icombo

Declarative Image Combination

Why?

I have been dabbling in board game design as a hobby with my family. The most toilsome part of the process for me is editing images for all the little icons. For example, let's say I need a set of icons to show that you can covert 2 logs into a board. I would need to open an image editor paste the various parts in there, make sure sizing is correct, etc. Then if I wanted to change the conversion to 3 logs into a board, I would have to open the image editor again. So I developed icombo to speed up this process and provide a declarative format (toml) that will handle joining the images, rotation and sizing to provide consistent results.

Now my workflow looks like this:

• go to game-icons.net and find the parts for the image I want to create

  

• drop them into my image_parts directory

• add a few lines to my icombo.toml file

  [[images]]
  name = "logs_to_boards"
  
      [[images.image_parts]]
      file_name = "log"
      count = 2
  
      # arrow faces up by default and rotates counter clockwise
      [[images.image_parts]]
      file_name = "arrow"
      rotation_degrees = 270
  
      [[images.image_parts]]
      file_name = "board"

• run icombo to produce logs_to_boards.png

  

Why TOML?

While my personal preference would by yml, I think toml is easer for non coder types

Setup

• Head over the the release page
• Download the artifact suffixed with example_project for your OS
• Extract the compressed file and run icombo
• Just the binaries are also available if you don't want an example project

Usage

• add the images you wish to combine to your image_input_directory in the example this is ./image_parts
• add your image definition to the icombo.toml file

  [[images]]
  # this image will be output to the image_output_directory as my_new_image.png
  name = "logs_to_boards"
  
      # image parts are read from top to bottom bulding the image from left to right
      [[images.image_parts]]
  
      # icombo will serach for log.png in the configured image_input_directory
      file_name = "log"
  
      # icombo will repeat the image based on count, if count is 1 you can remove this line
      count = 2
  
      # arrow faces up by default and rotates counter clockwise
      [[images.image_parts]]
  
      file_name = "arrow"
      
      # icombo will rotate the image based on rotation_degrees counter clockwise
      rotation_degrees = 270
  
      # simplest way to define a part, will add it once not changing rotation
      [[images.image_parts]]
      file_name = "board"

• save your file and run icombo then check your image_output_directory
• you can also define the following configurations in the icombo.toml file

  [options]
  # where icombo will look for the parts to build images
  image_input_directory = "./image_parts"
  
  # where icombo will output images
  image_output_directory = "./output_images"
  
  # the pixel size of a side of an image part
  # this configuration will make each image part a square whose sides are 64 pixels
  # if my image had 4 parts, the height would be 64 pixels and the width 256 pixels (4 * 64)
  image_part_size_pixels = 64
  
  # number of images that can be built simultaneously, if left at zero icombo will attempt to build all images simultaneously 
  concurrency = 0

Limitations

• only handles .png files
• only builds images horizontally from left to right
• cannot configure individual images with size
• no support for setting background color
• transparency untested

Possible Improvments

• address limitations above
• instead of reading each image part from disk everytime, store them in memory
  • this may or may not be helpful, need to test, possibly trading memory for speed
• add flags for config file path, now it must be at ./icombo.toml
• add functionality for handling other config formats (yml, json, etc)

Credits

• game-icons.net for the art
• @ozonru for the imaging package that made the image manipulation super easy
• @spf13 for the viper package's awesome config tooling