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Overview

The Map Editor is a graphical application for creating and editing GRPG game maps. It provides a visual interface for placing tiles and objects on a 16x16 grid to create map chunks.

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Installation

Build the map editor from source: 
cd ~/workspace/source/map-editor
go build -o map-editor

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Running the Editor

Launch the map editor: 
./map-editor
The editor window opens at 1640x1200 pixels with three main panels:
  • Editor: 16x16 grid for map editing
  • Controls: Action buttons and chunk coordinate inputs
  • Selector: Tabs for selecting tiles and objects

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Interface Layout

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Editor Panel

The main editing area displays a 16x16 grid (256 tiles total) where you can place tiles and objects by clicking.

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Controls Panel

The controls panel provides the following buttons and inputs: Asset Loading:
  • Load Textures: Load a .grpgtex texture pack file
  • Load Tiles: Load a .grpgtile tiles definition file
  • Load Objs: Load a .grpgobj objects definition file
Map Operations:
  • Save Map: Save the current map to a .grpgmap file
  • Load Map: Load an existing .grpgmap file
Editing Tools:
  • Set all empty tiles to currently selected: Fill all empty tiles with the selected tile
  • Clear Grid: Wipe the entire grid (with confirmation dialog)
  • Enable Eraser: Activate eraser mode to remove tiles/objects
Chunk Coordinates:
  • Chunk X: Input field for the map chunk’s X coordinate
  • Chunk Y: Input field for the map chunk’s Y coordinate
Both Chunk X and Chunk Y must be set before saving a map.

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Selector Panel

The selector panel has two tabs: Tiles Tab:
  • Displays all loaded tiles in a grid
  • Click a tile image to select it for placement
  • Shows the currently selected tile
Objs Tab:
  • Displays all loaded objects in a grid
  • Objects show flags: (s) for STATE, (i) for INTERACT
  • Click an object image to select it for placement
  • Shows the currently selected object

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Workflow

1

Load Assets

Load the required asset files in order:
  1. Click Load Textures and select your .grpgtex file
  2. Click Load Tiles and select your .grpgtile file
  3. Click Load Objs and select your .grpgobj file
2

Set Chunk Coordinates

Enter the chunk coordinates in the Chunk X and Chunk Y input fields.
3

Place Tiles

  1. Switch to the Tiles tab in the Selector panel
  2. Click a tile to select it
  3. Click on the grid to place the tile
  4. Repeat until all 256 tiles are filled
4

Place Objects (Optional)

  1. Switch to the Objs tab in the Selector panel
  2. Click an object to select it
  3. Click on the grid to place the object
5

Save Map

Click Save Map to export your map as a .grpgmap file.

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Editing Features

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Tile Placement

Tiles form the base layer of the map. Every grid cell must have a tile before the map can be saved.
  • Select a tile from the Tiles tab
  • Click on the grid to place it
  • The tile’s texture is displayed in the grid cell

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Object Placement

Objects are placed on top of tiles and are optional.
  • Select an object from the Objs tab
  • Click on a grid cell to place the object
  • Objects can have multiple states (indicated by the STATE flag)
  • Interactive objects show an (i) flag

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Eraser Mode

Enable eraser mode to remove tiles or objects:
  1. Click Enable Eraser
  2. Click on grid cells to erase their contents
  3. Select a tile or object to exit eraser mode

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Bulk Operations

Fill Empty Tiles:
  • Select a tile
  • Click Set all empty tiles to currently selected
  • All unfilled tiles will be set to the selected tile
Clear Grid:
  • Click Clear Grid
  • Confirm the dialog
  • All tiles and objects are removed from the grid

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Map File Format

Maps are saved in the .grpgmap binary format with the following structure: Header:
  • Magic: GRPGMAP\x00 (8 bytes)
  • Chunk X: uint16 (2 bytes)
  • Chunk Y: uint16 (2 bytes)
Zone Data:
  • Tiles: 256 tile IDs (uint8 each)
  • Objs: 256 object IDs (uint16 each, 0 = no object)
The map file references tiles and objects by their IDs from the loaded .grpgtile and .grpgobj files.

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Validation

The editor performs validation before saving:
All tiles must be filled: You cannot save a map with empty tile slots.
Chunk coordinates required: Both Chunk X and Chunk Y must be set to valid values (not -1).
Assets must be loaded: Textures must be loaded before loading tiles or objects.

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Loading Existing Maps

To load and edit an existing map:
  1. Load textures first (required)
  2. Click Load Map
  3. Select a .grpgmap file
  4. The chunk coordinates, tiles, and objects will be loaded into the editor
  5. Make your edits
  6. Save the map

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Source Code

The map editor source code is located at: 
~/workspace/source/map-editor/
Key files:
  • main.go:17 - Application entry point and UI layout
  • map.go:12 - Map save/load functionality
  • assets.go:33 - Asset loading (textures, tiles, objects)
  • grid.go - Grid rendering and interaction
  • selector.go:27 - Tile and object selector tabs
  • controls.go:11 - Control button implementations

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