== Bitmap Editor
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.
== Program input
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.
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