RenderData *r)
   return r->preview_pixel_size;
 }
 
-double BKE_scene_unit_scale(const UnitSettings *unit, const int unit_type, double value)
-{
-  if (unit->system == USER_UNIT_NONE) {
-    /* Never apply scale_length when not using a unit setting! */
-    return value;
-  }
-
-  switch (unit_type) {
-    case B_UNIT_LENGTH:
-    case B_UNIT_VELOCITY:
-    case B_UNIT_ACCELERATION:
-      return value * double(unit->scale_length);
-    case B_UNIT_AREA:
-    case B_UNIT_POWER:
-      return value * pow(unit->scale_length, 2);
-    case B_UNIT_VOLUME:
-      return value * pow(unit->scale_length, 3);
-    case B_UNIT_MASS:
-      return value * pow(unit->scale_length, 3);
-    case B_UNIT_CAMERA: /* *Do not* use scene's unit scale for camera focal lens! See #42026. */
-    case B_UNIT_WAVELENGTH: /* Wavelength values are independent of the scene scale. */
-    default:
-      return value;
-  }
-}
-
 /******************** multiview *************************/
 
 int BKE_scene_multiview_num_views_get(const RenderData *rd)

source/blender/blenkernel/intern/unit.cc

@@ -1886,6 +1886,32 @@ size_t BKE_unit_value_as_string(char *str,
   return unit_as_string_main(str, str_maxncpy, value, prec, type, do_split, pad, units);
 }
 
+double BKE_unit_value_scale(const UnitSettings *unit, const int unit_type, double value)
+{
+  if (unit->system == USER_UNIT_NONE) {
+    /* Never apply scale_length when not using a unit setting! */
+    return value;
+  }
+
+  switch (unit_type) {
+    case B_UNIT_LENGTH:
+    case B_UNIT_VELOCITY:
+    case B_UNIT_ACCELERATION:
+      return value * double(unit->scale_length);
+    case B_UNIT_AREA:
+    case B_UNIT_POWER:
+      return value * pow(unit->scale_length, 2);
+    case B_UNIT_VOLUME:
+      return value * pow(unit->scale_length, 3);
+    case B_UNIT_MASS:
+      return value * pow(unit->scale_length, 3);
+    case B_UNIT_CAMERA: /* *Do not* use scene's unit scale for camera focal lens! See #42026. */
+    case B_UNIT_WAVELENGTH: /* Wavelength values are independent of the scene scale. */
+    default:
+      return value;
+  }
+}
+
 BLI_INLINE bool isalpha_or_utf8(const int ch)
 {
   return (ch >= 128 || isalpha(ch));

source/blender/editors/interface/interface.cc

@@ -2832,12 +2832,12 @@ static double ui_get_but_scale_unit(uiBut *but, double value)
   const UnitSettings *unit = but->block->unit;
   const int unit_type = UI_but_unit_type_get(but);
 
-  /* Time unit is a bit special, not handled by BKE_scene_unit_scale() for now. */
+  /* Time unit is a bit special, not handled by #BKE_unit_value_scale() for now. */
   if (unit_type == PROP_UNIT_TIME) { /* WARNING: using evil_C :| */
     Scene *scene = CTX_data_scene(static_cast<const bContext *>(but->block->evil_C));
     return FRA2TIME(value);
   }
-  return BKE_scene_unit_scale(unit, RNA_SUBTYPE_UNIT_VALUE(unit_type), value);
+  return BKE_unit_value_scale(unit, RNA_SUBTYPE_UNIT_VALUE(unit_type), value);
 }
 
 void ui_but_convert_to_unit_alt_name(uiBut *but, char *str, size_t str_maxncpy)

source/blender/editors/util/numinput.cc

@@ -98,7 +98,7 @@ void outputNumInput(NumInput *n, char *str, const UnitSettings *unit_settings)
                         j;
 
     /* Use scale_length if needed! */
-    const float fac = float(BKE_scene_unit_scale(unit_settings, n->unit_type[j], 1.0));
+    const float fac = float(BKE_unit_value_scale(unit_settings, n->unit_type[j], 1.0));
 
     if (n->val_flag[i] & NUM_EDITED) {
       /* Get the best precision, allows us to draw '10.0001' as '10' instead! */
@@ -276,7 +276,7 @@ bool user_string_to_number(bContext *C,
   err_info.use_single_line_error = use_single_line_error;
   err_info.r_string = r_error;
 
-  double unit_scale = BKE_scene_unit_scale(unit, type, 1.0);
+  const double unit_scale = BKE_unit_value_scale(unit, type, 1.0);
   if (BKE_unit_string_contains_unit(str, type)) {
     char str_unit_convert[256];
     STRNCPY(str_unit_convert, str);