Tile Contents and Interactions

Relevant source files

The following files were used as context for generating this wiki page:

• src/TileContents.ts
• src/components/tileContents/Tomato.ts
• src/components/tileContents/Weed.ts
• src/components/tileContents/MoleHill.ts
• src/store/GridStore.ts
• src/components/grid/GridTile.ts
• src/components/CharacterContainer.ts
• src/utils/Grid.ts

The core gameplay of Farm Siege revolves around the state of an 8x8 grid. Each tile on this grid can contain different entities, such as plants, weeds, or moles. The TileContents system defines what can exist on a tile, how it is represented visually, and how it behaves over time. Player interactions, managed through the CharacterContainer, directly modify the state of these tiles.

The state of the entire grid is managed by the GridStore, which orchestrates the spawning, growth, and removal of tile contents. The visual representation of each tile and its content is handled by the GridTile component, which dynamically selects sprites based on the tile's current state. This document outlines the architecture of the tile content system, details each content type, and explains the player interaction logic.

Core Architecture

The system is built around a central enum, a data structure for tile state, and a store to manage the grid's state over time.

TileContents Enum

The TileContents enum is the foundation of the system, defining all possible types of content a tile can hold.

Sources: src/TileContents.ts:1-8

Enum Value	Description
Empty	The tile is empty and can be planted on.
Mole	A mole is currently on this tile. It can be removed by the player.
Molehill	A mound of dirt left behind by a mole. It can be cleared by the player.
Weed	A weed is on this tile. It can spread to adjacent empty tiles.
Plant	A tomato plant is on this tile. It grows over time and can be harvested.
Lightning	A temporary visual effect indicating a lightning strike has occurred.

Grid Data Structure

The state of the game grid is stored as a 2D array. Each element in the array is a TileData object, which contains the content type and an associated data object for stateful properties like a plant's age.

The diagram below shows the relationship between the main data types that form the grid.

Tile Rendering

The GridTile component is responsible for rendering a single tile and its contents. It uses a switch statement on the tileData.type to determine which sprite to display.

The following flowchart illustrates the rendering logic within GridTile.

Tile Content Types and Behavior

Each type of tile content has unique behaviors, managed primarily within the GridStore.

Plant (Tomato)

Plants are the primary objective for the player. They are placed by the player and grow over time.

• Growth: A plant's age is stored in its TileData.data object. The growPlants method in GridStore increments the age of all plants every 100ms.
• Visual Stages: The GridTile component renders different sprites for the tomato plant based on its age relative to values.plant.age.fullyGrown. The Tomato component also encapsulates this logic for use in instructions.
• Harvesting: Only fully grown plants yield points when removed by the player.

Sources: src/store/GridStore.ts:122-138, src/components/grid/GridTile.ts:84-87, src/components/tileContents/Tomato.ts:14-36, src/components/CharacterContainer.ts:96-99

Mole and Molehill

Moles are obstacles that appear periodically and can destroy plants.

• Spawning: The updateMole method in GridStore handles mole logic. A mole can spawn on a random tile. If a mole is already active, it moves to a new random tile, leaving a Molehill in its previous location.
• Destruction: If a mole spawns on or moves to a tile with a plant, the plant is destroyed.
• Removal: The player can remove a Mole for points or a Molehill to clear the tile.

The following diagram shows the lifecycle of a mole on the grid.

Weed

Weeds appear on empty tiles and can spread, preventing the player from planting.

• Spawning: updateWeed in GridStore has a chance to spawn a new weed on a random empty tile.
• Spreading: Existing weeds have a chance to spread to an adjacent empty tile. The probability of spreading decreases as the number of weeds increases (1 / Math.sqrt(foundWeed.length)).
• Component: The Weed component is a simple sprite wrapper for weed.png.

Sources: src/store/GridStore.ts:194-242, src/components/tileContents/Weed.ts

Lightning

Lightning is a random event that clears a 3x3 area of the grid.

• Strike: updateLightning in GridStore selects a random tile as the epicenter. It clears all content in a 3x3 area around that tile.
• Visuals: The Lightning component is displayed on the center tile of the strike.
• Duration: The lightning visual effect is temporary. A timer removes the Lightning content after 1.4 seconds, leaving an empty tile. The player cannot interact with a tile while the lightning effect is active.

Sources: src/store/GridStore.ts:244-289, src/store/GridStore.ts:81-83, src/components/grid/GridTile.ts:111-121

Player Interactions

The player, controlled via CharacterContainer, can interact with the grid to remove content or place new plants. The primary actions are "use" and "place".

Interaction Logic

The onTick method in CharacterContainer checks for player inputs and triggers actions on the GridStore.

Action	Key / Button	Functionality -
use	Space, ButtonB	Calls gridStore.removeContent on the player's current tile. The outcome depends on the content removed. -
place	KeyV, ButtonA	Calls gridStore.placePlant on the player's current tile. This places a new plant if the tile is empty and sets the character's held item to None.

Sources: src/components/CharacterContainer.ts:31-43, src/components/CharacterContainer.ts:94-136, src/components/CharacterContainer.ts:138-141

The sequence diagram below illustrates the process of a player harvesting a fully grown plant.

Interaction Outcomes

Removing content from a tile has different effects depending on the content type.

Content Removed	Score Awarded	Character Holds Item
Mole	values.scores.mole	HoldableItems.Hammer
Plant (fully grown)	values.scores.plant	HoldableItems.Shovel
Plant (not grown)	0	HoldableItems.Shovel
Weed	values.scores.weed	HoldableItems.Shovel
Molehill	0	HoldableItems.Shovel

Sources: src/components/CharacterContainer.ts:104-122

Conclusion

The tile content and interaction system is a dynamic and central part of Farm Siege. It defines the game's core entities, their life cycles, and how the player engages with them. The separation of concerns—with TileContents defining the types, GridStore managing state and logic, GridTile handling rendering, and CharacterContainer processing player input—creates a robust and extensible architecture for the game's primary loop. The interplay between automated events like mole spawning and direct player actions like harvesting creates the central challenge of the game.