From a62b2b1be2103d7de2fd66c7304b7473e369be3c Mon Sep 17 00:00:00 2001 From: Tiger Wang Date: Wed, 5 May 2021 14:25:10 +0100 Subject: Move item placement into item handlers (#5184) * Move item placement into item handlers + Add appropriate CanBeAt checks in cPlayer::PlaceBlocks, into which all placement handlers call. * Partly addresses #5157 * Fixes #4878 * Fixes #2919 * Fixes #4629 * Fixes #4239 * Fixes #4849 Co-authored-by: changyong guo Co-authored-by: Xotheus Co-authored-by: Krist Pregracke * Review fixes * Update APIDesc.lua * Rename Co-authored-by: changyong guo Co-authored-by: Xotheus Co-authored-by: Krist Pregracke --- src/Items/ItemLadder.h | 77 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 77 insertions(+) create mode 100644 src/Items/ItemLadder.h (limited to 'src/Items/ItemLadder.h') diff --git a/src/Items/ItemLadder.h b/src/Items/ItemLadder.h new file mode 100644 index 000000000..67de799c5 --- /dev/null +++ b/src/Items/ItemLadder.h @@ -0,0 +1,77 @@ + +#pragma once + +#include "ItemHandler.h" +#include "Blocks/BlockLadder.h" + + + + + +class cItemLadderHandler : + public cItemHandler +{ + using Super = cItemHandler; + +public: + + using Super::Super; + +private: + + /** Converts the block face of the neighbor to which the ladder is attached to the ladder block's meta. */ + static NIBBLETYPE BlockFaceToMetaData(eBlockFace a_NeighborBlockFace) + { + switch (a_NeighborBlockFace) + { + case BLOCK_FACE_ZM: return 0x2; + case BLOCK_FACE_ZP: return 0x3; + case BLOCK_FACE_XM: return 0x4; + case BLOCK_FACE_XP: return 0x5; + case BLOCK_FACE_YM: + case BLOCK_FACE_YP: return 0x2; + default: UNREACHABLE("Unsupported neighbor block face"); + } + } + + + virtual bool CommitPlacement(cPlayer & a_Player, const cItem & a_HeldItem, const Vector3i a_PlacePosition, eBlockFace a_ClickedBlockFace, const Vector3i a_CursorPosition) override + { + const auto & World = *a_Player.GetWorld(); + const auto ClickedBlockType = World.GetBlock(AddFaceDirection(a_PlacePosition, a_ClickedBlockFace, true)); + + // Try finding a suitable neighbor block face for the ladder; start with the given one: + if (!cBlockLadderHandler::CanBePlacedOn(ClickedBlockType, a_ClickedBlockFace)) + { + // Couldn't be placed on whatever face was clicked, last ditch resort - find another face: + a_ClickedBlockFace = FindSuitableFace(World, a_PlacePosition); + if (a_ClickedBlockFace == BLOCK_FACE_NONE) + { + // No attachable face found - don't place the ladder: + return false; + } + } + + return a_Player.PlaceBlock(a_PlacePosition, E_BLOCK_LADDER, BlockFaceToMetaData(a_ClickedBlockFace)); + } + + + /** Returns a suitable neighbor's blockface to place the ladder at the specified position. + Returns BLOCK_FACE_NONE on failure. */ + static eBlockFace FindSuitableFace(const cWorld & a_World, const Vector3i a_Position) + { + for (const auto Face : { BLOCK_FACE_ZM, BLOCK_FACE_XP, BLOCK_FACE_ZP, BLOCK_FACE_XM }) // Loop through all faces in specific order. + { + // The direction of Face is relative to the direction the ladder faces. + // This is the position, computed inverted, that such a ladder would attach to. + const auto NeighborPosition = AddFaceDirection(a_Position, Face, true); + + if (cBlockLadderHandler::CanBePlacedOn(a_World.GetBlock(NeighborPosition), Face)) + { + return Face; + } + } + + return BLOCK_FACE_NONE; + } +}; -- cgit v1.2.3