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The grpgpack command-line tool is used to pack game data (textures, tiles, objects, items, and NPCs) into optimized binary formats for GRPG.

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Installation

The data packer is built from the source code in data-packer/main.go.

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Commands

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tex

Packs texture files into a .grpgtex format. Syntax: 
grpgpack tex [flags]
Flags:
FlagShortTypeRequiredDefaultDescription
--manifest-mstringYes-Path to the texture manifest file
--output-ostringNotextures.grpgtexOutput file path
Example: 
grpgpack tex --manifest textures/manifest.cfg --output build/textures.grpgtex
Manifest Format: The texture manifest uses a .cfg format with [Texture] sections: 
[Texture "grass"]
name = grass
id = 1
path = assets/textures/grass.png
Notes:
  • Input images must be in PNG format
  • Textures are encoded to JPEG XL format (quality 100, effort 10)
  • ID 0 is reserved and cannot be used
  • Each texture requires a unique internal name and ID

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tile

Packs tile definitions into a .grpgtile format. Syntax: 
grpgpack tile [flags]
Flags:
FlagShortTypeRequiredDefaultDescription
--manifest-mstringYes-Path to the tile manifest file
--output-ostringNotiles.grpgtileOutput file path
--textures-tstringYes-Path to the .grpgtex file to reference
Example: 
grpgpack tile --manifest tiles/manifest.cfg --textures build/textures.grpgtex --output build/tiles.grpgtile
Manifest Format: 
[Tile "grass_tile"]
name = grass_tile
id = 1
tex_name = grass
Notes:
  • Requires a pre-built .grpgtex file
  • The tex_name field must match a texture name from the textures file
  • Tiles reference textures by their internal name

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obj

Packs object definitions into a .grpgobj format. Syntax: 
grpgpack obj [flags]
Flags:
FlagShortTypeRequiredDefaultDescription
--manifest-mstringYes-Path to the object manifest file
--output-ostringNoobjs.grpgobjOutput file path
--textures-tstringYes-Path to the .grpgtex file to reference
Example: 
grpgpack obj --manifest objects/manifest.cfg --textures build/textures.grpgtex --output build/objs.grpgobj
Notes:
  • Requires a pre-built .grpgtex file
  • Objects reference textures from the provided texture file

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item

Packs item definitions into a .grpgitem format. Syntax: 
grpgpack item [flags]
Flags:
FlagShortTypeRequiredDefaultDescription
--manifest-mstringYes-Path to the item manifest file
--output-ostringNoitems.grpgitemOutput file path
--textures-tstringYes-Path to the .grpgtex file to reference
Example: 
grpgpack item --manifest items/manifest.cfg --textures build/textures.grpgtex --output build/items.grpgitem
Notes:
  • Requires a pre-built .grpgtex file
  • Items reference textures from the provided texture file

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npc

Packs NPC definitions into a .grpgnpc format. Syntax: 
grpgpack npc [flags]
Flags:
FlagShortTypeRequiredDefaultDescription
--manifest-mstringYes-Path to the NPC manifest file
--output-ostringNoitems.grpgitemOutput file path
--textures-tstringYes-Path to the .grpgtex file to reference
Example: 
grpgpack npc --manifest npcs/manifest.cfg --textures build/textures.grpgtex --output build/npcs.grpgnpc
Notes:
  • Requires a pre-built .grpgtex file
  • NPCs reference textures from the provided texture file

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Build Pipeline

The typical build order for game data:
  1. Pack textures first (no dependencies): 
    grpgpack tex --manifest textures/manifest.cfg --output build/textures.grpgtex
  2. Pack tiles, objects, items, and NPCs (all require textures): 
    grpgpack tile --manifest tiles/manifest.cfg --textures build/textures.grpgtex --output build/tiles.grpgtile
grpgpack obj --manifest objects/manifest.cfg --textures build/textures.grpgtex --output build/objs.grpgobj
grpgpack item --manifest items/manifest.cfg --textures build/textures.grpgtex --output build/items.grpgitem
grpgpack npc --manifest npcs/manifest.cfg --textures build/textures.grpgtex --output build/npcs.grpgnpc

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Error Handling

All commands will return an error if:
  • Required flags are missing
  • Manifest files cannot be read or parsed
  • Referenced texture files are missing or invalid
  • Output files cannot be created

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Source Code

Implementation: data-packer/main.go:18-112 Command implementations:
  • Textures: data-packer/textures/cmd.go:18-56
  • Tiles: data-packer/tiles/cmd.go:13-57
  • Objects: data-packer/objs/cmd.go:13-60
  • Items: data-packer/items/cmd.go:13-56
  • NPCs: data-packer/npcs/cmd.go:13-57

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