Class: ImgToScript::Generators::HexMask::Enhanced

Inherits:

ImgToScript::Generators::HexMask

• Object
• ImgToScript::Generators::HexMask
• ImgToScript::Generators::HexMask::Enhanced

Defined in:

lib/img_to_script/generators/hex_mask/enhanced.rb

Overview

Generates image rendering script using the DRAW/M statement with the ‘enhancements’.

To save space at the MPO-10 cart, it’s possible to replacelong sequences of repeating chunks with a shorter (in terms of number of chars required to store the statement) code, e.g.:

xxDRAWMFFAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAFF // 43 bytes – 16 x ‘AA’. xxDRAWMFF:FORI=1TO16:DRAWMAA:NEXTI:DRAWMFF // 42 bytes – repeating chunks were replaced with a loop.

Same principle could be applied to eliminate long sequences of white pixels, e.g.: xxDRAWMFF00000000000000000000FF // 31 bytes – 10 x ‘00’. xxDRAWMFF:DRAWOxxx,yy:DRAWMFF // 29 bytes – replaced with a manual shift.

The algorithm is:

1. apply RLE to the array of hex chunks (DRAW/M arguments);

2. loop through the array of run-lengths: take an element (a ‘chunk’) and heck if it’s run-length is larger than an estimated value (MIN_REP_CHUNKS or MIN_REP_WH_CHUNKS);

3. if true: add pending chunks to the BASIC code; then append a FOR-NEXT loop or DRAW/O. Clear pending chunks array and continue to loop through the array of run-lengths.

4. otherwise: add current chunk to the array of pending chunks;

5. after the loop: add pending chunks.

Constant Summary

MIN_REP_CHUNKS =

16

MIN_REP_WH_CHUNKS =

9