Fix set_camera() not being resettable

builtin/game/features.lua

@@ -54,6 +54,7 @@ core.features = {
 	chunksize_vector = true,
 	item_inventory_image_animation = true,
 	get_modnames_load_order = true,
+	set_camera_resettable = true,
 }
 
 function core.has_feature(arg)

doc/lua_api.md

@@ -6123,7 +6123,7 @@ Utilities
       remove_item_match_meta = true,
       -- The HTTP API supports the HEAD and PATCH methods (5.12.0)
       httpfetch_additional_methods = true,
-      -- objects have get_guid method (5.13.0)
+      -- `ObjectRef:get_guid()` method exists (5.13.0)
       object_guids = true,
       -- The NodeTimer `on_timer` callback is passed additional `node` and `timeout` args (5.14.0)
       on_timer_four_args = true,
@@ -6136,8 +6136,10 @@ Utilities
       -- Item definition fields `inventory_image`, `inventory_overlay`, `wield_image`
       -- and `wield_overlay` accept a table containing animation definitions. (5.15.0)
       item_image_animation = true,
-      -- `core.get_modnames`' parameter `load_order` (5.16.0)
+      -- `core.get_modnames` has parameter `load_order` (5.16.0)
       get_modnames_load_order = true,
+      -- `ObjectRef:set_camera()` accepts `nil` to indicate reset (5.16.0)
+      set_camera_resettable = true,
   }
   ```
 
@@ -9395,21 +9397,24 @@ child will follow movement and rotation of that bone.
       Defaults to `thirdperson_back` if unspecified.
 * `get_eye_offset()`: Returns camera offset vectors as set via `set_eye_offset`.
 * `set_camera(params)`: Sets camera parameters.
+    * `params` must be a table to update the parameters or `nil` (requires >= 5.16.0)
+      to reset all parameters to defaults.
     * `mode`: Defines the camera mode used
       - `any`: free choice between all modes (default)
       - `first`: first-person camera
       - `third`: third-person camera
       - `third_front`: third-person camera, looking opposite of movement direction
-    * Supported by client since 5.12.0.
+    * Supported by clients since 5.12.0.
 * `get_camera()`: Returns the camera parameters as a table as above.
 * `send_mapblock(blockpos)`:
     * Sends an already loaded mapblock to the player.
     * Returns `false` if nothing was sent (note that this can also mean that
       the client already has the block)
     * Resource intensive - use sparsely
-* `set_lighting(light_definition)`: sets lighting for the player
-    * Passing no arguments resets lighting to its default values.
-    * `light_definition` is a table with the following optional fields:
+* `set_lighting(light_def)`: Sets lighting for the player
+    * `light_def` must be a table to update the parameters or `nil` to reset all
+      light parameters to defaults.
+    * Table fields:
       * `saturation` sets the saturation (vividness; default: `1.0`).
         * It is applied according to the function `result = b*(1-s) + c*s`, where:
           * `c` is the original color

src/client/camera.cpp

@@ -356,6 +356,7 @@ void Camera::update(LocalPlayer* player, f32 frametime, f32 tool_reload_ratio)
 		v3f eye_offset = player->getEyeOffset();
 		switch(m_camera_mode) {
 		case CAMERA_MODE_ANY:
+		case CameraMode_END:
 			assert(false);
 			break;
 		case CAMERA_MODE_FIRST:

src/client/game.cpp

@@ -2683,6 +2683,7 @@ void Game::processPlayerInteraction(f32 dtime, bool show_hud)
 
 	switch (camera->getCameraMode()) {
 	case CAMERA_MODE_ANY:
+	case CameraMode_END:
 		assert(false);
 		break;
 	case CAMERA_MODE_FIRST:

src/network/clientpackethandler.cpp

@@ -1597,6 +1597,8 @@ void Client::handleCommand_Camera(NetworkPacket* pkt)
 	u8 tmp;
 	*pkt >> tmp;
 	player->allowed_camera_mode = static_cast<CameraMode>(tmp);
+	if (player->allowed_camera_mode >= CameraMode_END)
+		player->allowed_camera_mode = CAMERA_MODE_ANY;
 
 	m_client_event_queue.push(new ClientEvent(CE_UPDATE_CAMERA));
 }

src/player.h

@@ -129,7 +129,9 @@ enum CameraMode : int {
 	CAMERA_MODE_ANY = 0,
 	CAMERA_MODE_FIRST,
 	CAMERA_MODE_THIRD,
-	CAMERA_MODE_THIRD_FRONT
+	CAMERA_MODE_THIRD_FRONT,
+
+	CameraMode_END // Dummy for validity check
 };
 
 extern const struct EnumString es_CameraMode[];

src/script/lua_api/l_object.cpp

@@ -533,12 +533,16 @@ int ObjectRef::l_set_camera(lua_State *L)
 	if (player == nullptr)
 		return 0;
 
-	luaL_checktype(L, 2, LUA_TTABLE);
+	if (lua_isnoneornil(L, 2)) {
+		player->allowed_camera_mode = CAMERA_MODE_ANY;
+	} else {
+		luaL_checktype(L, 2, LUA_TTABLE);
 
-	lua_getfield(L, -1, "mode");
-	if (lua_isstring(L, -1))
-		string_to_enum(es_CameraMode, player->allowed_camera_mode, lua_tostring(L, -1));
-	lua_pop(L, 1);
+		lua_getfield(L, -1, "mode");
+		if (lua_isstring(L, -1))
+			string_to_enum(es_CameraMode, player->allowed_camera_mode, lua_tostring(L, -1));
+		lua_pop(L, 1);
+	}
 
 	getServer(L)->SendCamera(player->getPeerId(), player);
 	return 0;