UI: New option to display factors as percentages

The option can be changed in the Preferences
in `Interface -> Editors -> Factor Display Type`.

Reviewers: campbellbarton, brecht, billreynish

Differential Revision: https://developer.blender.org/D4462

release/scripts/startup/bl_ui/space_userpref.py

@@ -215,6 +215,7 @@ class USERPREF_PT_interface_editors(PreferencePanel, Panel):
         flow.prop(view, "show_layout_ui", text="Corner Splitting")
         flow.prop(view, "color_picker_type")
         flow.row().prop(view, "header_align")
+        flow.prop(view, "factor_display_type")
 
 
 class USERPREF_PT_interface_menus(Panel):

source/blender/editors/interface/interface.c

@@ -2425,12 +2425,27 @@ void ui_but_string_get_ex(uiBut *but, char *str, const size_t maxlen, const int
 
 		value = ui_but_value_get(but);
 
+		PropertySubType subtype = PROP_NONE;
+		if (but->rnaprop) {
+			subtype = RNA_property_subtype(but->rnaprop);
+		}
+
 		if (ui_but_is_float(but)) {
+			int prec = (float_precision == -1) ? ui_but_calc_float_precision(but, value) : float_precision;
+
 			if (ui_but_is_unit(but)) {
-				ui_get_but_string_unit(but, str, maxlen, value, false, float_precision);
+				ui_get_but_string_unit(but, str, maxlen, value, false, prec);
+			}
+			else if (subtype == PROP_FACTOR) {
+				if (U.factor_display_type == USER_FACTOR_AS_FACTOR) {
+					BLI_snprintf(str, maxlen, "%.*f", prec, value);
+				}
+				else {
+					BLI_snprintf(str, maxlen, "%.*f", MAX2(0, prec - 2), value * 100);
+				}
+
 			}
 			else {
-				int prec = (float_precision == -1) ? ui_but_calc_float_precision(but, value) : float_precision;
 				if (use_exp_float) {
 					const int int_digits_num = integer_digits_f(value);
 					if (int_digits_num < -6 || int_digits_num > 12) {
@@ -2528,44 +2543,80 @@ static bool ui_set_but_string_eval_num_unit(bContext *C, uiBut *but, const char
 	return user_string_to_number(C, str, unit, type, r_value);
 }
 
+static bool ui_number_from_string(bContext *C, const char *str, double *r_value)
+{
+#ifdef WITH_PYTHON
+	return BPY_execute_string_as_number(C, NULL, str, true, r_value);
+#else
+	*r_value = atof(str);
+	return true;
+#endif
+}
+
+static bool ui_number_from_string_factor(bContext *C, const char *str, double *r_value)
+{
+	int len = strlen(str);
+	if (BLI_strn_endswith(str, "%", len)) {
+		char *str_new = BLI_strdupn(str, len - 1);
+		bool success = ui_number_from_string(C, str_new, r_value);
+		MEM_freeN(str_new);
+		*r_value /= 100.0;
+		return success;
+	}
+	else {
+		if (!ui_number_from_string(C, str, r_value)) {
+			return false;
+		}
+		if (U.factor_display_type == USER_FACTOR_AS_PERCENTAGE) {
+			*r_value /= 100.0;
+		}
+		return true;
+	}
+}
+
+static bool ui_number_from_string_percentage(bContext *C, const char *str, double *r_value)
+{
+	int len = strlen(str);
+	if (BLI_strn_endswith(str, "%", len)) {
+		char *str_new = BLI_strdupn(str, len - 1);
+		bool success = ui_number_from_string(C, str_new, r_value);
+		MEM_freeN(str_new);
+		return success;
+	}
+	else {
+		return ui_number_from_string(C, str, r_value);
+	}
+}
+
 bool ui_but_string_set_eval_num(bContext *C, uiBut *but, const char *str, double *r_value)
 {
-	bool ok = false;
-
-#ifdef WITH_PYTHON
-
-	if (str[0] != '\0') {
-		bool is_unit_but = (ui_but_is_float(but) && ui_but_is_unit(but));
-		/* only enable verbose if we won't run again with units */
-		if (BPY_execute_string_as_number(C, NULL, str, is_unit_but == false, r_value)) {
-			/* if the value parsed ok without unit conversion
-			 * this button may still need a unit multiplier */
-			if (is_unit_but) {
-				char str_new[128];
-
-				BLI_snprintf(str_new, sizeof(str_new), "%f", *r_value);
-				ok = ui_set_but_string_eval_num_unit(C, but, str_new, r_value);
-			}
-			else {
-				ok = true; /* parse normal string via py (no unit conversion needed) */
-			}
-		}
-		else if (is_unit_but) {
-			/* parse failed, this is a unit but so run replacements and parse again */
-			ok = ui_set_but_string_eval_num_unit(C, but, str, r_value);
-		}
+	if (str[0] == '\0') {
+		*r_value = 0.0;
+		return true;
 	}
 
-#else /* WITH_PYTHON */
+	PropertySubType subtype = PROP_NONE;
+	if (but->rnaprop) {
+		subtype = RNA_property_subtype(but->rnaprop);
+	}
 
-	*r_value = atof(str);
-	ok = true;
-
-	UNUSED_VARS(C, but);
-
-#endif /* WITH_PYTHON */
-
-	return ok;
+	if (ui_but_is_float(but)) {
+		if (ui_but_is_unit(but)) {
+			return ui_set_but_string_eval_num_unit(C, but, str, r_value);
+		}
+		else if (subtype == PROP_FACTOR) {
+			return ui_number_from_string_factor(C, str, r_value);
+		}
+		else if (subtype == PROP_PERCENTAGE) {
+			return ui_number_from_string_percentage(C, str, r_value);
+		}
+		else {
+			return ui_number_from_string(C, str, r_value);
+		}
+	}
+	else {
+		return ui_number_from_string(C, str, r_value);
+	}
 }
 
 /* just the assignment/free part */
@@ -3094,6 +3145,16 @@ static void ui_but_build_drawstr_float(uiBut *but, double value)
 		int prec = ui_but_calc_float_precision(but, value);
 		STR_CONCATF(but->drawstr, slen, "%.*f px", prec, value);
 	}
+	else if (subtype == PROP_FACTOR) {
+		int precision = ui_but_calc_float_precision(but, value);
+
+		if (U.factor_display_type == USER_FACTOR_AS_FACTOR) {
+			STR_CONCATF(but->drawstr, slen, "%.*f", precision, value);
+		}
+		else {
+			STR_CONCATF(but->drawstr, slen, "%.*f %%", MAX2(0, precision - 2), value * 100);
+		}
+	}
 	else if (ui_but_is_unit(but)) {
 		char new_str[sizeof(but->drawstr)];
 		ui_get_but_string_unit(but, new_str, sizeof(new_str), value, true, -1);

source/blender/makesdna/DNA_userdef_types.h

@@ -757,7 +757,9 @@ typedef struct UserDef {
 	/** #eMultiSample_Type, amount of samples for Grease Pencil. */
 	short gpencil_multisamples;
 
-	char _pad5[4];
+	char factor_display_type;
+
+	char _pad5[3];
 } UserDef;
 
 /* from blenkernel blender.c */
@@ -1111,6 +1113,12 @@ typedef enum eOpensubdiv_Computee_Type {
 	USER_OPENSUBDIV_COMPUTE_GLSL_COMPUTE = 6,
 } eOpensubdiv_Computee_Type;
 
+/** #UserDef.factor_display_type */
+typedef enum eUserpref_FactorDisplay {
+	USER_FACTOR_AS_FACTOR = 0,
+	USER_FACTOR_AS_PERCENTAGE = 1,
+} eUserpref_FactorDisplay;
+
 #ifdef __cplusplus
 }
 #endif

source/blender/makesrna/intern/rna_userdef.c

@@ -3775,6 +3775,17 @@ static void rna_def_userdef_view(BlenderRNA *brna)
 	                         "Show the frames per second screen refresh rate, while animation is played back");
 	RNA_def_property_update(prop, 0, "rna_userdef_update");
 
+	static const EnumPropertyItem factor_display_items[] = {
+		{USER_FACTOR_AS_FACTOR, "FACTOR", 0, "Factor", "Display factors as values between 0 and 1"},
+		{USER_FACTOR_AS_PERCENTAGE, "PERCENTAGE", 0, "Percentage", "Display factors as percentages"},
+		{0, NULL, 0, NULL, NULL},
+	};
+
+	prop = RNA_def_property(srna, "factor_display_type", PROP_ENUM, PROP_NONE);
+	RNA_def_property_enum_items(prop, factor_display_items);
+	RNA_def_property_ui_text(prop, "Factor Display Type", "How factor values are displayed");
+	RNA_def_property_update(prop, 0, "rna_userdef_update");
+
 	/* Weight Paint */
 
 	prop = RNA_def_property(srna, "use_weight_color_range", PROP_BOOLEAN, PROP_NONE);