There are some edge cases to Bresenham's line drawing algorithm with
cumul=dx. The fx-92 SC+ clearly checks cumul>dx, but for dx=1 and dy=1
this results in a horizontal line.
Apparently dx=dy is the only case where the fx-92 SC+ behaves
differently than cumul>dx, as seen with dx=5 dy=4 (causes cumul=dx after
2 iterations but does not trigger the condition).
Also allow the program to be interrupted with Escape while paused.
This change adds a [cond] grammar symbol corresponding to binary
relations in IF, IFELSE and WHILE conditions. It also adds support for
unary functions with parenthesis syntax. Other functions will need
specific rules depending on their operator precedence level.
Also adds the Window.save() function that implements the --save option
to save the output of the program into a bitmap file. This will be used
to perform automated unit tests.
This change lays the ground for automated unit tests. It adds
command-line options to select the input language format between URL
(hexa text) and plain text, change a few output settings, and redirect
graphical output to an image.
A text lexer has also been added so that unit tests and new programs can
be written in an English-like syntax instead of raw hexadecimal.
The program is currently able to lex most useful tokens, and parse
constructs associated with them on simple examples.
Unit tests are still missing to formally ensure everything's right.
Lephe
Pavel Demin