Function GUIPlaceProcDragXY

src/terraform_gui.cpp:112–145

* A central place to handle all X_AND_Y dragged GUI functions. * @param proc Procedure related to the dragging * @param start_tile Begin of the dragging * @param end_tile End of the dragging * @return Returns true if the action was found and handled, and false otherwise. This * allows for additional implements that are more local. For example X_Y drag * of convertrail which belongs i

 * of convertrail which belongs in rail_gui.cpp and not terraform_gui.cpp
 */
bool GUIPlaceProcDragXY(ViewportDragDropSelectionProcess proc, TileIndex start_tile, TileIndex end_tile)
{
	if (!_settings_game.construction.freeform_edges) {
		/* When end_tile is MP_VOID, the error tile will not be visible to the
		 * user. This happens when terraforming at the southern border. */
		if (TileX(end_tile) == Map::MaxX()) end_tile += TileDiffXY(-1, 0);
		if (TileY(end_tile) == Map::MaxY()) end_tile += TileDiffXY(0, -1);
	}

	switch (proc) {
		case DDSP_DEMOLISH_AREA:
			Command<CMD_CLEAR_AREA>::Post(STR_ERROR_CAN_T_CLEAR_THIS_AREA, CcPlaySound_EXPLOSION, end_tile, start_tile, _ctrl_pressed);
			break;
		case DDSP_RAISE_AND_LEVEL_AREA:
			Command<CMD_LEVEL_LAND>::Post(STR_ERROR_CAN_T_RAISE_LAND_HERE, CcTerraform, end_tile, start_tile, _ctrl_pressed, LM_RAISE);
			break;
		case DDSP_LOWER_AND_LEVEL_AREA:
			Command<CMD_LEVEL_LAND>::Post(STR_ERROR_CAN_T_LOWER_LAND_HERE, CcTerraform, end_tile, start_tile, _ctrl_pressed, LM_LOWER);
			break;
		case DDSP_LEVEL_AREA:
			Command<CMD_LEVEL_LAND>::Post(STR_ERROR_CAN_T_LEVEL_LAND_HERE, CcTerraform, end_tile, start_tile, _ctrl_pressed, LM_LEVEL);
			break;
		case DDSP_CREATE_ROCKS:
			GenerateRockyArea(end_tile, start_tile);
			break;
		case DDSP_CREATE_DESERT:
			GenerateDesertArea(end_tile, start_tile);
			break;
		default:
			return false;
	}

	return true;
}

/**
 * Start a drag for demolishing an area.