Add SettingOnGuiCtrlType mode for setting value dparam overrides

src/settings_gui.cpp

@@ -1518,6 +1518,7 @@ static const void *ResolveObject(const GameSettings *settings_ptr, const IntSett
  */
 void SettingEntry::SetValueDParams(uint first_param, int32_t value) const
 {
+	const uint initial_first_param = first_param;
 	if (this->setting->IsBoolSetting()) {
 		SetDParam(first_param++, value != 0 ? STR_CONFIG_SETTING_ON : STR_CONFIG_SETTING_OFF);
 	} else if (this->setting->flags & SF_DEC1SCALE) {
@@ -1547,6 +1548,13 @@ void SettingEntry::SetValueDParams(uint first_param, int32_t value) const
 		}
 		SetDParam(first_param++, value);
 	}
+	if (this->setting->guiproc != nullptr) {
+		SettingOnGuiCtrlData data;
+		data.type = SOGCT_VALUE_DPARAMS;
+		data.offset = initial_first_param;
+		data.val = value;
+		this->setting->guiproc(data);
+	}
 }
 
 /**

src/settings_internal.h

@@ -85,6 +85,7 @@ enum SettingType {
 
 enum SettingOnGuiCtrlType {
 	SOGCT_DESCRIPTION_TEXT,   ///< Description text callback
+	SOGCT_VALUE_DPARAMS,      ///< Value dparam override callback
 	SOGCT_GUI_DROPDOWN_ORDER, ///< SF_GUI_DROPDOWN reordering callback
 	SOGCT_CFG_NAME,           ///< Config file name override
 	SOGCT_CFG_FALLBACK_NAME,  ///< Config file name within group fallback
@@ -95,6 +96,7 @@ enum SettingOnGuiCtrlType {
 struct SettingOnGuiCtrlData {
 	SettingOnGuiCtrlType type;
 	StringID text;
+	uint offset;
 	int val;
 	const char *str = nullptr;
 	int output = 0;