Bitmap Editor - Ruby App

A work in progress as of September 2016.

A Ruby 2.3 program that simulates a basic interactive bitmap editor. Bitmaps are represented as an M x N matrix of pixels with each element representing a colour.

The input consists of a string containing a sequence of commands, where a command is represented by a single capital letter at the beginning of the line. Parameters of the command are separated by white spaces and they follow the command character.

Pixel co-ordinates are a pair of integers: a column number between 1 and 250, and a row number between 1 and 250. Bitmaps starts at coordinates 1,1. Colours are specified by capital letters.

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Commands:

There are 8 supported commands:

• I M N - Create a new M x N image with all pixels coloured white (O).
• C - Clears the table, setting all pixels to white (O).
• L X Y C - Colours the pixel (X,Y) with colour C.
• V X Y1 Y2 C - Draw a vertical segment of colour C in column X between rows Y1 and Y2 (inclusive).
• H X1 X2 Y C - Draw a horizontal segment of colour C in row Y between columns X1 and X2 (inclusive).
• S - Show the contents of the current image
• ? - Displays help text
• X - Terminate the session

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Usage:

ruby runner.rb

Run the specs:

rspec

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Example usage:

• S (Show Command)

> S
    1    2    3    4    5    6
1 ["O", "O", "O", "O", "O", "O"]
2 ["O", "O", "O", "O", "O", "O"]
3 ["O", "O", "O", "O", "O", "O"]
4 ["O", "O", "O", "O", "O", "O"]
5 ["O", "O", "O", "O", "O", "O"]
6 ["O", "O", "O", "O", "O", "O"]
Command executed successfully.

• L 1 1 C (Paint a single pixel of color C in pixel 1,1)

> L 1 1 C
Command executed successfully.
--------
> S
    1    2    3    4    5    6
1 ["C", "O", "O", "O", "O", "O"]
2 ["O", "O", "O", "O", "O", "O"]
3 ["O", "O", "O", "O", "O", "O"]
4 ["O", "O", "O", "O", "O", "O"]
5 ["O", "O", "O", "O", "O", "O"]
6 ["O", "O", "O", "O", "O", "O"]
Command executed successfully.
--------

• V 1 1 6 C - Draw a vertical segment of colour C in column 1 between rows 1 and 6

> V 1 1 6 C
Command executed successfully.
--------
> S
    1    2    3    4    5    6
1 ["C", "O", "O", "O", "O", "O"]
2 ["C", "O", "O", "O", "O", "O"]
3 ["C", "O", "O", "O", "O", "O"]
4 ["C", "O", "O", "O", "O", "O"]
5 ["C", "O", "O", "O", "O", "O"]
6 ["C", "O", "O", "O", "O", "O"]
Command executed successfully.
--------

• C - Clears the bitmap

> C
Command executed successfully.
--------
> S
    1    2    3    4    5    6
1 ["O", "O", "O", "O", "O", "O"]
2 ["O", "O", "O", "O", "O", "O"]
3 ["O", "O", "O", "O", "O", "O"]
4 ["O", "O", "O", "O", "O", "O"]
5 ["O", "O", "O", "O", "O", "O"]
6 ["O", "O", "O", "O", "O", "O"]
Command executed successfully.
--------

• H 1 6 1 C - Draw a horizontal segment of colour C in row 1 between columns 1 and 6

> H 1 6 1 C
Command executed successfully.
--------
> S
    1    2    3    4    5    6
1 ["C", "C", "C", "C", "C", "C"]
2 ["O", "O", "O", "O", "O", "O"]
3 ["O", "O", "O", "O", "O", "O"]
4 ["O", "O", "O", "O", "O", "O"]
5 ["O", "O", "O", "O", "O", "O"]
6 ["O", "O", "O", "O", "O", "O"]
Command executed successfully.
--------

• F 1 1 C - Colours horizontally or vertically adjacent cells in the specified color if they are the same original color as the one being targeted.

Given the following grid:
> S
    1    2    3    4    5    6
1 ["A", "A", "O", "O", "O", "O"]
2 ["O", "A", "O", "O", "O", "O"]
3 ["O", "A", "A", "A", "O", "O"]
4 ["O", "O", "O", "A", "O", "O"]
5 ["O", "O", "O", "O", "O", "O"]
6 ["O", "O", "O", "O", "O", "O"]
Command executed successfully.
--------
> F 1 1 C
Command executed successfully.
--------
> S
    1    2    3    4    5    6
1 ["C", "C", "O", "O", "O", "O"]
2 ["O", "C", "O", "O", "O", "O"]
3 ["O", "C", "C", "C", "O", "O"]
4 ["O", "O", "O", "C", "O", "O"]
5 ["O", "O", "O", "O", "O", "O"]
6 ["O", "O", "O", "O", "O", "O"]
Command executed successfully.
--------

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