griddle/README.md

# griddle

`griddle` is a program for practicing drawing using the [Grid Technique](https://www.art-is-fun.com/grid-method).
It takes an input image and uses [ImageMagick](https://imagemagick.org) to automatically draw a grid (of specified dimensions) over it.

## Installation
`griddle` is a shell script; you can copy it to somewhere in your `$PATH` or just clone the repository and execute it.

## Usage
The CLI interface for `griddle` is `griddle <inputfile> <number_of_columns> <number_of_rows> <outputfile>`.
This is the number of **columns** and **rows**, not the number of separators.
For example, specifying "2" columns will result in **one** line splitting the image vertically.
Border lines around the edge of the image are always generated.

`griddle` also generates an image named "blank_grid.png", which is an exact copy of the grid generated on top of the input image, but with a blank white background.
This can then be printed out and used to draw on, instead of manually trying to recreate the grid on paper, if you both have a printer and are using a kind of paper that can be used in said printer.
(I don't have a printer, but I figured someone might find this feature useful.)

It supports any input and output file formats that ImageMagick supports.
The input and output files don't need to be the same format; you can input a PNG and output a JPEG, for example.

## Planned Features
- Improve the CLI interface with `--options` to remove the arbitrary ordering of `<number_of_columns>` and `<number_of_rows>`.
- Make border lines optional.
- Allow the user to adjust the color and transparency of grid lines.
- Add a default output filename (something like `<inputfilename>_grid.<inputextension>`) if no output filename is explicitly given.